from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.units import cm, mm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle,
    HRFlowable, KeepTogether, PageBreak
)
from reportlab.lib.enums import TA_LEFT, TA_CENTER, TA_JUSTIFY
from reportlab.pdfgen import canvas
from reportlab.platypus.flowables import Flowable

OUTPUT = "/tmp/workspace/clinical-signs/General_Physical_Examination_Signs.pdf"

# ── Colors ────────────────────────────────────────────────────────────────────
NAVY     = colors.HexColor("#1B3A6B")
TEAL     = colors.HexColor("#1A7A8A")
LIGHTBLUE= colors.HexColor("#E8F4F8")
AMBER    = colors.HexColor("#F5A623")
LIGHT_AMBER = colors.HexColor("#FFF8EC")
GREEN    = colors.HexColor("#2E7D32")
LIGHT_GREEN = colors.HexColor("#E8F5E9")
RED      = colors.HexColor("#C62828")
LIGHT_RED = colors.HexColor("#FFEBEE")
PURPLE   = colors.HexColor("#6A1B9A")
LIGHT_PURPLE = colors.HexColor("#F3E5F5")
ORANGE   = colors.HexColor("#E65100")
LIGHT_ORANGE = colors.HexColor("#FFF3E0")
CYAN     = colors.HexColor("#006064")
LIGHT_CYAN = colors.HexColor("#E0F7FA")
DARK_GRAY= colors.HexColor("#424242")
MID_GRAY = colors.HexColor("#757575")
LIGHT_GRAY = colors.HexColor("#F5F5F5")
WHITE    = colors.white
BLACK    = colors.black

# ── Page numbering canvas ─────────────────────────────────────────────────────
def add_page_number(canvas, doc):
    canvas.saveState()
    canvas.setFont("Helvetica", 8)
    canvas.setFillColor(MID_GRAY)
    w, h = A4
    canvas.drawCentredString(w / 2, 15 * mm,
        f"General Physical Examination Signs  |  Page {doc.page}")
    canvas.setStrokeColor(colors.HexColor("#DDDDDD"))
    canvas.setLineWidth(0.5)
    canvas.line(20 * mm, 20 * mm, w - 20 * mm, 20 * mm)
    canvas.restoreState()

# ── Document setup ────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=2*cm, leftMargin=2*cm,
    topMargin=2.5*cm, bottomMargin=2.5*cm,
)

styles = getSampleStyleSheet()

# Custom styles
def S(name, **kw):
    base = kw.pop("parent", "Normal")
    s = ParagraphStyle(name, parent=styles[base], **kw)
    return s

cover_title  = S("CoverTitle",  fontSize=30, textColor=WHITE, alignment=TA_CENTER,
                 leading=38, fontName="Helvetica-Bold")
cover_sub    = S("CoverSub",    fontSize=14, textColor=colors.HexColor("#B0D4E8"),
                 alignment=TA_CENTER, leading=20)
cover_src    = S("CoverSrc",    fontSize=10, textColor=colors.HexColor("#90CAF9"),
                 alignment=TA_CENTER)
sign_title   = S("SignTitle",   fontSize=18, textColor=WHITE,
                 fontName="Helvetica-Bold", leading=24, alignment=TA_LEFT)
section_h    = S("SectionH",    fontSize=11, textColor=NAVY,
                 fontName="Helvetica-Bold", leading=16, spaceAfter=4)
body         = S("Body",        fontSize=10, textColor=DARK_GRAY,
                 leading=15, spaceAfter=4, alignment=TA_JUSTIFY)
bullet_style = S("Bullet",      fontSize=10, textColor=DARK_GRAY,
                 leading=14, leftIndent=12, firstLineIndent=-8, spaceAfter=2)
note_style   = S("Note",        fontSize=9,  textColor=colors.HexColor("#555555"),
                 leading=13, leftIndent=8, fontName="Helvetica-Oblique")
tbl_hdr      = S("TblHdr",      fontSize=9,  textColor=WHITE,
                 fontName="Helvetica-Bold", alignment=TA_CENTER)
tbl_cell     = S("TblCell",     fontSize=9,  textColor=DARK_GRAY,
                 leading=12, alignment=TA_LEFT)
tbl_cell_c   = S("TblCellC",    fontSize=9,  textColor=DARK_GRAY,
                 leading=12, alignment=TA_CENTER)
summary_h    = S("SummaryH",    fontSize=9,  textColor=WHITE,
                 fontName="Helvetica-Bold", alignment=TA_CENTER)

