#!/usr/bin/env python3
"""
ICU ECG Pattern Reference PDF Generator
Visual quick-reference for bedside use
"""

from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.units import cm, mm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether, PageBreak
)
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_RIGHT
from reportlab.graphics.shapes import (
    Drawing, PolyLine, Rect, String, Line, Circle, Group
)
from reportlab.graphics import renderPDF
from reportlab.platypus import Flowable
import math

# ── Color Palette ────────────────────────────────────────────────────────────
RED       = colors.HexColor('#C0392B')
DARK_RED  = colors.HexColor('#7B241C')
GREEN     = colors.HexColor('#1E8449')
DARK_GREEN= colors.HexColor('#145A32')
BLUE      = colors.HexColor('#1A5276')
LIGHT_BLUE= colors.HexColor('#2E86C1')
ORANGE    = colors.HexColor('#D35400')
PURPLE    = colors.HexColor('#6C3483')
DARK_GRAY = colors.HexColor('#2C3E50')
MID_GRAY  = colors.HexColor('#7F8C8D')
LIGHT_GRAY= colors.HexColor('#F2F3F4')
ECG_BG    = colors.HexColor('#FFF9F9')
ECG_GRID  = colors.HexColor('#FFCCCC')
ECG_LINE  = colors.HexColor('#C0392B')
WHITE     = colors.white
BLACK     = colors.black
YELLOW_BG = colors.HexColor('#FDFEFE')
HEADER_BG = colors.HexColor('#1A5276')
ALERT_BG  = colors.HexColor('#FDEDEC')
INFO_BG   = colors.HexColor('#EBF5FB')
WARN_BG   = colors.HexColor('#FEF9E7')
GOOD_BG   = colors.HexColor('#EAFAF1')

# ── ECG Waveform Drawing Flowable ────────────────────────────────────────────

class ECGWaveform(Flowable):
    """Draw an ECG waveform with grid background and labeling."""

    def __init__(self, width, height, points, label="", color=None,
                 show_grid=True, label_points=None, bg_color=None):
        Flowable.__init__(self)
        self.width = width
        self.height = height
        self.points = points          # list of (x, y) in 0-1 space
        self.label = label
        self.color = color or ECG_LINE
        self.show_grid = show_grid
        self.label_points = label_points or []   # [(x, y, text), ...]
        self.bg_color = bg_color or ECG_BG

    def draw(self):
        c = self.canv
        w, h = self.width, self.height
        pad = 4

        # Background
        c.setFillColor(self.bg_color)
        c.roundRect(0, 0, w, h, 3, fill=1, stroke=0)

        # Grid lines
        if self.show_grid:
            c.setStrokeColor(ECG_GRID)
            c.setLineWidth(0.3)
            # Vertical grid every ~5mm
            step = w / 20
            for i in range(1, 20):
                c.line(i * step, pad, i * step, h - pad)
            # Horizontal grid every 25% height
            for frac in [0.25, 0.5, 0.75]:
                y = pad + frac * (h - 2 * pad)
                c.line(pad, y, w - pad, y)

        # Border
        c.setStrokeColor(colors.HexColor('#DDDDDD'))
        c.setLineWidth(0.5)
        c.roundRect(0, 0, w, h, 3, fill=0, stroke=1)

        # Waveform
        if len(self.points) >= 2:
            c.setStrokeColor(self.color)
            c.setLineWidth(1.8)
            path = c.beginPath()
            x0 = pad + self.points[0][0] * (w - 2 * pad)
            y0 = pad + self.points[0][1] * (h - 2 * pad)
            path.moveTo(x0, y0)
            for px, py in self.points[1:]:
                x = pad + px * (w - 2 * pad)
                y = pad + py * (h - 2 * pad)
                path.lineTo(x, y)
            c.drawPath(path, stroke=1, fill=0)

        # Baseline reference (dotted)
        c.setStrokeColor(MID_GRAY)
        c.setLineWidth(0.4)
        c.setDash([2, 3])
        mid_y = pad + 0.35 * (h - 2 * pad)
        c.line(pad, mid_y, w - pad, mid_y)
        c.setDash([])

        # Annotation labels on waveform
        c.setFont("Helvetica-Bold", 6.5)
        for lx, ly, lt in self.label_points:
            x = pad + lx * (w - 2 * pad)
            y = pad + ly * (h - 2 * pad)
            c.setFillColor(DARK_GRAY)
            c.drawCentredString(x, y, lt)

        # Label bottom-left
        if self.label:
            c.setFont("Helvetica-Bold", 7.5)
            c.setFillColor(DARK_GRAY)
            c.drawString(5, 4, self.label)


def make_ecg(width, height, pattern_type, **kwargs):
    """Factory – returns an ECGWaveform for the named pattern."""

    baseline = 0.35   # y-fraction for isoelectric line
    top = 0.92
    peak_qrs = 0.95
    trough_qrs = 0.02
    mid = 0.5

    # ── helpers ────────────────────────────────────────────────────────
    def segment(x0, y0, x1, y1, n=2):
        """Straight segment as list of points."""
        return [(x0 + (x1 - x0) * i / (n - 1),
                 y0 + (y1 - y0) * i / (n - 1)) for i in range(n)]

    def p_wave(cx, amp=0.12, w=0.06):
        """Smooth P wave (half-sine)."""
        pts = []
        for i in range(12):
            t = i / 11
            pts.append((cx - w / 2 + t * w, baseline + amp * math.sin(math.pi * t)))
        return pts

    def normal_beat(offset=0.0, scale=1.0):
        """One normal PQRST beat."""
        b = baseline
        pts = []
        # Baseline approach
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        # P wave
        pts += p_wave(offset + 0.09, amp=0.10 * scale)
        # PR segment
        pts += segment(offset + 0.12, b, offset + 0.17, b)
        # Q
        pts += segment(offset + 0.17, b, offset + 0.19, b - 0.06 * scale)
        # R
        pts += segment(offset + 0.19, b - 0.06 * scale, offset + 0.21, b + 0.55 * scale)
        # S
        pts += segment(offset + 0.21, b + 0.55 * scale, offset + 0.23, b - 0.08 * scale)
        # Return to baseline
        pts += segment(offset + 0.23, b - 0.08 * scale, offset + 0.26, b)
        # ST segment (flat at baseline)
        pts += segment(offset + 0.26, b, offset + 0.32, b)
        # T wave
        pts += p_wave(offset + 0.37, amp=0.13 * scale, w=0.10)
        # Return to baseline
        pts += segment(offset + 0.43, b, offset + 0.50, b)
        return pts

    def st_elevation_beat(offset=0.0, elev=0.15):
        """Beat with ST elevation."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        pts += p_wave(offset + 0.09, amp=0.10)
        pts += segment(offset + 0.12, b, offset + 0.17, b)
        pts += segment(offset + 0.17, b, offset + 0.19, b - 0.06)
        pts += segment(offset + 0.19, b - 0.06, offset + 0.21, b + 0.55)
        pts += segment(offset + 0.21, b + 0.55, offset + 0.24, b - 0.04)
        # ST elevated & straight/oblique
        pts += segment(offset + 0.24, b - 0.04, offset + 0.26, b + elev)
        pts += segment(offset + 0.26, b + elev, offset + 0.33, b + elev)
        # T wave (tall hyperacute-ish)
        pts += p_wave(offset + 0.38, amp=0.18, w=0.10)
        pts += segment(offset + 0.43, b, offset + 0.50, b)
        return pts

    def st_depression_beat(offset=0.0, dep=0.12):
        """Beat with horizontal ST depression."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        pts += p_wave(offset + 0.09, amp=0.10)
        pts += segment(offset + 0.12, b, offset + 0.17, b)
        pts += segment(offset + 0.17, b, offset + 0.19, b - 0.06)
        pts += segment(offset + 0.19, b - 0.06, offset + 0.21, b + 0.55)
        pts += segment(offset + 0.21, b + 0.55, offset + 0.24, b - 0.04)
        pts += segment(offset + 0.24, b - 0.04, offset + 0.26, b - dep)
        pts += segment(offset + 0.26, b - dep, offset + 0.33, b - dep)
        pts += p_wave(offset + 0.37, amp=0.10, w=0.10)
        pts += segment(offset + 0.43, b, offset + 0.50, b)
        return pts

    def t_inversion_beat(offset=0.0):
        """Beat with inverted T wave."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        pts += p_wave(offset + 0.09, amp=0.10)
        pts += segment(offset + 0.12, b, offset + 0.17, b)
        pts += segment(offset + 0.17, b, offset + 0.19, b - 0.06)
        pts += segment(offset + 0.19, b - 0.06, offset + 0.21, b + 0.55)
        pts += segment(offset + 0.21, b + 0.55, offset + 0.24, b - 0.04)
        pts += segment(offset + 0.24, b - 0.04, offset + 0.26, b)
        pts += segment(offset + 0.26, b, offset + 0.33, b)
        # Inverted T
        for i in range(12):
            t = i / 11
            cx = offset + 0.37
            w2 = 0.10
            x = cx - w2 / 2 + t * w2
            y = b - 0.13 * math.sin(math.pi * t)
            pts.append((x, y))
        pts += segment(offset + 0.43, b, offset + 0.50, b)
        return pts

