from pptx import Presentation
from pptx.util import Inches, Pt, Emu
from pptx.dml.color import RGBColor
from pptx.enum.text import PP_ALIGN, MSO_ANCHOR
from pptx.util import Inches, Pt
from io import BytesIO

# ── Colour palette ──────────────────────────────────────────────
C_DARK_BLUE  = RGBColor(0x1B, 0x3A, 0x6B)   # header / title bg
C_MID_BLUE   = RGBColor(0x26, 0x5E, 0xAD)   # accent bar
C_LIGHT_BLUE = RGBColor(0xD6, 0xE8, 0xF8)   # content bg
C_TEAL       = RGBColor(0x00, 0x7B, 0x83)   # exam box bg
C_WHITE      = RGBColor(0xFF, 0xFF, 0xFF)
C_BLACK      = RGBColor(0x1A, 0x1A, 0x1A)
C_YELLOW     = RGBColor(0xFF, 0xD7, 0x00)   # highlight
C_ORANGE     = RGBColor(0xF0, 0x7B, 0x10)   # key concept box
C_GREEN      = RGBColor(0x1F, 0x7A, 0x4D)   # answer text
C_RED        = RGBColor(0xC0, 0x39, 0x2B)

prs = Presentation()
prs.slide_width  = Inches(13.333)
prs.slide_height = Inches(7.5)
blank = prs.slide_layouts[6]

# ── Helper functions ─────────────────────────────────────────────
def add_rect(slide, x, y, w, h, fill_rgb):
    shape = slide.shapes.add_shape(
        1,  # MSO_SHAPE_TYPE.RECTANGLE = 1; using int directly
        Inches(x), Inches(y), Inches(w), Inches(h)
    )
    shape.fill.solid()
    shape.fill.fore_color.rgb = fill_rgb
    shape.line.fill.background()
    return shape

def add_tb(slide, x, y, w, h, text, size=18, bold=False, color=C_BLACK,
           align=PP_ALIGN.LEFT, wrap=True, italic=False):
    tb = slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h))
    tf = tb.text_frame
    tf.word_wrap = wrap
    tf.margin_left  = Inches(0.08)
    tf.margin_right = Inches(0.08)
    tf.margin_top   = Inches(0.04)
    tf.margin_bottom= Inches(0.04)
    p = tf.paragraphs[0]
    p.alignment = align
    run = p.add_run()
    run.text = text
    run.font.name  = "Calibri"
    run.font.size  = Pt(size)
    run.font.bold  = bold
    run.font.italic= italic
    run.font.color.rgb = color
    return tb

def add_multiline_tb(slide, x, y, w, h, lines, size=16, color=C_BLACK,
                     bold_first=False, indent_rest=False, line_spacing=None):
    """lines: list of (text, bold, color_override_or_None)"""
    tb = slide.shapes.add_textbox(Inches(x), Inches(y), Inches(w), Inches(h))
    tf = tb.text_frame
    tf.word_wrap = True
    tf.margin_left  = Inches(0.1)
    tf.margin_right = Inches(0.1)
    tf.margin_top   = Inches(0.04)
    tf.margin_bottom= Inches(0.04)
    first = True
    for (txt, bld, col) in lines:
        if first:
            p = tf.paragraphs[0]
            first = False
        else:
            p = tf.add_paragraph()
        if indent_rest and not bld:
            p.space_before = Pt(2)
        run = p.add_run()
        run.text = txt
        run.font.name = "Calibri"
        run.font.size = Pt(size)
        run.font.bold = bld
        run.font.color.rgb = col if col else color
    return tb

def header_bar(slide, title, subtitle=None):
    add_rect(slide, 0, 0, 13.333, 1.15, C_DARK_BLUE)
    add_rect(slide, 0, 1.15, 13.333, 0.08, C_MID_BLUE)
    add_tb(slide, 0.3, 0.1, 12.7, 0.8, title, size=30, bold=True,
           color=C_WHITE, align=PP_ALIGN.LEFT)
    if subtitle:
        add_tb(slide, 0.3, 0.78, 12.7, 0.38, subtitle, size=14,
               color=C_LIGHT_BLUE, align=PP_ALIGN.LEFT)

def section_box(slide, x, y, w, h, heading, content_lines, size=15,
                bg=C_LIGHT_BLUE, head_bg=C_MID_BLUE):
    add_rect(slide, x, y, w, 0.38, head_bg)
    add_tb(slide, x+0.1, y+0.02, w-0.2, 0.34, heading, size=15,
           bold=True, color=C_WHITE)
    add_rect(slide, x, y+0.38, w, h-0.38, bg)
    add_multiline_tb(slide, x+0.1, y+0.42, w-0.2, h-0.5,
                     content_lines, size=size)

def exam_box(slide, x, y, w, h, question, answer):
    add_rect(slide, x, y, w, 0.38, C_TEAL)
    add_tb(slide, x+0.1, y+0.02, w-0.2, 0.34,
           "✎  EXAM-STYLE QUESTION", size=13, bold=True, color=C_YELLOW)
    add_rect(slide, x, y+0.38, w, h-0.38, RGBColor(0xE6, 0xF4, 0xF5))
    add_multiline_tb(slide, x+0.1, y+0.42, w-0.2, h-0.52, [
        (question, True, C_BLACK),
        ("", False, C_BLACK),
        ("Answer: " + answer, False, C_GREEN),
    ], size=14)

def footer(slide, num):
    add_rect(slide, 0, 7.2, 13.333, 0.3, C_DARK_BLUE)
    add_tb(slide, 0.3, 7.22, 8, 0.26,
           "Capillary Exchange & Edema  |  Human Physiology PHYS 102",
           size=10, color=C_LIGHT_BLUE)
    add_tb(slide, 12.5, 7.22, 0.8, 0.26, str(num), size=10,
           color=C_LIGHT_BLUE, align=PP_ALIGN.RIGHT)