# ── Helper: colored header banner for each sign ───────────────────────────────
class ColorBanner(Flowable):
    def __init__(self, text, bg_color, width=None, height=42):
        super().__init__()
        self.text = text
        self.bg = bg_color
        self._w = width or (A4[0] - 4*cm)
        self._h = height

    def wrap(self, aW, aH):
        self._w = aW
        return aW, self._h

    def draw(self):
        c = self.canv
        c.setFillColor(self.bg)
        c.roundRect(0, 0, self._w, self._h, 6, fill=1, stroke=0)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 18)
        c.drawString(14, 12, self.text)

def make_table(headers, rows, col_widths, header_color, row_colors=None):
    data = [[Paragraph(h, tbl_hdr) for h in headers]]
    for row in rows:
        data.append([Paragraph(str(c), tbl_cell) for c in row])
    if row_colors is None:
        row_colors = [LIGHT_GRAY, WHITE]
    ts = TableStyle([
        ("BACKGROUND", (0, 0), (-1, 0), header_color),
        ("ROWBACKGROUNDS", (0, 1), (-1, -1), row_colors),
        ("GRID", (0, 0), (-1, -1), 0.4, colors.HexColor("#CCCCCC")),
        ("VALIGN", (0, 0), (-1, -1), "MIDDLE"),
        ("TOPPADDING",    (0, 0), (-1, -1), 5),
        ("BOTTOMPADDING", (0, 0), (-1, -1), 5),
        ("LEFTPADDING",   (0, 0), (-1, -1), 6),
        ("RIGHTPADDING",  (0, 0), (-1, -1), 6),
        ("ROUNDEDCORNERS", [4]),
    ])
    t = Table(data, colWidths=col_widths)
    t.setStyle(ts)
    return t

def bullet(text):
    return Paragraph(f"<b>\u2022</b>  {text}", bullet_style)

def note(text):
    return Paragraph(f"\u2139\ufe0f  {text}", note_style)

def sp(n=6):
    return Spacer(1, n)

story = []
W = A4[0] - 4*cm  # usable width

# ══════════════════════════════════════════════════════════════════════════════
# COVER PAGE
# ══════════════════════════════════════════════════════════════════════════════
class CoverPage(Flowable):
    def wrap(self, aW, aH):
        return aW, aH
    def draw(self):
        c = self.canv
        w, h = A4
        # Background gradient (simulate with rectangles)
        for i in range(30):
            frac = i / 30
            r = 0.106 + frac * 0.04
            g = 0.227 + frac * 0.05
            b = 0.420 + frac * 0.08
            c.setFillColorRGB(r, g, b)
            c.rect(0, h - (i+1)*(h/30), w, h/30, fill=1, stroke=0)
        # Accent bar
        c.setFillColor(TEAL)
        c.rect(0, h*0.38, w, 4, fill=1, stroke=0)
        # Title
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 34)
        c.drawCentredString(w/2, h*0.72, "General Physical")
        c.drawCentredString(w/2, h*0.65, "Examination Signs")
        # Subtitle
        c.setFont("Helvetica", 15)
        c.setFillColor(colors.HexColor("#B0D4E8"))
        c.drawCentredString(w/2, h*0.58, "Pallor · Icterus · Lymphadenopathy · Cyanosis")
        c.drawCentredString(w/2, h*0.54, "Clubbing · Edema · Dehydration")
        # Divider
        c.setStrokeColor(AMBER)
        c.setLineWidth(2)
        c.line(w*0.2, h*0.50, w*0.8, h*0.50)
        # Source line
        c.setFont("Helvetica-Oblique", 10)
        c.setFillColor(colors.HexColor("#90CAF9"))
        c.drawCentredString(w/2, h*0.45,
            "Sources: Harrison's Principles of Internal Medicine 22E (2025),")
        c.drawCentredString(w/2, h*0.42,
            "Goldman-Cecil Medicine, Brenner & Rector's The Kidney,")
        c.drawCentredString(w/2, h*0.39,
            "Schwartz's Principles of Surgery, Tintinalli's Emergency Medicine")
        # Bottom strip
        c.setFillColor(TEAL)
        c.rect(0, 0, w, h*0.12, fill=1, stroke=0)
        c.setFillColor(WHITE)
        c.setFont("Helvetica-Bold", 12)
        c.drawCentredString(w/2, h*0.06, "Clinical Medicine Reference")
        c.setFont("Helvetica", 9)
        c.setFillColor(colors.HexColor("#B0D4E8"))
        c.drawCentredString(w/2, h*0.04, "Based on authoritative medical textbooks")