    def af_beat(offset=0.0):
        """Irregular AF-like beat (no P, narrow QRS, irregular baseline)."""
        b = baseline
        pts = []
        # Fibrillatory baseline
        for i in range(30):
            x = offset + i * 0.006
            y = b + 0.03 * math.sin(i * 1.8) + 0.02 * math.sin(i * 3.5)
            pts.append((x, y))
        # QRS at irregular position
        qrs_x = offset + 0.18
        pts += segment(qrs_x, b, qrs_x + 0.01, b - 0.04)
        pts += segment(qrs_x + 0.01, b - 0.04, qrs_x + 0.03, b + 0.55)
        pts += segment(qrs_x + 0.03, b + 0.55, qrs_x + 0.05, b - 0.06)
        pts += segment(qrs_x + 0.05, b - 0.06, qrs_x + 0.07, b)
        # More fibbrillation
        for i in range(18):
            x = offset + 0.26 + i * 0.006
            y = b + 0.025 * math.sin(i * 2.1) + 0.015 * math.sin(i * 4.0)
            pts.append((x, y))
        # Another QRS at different spacing
        qrs2 = offset + 0.38
        pts += segment(qrs2, b, qrs2 + 0.01, b - 0.04)
        pts += segment(qrs2 + 0.01, b - 0.04, qrs2 + 0.03, b + 0.52)
        pts += segment(qrs2 + 0.03, b + 0.52, qrs2 + 0.05, b - 0.05)
        pts += segment(qrs2 + 0.05, b - 0.05, qrs2 + 0.07, b)
        # Tail
        for i in range(10):
            x = offset + 0.46 + i * 0.004
            y = b + 0.02 * math.sin(i * 2.5)
            pts.append((x, y))
        return pts

    def vt_beat(offset=0.0, n=2):
        """Wide complex VT beats."""
        b = baseline
        pts = []
        for beat in range(n):
            o = offset + beat * 0.45
            pts += segment(o + 0.00, b, o + 0.03, b)
            # Wide bizarre QRS
            pts += segment(o + 0.03, b, o + 0.06, b + 0.20)
            pts += segment(o + 0.06, b + 0.20, o + 0.10, b + 0.65)
            pts += segment(o + 0.10, b + 0.65, o + 0.14, b - 0.05)
            pts += segment(o + 0.14, b - 0.05, o + 0.20, b + 0.08)
            pts += segment(o + 0.20, b + 0.08, o + 0.24, b - 0.03)
            pts += segment(o + 0.24, b - 0.03, o + 0.28, b)
            pts += segment(o + 0.28, b, o + 0.32, b)
            # Discordant T
            for i in range(8):
                t = i / 7
                cx = o + 0.37
                x = cx - 0.06 + t * 0.12
                y = b - 0.10 * math.sin(math.pi * t)
                pts.append((x, y))
            pts += segment(o + 0.44, b, o + 0.45, b)
        return pts

    def vf_wave(offset=0.0):
        """VF - chaotic undulation."""
        b = baseline
        pts = []
        for i in range(120):
            x = offset + i * 0.008
            if x > 1.0:
                break
            amp = 0.25 + 0.10 * math.sin(i * 0.7)
            y = b + amp * math.sin(i * 0.9 + 1.2) * math.cos(i * 0.4)
            pts.append((x, y))
        return pts

    def flutter_wave(offset=0.0):
        """Atrial flutter sawtooth."""
        b = baseline
        pts = []
        # Regular sawtooth flutter waves
        for wave in range(6):
            o = offset + wave * 0.12
            pts += segment(o + 0.00, b, o + 0.07, b + 0.22)
            pts += segment(o + 0.07, b + 0.22, o + 0.12, b)
        # One QRS (2:1)
        qrs_x = offset + 0.24
        pts += segment(qrs_x, b, qrs_x + 0.01, b - 0.03)
        pts += segment(qrs_x + 0.01, b - 0.03, qrs_x + 0.025, b + 0.55)
        pts += segment(qrs_x + 0.025, b + 0.55, qrs_x + 0.04, b - 0.05)
        pts += segment(qrs_x + 0.04, b - 0.05, qrs_x + 0.06, b)
        # More flutter
        for wave in range(5):
            o = offset + 0.31 + wave * 0.12
            pts += segment(o + 0.00, b, o + 0.07, b + 0.22)
            pts += segment(o + 0.07, b + 0.22, o + 0.12, b)
        # Second QRS
        qrs2 = offset + 0.61
        pts += segment(qrs2, b, qrs2 + 0.01, b - 0.03)
        pts += segment(qrs2 + 0.01, b - 0.03, qrs2 + 0.025, b + 0.55)
        pts += segment(qrs2 + 0.025, b + 0.55, qrs2 + 0.04, b - 0.05)
        pts += segment(qrs2 + 0.04, b - 0.05, qrs2 + 0.06, b)
        for i in range(15):
            o2 = offset + 0.68 + i * 0.02
            pts.append((o2, b + 0.18 * math.sin(i * 1.6)))
        return pts

    def heart_block_3rd(offset=0.0):
        """3rd degree heart block - P waves marching through, QRS escape."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.03, b)
        # P wave 1
        pts += p_wave(offset + 0.06, amp=0.10)
        pts += segment(offset + 0.10, b, offset + 0.15, b)
        # QRS escape (narrow, slow)
        pts += segment(offset + 0.15, b, offset + 0.17, b - 0.04)
        pts += segment(offset + 0.17, b - 0.04, offset + 0.19, b + 0.45)
        pts += segment(offset + 0.19, b + 0.45, offset + 0.21, b - 0.05)
        pts += segment(offset + 0.21, b - 0.05, offset + 0.23, b)
        pts += segment(offset + 0.23, b, offset + 0.28, b)
        # P wave 2 (different timing from QRS)
        pts += p_wave(offset + 0.31, amp=0.10)
        pts += segment(offset + 0.35, b, offset + 0.38, b)
        # P wave 3
        pts += p_wave(offset + 0.44, amp=0.10)
        pts += segment(offset + 0.48, b, offset + 0.50, b)
        # Another escape QRS
        pts += segment(offset + 0.50, b, offset + 0.52, b - 0.04)
        pts += segment(offset + 0.52, b - 0.04, offset + 0.54, b + 0.45)
        pts += segment(offset + 0.54, b + 0.45, offset + 0.56, b - 0.05)
        pts += segment(offset + 0.56, b - 0.05, offset + 0.58, b)
        # P wave 4
        pts += segment(offset + 0.58, b, offset + 0.64, b)
        pts += p_wave(offset + 0.67, amp=0.10)
        pts += segment(offset + 0.72, b, offset + 0.80, b)
        # P wave 5
        pts += p_wave(offset + 0.83, amp=0.10)
        pts += segment(offset + 0.87, b, offset + 1.00, b)
        return pts

    def hyperkalemia_ecg(offset=0.0):
        """Tall tented T waves + wide QRS (moderate hyperK)."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        # Flat/absent P
        pts += segment(offset + 0.05, b, offset + 0.11, b + 0.03)
        pts += segment(offset + 0.11, b + 0.03, offset + 0.15, b)
        pts += segment(offset + 0.15, b, offset + 0.18, b)
        # Wide QRS
        pts += segment(offset + 0.18, b, offset + 0.20, b - 0.04)
        pts += segment(offset + 0.20, b - 0.04, offset + 0.23, b + 0.52)
        pts += segment(offset + 0.23, b + 0.52, offset + 0.29, b - 0.06)
        pts += segment(offset + 0.29, b - 0.06, offset + 0.33, b)
        pts += segment(offset + 0.33, b, offset + 0.36, b)
        # Tall symmetric (tented) T wave
        for i in range(16):
            t = i / 15
            cx = offset + 0.43
            x = cx - 0.07 + t * 0.14
            y = b + 0.42 * math.sin(math.pi * t)  # Very tall!
            pts.append((x, y))
        pts += segment(offset + 0.50, b, offset + 0.55, b)
        return pts

    def hypokalemia_ecg(offset=0.0):
        """Flat T + prominent U wave."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        pts += p_wave(offset + 0.09, amp=0.10)
        pts += segment(offset + 0.12, b, offset + 0.17, b)
        pts += segment(offset + 0.17, b, offset + 0.19, b - 0.04)
        pts += segment(offset + 0.19, b - 0.04, offset + 0.21, b + 0.50)
        pts += segment(offset + 0.21, b + 0.50, offset + 0.23, b - 0.05)
        pts += segment(offset + 0.23, b - 0.05, offset + 0.26, b)
        pts += segment(offset + 0.26, b, offset + 0.30, b)
        # Flat/small T
        for i in range(8):
            t = i / 7
            cx = offset + 0.33
            x = cx - 0.04 + t * 0.08
            y = b + 0.04 * math.sin(math.pi * t)
            pts.append((x, y))
        # U wave
        pts += segment(offset + 0.38, b, offset + 0.40, b)
        for i in range(10):
            t = i / 9
            cx = offset + 0.44
            x = cx - 0.04 + t * 0.08
            y = b + 0.11 * math.sin(math.pi * t)
            pts.append((x, y))
        pts += segment(offset + 0.49, b, offset + 0.55, b)
        return pts