# ════════════════════════════════════════════════════════════════
# SLIDE 1 – TITLE
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
add_rect(slide, 0, 0, 13.333, 7.5, C_DARK_BLUE)
add_rect(slide, 0, 2.8, 13.333, 0.12, C_YELLOW)
add_tb(slide, 1, 0.8, 11.3, 1.1,
       "CAPILLARY EXCHANGE & EDEMA",
       size=40, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)
add_tb(slide, 1, 1.95, 11.3, 0.6,
       "A Simplified Explanation for Easier Understanding",
       size=20, color=C_LIGHT_BLUE, align=PP_ALIGN.CENTER, italic=True)
add_tb(slide, 1, 3.1, 11.3, 0.55,
       "Human Physiology  |  PHYS 102",
       size=18, bold=True, color=C_YELLOW, align=PP_ALIGN.CENTER)
add_tb(slide, 1, 3.75, 11.3, 0.5,
       "Topics: Capillary Structure • Starling Forces • Edema Pathophysiology • Clinical Causes • Treatment",
       size=14, color=C_LIGHT_BLUE, align=PP_ALIGN.CENTER)
# bottom tagline
add_rect(slide, 0, 6.8, 13.333, 0.7, C_MID_BLUE)
add_tb(slide, 0.5, 6.85, 12, 0.5,
       "Think of a capillary as a leaky pipe with valves — this lecture explains why leaks happen and how the body stops them.",
       size=13, color=C_WHITE, align=PP_ALIGN.CENTER, italic=True)

# ════════════════════════════════════════════════════════════════
# SLIDE 2 – WHAT IS CAPILLARY EXCHANGE?
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "What is Capillary Exchange?",
           "The microscopic trade route between blood and body tissues")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

section_box(slide, 0.3, 1.4, 8.2, 2.5, "DEFINITION",
    [("Movement of nutrients, gases, wastes, and fluid between blood and interstitial fluid through capillary walls.", False, None),
     ("", False, None),
     ("• Occurs at the capillary bed — between metarterioles & venules.", False, None),
     ("• Capillary wall = single layer of endothelial cells, only 0.5 µm thick.", False, None),
     ("• Tiny gaps called intercellular clefts (6–7 nm) allow selective passage.", False, None)], size=15)

section_box(slide, 0.3, 4.05, 8.2, 2.55, "ANALOGY: THE LEAKY PIPE",
    [("Imagine your blood vessel as a thin water pipe with microscopic holes.", False, None),
     ("The holes are just big enough to let small molecules (O₂, glucose) through —", False, None),
     ("but NOT big enough for large proteins or blood cells.", False, None),
     ("The precapillary sphincter = a tap that opens/closes to control flow.", False, None)],
    size=15, bg=RGBColor(0xFF, 0xF5, 0xCC), head_bg=C_ORANGE)

# Key box right side
add_rect(slide, 8.7, 1.4, 4.3, 5.2, RGBColor(0xEB, 0xF5, 0xEB))
add_rect(slide, 8.7, 1.4, 4.3, 0.38, C_GREEN)
add_tb(slide, 8.8, 1.42, 4.1, 0.34, "KEY PLAYERS", size=14, bold=True, color=C_WHITE)
add_multiline_tb(slide, 8.8, 1.85, 4.1, 4.6, [
    ("OUT of capillary:", True, C_DARK_BLUE),
    ("  O₂, glucose, amino acids,", False, None),
    ("  fatty acids, hormones, H₂O,", False, None),
    ("  electrolytes (Na⁺, K⁺, Cl⁻)", False, None),
    ("", False, None),
    ("INTO capillary:", True, C_DARK_BLUE),
    ("  CO₂, urea, creatinine,", False, None),
    ("  metabolic wastes, H⁺, H₂O", False, None),
    ("", False, None),
    ("STAY inside:", True, C_DARK_BLUE),
    ("  RBC, WBC, Platelets,", False, None),
    ("  Plasma proteins", False, None),
    ("  (all too large to pass)", False, None),
], size=14)

exam_box(slide, 0.3, 6.65, 8.2, 0.78,
         "Why can RBCs NOT pass through intercellular clefts?",
         "RBCs are too large (6–8 µm diameter) for the 6–7 nm wide clefts.")
footer(slide, 2)

# ════════════════════════════════════════════════════════════════
# SLIDE 3 – STARLING FORCES (The 4 pressures)
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Starling Forces: The 4 Pressures That Control Fluid Movement",
           "Balance of these forces = no edema. Imbalance = edema.")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