story.append(CoverPage())
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 1. PALLOR
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("1.  PALLOR", RED))
story.append(sp(10))

story.append(Paragraph(
    "Pallor refers to a reduction in the redness of the skin and mucous membranes, "
    "most often reflecting decreased hemoglobin concentration, decreased blood flow, or vasoconstriction.",
    body))
story.append(sp(8))

story.append(Paragraph("Best Sites to Assess", section_h))
tbl = make_table(
    ["Site", "Clinical Significance"],
    [
        ["Conjunctival mucosa", "Most specific — pallor here indicates Hb < 9 g/dL"],
        ["Palm creases", "Pale creases suggest Hb < 7 g/dL"],
        ["Nail beds", "Pallor visible with moderate-severe anemia"],
        ["Tongue / buccal mucosa", "Seen in severe anemia"],
    ],
    [W*0.35, W*0.65], RED, [LIGHT_RED, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Common Causes", section_h))
for c_ in [
    "<b>Anemia</b> (most common) — iron deficiency, hemolytic anemia, aplastic anemia, B12/folate deficiency, blood loss",
    "<b>Shock / acute blood loss</b> — cutaneous vasoconstriction shunts blood centrally",
    "<b>Vasospasm</b> — cold exposure, anxiety, Raynaud's phenomenon",
    "<b>Hypothyroidism</b> — myxedema causes waxy pallor",
    "<b>Malignancy</b> — leukemia, lymphoma, bone marrow infiltration",
]:
    story.append(bullet(c_))
story.append(sp(10))

story.append(Paragraph("Grading of Pallor", section_h))
tbl2 = make_table(
    ["Grade", "Finding", "Approx. Hb"],
    [
        ["Mild",     "Pallor only on close inspection of conjunctiva",          "> 9 g/dL"],
        ["Moderate", "Clear conjunctival and palmar pallor",                    "7–9 g/dL"],
        ["Severe",   "Pallor of tongue, buccal mucosa, nail beds",              "< 7 g/dL"],
    ],
    [W*0.15, W*0.55, W*0.30], RED, [LIGHT_RED, WHITE]
)
story.append(tbl2)
story.append(sp(8))
story.append(note(
    'Goldman-Cecil Medicine: "Pallor of the conjunctival mucosa generally indicates '
    'a hemoglobin concentration less than 9 g/dL"'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 2. ICTERUS (JAUNDICE)
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("2.  ICTERUS  (Jaundice)", colors.HexColor("#F57F17")))
story.append(sp(10))

story.append(Paragraph(
    "Icterus is a yellow discoloration of the skin, sclera, and mucous membranes due to "
    "accumulation of bilirubin (> 2–3 mg/dL in serum). It is first visible in the sclera "
    "and should be assessed in natural light.",
    body))
story.append(sp(8))