    def pericarditis_ecg(offset=0.0):
        """Diffuse saddle-shaped ST elevation + PR depression."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.05, b)
        pts += p_wave(offset + 0.09, amp=0.10)
        # PR depression
        pts += segment(offset + 0.12, b, offset + 0.13, b - 0.04)
        pts += segment(offset + 0.13, b - 0.04, offset + 0.17, b - 0.04)
        pts += segment(offset + 0.17, b - 0.04, offset + 0.19, b - 0.04)
        pts += segment(offset + 0.19, b - 0.04, offset + 0.21, b + 0.48)
        pts += segment(offset + 0.21, b + 0.48, offset + 0.23, b - 0.02)
        # Saddle-shaped ST elevation (curved upward)
        for i in range(12):
            t = i / 11
            x = offset + 0.24 + t * 0.12
            # Saddle = concave upward
            y = b + 0.12 - 0.04 * math.cos(math.pi * t)
            pts.append((x, y))
        # T wave (upright, following ST)
        pts += p_wave(offset + 0.40, amp=0.16, w=0.10)
        pts += segment(offset + 0.46, b, offset + 0.55, b)
        return pts

    def torsades_ecg(offset=0.0):
        """Torsades de pointes - twisting QRS."""
        b = baseline
        pts = []
        for beat in range(5):
            o = offset + beat * 0.19
            phase = beat * math.pi * 0.7
            amp = 0.55 * math.sin(phase + 0.5)
            sign = 1 if amp > 0 else -1
            amp = max(0.25, abs(amp)) * sign
            # Brief QRS
            pts += segment(o, b, o + 0.02, b + amp * 0.3)
            pts += segment(o + 0.02, b + amp * 0.3, o + 0.05, b + amp)
            pts += segment(o + 0.05, b + amp, o + 0.08, b - amp * 0.2)
            pts += segment(o + 0.08, b - amp * 0.2, o + 0.10, b)
            # Discordant T
            for i in range(6):
                t2 = i / 5
                x = o + 0.12 + t2 * 0.06
                y = b - amp * 0.3 * math.sin(math.pi * t2)
                pts.append((x, y))
            pts += segment(o + 0.18, b, o + 0.19, b)
        return pts

    def prolonged_qt(offset=0.0):
        """Normal QRS, prolonged QT interval."""
        b = baseline
        pts = []
        pts += segment(offset + 0.00, b, offset + 0.04, b)
        pts += p_wave(offset + 0.08, amp=0.10)
        pts += segment(offset + 0.11, b, offset + 0.15, b)
        pts += segment(offset + 0.15, b, offset + 0.17, b - 0.04)
        pts += segment(offset + 0.17, b - 0.04, offset + 0.19, b + 0.52)
        pts += segment(offset + 0.19, b + 0.52, offset + 0.21, b - 0.05)
        pts += segment(offset + 0.21, b - 0.05, offset + 0.24, b)
        # Very prolonged ST before T wave
        pts += segment(offset + 0.24, b, offset + 0.42, b)
        # T wave
        pts += p_wave(offset + 0.47, amp=0.12, w=0.10)
        pts += segment(offset + 0.53, b, offset + 0.60, b)
        return pts

    def wenckebach_ecg(offset=0.0):
        """Mobitz I - PR progressively lengthens, then dropped beat."""
        b = baseline
        pts = []
        pr_delays = [0.04, 0.06, 0.09]  # Increasing PR
        beat_starts = [0.00, 0.22, 0.46]
        for i, (bs, pr) in enumerate(zip(beat_starts, pr_delays)):
            o = offset + bs
            pts += segment(o, b, o + 0.02, b)
            pts += p_wave(o + 0.03, amp=0.09)
            pts += segment(o + 0.06, b, o + 0.06 + pr, b)
            qrs_start = o + 0.06 + pr
            pts += segment(qrs_start, b, qrs_start + 0.01, b - 0.03)
            pts += segment(qrs_start + 0.01, b - 0.03, qrs_start + 0.03, b + 0.45)
            pts += segment(qrs_start + 0.03, b + 0.45, qrs_start + 0.05, b - 0.04)
            pts += segment(qrs_start + 0.05, b - 0.04, qrs_start + 0.07, b)
            pts += segment(qrs_start + 0.07, b, qrs_start + 0.10, b)
            pts += p_wave(qrs_start + 0.12, amp=0.09, w=0.05)
            pts += segment(qrs_start + 0.16, b, qrs_start + 0.20, b)
        # Dropped beat - just P wave, no QRS
        o_drop = offset + 0.73
        pts += p_wave(o_drop, amp=0.09)
        pts += segment(o_drop + 0.04, b, o_drop + 0.27, b)
        return pts

    # ── Pattern dispatch ────────────────────────────────────────────────
    patterns = {
        'normal':        (normal_beat(0.05) + normal_beat(0.55),
                          [(0.26, 0.96, 'P'), (0.31, 0.98, 'Q'), (0.33, 0.99, 'R'),
                           (0.35, 0.97, 'S'), (0.44, 0.93, 'T')]),
        'st_elevation':  (st_elevation_beat(0.05) + st_elevation_beat(0.55),
                          [(0.36, 0.97, 'ST↑')]),
        'st_depression': (st_depression_beat(0.05) + st_depression_beat(0.55),
                          [(0.36, 0.97, 'ST↓')]),
        't_inversion':   (t_inversion_beat(0.05) + t_inversion_beat(0.55),
                          [(0.44, 0.97, '-T')]),
        'af':            (af_beat(0.00), [(0.15, 0.97, 'No P')]),
        'flutter':       (flutter_wave(0.00), [(0.07, 0.96, 'Sawtooth')]),
        'vt':            (vt_beat(0.02, n=2), [(0.15, 0.97, 'Wide QRS')]),
        'vf':            (vf_wave(0.00), [(0.50, 0.97, 'Chaotic')]),
        'chb':           (heart_block_3rd(0.00), [(0.50, 0.97, 'P≠QRS')]),
        'hyperkalemia':  (hyperkalemia_ecg(0.05), [(0.43, 0.97, 'Tall T')]),
        'hypokalemia':   (hypokalemia_ecg(0.05), [(0.44, 0.97, 'U wave')]),
        'pericarditis':  (pericarditis_ecg(0.05), [(0.30, 0.97, 'Saddle ST↑')]),
        'torsades':      (torsades_ecg(0.00), [(0.50, 0.97, 'Twisting')]),
        'prolonged_qt':  (prolonged_qt(0.05), [(0.38, 0.97, 'Long QT')]),
        'wenckebach':    (wenckebach_ecg(0.00), [(0.88, 0.97, 'Drop')]),
    }

    pts_data, lp = patterns.get(pattern_type, patterns['normal'])
    color = kwargs.pop('color', ECG_LINE)
    label = kwargs.pop('label', '')
    return ECGWaveform(width, height, pts_data, label=label, color=color,
                       label_points=lp, **kwargs)


# ── Styled helpers ────────────────────────────────────────────────────────────

def build_styles():
    styles = getSampleStyleSheet()

    styles.add(ParagraphStyle('DocTitle',
        fontSize=22, fontName='Helvetica-Bold',
        textColor=WHITE, alignment=TA_CENTER, spaceAfter=2))
    styles.add(ParagraphStyle('DocSubtitle',
        fontSize=11, fontName='Helvetica',
        textColor=colors.HexColor('#AED6F1'), alignment=TA_CENTER, spaceAfter=0))
    styles.add(ParagraphStyle('SectionHeader',
        fontSize=12, fontName='Helvetica-Bold',
        textColor=WHITE, alignment=TA_LEFT, spaceAfter=3,
        leftIndent=4))
    styles.add(ParagraphStyle('CardTitle',
        fontSize=9.5, fontName='Helvetica-Bold',
        textColor=DARK_GRAY, spaceAfter=1, leftIndent=2))
    styles.add(ParagraphStyle('CardBody',
        fontSize=7.5, fontName='Helvetica',
        textColor=DARK_GRAY, spaceAfter=1, leftIndent=2, leading=10))
    styles.add(ParagraphStyle('AlertText',
        fontSize=7.5, fontName='Helvetica-Bold',
        textColor=RED, spaceAfter=1, leftIndent=2))
    styles.add(ParagraphStyle('GoodText',
        fontSize=7.5, fontName='Helvetica-Bold',
        textColor=DARK_GREEN, spaceAfter=1, leftIndent=2))
    styles.add(ParagraphStyle('TableHeader',
        fontSize=8, fontName='Helvetica-Bold',
        textColor=WHITE, alignment=TA_CENTER))
    styles.add(ParagraphStyle('TableCell',
        fontSize=7.5, fontName='Helvetica',
        textColor=DARK_GRAY, alignment=TA_LEFT, leading=10))
    styles.add(ParagraphStyle('TableCellBold',
        fontSize=7.5, fontName='Helvetica-Bold',
        textColor=DARK_GRAY, alignment=TA_LEFT))
    styles.add(ParagraphStyle('FooterText',
        fontSize=6.5, fontName='Helvetica',
        textColor=MID_GRAY, alignment=TA_CENTER))
    styles.add(ParagraphStyle('PageTitle',
        fontSize=13, fontName='Helvetica-Bold',
        textColor=WHITE, alignment=TA_LEFT, spaceAfter=2, leftIndent=6))
    return styles