# Table header
add_rect(slide, 0.3, 1.4, 12.7, 0.42, C_DARK_BLUE)
for col, txt, xpos, wid in [
    ("Force", "FORCE", 0.3, 3.0),
    ("Direction", "DIRECTION", 3.3, 2.8),
    ("Value", "VALUE", 6.1, 2.4),
    ("Analogy", "ANALOGY / PLAIN ENGLISH", 8.5, 4.5)]:
    add_tb(slide, xpos+0.05, 1.42, wid-0.1, 0.38, txt, size=13, bold=True, color=C_WHITE)

rows = [
    ("Capillary Hydrostatic Pressure (CHP)", "PUSHES fluid OUT of capillary", "Arterial end: 30 mmHg\nVenous end: 15 mmHg", "Water pressure in a hose — forces water out through holes.", C_LIGHT_BLUE),
    ("Plasma Colloid Osmotic Pressure (POP)", "PULLS fluid INTO capillary", "28 mmHg", "Proteins in blood act like a sponge — they suck water back in.", RGBColor(0xE8, 0xF8, 0xE8)),
    ("Interstitial Fluid Colloid Osmotic Pressure (IOP)", "PULLS fluid OUT of capillary", "8 mmHg", "Small amount of protein in tissue fluid gently draws water out.", C_LIGHT_BLUE),
    ("Interstitial Fluid Hydrostatic Pressure (IHP)", "PUSHES fluid INTO capillary (minor)", "~0 mmHg", "Back-pressure from tissue resisting more fluid entry.", RGBColor(0xE8, 0xF8, 0xE8)),
]

y = 1.82
for (force, dirn, val, analogy, bg) in rows:
    add_rect(slide, 0.3, y, 12.7, 0.9, bg)
    add_tb(slide, 0.35, y+0.04, 2.9, 0.82, force, size=12, bold=True, color=C_DARK_BLUE)
    add_tb(slide, 3.35, y+0.04, 2.7, 0.82, dirn, size=12, color=C_MID_BLUE, bold=True)
    add_tb(slide, 6.15, y+0.04, 2.3, 0.82, val, size=13, bold=True, color=C_ORANGE)
    add_tb(slide, 8.55, y+0.04, 4.4, 0.82, analogy, size=12, color=C_BLACK, italic=True)
    # divider line
    add_rect(slide, 0.3, y+0.88, 12.7, 0.02, RGBColor(0xCC, 0xCC, 0xCC))
    y += 0.9

# Net filtration formula box
add_rect(slide, 0.3, 5.5, 12.7, 0.65, C_ORANGE)
add_tb(slide, 0.5, 5.52, 12.3, 0.6,
       "Net Filtration = (CHP + IOP) − (POP + IHP)      Arterial end: (30+8)−(28+0) = +10 → fluid OUT   |   Venous end: (15+8)−(28+0) = −5 → fluid IN",
       size=14, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

exam_box(slide, 0.3, 6.2, 12.7, 0.78,
         "At the venous end, net filtration pressure = (15+8)−(28+0) = −5 mmHg. What does this mean?",
         "Negative = net REABSORPTION. Fluid is pulled back into the capillary at the venous end.")
footer(slide, 3)

# ════════════════════════════════════════════════════════════════
# SLIDE 4 – WHAT IS EDEMA?
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "What is Edema?",
           "When the balance of Starling forces is disturbed")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

add_rect(slide, 0.3, 1.38, 12.7, 0.5, C_RED)
add_tb(slide, 0.5, 1.4, 12.3, 0.46,
       "DEFINITION: Abnormal accumulation of excess fluid in interstitial spaces and/or body cavities, causing visible swelling.",
       size=15, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

# Two type boxes side by side
section_box(slide, 0.3, 2.0, 6.1, 2.7, "PITTING EDEMA",
    [("Fluid is free-moving & low in protein.", False, None),
     ("When you press the skin → a pit/dent forms.", False, None),
     ("", False, None),
     ("Causes:", True, C_MID_BLUE),
     ("  • ↑ Capillary hydrostatic pressure (e.g. heart failure)", False, None),
     ("  • ↓ Plasma oncotic pressure (e.g. low albumin)", False, None),
     ("  • ↑ Capillary permeability (e.g. inflammation)", False, None),
     ("  • Na⁺ & water retention (e.g. kidney/liver disease)", False, None),
     ], size=14)

section_box(slide, 6.6, 2.0, 6.4, 2.7, "NON-PITTING EDEMA",
    [("Fluid is bound to proteins, cells, fibrosis, or mucopolysaccharides.", False, None),
     ("No dent forms on pressing.", False, None),
     ("", False, None),
     ("Causes:", True, C_MID_BLUE),
     ("  • Lymphedema (blocked lymph vessels)", False, None),
     ("  • Myxedema (hypothyroidism)", False, None),
     ("  • Lipedema (fat tissue deposition)", False, None),
     ("  • Glycosaminoglycan (GAG) accumulation", False, None),
    ], size=14)

# Simple rule box
add_rect(slide, 0.3, 4.82, 12.7, 0.52, C_MID_BLUE)
add_tb(slide, 0.5, 4.84, 12.3, 0.48,
       "SIMPLE RULE:  Pitting = water is free (press it, it moves).  Non-Pitting = fluid is 'trapped' by proteins or structural changes.",
       size=14, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