story.append(Paragraph("Classification by Type", section_h))
tbl = make_table(
    ["Type", "Bilirubin Fraction", "Causes"],
    [
        ["Pre-hepatic\n(Hemolytic)",    "Indirect (unconjugated)",  "Hemolytic anemia, G6PD deficiency, sickle cell, thalassemia"],
        ["Hepatic\n(Hepatocellular)",   "Mixed",                    "Viral hepatitis, cirrhosis, drugs, Wilson's disease, alcoholic hepatitis"],
        ["Post-hepatic\n(Obstructive)", "Direct (conjugated)",      "Gallstones, carcinoma head of pancreas, cholangitis, cholestasis"],
    ],
    [W*0.22, W*0.25, W*0.53], colors.HexColor("#F57F17"), [LIGHT_AMBER, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Key Clinical Associations", section_h))
for c_ in [
    "<b>Dark urine + pale stools</b> — obstructive (conjugated) jaundice",
    "<b>Charcot's triad</b> (fever + rigors + jaundice) — ascending cholangitis",
    "<b>Jaundice + raised JVP</b> — congestive hepatomegaly, right heart failure",
    "<b>Painless jaundice + palpable gallbladder</b> — Courvoisier's sign (carcinoma head of pancreas)",
    "<b>Jaundice + splenomegaly + anemia</b> — hemolytic jaundice",
    "<b>Jaundice in newborn</b> — physiological vs. pathological (Rh/ABO incompatibility)",
]:
    story.append(bullet(c_))
story.append(sp(8))
story.append(note(
    'Harrison\'s: "Jaundice, which may be visible first in the sclerae, has a broad differential '
    'diagnosis but, in the appropriate setting, can be consistent with advanced right heart failure '
    'and congestive hepatomegaly"'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 3. LYMPHADENOPATHY
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("3.  LYMPHADENOPATHY", PURPLE))
story.append(sp(10))

story.append(Paragraph(
    "Pathological enlargement of lymph nodes. Normal nodes are < 1 cm (< 1.5 cm in the inguinal region). "
    "Key initial assessment: generalized vs. localized, size, consistency, tenderness, fixation, "
    "and overlying skin changes.",
    body))
story.append(sp(8))

story.append(Paragraph("Causes by Region", section_h))
tbl = make_table(
    ["Region", "Common Causes"],
    [
        ["Cervical",        "EBV (mononucleosis), TB, oral/pharyngeal infections, lymphoma, thyroid cancer"],
        ["Axillary",        "Breast cancer, cat-scratch disease, melanoma, local infections"],
        ["Inguinal",        "STIs (syphilis, chancroid), lower limb infections, lymphoma"],
        ["Mediastinal",     "Sarcoidosis, lymphoma, TB, lung cancer, histoplasmosis"],
        ["Generalized",     "HIV, EBV, CMV, SLE, sarcoidosis, leukemia, lymphoma, drug reactions"],
    ],
    [W*0.22, W*0.78], PURPLE, [LIGHT_PURPLE, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Red Flag Features (biopsy indicated)", section_h))
for c_ in [
    "Firm/hard, non-tender, fixed to underlying structures",
    "Size > 2 cm, especially if progressive",
    "<b>Supraclavicular location</b> — always sinister (Virchow's node / Troisier's sign)",
    "Associated constitutional symptoms: fever, night sweats, weight loss (B symptoms of lymphoma)",
    "Duration > 6 weeks without obvious cause",
]:
    story.append(bullet(c_))
story.append(sp(10))