def section_header(title, styles, bg=HEADER_BG):
    """Colored section header bar."""
    return Table(
        [[Paragraph(title, styles['SectionHeader'])]],
        colWidths=[17.5 * cm],
        style=TableStyle([
            ('BACKGROUND', (0, 0), (-1, -1), bg),
            ('TOPPADDING', (0, 0), (-1, -1), 5),
            ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
            ('LEFTPADDING', (0, 0), (-1, -1), 6),
            ('ROUNDEDCORNERS', [4, 4, 4, 4]),
        ])
    )


def ecg_card(waveform, title, bullets, styles, bg=ECG_BG, alert=False):
    """A single ECG pattern card: waveform + description."""
    title_color = RED if alert else BLUE
    title_style = ParagraphStyle('_ct', fontSize=9, fontName='Helvetica-Bold',
                                 textColor=title_color, spaceAfter=2, leftIndent=2)
    bullet_style = ParagraphStyle('_cb', fontSize=7.2, fontName='Helvetica',
                                  textColor=DARK_GRAY, leftIndent=4, leading=9.5)
    content = [Paragraph(title, title_style)]
    for b in bullets:
        content.append(Paragraph(f"• {b}", bullet_style))

    # Build inner table: waveform | text
    inner = Table(
        [[waveform, [c for c in content]]],
        colWidths=[6.8 * cm, 9.5 * cm],
        style=TableStyle([
            ('VALIGN', (0, 0), (-1, -1), 'TOP'),
            ('LEFTPADDING', (0, 0), (0, 0), 3),
            ('RIGHTPADDING', (0, 0), (0, 0), 4),
            ('LEFTPADDING', (1, 0), (1, 0), 3),
            ('TOPPADDING', (0, 0), (-1, -1), 4),
            ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ])
    )
    wrapper = Table(
        [[inner]],
        colWidths=[17.0 * cm],
        style=TableStyle([
            ('BACKGROUND', (0, 0), (-1, -1), bg),
            ('BOX', (0, 0), (-1, -1), 0.6, colors.HexColor('#CCCCCC')),
            ('ROUNDEDCORNERS', [4, 4, 4, 4]),
            ('TOPPADDING', (0, 0), (-1, -1), 0),
            ('BOTTOMPADDING', (0, 0), (-1, -1), 0),
        ])
    )
    return wrapper


# ── Cover Page ───────────────────────────────────────────────────────────────

def build_cover(styles):
    elems = []

    # Large colored banner
    banner = Table(
        [[Paragraph("🫀  ICU ECG REFERENCE", styles['DocTitle']),
          Paragraph("Quick Pattern Guide for Bedside Use", styles['DocSubtitle'])]],
        colWidths=[17.5 * cm],
        style=TableStyle([
            ('BACKGROUND', (0, 0), (-1, -1), HEADER_BG),
            ('TOPPADDING', (0, 0), (-1, -1), 14),
            ('BOTTOMPADDING', (0, 0), (-1, -1), 14),
            ('SPAN', (0, 0), (0, 1)),
        ])
    )

    # Re-do as single-column
    banner = Table(
        [[Paragraph("ICU ECG PATTERN REFERENCE", styles['DocTitle'])],
         [Paragraph("Quick Visual Guide for Bedside Use  |  Hindi-English", styles['DocSubtitle'])]],
        colWidths=[17.5 * cm],
        style=TableStyle([
            ('BACKGROUND', (0, 0), (-1, -1), HEADER_BG),
            ('TOPPADDING', (0, 0), (-1, -1), 12),
            ('BOTTOMPADDING', (0, 0), (-1, -1), 12),
            ('LEFTPADDING', (0, 0), (-1, -1), 10),
        ])
    )
    elems.append(banner)
    elems.append(Spacer(1, 0.3 * cm))

    # Contents overview table
    contents_data = [
        [Paragraph("SECTION", styles['TableHeader']),
         Paragraph("TOPICS", styles['TableHeader'])],
        ["Page 1", "Normal ECG + ECG Basics (PQRST)"],
        ["Page 2", "ST Elevation - STEMI Patterns & Localization"],
        ["Page 3", "ST Depression, T-wave Changes, Pericarditis"],
        ["Page 4", "Supraventricular Arrhythmias (AF, Flutter, SVT)"],
        ["Page 5", "Ventricular Arrhythmias (VT, VF, Torsades)"],
        ["Page 6", "Bradyarrhythmias & Heart Blocks"],
        ["Page 7", "Electrolyte ECG Changes (HyperK, HypoK, Ca, Mg)"],
        ["Page 8", "Special Patterns (PE, Tamponade, Hypothermia, Digoxin)"],
        ["Page 9", "ICU Emergency Quick-Action Table"],
    ]
    t_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), HEADER_BG),
        ('BACKGROUND', (0, 1), (-1, 1), INFO_BG),
        ('BACKGROUND', (0, 2), (-1, 2), LIGHT_GRAY),
        ('BACKGROUND', (0, 3), (-1, 3), INFO_BG),
        ('BACKGROUND', (0, 4), (-1, 4), LIGHT_GRAY),
        ('BACKGROUND', (0, 5), (-1, 5), INFO_BG),
        ('BACKGROUND', (0, 6), (-1, 6), LIGHT_GRAY),
        ('BACKGROUND', (0, 7), (-1, 7), INFO_BG),
        ('BACKGROUND', (0, 8), (-1, 8), LIGHT_GRAY),
        ('BACKGROUND', (0, 9), (-1, 9), INFO_BG),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTSIZE', (0, 1), (-1, -1), 9),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), BLUE),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ])
    tbl = Table(contents_data, colWidths=[3 * cm, 14.5 * cm], style=t_style)
    elems.append(tbl)
    elems.append(Spacer(1, 0.3 * cm))

    # How to use box
    how_data = [[
        Paragraph(
            "<b>HOW TO USE THIS REFERENCE / Kaise Use Karein:</b><br/>"
            "1. ECG dekho → pattern identify karo → iss guide mein match karo<br/>"
            "2. Diagnosis confirm karo → Emergency Action Table (Page 9) dekho<br/>"
            "3. Patient stable hai ya nahi - PEHLE yeh decide karo<br/>"
            "4. Unstable = SHOCK / DEFIB / CPR pehle, phir diagnosis<br/>"
            "<i>Note: Ye guide clinical judgment ki jagah nahi le sakti. Doctor se confirm karo.</i>",
            ParagraphStyle('hw', fontSize=8, fontName='Helvetica',
                           textColor=DARK_GRAY, leading=12))
    ]]
    how_tbl = Table(how_data, colWidths=[17.5 * cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), WARN_BG),
        ('BOX', (0, 0), (-1, -1), 1, ORANGE),
        ('TOPPADDING', (0, 0), (-1, -1), 8),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 8),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(how_tbl)
    return elems


# ── Page builders ─────────────────────────────────────────────────────────────

def page_normal_ecg(styles):
    elems = [section_header("PAGE 1 — NORMAL ECG & BASICS", styles), Spacer(1, 0.2 * cm)]

    # Normal ECG card (wide)
    normal_wf = make_ecg(16 * cm, 3.2 * cm, 'normal', label='Normal Sinus Rhythm')
    elems.append(normal_wf)
    elems.append(Spacer(1, 0.2 * cm))

    # PQRST explanation table
    pq_data = [
        [Paragraph("WAVE", styles['TableHeader']),
         Paragraph("NORMAL VALUE", styles['TableHeader']),
         Paragraph("MEANING", styles['TableHeader'])],
        ["P Wave", "< 0.12 sec, < 2.5 mm", "Atria ka depolarization (SA node se)"],
        ["PR Interval", "0.12 – 0.20 sec (3-5 boxes)", "AV node delay – agar > 0.20 = 1st degree block"],
        ["QRS Complex", "< 0.12 sec (< 3 boxes)", "Ventricles ka depolarization – agar wide = BBB ya VT"],
        ["ST Segment", "Isoelectric (flat, at baseline)", "STEMI = elevation; NSTEMI/Ischemia = depression"],
        ["T Wave", "Upright in most leads", "Repolarization – inversion = ischemia"],
        ["QT Interval", "< 440 ms men / < 460 ms women", "Lamba = Torsades risk (drugs, hypoK, hypoMg)"],
        ["QTc (corrected)", "Bazett: QT / √RR", "Correct for heart rate"],
    ]
    pq_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), HEADER_BG),
        ('BACKGROUND', (0, 1), (-1, 1), INFO_BG),
        ('BACKGROUND', (0, 2), (-1, 2), LIGHT_GRAY),
        ('BACKGROUND', (0, 3), (-1, 3), INFO_BG),
        ('BACKGROUND', (0, 4), (-1, 4), LIGHT_GRAY),
        ('BACKGROUND', (0, 5), (-1, 5), INFO_BG),
        ('BACKGROUND', (0, 6), (-1, 6), LIGHT_GRAY),
        ('BACKGROUND', (0, 7), (-1, 7), INFO_BG),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), BLUE),
        ('FONTSIZE', (0, 1), (-1, -1), 8),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 6),
    ])
    pq_tbl = Table(pq_data, colWidths=[3.5 * cm, 5.0 * cm, 9.0 * cm], style=pq_style)
    elems.append(pq_tbl)
    elems.append(Spacer(1, 0.2 * cm))