# Grading table
add_rect(slide, 0.3, 5.4, 12.7, 0.36, C_DARK_BLUE)
for xp, wid, txt in [(0.3,2.0,"GRADE"), (2.3,2.5,"DEPTH"), (4.8,3.7,"PERSISTENCE"), (8.5,4.5,"CLINICAL SIGNIFICANCE")]:
    add_tb(slide, xp+0.05, 5.42, wid-0.1, 0.32, txt, size=12, bold=True, color=C_WHITE)
gy = 5.76
for grade, depth, persist, sig, bg in [
    ("1+", "2 mm", "Disappears immediately", "Mild — monitor", C_LIGHT_BLUE),
    ("2+", "4 mm", "Disappears < 15 sec", "Moderate", RGBColor(0xE8, 0xF8, 0xE8)),
    ("3+", "6 mm", "Disappears in 1 min", "Severe — investigate urgently", C_LIGHT_BLUE),
    ("4+", "8 mm", "Disappears > 2 min", "CRITICAL — immediate Rx", RGBColor(0xFF, 0xEB, 0xEB)),
]:
    add_rect(slide, 0.3, gy, 12.7, 0.32, bg)
    for xp, wid, val in [(0.3,2.0,grade),(2.3,2.5,depth),(4.8,3.7,persist),(8.5,4.5,sig)]:
        add_tb(slide, xp+0.05, gy+0.02, wid-0.1, 0.28, val, size=12,
               color=C_RED if "CRITICAL" in val else C_BLACK)
    gy += 0.32
footer(slide, 4)

# ════════════════════════════════════════════════════════════════
# SLIDE 5 – PATHOPHYSIOLOGY: INCREASED HYDROSTATIC PRESSURE
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Pathophysiology 1: Increased Hydrostatic Pressure",
           "The hose pressure is too high — fluid is forced out faster than it comes back")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

# Mechanism summary
add_rect(slide, 0.3, 1.38, 12.7, 0.44, C_ORANGE)
add_tb(slide, 0.5, 1.4, 12.3, 0.4,
       "MECHANISM: ↑ CHP while POP stays the same → outward force > inward force → net fluid leaks into tissues = EDEMA",
       size=14, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

causes = [
    ("RIGHT HEART FAILURE (RHF)", 
     "RV fails to pump → blood backs up in veins → ↑ venous hydrostatic pressure → fluid forced into systemic tissues → PERIPHERAL EDEMA (legs, ankles).",
     "Why peripheral and not pulmonary? Because RHF backs up into the systemic (body) veins, not the lungs."),
    ("LEFT HEART FAILURE (LHF)",
     "LV fails → blood backs up into pulmonary veins → ↑ pulmonary capillary pressure → fluid leaks into lung tissue → PULMONARY EDEMA → shortness of breath (orthopnea).",
     "Patient cannot lie flat — fluid moves to upper lungs. They sleep propped up on pillows."),
    ("POSTURAL / GRAVITATIONAL EDEMA",
     "Prolonged standing (e.g. traffic police) → gravity pools blood in leg veins → ↑ hydrostatic pressure in legs → transient ankle/leg edema.",
     "Relieved by elevation of legs because gravity no longer pools blood."),
    ("DVT / RENAL / LIVER DISEASE",
     "DVT blocks venous return → ↑ local HP. Renal disease → Na⁺ + H₂O retention → ↑ circulating volume → ↑ HP. Liver disease → portal HTN → ascites.",
     "All share the same endpoint: more pressure pushing fluid out."),
]
y = 1.9
for (title, mech, simple) in causes:
    add_rect(slide, 0.3, y, 12.7, 0.36, C_MID_BLUE)
    add_tb(slide, 0.4, y+0.02, 12.5, 0.32, title, size=13, bold=True, color=C_WHITE)
    add_tb(slide, 0.4, y+0.37, 9.4, 0.5, mech, size=13, color=C_BLACK)
    add_rect(slide, 9.85, y+0.37, 3.15, 0.5, RGBColor(0xFF, 0xF5, 0xCC))
    add_tb(slide, 9.95, y+0.38, 3.0, 0.48, simple, size=11, color=RGBColor(0x5A,0x3E,0x00), italic=True)
    y += 0.92

exam_box(slide, 0.3, 6.58, 12.7, 0.85,
         "A patient with RHF develops bilateral leg swelling. Explain the mechanism step by step.",
         "RV fails → venous back-pressure ↑ → CHP ↑ in systemic capillaries → net filtration ↑ → fluid accumulates in interstitium → bilateral pitting pedal edema.")
footer(slide, 5)

# ════════════════════════════════════════════════════════════════
# SLIDE 6 – PATHOPHYSIOLOGY: DECREASED ONCOTIC PRESSURE
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Pathophysiology 2: Decreased Oncotic Pressure",
           "The 'sponge' in blood loses its suction — fluid stays in tissues")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

add_rect(slide, 0.3, 1.38, 12.7, 0.44, C_ORANGE)
add_tb(slide, 0.5, 1.4, 12.3, 0.4,
       "MECHANISM: ↓ Albumin → ↓ POP (inward force) while CHP stays same → fluid leaks out and is NOT pulled back = EDEMA",
       size=14, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

# Albumin sources
add_rect(slide, 0.3, 1.9, 6.2, 0.36, C_DARK_BLUE)
add_tb(slide, 0.4, 1.92, 6.0, 0.32, "WHERE ALBUMIN COMES FROM", size=13, bold=True, color=C_WHITE)
add_multiline_tb(slide, 0.3, 2.28, 6.2, 0.7, [
    ("1. Dietary protein absorbed via GIT", False, None),
    ("2. Synthesised by the liver", False, None),
    ("→ Any problem with diet, gut, or liver = ↓ albumin = ↓ oncotic pressure", True, C_ORANGE),
], size=13)