story.append(Paragraph("Node Characteristics", section_h))
tbl2 = make_table(
    ["Feature", "Likely Benign", "Likely Malignant"],
    [
        ["Consistency", "Soft, rubbery",          "Hard, stony"],
        ["Tenderness",  "Tender (infection)",      "Usually non-tender"],
        ["Mobility",    "Mobile",                  "Fixed, matted"],
        ["Skin",        "Normal",                  "Erythema, sinus tract"],
    ],
    [W*0.25, W*0.375, W*0.375], PURPLE, [LIGHT_PURPLE, WHITE]
)
story.append(tbl2)
story.append(sp(8))
story.append(note(
    'Harrison\'s: "Determining whether the patient has generalized versus localized lymphadenopathy '
    'can help narrow the differential diagnosis, as various infections present differently"'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 4. CYANOSIS
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("4.  CYANOSIS", NAVY))
story.append(sp(10))

story.append(Paragraph(
    "Cyanosis is a bluish discoloration of skin and mucous membranes due to increased "
    "deoxyhemoglobin (> 5 g/dL in capillaries). It requires at least 5 g/dL of reduced Hb "
    "to be clinically visible. <b>Note:</b> In severe anemia, cyanosis may be absent even "
    "with very low O2 saturation because total Hb is too low.",
    body))
story.append(sp(8))

story.append(Paragraph("Types of Cyanosis", section_h))
tbl = make_table(
    ["Type", "Location", "Mechanism", "Causes"],
    [
        ["Central",
         "Tongue, lips, oral mucosa (warm areas)",
         "Arterial desaturation or R-to-L shunting",
         "COPD, pneumonia, pulmonary edema, cyanotic CHD (Fallot's, Eisenmenger's), pulmonary AV malformation"],
        ["Peripheral\n(Acrocyanosis)",
         "Fingers, toes, ears, nose",
         "Reduced extremity blood flow, increased O2 extraction",
         "Heart failure, shock, peripheral vascular disease, cold exposure, Raynaud's"],
        ["Differential\nCyanosis",
         "Lower limbs only (not upper limbs)",
         "PDA with pulmonary HTN, R-to-L shunt at great vessel level",
         "Large patent ductus arteriosus + Eisenmenger syndrome"],
        ["Peripheral only\n(no central)",
         "Extremities, spares tongue",
         "Venous stasis / vasoconstriction",
         "Cold, beta-blockers with unopposed alpha, venous occlusion"],
    ],
    [W*0.18, W*0.22, W*0.28, W*0.32], NAVY, [LIGHTBLUE, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Key Rule", section_h))
story.append(bullet(
    "<b>Central cyanosis</b> — affects the tongue and warm mucous membranes; "
    "implies arterial desaturation; always pathological"))
story.append(bullet(
    "<b>Peripheral cyanosis</b> — spares the tongue; may be benign (cold) or pathological"))
story.append(bullet(
    "Check SaO2 with pulse oximetry to confirm; however, methemoglobinemia gives "
    "falsely high/normal pulse ox reading"))
story.append(sp(8))
story.append(note(
    'Harrison\'s: "Central cyanosis occurs with significant right-to-left shunting at the level '
    'of the heart or lungs... Peripheral cyanosis or acrocyanosis is usually related to reduced '
    'extremity blood flow due to small vessel constriction"'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 5. CLUBBING
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("5.  CLUBBING", TEAL))
story.append(sp(10))

story.append(Paragraph(
    "Clubbing is the bulbous enlargement of distal fingers and toes due to proliferation of "
    "connective tissue on the dorsal surface, with increased sponginess at the nail base. "
    "The mechanism involves humoral substances causing dilation of distal digital vessels "
    "and growth factors from platelet precursors in digital circulation.",
    body))
story.append(sp(8))