    # Heart rate calculation box
    hr_data = [[
        Paragraph(
            "<b>HEART RATE CALCULATION:</b>  300 ÷ (number of large boxes between R-R)  "
            "| 1 large box = 0.20 sec | 1 small box = 0.04 sec<br/>"
            "<b>Speed memory:</b>  1 box=300 | 2=150 | 3=100 | 4=75 | 5=60 | 6=50",
            ParagraphStyle('hr', fontSize=8, fontName='Helvetica',
                           textColor=DARK_GRAY, leading=12))
    ]]
    hr_tbl = Table(hr_data, colWidths=[17.5 * cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), GOOD_BG),
        ('BOX', (0, 0), (-1, -1), 0.8, GREEN),
        ('TOPPADDING', (0, 0), (-1, -1), 6),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 6),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(hr_tbl)
    return elems


def page_stemi(styles):
    elems = [section_header("PAGE 2 — ST ELEVATION (STEMI)", styles, RED), Spacer(1, 0.15 * cm)]

    # STEMI criteria
    crit_data = [[
        Paragraph(
            "<b>STEMI CRITERIA (Washington Manual):</b>  2+ contiguous leads mein ST elevation needed<br/>"
            "Men >40 yr: ≥2mm in V2-V3, ≥1mm others  |  Men <40 yr: ≥2.5mm in V2-V3  |  Women: ≥1.5mm in V2-V3, ≥1mm others<br/>"
            "<b>DOOR-TO-BALLOON TARGET: &lt; 90 minutes  →  Activate Cath Lab IMMEDIATELY</b>",
            ParagraphStyle('cr', fontSize=8, fontName='Helvetica',
                           textColor=DARK_GRAY, leading=12))
    ]]
    crit_tbl = Table(crit_data, colWidths=[17.5 * cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), ALERT_BG),
        ('BOX', (0, 0), (-1, -1), 1.2, RED),
        ('TOPPADDING', (0, 0), (-1, -1), 6),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 6),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(crit_tbl)
    elems.append(Spacer(1, 0.2 * cm))

    # ST elevation waveform
    wf = make_ecg(7 * cm, 2.6 * cm, 'st_elevation', color=RED, label='ST Elevation (STEMI)')
    normal = make_ecg(7 * cm, 2.6 * cm, 'normal', label='Normal (compare)')

    side_tbl = Table([[wf, Spacer(0.3 * cm, 1), normal]],
                     colWidths=[7.2 * cm, 0.3 * cm, 7.2 * cm],
                     style=TableStyle([('VALIGN', (0, 0), (-1, -1), 'TOP')]))
    elems.append(side_tbl)
    elems.append(Spacer(1, 0.2 * cm))

    # Localization table
    loc_data = [
        [Paragraph("LOCATION", styles['TableHeader']),
         Paragraph("LEADS", styles['TableHeader']),
         Paragraph("ARTERY (Rosen's)", styles['TableHeader']),
         Paragraph("RECIPROCAL CHANGES", styles['TableHeader'])],
        ["Anterior STEMI", "V1 – V4", "LAD (Left Anterior Descending)", "ST↓ in II, III, aVF"],
        ["Lateral STEMI", "I, aVL, V5, V6", "LCX (Left Circumflex)", "ST↓ in inferior leads"],
        ["Anterolateral", "V1–V6, I, aVL", "Proximal LAD / Left Main", "ST↓ inferior + right"],
        ["Inferior STEMI", "II, III, aVF", "RCA (Right Coronary Artery)", "ST↓ in I, aVL"],
        ["Right Ventricular", "V3R, V4R elevation", "Proximal RCA", "Check if Inferior STEMI"],
        ["Posterior STEMI", "V7-V9 elevation", "LCX (often missed!)", "ST↓ + Tall R in V1-V3"],
        ["aVR elevation", "aVR ↑ + diffuse ST↓", "Left Main / Proximal LAD", "Global subendocardial"],
    ]
    loc_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), RED),
        ('BACKGROUND', (0, 1), (-1, 1), colors.HexColor('#FDEDEC')),
        ('BACKGROUND', (0, 2), (-1, 2), LIGHT_GRAY),
        ('BACKGROUND', (0, 3), (-1, 3), colors.HexColor('#FDEDEC')),
        ('BACKGROUND', (0, 4), (-1, 4), LIGHT_GRAY),
        ('BACKGROUND', (0, 5), (-1, 5), colors.HexColor('#FDEDEC')),
        ('BACKGROUND', (0, 6), (-1, 6), LIGHT_GRAY),
        ('BACKGROUND', (0, 7), (-1, 7), ALERT_BG),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), RED),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
    ])
    loc_tbl = Table(loc_data,
                    colWidths=[3.8 * cm, 3.0 * cm, 5.5 * cm, 5.2 * cm],
                    style=loc_style)
    elems.append(loc_tbl)
    elems.append(Spacer(1, 0.15 * cm))

    # LBBB note
    lbbb_data = [[
        Paragraph(
            "<b>NEW LBBB + Chest Pain = Treat as STEMI (Sgarbossa Criteria)</b><br/>"
            "Concordant ST↑ >1mm | Discordant ST↑ >5mm | ST↓ >1mm in V1-V3",
            ParagraphStyle('lb', fontSize=8, fontName='Helvetica',
                           textColor=DARK_GRAY, leading=11))
    ]]
    lbbb_tbl = Table(lbbb_data, colWidths=[17.5 * cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), WARN_BG),
        ('BOX', (0, 0), (-1, -1), 0.8, ORANGE),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(lbbb_tbl)
    return elems


def page_st_depression_t(styles):
    elems = [section_header("PAGE 3 — ST DEPRESSION, T-WAVE CHANGES & PERICARDITIS", styles, PURPLE), Spacer(1, 0.15 * cm)]

    wf_dep  = make_ecg(5.3 * cm, 2.5 * cm, 'st_depression', color=ORANGE, label='ST Depression')
    wf_tinv = make_ecg(5.3 * cm, 2.5 * cm, 't_inversion',  color=PURPLE, label='T Inversion')
    wf_peri = make_ecg(5.3 * cm, 2.5 * cm, 'pericarditis', color=BLUE,   label='Pericarditis')

    row_tbl = Table([[wf_dep, Spacer(0.2*cm,1), wf_tinv, Spacer(0.2*cm,1), wf_peri]],
                    colWidths=[5.5*cm, 0.2*cm, 5.5*cm, 0.2*cm, 5.5*cm],
                    style=TableStyle([('VALIGN',(0,0),(-1,-1),'TOP')]))
    elems.append(row_tbl)
    elems.append(Spacer(1, 0.2 * cm))

    changes_data = [
        [Paragraph("FINDING", styles['TableHeader']),
         Paragraph("PATTERN", styles['TableHeader']),
         Paragraph("THINK", styles['TableHeader']),
         Paragraph("ACTION", styles['TableHeader'])],
        ["Horizontal ST↓", "Flat depression ≥1mm", "NSTEMI / Unstable Angina", "Troponin, heparin, cardiology"],
        ["Downsloping ST↓", "ST slopes down", "Significant ischemia", "Urgent cardiology review"],
        ["ST↓ V1-V3 only", "Isolated posterior", "Posterior STEMI!", "Add V7-V9 leads"],
        ["T inversion", "Inverted T wave", "Ischemia, PE, post-MI", "Echo, troponin, CTPA"],
        ["Wellens' Pattern", "Biphasic/deep T↓ V2-V3", "LAD critical stenosis", "Urgent angiography"],
        ["Hyperacute T", "Tall, peaked, symmetric", "Very early STEMI (mins)", "Serial ECG, troponin"],
        ["Diffuse ST↑ all leads", "Saddle-shaped + PR↓", "Pericarditis", "Echo, NSAIDs, colchicine"],
        ["CVA T-waves", "Deep wide T inversion", "Subarachnoid hemorrhage", "CT head, neurosurgery"],
    ]
    ch_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), PURPLE),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), PURPLE),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [LIGHT_GRAY, WHITE]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
    ])
    ch_tbl = Table(changes_data, colWidths=[4.0*cm, 3.8*cm, 5.0*cm, 4.7*cm], style=ch_style)
    elems.append(ch_tbl)
    return elems


def page_supra_arrhythmias(styles):
    elems = [section_header("PAGE 4 — SUPRAVENTRICULAR ARRHYTHMIAS (SVT, AF, FLUTTER)", styles, BLUE), Spacer(1, 0.15 * cm)]