# 3 causes
causes2 = [
    ("KWASHIORKOR\n(Malnutrition)", "Inadequate dietary protein → no raw material for albumin synthesis → ↓ POP → fluid leaks into abdomen and tissues → characteristic 'pot belly' (ascites + peripheral edema).", "The child looks thin in limbs but has a swollen abdomen. The belly is not fat — it is fluid!"),
    ("CIRRHOSIS\n(Liver Disease)", "Damaged liver hepatocytes → ↓ albumin synthesis → ↓ POP. Also: portal hypertension → ↑ capillary HP in portal system → ASCITES.", "Two mechanisms at once: liver makes less sponge-protein AND portal pressure rises."),
    ("NEPHROTIC SYNDROME\n(Kidney Disease)", "Damaged glomeruli become 'leaky' → protein (albumin) spills into urine (proteinuria) → ↓ plasma albumin → ↓ POP → generalised edema.", "Hallmark: frothy urine (protein) + swollen face in the morning (periorbital edema)."),
]
y = 3.1
for (title, mech, simple) in causes2:
    add_rect(slide, 0.3, y, 12.7, 0.36, C_MID_BLUE)
    add_tb(slide, 0.4, y+0.02, 12.5, 0.32, title, size=13, bold=True, color=C_WHITE)
    add_tb(slide, 0.4, y+0.37, 9.4, 0.52, mech, size=13, color=C_BLACK)
    add_rect(slide, 9.85, y+0.37, 3.15, 0.52, RGBColor(0xFF, 0xF5, 0xCC))
    add_tb(slide, 9.95, y+0.38, 3.0, 0.5, simple, size=11, color=RGBColor(0x5A,0x3E,0x00), italic=True)
    y += 0.96

exam_box(slide, 0.3, 6.0, 12.7, 0.85,
         "A 5-year-old in a famine zone has a distended abdomen. Serum albumin = 1.8 g/dL. Explain the edema.",
         "Severe malnutrition → ↓ dietary protein → ↓ albumin synthesis → ↓ plasma oncotic pressure → fluid not reabsorbed → accumulates in abdomen (ascites) + peripheral tissues = Kwashiorkor edema.")
footer(slide, 6)

# ════════════════════════════════════════════════════════════════
# SLIDE 7 – PATHOPHYSIOLOGY: LYMPHATIC OBSTRUCTION & ↑ PERMEABILITY
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Pathophysiology 3 & 4: Lymphatic Obstruction & Increased Permeability",
           "When the drainage system fails — or the capillary wall itself breaks down")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

# Lymphedema section
add_rect(slide, 0.3, 1.38, 6.2, 0.4, C_DARK_BLUE)
add_tb(slide, 0.4, 1.4, 6.0, 0.36, "MECHANISM 3: LYMPHATIC OBSTRUCTION", size=13, bold=True, color=C_WHITE)
add_multiline_tb(slide, 0.3, 1.82, 6.2, 1.9, [
    ("Lymphatic system normally drains the ~3 L/day of fluid not reabsorbed at the venous end.", False, None),
    ("If lymph vessels are BLOCKED or ABSENT, this fluid accumulates → non-pitting lymphedema.", False, None),
    ("", False, None),
    ("Examples:", True, C_DARK_BLUE),
    ("• Post-mastectomy: axillary nodes removed → arm lymphedema.", False, None),
    ("• Filariasis (elephantiasis): Wuchereria bancrofti larvae block lymphatics → gross leg swelling.", False, None),
    ("• Milroy Disease: hereditary — lymphatics never develop normally → edema from birth.", False, None),
], size=13)

# Increased permeability
add_rect(slide, 0.3, 3.85, 6.2, 0.4, C_RED)
add_tb(slide, 0.4, 3.87, 6.0, 0.36, "MECHANISM 4: INCREASED CAPILLARY PERMEABILITY", size=13, bold=True, color=C_WHITE)
add_multiline_tb(slide, 0.3, 4.29, 6.2, 1.85, [
    ("Inflammation releases histamine, bradykinin, prostaglandins → gaps form in endothelium.", False, None),
    ("Both fluid AND proteins leak out → ↑ interstitial oncotic pressure (more protein outside) + ↓ plasma oncotic pressure → fluid exits AND is not pulled back.", False, None),
    ("", False, None),
    ("Causes: Burns, insect bites, cellulitis, allergic reactions, sepsis, angioedema.", False, None),
    ("Pitting at first, may become non-pitting as proteins accumulate in tissue.", False, None),
], size=13)

# Analogy box
add_rect(slide, 6.65, 1.38, 6.4, 5.2, RGBColor(0xFF, 0xFD, 0xE7))
add_rect(slide, 6.65, 1.38, 6.4, 0.4, C_ORANGE)
add_tb(slide, 6.75, 1.4, 6.2, 0.36, "SIMPLE ANALOGIES", size=13, bold=True, color=C_WHITE)
add_multiline_tb(slide, 6.75, 1.83, 6.2, 4.65, [
    ("Lymphedema = blocked drain", True, C_DARK_BLUE),
    ("Your sink fills up not because the tap is running too hard,", False, None),
    ("but because the drain is clogged.", False, None),
    ("", False, None),
    ("Increased permeability = cracked pipe", True, C_RED),
    ("The pipe develops cracks (from inflammation).", False, None),
    ("Now BOTH water AND salt pour out.", False, None),
    ("Salt outside draws more water out — double trouble.", False, None),
    ("", False, None),
    ("Milroy Disease = pipe never built", True, C_MID_BLUE),
    ("No lymphatic drainage from birth.", False, None),
    ("Fluid has nowhere to go from day 1.", False, None),
    ("", False, None),
    ("Filariasis = pipe invaded by worms", True, C_ORANGE),
    ("Wuchereria bancrofti larvae physically", False, None),
    ("block the lymph vessels — think", False, None),
    ("roots blocking an underground drain.", False, None),
], size=13)