story.append(Paragraph("Stages / Clinical Features", section_h))
tbl = make_table(
    ["Stage", "Finding"],
    [
        ["Stage 1", "Increased fluctuation/sponginess of nail bed"],
        ["Stage 2", "Loss of normal angle between nail base and skin (Lovibond angle > 180 deg)"],
        ["Stage 3", "Drumstick / parrot-beak appearance; nail curves over the fingertip"],
        ["Stage 4", "Hypertrophic osteoarthropathy — periosteal new bone, painful joints in shoulders, knees, wrists"],
    ],
    [W*0.15, W*0.85], TEAL, [LIGHT_CYAN, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Causes", section_h))
tbl2 = make_table(
    ["System", "Examples"],
    [
        ["Respiratory (most common)", "Lung cancer, bronchiectasis, lung abscess, cystic fibrosis, TB, mesothelioma, sarcoidosis, asbestosis"],
        ["Cardiac",                   "Cyanotic congenital heart disease, infective endocarditis"],
        ["Gastrointestinal",          "Inflammatory bowel disease (Crohn's > UC), hepatic cirrhosis, celiac disease"],
        ["Hereditary / Idiopathic",   "Primary hypertrophic osteoarthropathy (pachydermoperiostosis)"],
        ["Occupational",              "Jackhammer operators (vibration)"],
    ],
    [W*0.30, W*0.70], TEAL, [LIGHT_CYAN, WHITE]
)
story.append(tbl2)
story.append(sp(10))

story.append(Paragraph("Schamroth's Window Test", section_h))
story.append(Paragraph(
    "Place dorsal surfaces of the same fingers of each hand together. "
    "Normally, a diamond-shaped window is visible at the base of the nails. "
    "<b>Loss of this window = positive test (clubbing present).</b>",
    body))
story.append(sp(8))
story.append(note(
    'Harrison\'s: "Clubbing may be hereditary, idiopathic, or acquired and associated with '
    'a variety of disorders, including cyanotic congenital heart disease, infective endocarditis, '
    'and a variety of pulmonary conditions... In certain circumstances, clubbing is reversible, '
    'such as following lung transplantation for cystic fibrosis"'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 6. EDEMA
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("6.  EDEMA", GREEN))
story.append(sp(10))

story.append(Paragraph(
    "Edema is clinically evident excess of interstitial fluid. Approximately 4–5 liters of "
    "excess fluid must accumulate before pitting edema becomes palpable. It represents an "
    "imbalance between forces promoting fluid movement into the interstitium and those "
    "promoting its return to the vasculature.",
    body))
story.append(sp(8))

story.append(Paragraph("Mechanisms", section_h))
for i, c_ in enumerate([
    "Increased capillary hydrostatic pressure — heart failure, venous obstruction, portal hypertension",
    "Decreased plasma oncotic pressure — hypoalbuminemia (nephrotic syndrome, cirrhosis, malnutrition, protein-losing enteropathy)",
    "Increased capillary permeability — inflammation, anaphylaxis, burns, sepsis, angioedema",
    "Lymphatic obstruction — lymphoedema, filariasis, malignant obstruction, post-surgical",
    "Na+/water retention — renal failure, hyperaldosteronism, RAAS activation",
], start=1):
    story.append(bullet(f"<b>{i}.</b>  {c_}"))
story.append(sp(10))

story.append(Paragraph("Types of Edema", section_h))
tbl = make_table(
    ["Type", "Features", "Causes"],
    [
        ["Pitting",     "Pit remains after finger pressure",          "Cardiac, renal, hepatic, nutritional"],
        ["Non-pitting", "No pit (firm / brawny)",                     "Hypothyroidism (myxedema), lymphedema"],
        ["Dependent",   "Feet/ankles in ambulatory; sacrum in bedridden", "Right heart failure (most common)"],
        ["Periorbital", "Around eyes, worse in morning",              "Nephrotic syndrome, hypothyroidism"],
        ["Anasarca",    "Generalized body edema including ascites",   "Severe hypoalbuminemia, advanced heart failure"],
        ["Pulmonary",   "Crepitations at lung bases, orthopnoea",     "Left heart failure, ARDS"],
    ],
    [W*0.18, W*0.40, W*0.42], GREEN, [LIGHT_GREEN, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Grading of Pitting Edema", section_h))
tbl2 = make_table(
    ["Grade", "Pit Depth", "Recovery Time"],
    [
        ["1+", "2 mm",   "< 2 seconds"],
        ["2+", "4 mm",   "2–5 seconds"],
        ["3+", "6 mm",   "5–30 seconds"],
        ["4+", "> 8 mm", "> 30 seconds"],
    ],
    [W*0.20, W*0.40, W*0.40], GREEN, [LIGHT_GREEN, WHITE]
)
story.append(tbl2)
story.append(sp(8))
story.append(note(
    'Harrison\'s: "Edema represents an excess of interstitial fluid that has become evident '
    'clinically." — Elevated JVP + bilateral dependent edema = right heart failure etiology'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# 7. DEHYDRATION
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("7.  DEHYDRATION", ORANGE))
story.append(sp(10))