    wf_af  = make_ecg(8.0*cm, 2.6*cm, 'af',      color=BLUE,   label='Atrial Fibrillation')
    wf_fl  = make_ecg(8.0*cm, 2.6*cm, 'flutter',  color=PURPLE, label='Atrial Flutter')

    row = Table([[wf_af, Spacer(0.3*cm,1), wf_fl]],
                colWidths=[8.3*cm, 0.3*cm, 8.3*cm],
                style=TableStyle([('VALIGN',(0,0),(-1,-1),'TOP')]))
    elems.append(row)
    elems.append(Spacer(1, 0.2*cm))

    arr_data = [
        [Paragraph("ARRHYTHMIA", styles['TableHeader']),
         Paragraph("ECG FINDINGS", styles['TableHeader']),
         Paragraph("STABLE TREATMENT", styles['TableHeader']),
         Paragraph("UNSTABLE TREATMENT", styles['TableHeader'])],
        ["Sinus Tachycardia", "Normal P before QRS\nHR 100-150, regular", "Treat CAUSE (sepsis/fever/pain)\nNO specific antiarrhythmic", "—"],
        ["Atrial Fibrillation", "Irregularly irregular\nNo P waves, chaotic baseline\nVariable R-R intervals", "Rate control:\nMetoprolol 5mg IV\nor Diltiazem 0.25mg/kg IV\nAnticoag if >48hrs", "DC Cardioversion\n100-200J sync\nStat"],
        ["Atrial Flutter", "Regular sawtooth P waves\n300/min flutter, 150 ventricular\n2:1 or 4:1 block", "Rate control same as AF\nCardioversion 50-100J", "DC Cardioversion\n50-100J sync"],
        ["SVT (AVNRT)", "Narrow QRS tachycardia\nHR 150-250\nNo visible P waves", "Vagal maneuvers first\nAdenosine 6mg rapid IV\n(warn patient!)", "DC Cardioversion\n50-100J sync"],
        ["Sinus Bradycardia", "Normal P-QRS-T, HR<60\nRegular rhythm", "If asymptomatic: observe\nAtropine 0.5mg IV if symptomatic", "Pacing if refractory"],
    ]
    arr_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), BLUE),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), BLUE),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [INFO_BG, WHITE]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
    ])
    arr_tbl = Table(arr_data, colWidths=[3.5*cm, 5.0*cm, 5.0*cm, 4.0*cm], style=arr_style)
    elems.append(arr_tbl)
    elems.append(Spacer(1, 0.15*cm))

    # Adenosine warning
    aden_data = [[
        Paragraph(
            "<b>⚠ ADENOSINE WARNING:</b>  WPW (Wolff-Parkinson-White) mein AVOID karo — AF with rapid conduction trigger ho sakti hai  |  "
            "Always with crash cart ready  |  Central line se better, peripheral IV se bhi hota hai (rapid flush ke saath)",
            ParagraphStyle('aw', fontSize=8, fontName='Helvetica', textColor=DARK_GRAY, leading=11))
    ]]
    aden_tbl = Table(aden_data, colWidths=[17.5*cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), WARN_BG),
        ('BOX', (0, 0), (-1, -1), 0.8, ORANGE),
        ('TOPPADDING', (0, 0), (-1, -1), 5),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 5),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(aden_tbl)
    return elems


def page_ventricular_arrhythmias(styles):
    elems = [section_header("PAGE 5 — VENTRICULAR ARRHYTHMIAS (VT, VF, TORSADES) — HIGH ALERT!", styles, RED), Spacer(1, 0.15*cm)]

    wf_vt  = make_ecg(5.3*cm, 2.6*cm, 'vt',      color=RED,    label='Ventricular Tachycardia (VT)')
    wf_vf  = make_ecg(5.3*cm, 2.6*cm, 'vf',      color=DARK_RED,label='Ventricular Fibrillation (VF)')
    wf_tor = make_ecg(5.3*cm, 2.6*cm, 'torsades', color=PURPLE, label='Torsades de Pointes')

    row = Table([[wf_vt, Spacer(0.2*cm,1), wf_vf, Spacer(0.2*cm,1), wf_tor]],
                colWidths=[5.5*cm,0.2*cm,5.5*cm,0.2*cm,5.5*cm],
                style=TableStyle([('VALIGN',(0,0),(-1,-1),'TOP')]))
    elems.append(row)
    elems.append(Spacer(1, 0.2*cm))

    v_data = [
        [Paragraph("RHYTHM", styles['TableHeader']),
         Paragraph("ECG PATTERN", styles['TableHeader']),
         Paragraph("PULSE?", styles['TableHeader']),
         Paragraph("TREATMENT", styles['TableHeader'])],
        ["Monomorphic VT", "Wide QRS >0.12s\nRegular rate >100\nAV dissociation\nFusion/capture beats", "YES - Stable", "Amiodarone 150mg IV over 10min\nthen 1mg/min infusion"],
        ["Monomorphic VT", "Same wide QRS", "YES - Unstable\n(BP↓, syncope)", "SYNCHRONIZED DC Cardioversion\n100-200J biphasic"],
        ["Pulseless VT", "Wide complex, NO PULSE", "NO", "DEFIBRILLATE (unsynchronized)\n200J → CPR → 300J → CPR → 360J"],
        ["Ventricular Fibrillation", "Chaotic, no QRS\nNO PULSE", "NO", "DEFIBRILLATE 200J → CPR\nEpinephrine 1mg IV q3-5min\nAmiodarone 300mg IV"],
        ["Torsades de Pointes", "Twisting QRS amplitude\nPolymorphic, QT prolonged", "Usually YES", "MgSO4 2g IV over 5min STAT\nStop QT-prolonging drugs\nK+ >4.5 mEq/L target"],
        ["Accelerated Idioventricular", "Wide QRS, HR 60-100\nPost-MI reperfusion", "YES", "Usually benign\nReperfusion rhythm — observe"],
    ]
    v_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), RED),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), RED),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [colors.HexColor('#FDEDEC'), WHITE]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
    ])
    v_tbl = Table(v_data, colWidths=[3.8*cm, 5.0*cm, 2.8*cm, 5.9*cm], style=v_style)
    elems.append(v_tbl)
    elems.append(Spacer(1, 0.15*cm))

    # QT prolonging drugs
    qt_data = [[
        Paragraph(
            "<b>COMMON QT-PROLONGING DRUGS IN ICU (Torsades Risk):</b><br/>"
            "Amiodarone | Haloperidol | Methadone | Azithromycin | Fluconazole | Ondansetron | "
            "Ciprofloxacin | Metronidazole | Quetiapine | TCA antidepressants | Hydroxychloroquine<br/>"
            "<b>QTc >500ms = Stop offending drug + MgSO4 + K⁺ correction</b>",
            ParagraphStyle('qt', fontSize=8, fontName='Helvetica', textColor=DARK_GRAY, leading=11))
    ]]
    qt_tbl = Table(qt_data, colWidths=[17.5*cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), ALERT_BG),
        ('BOX', (0, 0), (-1, -1), 1.0, RED),
        ('TOPPADDING', (0, 0), (-1, -1), 6),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 6),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(qt_tbl)
    return elems


def page_bradyarrhythmias(styles):
    elems = [section_header("PAGE 6 — BRADYARRHYTHMIAS & HEART BLOCKS", styles, DARK_GREEN), Spacer(1, 0.15*cm)]

    wf_chb = make_ecg(8.0*cm, 2.6*cm, 'chb',       color=DARK_GREEN, label='Complete Heart Block (3rd Degree)')
    wf_wen = make_ecg(8.0*cm, 2.6*cm, 'wenckebach', color=GREEN,      label='Mobitz I (Wenckebach)')

    row = Table([[wf_chb, Spacer(0.3*cm,1), wf_wen]],
                colWidths=[8.3*cm, 0.3*cm, 8.3*cm],
                style=TableStyle([('VALIGN',(0,0),(-1,-1),'TOP')]))
    elems.append(row)
    elems.append(Spacer(1, 0.2*cm))