exam_box(slide, 0.3, 6.25, 6.3, 0.95,
         "Why is edema in filariasis NON-pitting?",
         "Chronic lymph obstruction → protein-rich fluid trapped in tissue → proteins + fibrosis bind fluid → no pit on pressure.")
exam_box(slide, 6.65, 6.25, 6.4, 0.95,
         "Burns cause edema. Which mechanism?",
         "Heat destroys endothelial cells → ↑ capillary permeability → fluid + protein leak into interstitium → pitting (early) / non-pitting (later as proteins trap fluid).")
footer(slide, 7)

# ════════════════════════════════════════════════════════════════
# SLIDE 8 – CLINICAL APPROACH & TREATMENT
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Clinical Approach & Treatment of Edema",
           "Remember: Edema is a SIGN, not a disease — treat the underlying cause first")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

add_rect(slide, 0.3, 1.38, 12.7, 0.42, C_MID_BLUE)
add_tb(slide, 0.5, 1.4, 12.3, 0.38,
       "CLINICAL ASSESSMENT: Unilateral or Bilateral?  Pitting or Non-Pitting?  Any JVD or crackles?  Morning (periorbital) or Evening (leg)?",
       size=13, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

tx_data = [
    ("Mechanism", "Cause", "First-line Treatment", "Key Point",
     C_DARK_BLUE, C_WHITE, True),
    ("↑ Hydrostatic P", "Heart Failure", "Loop diuretics (Furosemide)", "Reduce circulating volume → ↓ capillary HP",
     RGBColor(0xD6,0xE8,0xF8), C_BLACK, False),
    ("↑ Hydrostatic P", "DVT", "Heparin / Rivaroxaban / Apixaban", "Remove clot → restore venous return",
     RGBColor(0xE8,0xF8,0xE8), C_BLACK, False),
    ("↑ Hydrostatic P", "Postural edema", "Leg elevation, compression stockings", "Use stockings cautiously if arterial disease suspected",
     RGBColor(0xD6,0xE8,0xF8), C_BLACK, False),
    ("↑ Hydrostatic P", "Na⁺ retention (renal)", "Low-Na diet + diuretics", "2–3 weeks for idiopathic edema",
     RGBColor(0xE8,0xF8,0xE8), C_BLACK, False),
    ("↓ Oncotic P", "Kwashiorkor", "Nutritional rehabilitation (protein)", "Correct the protein deficiency",
     RGBColor(0xD6,0xE8,0xF8), C_BLACK, False),
    ("↓ Oncotic P", "Nephrotic Syndrome", "Treat underlying cause + albumin infusion", "Protein replacement restores oncotic pressure",
     RGBColor(0xE8,0xF8,0xE8), C_BLACK, False),
    ("↓ Oncotic P", "Cirrhosis", "Spironolactone + furosemide, paracentesis", "Portal HTN + ↓ albumin = dual mechanism",
     RGBColor(0xD6,0xE8,0xF8), C_BLACK, False),
    ("Lymphatic obs.", "Lymphedema", "Complete Decongestive Therapy (CDT)", "Manual lymphatic drainage + compression + exercise",
     RGBColor(0xE8,0xF8,0xE8), C_BLACK, False),
    ("↑ Permeability", "Burns / Allergy", "Treat cause (antihistamine, steroids, wound care)", "Reduce inflammatory mediators → seal capillary gaps",
     RGBColor(0xD6,0xE8,0xF8), C_BLACK, False),
]

col_x  = [0.3, 3.0, 5.7, 9.1]
col_w  = [2.65, 2.65, 3.35, 4.15]
ty = 1.85
for row in tx_data:
    mech, cause, tx, note, bg, fg, hdr = row
    add_rect(slide, 0.3, ty, 12.7, 0.36, bg)
    for i, val in enumerate([mech, cause, tx, note]):
        add_tb(slide, col_x[i]+0.05, ty+0.02, col_w[i]-0.1, 0.32,
               val, size=12, bold=hdr, color=fg)
    ty += 0.36

exam_box(slide, 0.3, 5.4, 12.7, 0.82,
         "Why is furosemide (a loop diuretic) used in heart failure edema? What is its mechanism?",
         "Furosemide blocks Na⁺/K⁺/2Cl⁻ cotransporter in loop of Henle → ↑ urine output → ↓ circulating blood volume → ↓ venous pressure → ↓ capillary hydrostatic pressure → edema resolves.")
add_rect(slide, 0.3, 6.27, 12.7, 0.42, C_RED)
add_tb(slide, 0.5, 6.29, 12.3, 0.38,
       "⚠  Compression stockings are CONTRAINDICATED in peripheral arterial disease — they restrict arterial flow and can worsen ischaemia.",
       size=13, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)
footer(slide, 8)

# ════════════════════════════════════════════════════════════════
# SLIDE 9 – SUMMARY FLOWCHART
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Summary: Pathophysiology of Edema at a Glance",
           "One flowchart to connect all four mechanisms")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