story.append(Paragraph(
    "Dehydration is a deficit of total body water, most commonly from inadequate intake "
    "or excess losses (vomiting, diarrhea, burns, excessive sweating, diabetes insipidus). "
    "Clinical assessment relies on a combination of signs, as no single sign is perfectly reliable.",
    body))
story.append(sp(8))

story.append(Paragraph("Clinical Signs by Severity", section_h))
tbl = make_table(
    ["Severity", "% Body Wt Loss", "Signs & Symptoms"],
    [
        ["Mild",     "< 5%",    "Thirst, dry mouth, slightly decreased urine output"],
        ["Moderate", "5–10%",   "Tachycardia, reduced skin turgor, sunken eyes, dry mucous membranes, oliguria, irritability"],
        ["Severe",   "> 10%",   "Altered sensorium/confusion, hypotension, absent urine output, delayed capillary refill (> 2 sec), shock"],
    ],
    [W*0.15, W*0.18, W*0.67], ORANGE, [LIGHT_ORANGE, WHITE]
)
story.append(tbl)
story.append(sp(10))

story.append(Paragraph("Most Reliable Clinical Signs (Evidence-Based)", section_h))
for c_ in [
    "<b>Delayed capillary refill time</b> (> 2 sec) — most reliable single sign",
    "<b>Reduced skin turgor / tenting</b> — assessed over abdomen/chest; less reliable in elderly",
    "<b>Dry mucous membranes</b> — tongue and oral mucosa",
    "<b>Sunken fontanelle</b> — in infants",
    "<b>Abnormal respiratory pattern</b> — Kussmaul breathing in metabolic acidosis from severe dehydration",
    "<b>Tachycardia</b> — earliest cardiovascular sign",
]:
    story.append(bullet(c_))
story.append(sp(10))

story.append(Paragraph("Types of Dehydration", section_h))
tbl2 = make_table(
    ["Type", "Serum Na", "Cause"],
    [
        ["Isotonic",   "Normal (135–145 mEq/L)", "Diarrhea, vomiting (most common)"],
        ["Hypertonic", "> 145 mEq/L",            "Diabetes insipidus, inadequate free water intake, fever with insensible losses"],
        ["Hypotonic",  "< 135 mEq/L",            "Adrenal insufficiency, excessive hypotonic fluid losses, over-correction"],
    ],
    [W*0.18, W*0.25, W*0.57], ORANGE, [LIGHT_ORANGE, WHITE]
)
story.append(tbl2)
story.append(sp(8))
story.append(note(
    'Brenner & Rector\'s The Kidney: "Delayed capillary refill time, reduced skin turgor, and '
    'deep respirations were the most useful clinical signs [of dehydration]"'
))
story.append(PageBreak())

# ══════════════════════════════════════════════════════════════════════════════
# SUMMARY TABLE
# ══════════════════════════════════════════════════════════════════════════════
story.append(ColorBanner("QUICK SUMMARY TABLE", DARK_GRAY))
story.append(sp(12))