    hb_data = [
        [Paragraph("BLOCK TYPE", styles['TableHeader']),
         Paragraph("ECG FINDING", styles['TableHeader']),
         Paragraph("RISK", styles['TableHeader']),
         Paragraph("ICU ACTION", styles['TableHeader'])],
        ["1st Degree AV Block", "PR >0.20s (>5 small boxes)\nEvery P conducts normally", "Low\nUsually benign", "Monitor, check drugs\n(digoxin, beta-blockers)"],
        ["2nd Degree - Mobitz I (Wenckebach)", "PR progressively lengthens\nthen P wave drops (no QRS)\nPattern repeats", "Low-Moderate\nRarely progresses", "Observe, atropine if symptomatic\nCheck inferior MI"],
        ["2nd Degree - Mobitz II", "Fixed PR interval\nSuddenly P wave drops — no QRS\nNo warning!", "HIGH — can progress to CHB\nUnpredictable", "Transcutaneous pacing ready\nPermanent pacemaker indication\nCardiology STAT"],
        ["3rd Degree (Complete Heart Block)", "P waves & QRS completely INDEPENDENT\nP rate > QRS rate (dissociation)\nEscape rhythm: 30-50 bpm", "CRITICAL\nLow cardiac output", "Emergency pacing STAT\nAtropine 0.5-1mg IV (temp)\nDopamine/Epinephrine if needed"],
        ["Sinus Node Dysfunction", "Sinus pause >3s\nor HR <40 consistently", "Symptomatic bradycardia", "Atropine → pacing\nCheck hypothyroidism, drugs"],
    ]
    hb_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), DARK_GREEN),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), DARK_GREEN),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [GOOD_BG, WHITE]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        # Highlight Mobitz II and CHB rows
        ('BACKGROUND', (0, 3), (-1, 3), colors.HexColor('#FEF5E7')),
        ('BACKGROUND', (0, 4), (-1, 4), ALERT_BG),
    ])
    hb_tbl = Table(hb_data, colWidths=[4.0*cm, 5.0*cm, 3.5*cm, 5.0*cm], style=hb_style)
    elems.append(hb_tbl)
    elems.append(Spacer(1, 0.15*cm))

    causes_data = [[
        Paragraph(
            "<b>ICU CAUSES OF BRADYCARDIA:</b>  Beta-blocker/CCB overdose | Digoxin toxicity | "
            "Inferior STEMI (RCA → SA/AV node ischemia) | Hypothyroidism | Hypothermia | "
            "Raised ICP (Cushing reflex) | Vasovagal | Hyperkalemia | Post-cardiac surgery",
            ParagraphStyle('bc', fontSize=8, fontName='Helvetica', textColor=DARK_GRAY, leading=11))
    ]]
    causes_tbl = Table(causes_data, colWidths=[17.5*cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), GOOD_BG),
        ('BOX', (0, 0), (-1, -1), 0.8, GREEN),
        ('TOPPADDING', (0, 0), (-1, -1), 6),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 6),
        ('LEFTPADDING', (0, 0), (-1, -1), 8),
    ]))
    elems.append(causes_tbl)
    return elems


def page_electrolytes(styles):
    elems = [section_header("PAGE 7 — ELECTROLYTE ECG CHANGES (Harrison's Principles)", styles, ORANGE), Spacer(1, 0.15*cm)]

    wf_hik = make_ecg(5.3*cm, 2.5*cm, 'hyperkalemia', color=RED,   label='Hyperkalemia (K⁺ >5.5)')
    wf_lok = make_ecg(5.3*cm, 2.5*cm, 'hypokalemia',  color=BLUE,  label='Hypokalemia (K⁺ <3.5)')
    wf_qtl = make_ecg(5.3*cm, 2.5*cm, 'prolonged_qt', color=PURPLE,label='Prolonged QT (Ca↓/Mg↓/Drugs)')

    row = Table([[wf_hik, Spacer(0.2*cm,1), wf_lok, Spacer(0.2*cm,1), wf_qtl]],
                colWidths=[5.5*cm,0.2*cm,5.5*cm,0.2*cm,5.5*cm],
                style=TableStyle([('VALIGN',(0,0),(-1,-1),'TOP')]))
    elems.append(row)
    elems.append(Spacer(1, 0.2*cm))

    el_data = [
        [Paragraph("ELECTROLYTE", styles['TableHeader']),
         Paragraph("ECG CHANGES (Sequence)", styles['TableHeader']),
         Paragraph("TREATMENT", styles['TableHeader'])],
        ["Hyperkalemia K⁺ >5.5\n(CRITICAL >6.5)", "Early: Tall PEAKED (tented) T waves ← FIRST SIGN\nModerate: PR↑, P wave flat/absent, wide QRS\nSevere: Sine wave pattern → Asystole / VF",
         "1. Calcium gluconate 10% 10ml IV (membrane stabilize)\n2. Insulin 10U + Dextrose 50% 50ml IV\n3. Salbutamol nebulizer\n4. Kayexalate / Dialysis"],
        ["Hypokalemia K⁺ <3.5", "ST depression, T wave flat/inverted\nProminent U wave (after T wave)\nQT prolongation → Torsades risk\nPR prolongation",
         "IV KCl: Max 10 mEq/hr peripheral\n20 mEq/hr central line\nTarget K⁺ >4.0 in cardiac patients\nAlways correct Mg2+ together"],
        ["Hypocalcemia Ca <8.5", "QT prolongation (ST segment lengthens)\nNo QRS change\nSevere: Cardiac arrest risk",
         "IV Calcium gluconate 10ml 10%\nor Calcium chloride 5-10ml 10%\n(Central line preferred for CaCl)"],
        ["Hypercalcemia Ca >10.5", "QT shortening\nOsborn-like J point changes\nBradycardia, AV blocks\nBundle branch blocks",
         "IV saline hydration\nFurosemide\nBisphosphonates\nDialysis if severe"],
        ["Hypomagnesemia Mg <1.7", "QT prolongation\nTorsades de Pointes\nFlattened T waves\nU waves",
         "MgSO4 1-2g IV over 15-60min\nReplace K⁺ simultaneously\n(HypoMg causes refractory hypoK)"],
        ["Hypothermia Temp <32°C", "Osborn wave (J wave) — notch at J point\nBradycardia, QT prolongation\nPR/QRS widening\nVF risk at <28°C",
         "Rewarm (active external/internal)\nManage VF with defibrillation\n(May need repeated shocks)"],
    ]
    el_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), ORANGE),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), ORANGE),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [WARN_BG, WHITE]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        # Highlight hyperkalemia (most critical)
        ('BACKGROUND', (0, 1), (-1, 1), ALERT_BG),
    ])
    el_tbl = Table(el_data, colWidths=[3.5*cm, 7.2*cm, 6.8*cm], style=el_style)
    elems.append(el_tbl)
    return elems


def page_special_patterns(styles):
    elems = [section_header("PAGE 8 — SPECIAL ICU PATTERNS (PE, TAMPONADE, DIGOXIN, HYPOTHERMIA)", styles, DARK_GRAY), Spacer(1, 0.15*cm)]

    sp_data = [
        [Paragraph("CONDITION", styles['TableHeader']),
         Paragraph("ECG FINDINGS", styles['TableHeader']),
         Paragraph("KEY DIFFERENTIATOR", styles['TableHeader']),
         Paragraph("ACTION", styles['TableHeader'])],
        ["Pulmonary Embolism (PE)", "Sinus tachycardia (most common!)\nS1Q3T3 pattern (only 20%)\nNew RBBB\nT inversion V1-V4 (RV strain)\nAF (new onset)",
         "S1Q3T3 = S wave in I\nQ wave in III, T inversion III",
         "CTPA (gold standard)\nEchocardiography\nAnticoagulation\n(Thrombolysis if massive)"],
        ["Cardiac Tamponade", "Sinus tachycardia\nLow voltage (small QRS all leads)\nElectrical alternans (QRS size alternates beat-to-beat)\nPR segment flattening",
         "Electrical alternans = highly specific\nConfirm with ECHO\nPulsus paradoxus clinically",
         "Emergency pericardiocentesis\nEcho-guided preferred"],
        ["Digoxin Effect (Therapeutic)", "Scooped/Salvador Dali moustache ST↓\nQT shortening\nT wave flattening/inversion\nBradycardia",
         "Scooped ST = therapeutic\nNOT toxicity per se",
         "Monitor digoxin level\nMaintain K⁺ >3.5"],
        ["Digoxin Toxicity", "Bradycardia + AV blocks\nBidirectional VT (pathognomonic!)\nPAT with block\nVT / VF",
         "Bidirectional VT = digoxin until proven otherwise",
         "Digoxin-Fab (Digibind) STAT\nNo cardioversion!\nPotassium correction"],
        ["Pericarditis", "Diffuse saddle-shaped ST↑ ALL leads\nPR depression (pathognomonic)\nNo reciprocal changes\nNo Q waves",
         "Diffuse (not localized) ST↑\nPR depression key!",
         "NSAIDs + Colchicine\nEchocardiography\nRule out STEMI"],
        ["LVH (Left Ventricular Hypertrophy)", "Tall R in V5-V6 (>25mm)\nDeep S in V1-V2\nST↓ and T inversion V4-V6 (strain pattern)\nLAD (Left Axis Deviation)",
         "Strain pattern mimics ischemia\nVoltage criteria needed",
         "Echo for confirmation\nBP control\nMonitor for LBBB"],
        ["Early Repolarization", "J-point elevation V2-V5\nNotching at J-point\nConcave ST elevation\nNormal T waves",
         "Young healthy patients\nAsymptomatic\nSt concave (vs STEMI oblique/convex)",
         "Usually benign\nSerial ECG if symptoms\nRule out STEMI"],
        ["WPW (Wolff-Parkinson-White)", "Short PR (<0.12s)\nDelta wave (slurred QRS onset)\nWide QRS\nST/T changes secondary",
         "Delta wave = key finding\nAF with WPW very dangerous",
         "Avoid adenosine/digoxin/beta-blockers!\nProcainamide if AF+WPW\nRFA ablation"],
    ]
    sp_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), DARK_GRAY),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), DARK_GRAY),
        ('FONTSIZE', (0, 0), (-1, -1), 7.2),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [LIGHT_GRAY, WHITE]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
    ])
    sp_tbl = Table(sp_data, colWidths=[3.3*cm, 5.2*cm, 4.5*cm, 4.5*cm], style=sp_style)
    elems.append(sp_tbl)
    return elems


def page_emergency_table(styles):
    elems = [section_header("PAGE 9 — ICU ECG EMERGENCY QUICK-ACTION TABLE", styles, RED), Spacer(1, 0.15*cm)]