# Central concept
add_rect(slide, 4.67, 1.45, 3.9, 0.6, C_RED)
add_tb(slide, 4.77, 1.47, 3.7, 0.56, "EDEMA\n(↑ Interstitial Fluid)", size=15, bold=True,
       color=C_WHITE, align=PP_ALIGN.CENTER)

# Arrow label helper
def flow_box(slide, x, y, w, h, label, text, bg, fg=C_BLACK):
    add_rect(slide, x, y, w, 0.34, C_DARK_BLUE)
    add_tb(slide, x+0.05, y+0.02, w-0.1, 0.3, label, size=12, bold=True, color=C_WHITE)
    add_rect(slide, x, y+0.34, w, h-0.34, bg)
    add_tb(slide, x+0.05, y+0.36, w-0.1, h-0.4, text, size=12, color=fg, wrap=True)

flow_box(slide, 0.3, 2.3, 3.0, 1.8,
         "1. ↑ HYDROSTATIC P",
         "↑ CHP > POP\n→ More fluid forced out\nCauses: HF, DVT, renal Dz, postural",
         C_LIGHT_BLUE)
flow_box(slide, 3.5, 2.3, 3.0, 1.8,
         "2. ↓ ONCOTIC P",
         "↓ POP < CHP\n→ Less fluid pulled back\nCauses: ↓albumin (liver, kidney, diet)",
         RGBColor(0xE8,0xF8,0xE8))
flow_box(slide, 6.9, 2.3, 3.0, 1.8,
         "3. LYMPHATIC OBS.",
         "Normal HP & POP\n→ Drainage fails\nCauses: mastectomy, filariasis, Milroy",
         RGBColor(0xFF,0xF0,0xCC))
flow_box(slide, 10.1, 2.3, 3.0, 1.8,
         "4. ↑ PERMEABILITY",
         "Gaps in endothelium\n→ Fluid + protein leak\nCauses: burns, allergy, sepsis",
         RGBColor(0xFF,0xE8,0xE8))

# arrows (simple text)
for ax in [1.8, 5.0, 8.4, 11.6]:
    add_tb(slide, ax, 4.08, 0.5, 0.5, "↓", size=22, bold=True,
           color=C_DARK_BLUE, align=PP_ALIGN.CENTER)

# Result row
add_rect(slide, 0.3, 4.55, 12.7, 0.4, C_ORANGE)
add_tb(slide, 0.5, 4.57, 12.3, 0.36,
       "All four paths lead to the same result: MORE FLUID IN TISSUES THAN THE BODY CAN REABSORB OR DRAIN",
       size=14, bold=True, color=C_WHITE, align=PP_ALIGN.CENTER)

# Quick recall table
add_rect(slide, 0.3, 5.05, 12.7, 0.34, C_DARK_BLUE)
for xp, wid, hd in [(0.3,4.1,"MECHANISM"),(4.4,3.1,"CLASSIC CAUSE"),(7.5,2.8,"EDEMA TYPE"),(10.3,2.7,"QUICK TEST")]:
    add_tb(slide, xp+0.05, 5.07, wid-0.1, 0.3, hd, size=12, bold=True, color=C_WHITE)
ry = 5.39
for mech, cause, etype, tip, bg in [
    ("↑ Hydrostatic Pressure","Heart Failure / DVT","Pitting, bilateral","JVD, crackles",C_LIGHT_BLUE),
    ("↓ Oncotic Pressure","Nephrotic / Cirrhosis / Kwashiorkor","Pitting, generalised","Low albumin, frothy urine",RGBColor(0xE8,0xF8,0xE8)),
    ("Lymphatic Obstruction","Filariasis / Post-mastectomy","Non-pitting, unilateral","History of cancer Rx / tropical Dz",C_LIGHT_BLUE),
    ("↑ Capillary Permeability","Burns / Allergy / Sepsis","Pitting → Non-pitting","Acute onset, skin changes",RGBColor(0xE8,0xF8,0xE8)),
]:
    add_rect(slide, 0.3, ry, 12.7, 0.32, bg)
    for xp, wid, val in [(0.3,4.1,mech),(4.4,3.1,cause),(7.5,2.8,etype),(10.3,2.7,tip)]:
        add_tb(slide, xp+0.05, ry+0.02, wid-0.1, 0.28, val, size=11, color=C_BLACK)
    ry += 0.32
footer(slide, 9)

# ════════════════════════════════════════════════════════════════
# SLIDE 10 – EXAM PRACTICE PAGE
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
header_bar(slide, "Exam Practice Questions",
           "Test your understanding of capillary exchange and edema pathophysiology")
add_rect(slide, 0, 1.23, 13.333, 6.27, RGBColor(0xF4, 0xF8, 0xFF))