summary_data = [
    [Paragraph("<b>Sign</b>", tbl_hdr), Paragraph("<b>Key Site</b>", tbl_hdr),
     Paragraph("<b>Core Cause Group</b>", tbl_hdr), Paragraph("<b>Key Associations</b>", tbl_hdr)],
    [Paragraph("Pallor", tbl_cell), Paragraph("Conjunctiva, palm creases", tbl_cell),
     Paragraph("Anemia, shock", tbl_cell), Paragraph("Hb < 9 g/dL (conjunctival)", tbl_cell)],
    [Paragraph("Icterus", tbl_cell), Paragraph("Sclera first", tbl_cell),
     Paragraph("Pre/intra/post-hepatic", tbl_cell), Paragraph("Dark urine = conjugated; pale stools", tbl_cell)],
    [Paragraph("Lymphadenopathy", tbl_cell), Paragraph("All nodal groups", tbl_cell),
     Paragraph("Infection, malignancy, autoimmune", tbl_cell), Paragraph("Supraclavicular = always sinister", tbl_cell)],
    [Paragraph("Cyanosis", tbl_cell), Paragraph("Tongue (central), fingers (peripheral)", tbl_cell),
     Paragraph("Cardiopulmonary, R-L shunt", tbl_cell), Paragraph("Central > peripheral in severity", tbl_cell)],
    [Paragraph("Clubbing", tbl_cell), Paragraph("Fingers/toes (dorsal surface)", tbl_cell),
     Paragraph("Lung, heart, GI, hereditary", tbl_cell), Paragraph("Schamroth's sign for detection", tbl_cell)],
    [Paragraph("Edema", tbl_cell), Paragraph("Dependent areas, periorbital", tbl_cell),
     Paragraph("Cardiac, renal, hepatic, nutritional", tbl_cell), Paragraph("Pitting vs. non-pitting key distinction", tbl_cell)],
    [Paragraph("Dehydration", tbl_cell), Paragraph("Skin turgor, mucous membranes", tbl_cell),
     Paragraph("Fluid loss / inadequate intake", tbl_cell), Paragraph("Capillary refill most reliable sign", tbl_cell)],
]

row_bg = [
    LIGHT_RED, LIGHT_AMBER, LIGHT_PURPLE, LIGHTBLUE,
    LIGHT_CYAN, LIGHT_GREEN, LIGHT_ORANGE
]
ts = TableStyle([
    ("BACKGROUND", (0, 0), (-1, 0), DARK_GRAY),
    ("GRID", (0, 0), (-1, -1), 0.4, colors.HexColor("#BBBBBB")),
    ("VALIGN", (0, 0), (-1, -1), "MIDDLE"),
    ("TOPPADDING",    (0, 0), (-1, -1), 6),
    ("BOTTOMPADDING", (0, 0), (-1, -1), 6),
    ("LEFTPADDING",   (0, 0), (-1, -1), 6),
    ("RIGHTPADDING",  (0, 0), (-1, -1), 6),
])
for i, bg in enumerate(row_bg, start=1):
    ts.add("BACKGROUND", (0, i), (-1, i), bg)

summary_tbl = Table(summary_data, colWidths=[W*0.18, W*0.20, W*0.28, W*0.34])
summary_tbl.setStyle(ts)
story.append(summary_tbl)
story.append(sp(16))

# References
story.append(HRFlowable(width="100%", thickness=1, color=colors.HexColor("#CCCCCC")))
story.append(sp(8))
story.append(Paragraph("<b>References</b>", section_h))
refs = [
    "Harrison's Principles of Internal Medicine, 22nd Edition (2025) — McGraw Hill Medical",
    "Goldman-Cecil Medicine, International Edition, 2-Volume Set — Elsevier",
    "Brenner and Rector's The Kidney, 2-Volume Set — Elsevier",
    "Schwartz's Principles of Surgery, 11th Edition — McGraw Hill",
    "Tintinalli's Emergency Medicine: A Comprehensive Study Guide — McGraw Hill",
    "Barash, Cullen, and Stoelting's Clinical Anesthesia, 9th Edition",
]
for r in refs:
    story.append(Paragraph(f"• {r}", note_style))

# ── Build ─────────────────────────────────────────────────────────────────────
doc.build(story, onFirstPage=add_page_number, onLaterPages=add_page_number)
print(f"PDF created: {OUTPUT}")