    # UNSTABLE vs STABLE banner
    us_data = [[
        Paragraph(
            "<b>FIRST QUESTION ALWAYS: Patient STABLE hai ya UNSTABLE?</b><br/>"
            "UNSTABLE = ANY of: BP &lt;90/60 | Active chest pain | Altered sensorium | SpO2 &lt;90% | Signs of shock<br/>"
            "<b>If UNSTABLE → DC SHOCK / DEFIB / CPR PEHLE — phir diagnosis!</b>",
            ParagraphStyle('us', fontSize=9, fontName='Helvetica', textColor=WHITE, leading=13))
    ]]
    us_tbl = Table(us_data, colWidths=[17.5*cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), RED),
        ('TOPPADDING', (0, 0), (-1, -1), 8),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 8),
        ('LEFTPADDING', (0, 0), (-1, -1), 10),
        ('ROUNDEDCORNERS', [4,4,4,4]),
    ]))
    elems.append(us_tbl)
    elems.append(Spacer(1, 0.2*cm))

    em_data = [
        [Paragraph("ECG FINDING", styles['TableHeader']),
         Paragraph("DIAGNOSIS", styles['TableHeader']),
         Paragraph("IMMEDIATE ACTION", styles['TableHeader']),
         Paragraph("TIME TARGET", styles['TableHeader'])],
        ["VF / Pulseless VT", "Cardiac Arrest\n(Shockable rhythm)", "CPR + DEFIBRILLATE 200J\nEpinephrine 1mg q3-5min\nAmiodarone 300mg IV", "< 2 min"],
        ["STEMI (ST↑ ≥2 leads)", "Acute MI\nCoronary occlusion", "Activate Cath Lab\nAspirin 300mg + Heparin\nMorphine / O2 / Nitrates", "Door-to-balloon < 90 min"],
        ["VT with pulse, UNSTABLE", "Hemodynamic compromise", "SYNCHRONIZED cardioversion\n100-200J biphasic", "< 5 min"],
        ["VT with pulse, STABLE", "Ventricular tachycardia", "Amiodarone 150mg IV over 10min\nIdentify & treat cause", "< 30 min"],
        ["Torsades de Pointes", "Polymorphic VT\n(Long QT)", "MgSO4 2g IV over 5 min STAT\nStop QT drugs, correct K⁺", "< 10 min"],
        ["AF/Flutter UNSTABLE", "Rapid ventricular response\nHemodynamic compromise", "DC CARDIOVERSION\n100-200J (AF) / 50J (Flutter)", "< 5 min"],
        ["Complete Heart Block", "AV nodal failure\nEscape rhythm <50 bpm", "Atropine 0.5-1mg IV\nTranscutaneous pacing STAT\nCardiology consult", "< 5 min"],
        ["Tall peaked T waves", "Hyperkalemia\n(Cardiac arrest risk)", "Calcium gluconate 10ml 10% IV\nInsulin + Dextrose\nSalbutamol", "< 10 min"],
        ["Wide QRS + Bradycardia", "Hyperkalemia / Drug toxicity\nComplete heart block", "Calcium gluconate (if HyperK)\nStop offending drugs\nPacing if needed", "< 10 min"],
        ["S1Q3T3 + Tachycardia", "Pulmonary Embolism", "CTPA or Echo\nAnticoagulation (heparin)\nThrombolysis if massive", "< 60 min"],
        ["Low voltage + Electrical alternans", "Cardiac Tamponade", "Emergency pericardiocentesis\nEcho-guided\nVolume + vasopressors temp", "< 30 min"],
        ["Osborn (J) waves + Bradycardia", "Hypothermia", "Active rewarming\nVF → defibrillation\nHandle gently (VF risk)", "Continuous"],
    ]
    em_style = TableStyle([
        ('BACKGROUND', (0, 0), (-1, 0), RED),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTNAME', (0, 1), (0, -1), 'Helvetica-Bold'),
        ('TEXTCOLOR', (0, 1), (0, -1), RED),
        ('FONTSIZE', (0, 0), (-1, -1), 7.5),
        ('TEXTCOLOR', (0, 1), (-1, -1), DARK_GRAY),
        # Alternate rows
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [ALERT_BG, WHITE]),
        # Very critical rows brighter
        ('BACKGROUND', (0, 1), (-1, 1), colors.HexColor('#FADBD8')),  # VF
        ('BACKGROUND', (0, 2), (-1, 2), colors.HexColor('#FADBD8')),  # STEMI
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#CCCCCC')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 5),
        ('VALIGN', (0, 0), (-1, -1), 'TOP'),
    ])
    em_tbl = Table(em_data, colWidths=[4.0*cm, 3.5*cm, 6.3*cm, 3.0*cm], style=em_style)
    elems.append(em_tbl)
    elems.append(Spacer(1, 0.15*cm))

    # Footer
    foot_data = [[
        Paragraph(
            "Sources: Rosen's Emergency Medicine | Washington Manual of Medical Therapeutics | "
            "Harrison's Principles of Internal Medicine 22e | Current Surgical Therapy 14e | "
            "Miller's Anesthesia 10e  |  For educational use only — always confirm with supervising physician.",
            ParagraphStyle('ft', fontSize=7, fontName='Helvetica', textColor=MID_GRAY,
                           alignment=TA_CENTER, leading=9))
    ]]
    foot_tbl = Table(foot_data, colWidths=[17.5*cm], style=TableStyle([
        ('BACKGROUND', (0, 0), (-1, -1), LIGHT_GRAY),
        ('BOX', (0, 0), (-1, -1), 0.4, MID_GRAY),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 6),
    ]))
    elems.append(foot_tbl)
    return elems


# ── Header / Footer callback ─────────────────────────────────────────────────

def on_page(canvas, doc):
    """Draw page header and footer on every page."""
    canvas.saveState()
    w, h = A4

    # Top strip
    canvas.setFillColor(HEADER_BG)
    canvas.rect(0, h - 0.55*cm, w, 0.55*cm, fill=1, stroke=0)
    canvas.setFont('Helvetica-Bold', 7.5)
    canvas.setFillColor(WHITE)
    canvas.drawString(1.5*cm, h - 0.40*cm, "ICU ECG PATTERN REFERENCE")
    canvas.drawRightString(w - 1.5*cm, h - 0.40*cm, f"Page {doc.page}")

    # Bottom strip
    canvas.setFillColor(colors.HexColor('#EAECEE'))
    canvas.rect(0, 0, w, 0.45*cm, fill=1, stroke=0)
    canvas.setFont('Helvetica', 6.5)
    canvas.setFillColor(MID_GRAY)
    canvas.drawCentredString(w/2, 0.14*cm,
        "Educational Reference Only | Confirm with Supervising Physician | Sources: Rosen's EM, Harrison's, Washington Manual")

    canvas.restoreState()


# ── Main builder ─────────────────────────────────────────────────────────────

def build_pdf(output_path):
    doc = SimpleDocTemplate(
        output_path,
        pagesize=A4,
        leftMargin=1.2*cm, rightMargin=1.2*cm,
        topMargin=1.0*cm,  bottomMargin=0.8*cm,
        title="ICU ECG Pattern Reference",
        author="Orris Medical AI",
        subject="Critical Care ECG Quick Reference"
    )

    styles = build_styles()

    story = []

    # Cover
    story += build_cover(styles)
    story.append(PageBreak())

    # Page 1 - Normal ECG
    story += page_normal_ecg(styles)
    story.append(PageBreak())

    # Page 2 - STEMI
    story += page_stemi(styles)
    story.append(PageBreak())

    # Page 3 - ST depression / T changes
    story += page_st_depression_t(styles)
    story.append(PageBreak())

    # Page 4 - Supraventricular
    story += page_supra_arrhythmias(styles)
    story.append(PageBreak())

    # Page 5 - Ventricular arrhythmias
    story += page_ventricular_arrhythmias(styles)
    story.append(PageBreak())

    # Page 6 - Bradyarrhythmias
    story += page_bradyarrhythmias(styles)
    story.append(PageBreak())

    # Page 7 - Electrolytes
    story += page_electrolytes(styles)
    story.append(PageBreak())

    # Page 8 - Special patterns
    story += page_special_patterns(styles)
    story.append(PageBreak())

    # Page 9 - Emergency table
    story += page_emergency_table(styles)

    doc.build(story, onFirstPage=on_page, onLaterPages=on_page)
    print(f"PDF created: {output_path}")


if __name__ == "__main__":
    build_pdf("/home/daytona/workspace/ecg-reference/ICU_ECG_Reference.pdf")

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