questions = [
    ("Q1 – MCQ", 
     "A patient with liver cirrhosis develops ascites. Which Starling force is MOST directly reduced?",
     "A) Capillary hydrostatic pressure\nB) Plasma colloid osmotic pressure ✓\nC) Interstitial oncotic pressure\nD) Lymphatic flow",
     "Liver failure → ↓ albumin synthesis → ↓ plasma oncotic pressure."),
    ("Q2 – Short Answer",
     "Explain why a child with kwashiorkor has a swollen abdomen despite appearing malnourished.",
     "",
     "↓ Dietary protein → ↓ albumin → ↓ plasma oncotic pressure → fluid not reabsorbed → accumulates in peritoneal cavity (ascites) + peripheral tissues."),
    ("Q3 – Clinical",
     "A 60-yr-old woman who had left breast cancer surgery 2 years ago now has unilateral left arm swelling. Press on it — no pit forms. Diagnosis & mechanism?",
     "",
     "Post-mastectomy lymphedema. Axillary node clearance removed lymphatic drainage for that arm → chronic lymph accumulation → protein-rich non-pitting edema."),
    ("Q4 – Calculation",
     "CHP = 20 mmHg, POP = 28 mmHg, IOP = 8 mmHg, IHP = 0 mmHg. Calculate NFP. Will fluid move IN or OUT?",
     "NFP = (CHP + IOP) − (POP + IHP)",
     "NFP = (20+8) − (28+0) = 28 − 28 = 0 mmHg. Net equilibrium — no net movement. (Normal venous-end balance.)"),
    ("Q5 – Mechanism",
     "Why does furosemide reduce edema in heart failure but NOT in lymphedema?",
     "",
     "Furosemide works by ↓ blood volume → ↓ CHP. In lymphedema the Starling forces are NORMAL — the problem is absent/blocked drainage. Diuretics don't rebuild lymphatics."),
    ("Q6 – Spot Diagnosis",
     "A traveller returns from West Africa with massive leg swelling resembling an elephant's limb. Eosinophilia on blood film. Diagnosis & pathophysiology?",
     "",
     "Filariasis (elephantiasis). Wuchereria bancrofti larvae block lymphatics → chronic non-pitting lymphedema."),
]

qx = [0.3, 6.65]
qy_start = 1.42
qh = 0.9
for idx, (label, question, options, answer) in enumerate(questions):
    col = idx % 2
    row = idx // 2
    x = qx[col]
    y = qy_start + row * (qh + 0.08)
    add_rect(slide, x, y, 6.15, 0.3, C_TEAL)
    add_tb(slide, x+0.08, y+0.02, 6.0, 0.26, label, size=12, bold=True, color=C_YELLOW)
    add_rect(slide, x, y+0.3, 6.15, qh-0.3, RGBColor(0xE6,0xF4,0xF5))
    add_tb(slide, x+0.08, y+0.32, 5.98, 0.28, question, size=11, bold=True, color=C_BLACK)
    if options:
        add_tb(slide, x+0.08, y+0.58, 5.98, 0.28, options, size=10, color=C_BLACK)
    add_tb(slide, x+0.08, y+0.62, 5.98, 0.26, "▶ "+answer, size=10, color=C_GREEN, italic=True)

footer(slide, 10)

# ════════════════════════════════════════════════════════════════
# SLIDE 11 – TAKE HOME & REFERENCES
# ════════════════════════════════════════════════════════════════
slide = prs.slides.add_slide(blank)
add_rect(slide, 0, 0, 13.333, 7.5, C_DARK_BLUE)
add_rect(slide, 0, 2.6, 13.333, 0.1, C_YELLOW)

add_tb(slide, 1, 0.35, 11.3, 0.9,
       "TAKE-HOME MESSAGE", size=32, bold=True, color=C_YELLOW, align=PP_ALIGN.CENTER)

msgs = [
    "1.  Starling forces are in constant balance — edema happens when that balance breaks.",
    "2.  Four mechanisms: ↑ Hydrostatic P | ↓ Oncotic P | Lymphatic obstruction | ↑ Permeability.",
    "3.  Albumin is the main osmotic sponge in blood — always check albumin first.",
    "4.  Pitting = free fluid. Non-pitting = fluid trapped by protein/structural change.",
    '5.  "Swelling is considered normal until it becomes life-threatening." — Investigate HOW and WHY.',
]
add_multiline_tb(slide, 1, 1.2, 11.3, 1.3, [(m, False, C_WHITE) for m in msgs], size=15)

add_tb(slide, 1, 2.75, 11.3, 0.55,
       "REFERENCES", size=18, bold=True, color=C_YELLOW, align=PP_ALIGN.LEFT)

refs = [
    "Davidson's Principles and Practice of Medicine. Elsevier, 2010.",
    "Guyton AC & Hall JE. Textbook of Medical Physiology, 14th ed. Elsevier.",
    "Scallan J, Huxley VH, Korthuis RJ. Pathophysiology of Edema Formation. NCBI Bookshelf, 2010.",
    "Osmosis & Singh A. Edema Grading — Pitting Edema. osmosis.org.",
]
add_multiline_tb(slide, 1, 3.35, 11.3, 1.8,
    [(r, False, RGBColor(0xCC,0xDD,0xFF)) for r in refs], size=13)

add_rect(slide, 0, 6.5, 13.333, 1.0, C_MID_BLUE)
add_tb(slide, 1, 6.58, 11.3, 0.8,
       "Human Physiology PHYS 102  |  Capillary Exchange & Edema  |  Draft Teaching Presentation",
       size=14, color=C_WHITE, align=PP_ALIGN.CENTER, italic=True)

# ── SAVE ────────────────────────────────────────────────────────
out = "/tmp/workspace/capillary-edema/Capillary_Exchange_Edema_Teaching_Draft.pptx"
buf = BytesIO()
prs.save(buf)
with open(out, "wb") as f:
    f.write(buf.getvalue())
print("Saved to", out)