from reportlab.lib.pagesizes import A4
from reportlab.lib import colors
from reportlab.lib.units import mm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, Spacer, Table, TableStyle, HRFlowable
)
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.enums import TA_CENTER, TA_LEFT
from reportlab.platypus import KeepTogether

OUTPUT = "/home/daytona/workspace/shock-reference/Shock_Reference_Card.pdf"

# ── Colour palette ──────────────────────────────────────────────────────────
NAVY      = colors.HexColor("#1A237E")
TEAL      = colors.HexColor("#006064")
RED_DARK  = colors.HexColor("#B71C1C")
AMBER     = colors.HexColor("#E65100")
GREEN_DK  = colors.HexColor("#1B5E20")
PURPLE    = colors.HexColor("#4A148C")
BLUE_LT   = colors.HexColor("#E3F2FD")
TEAL_LT   = colors.HexColor("#E0F7FA")
RED_LT    = colors.HexColor("#FFEBEE")
AMBER_LT  = colors.HexColor("#FFF3E0")
GREEN_LT  = colors.HexColor("#F1F8E9")
PURPLE_LT = colors.HexColor("#F3E5F5")
GREY_LT   = colors.HexColor("#F5F5F5")
WHITE     = colors.white
BLACK     = colors.black

# ── Styles ───────────────────────────────────────────────────────────────────
base = getSampleStyleSheet()

def S(name, **kw):
    return ParagraphStyle(name, **kw)

title_style = S("title",
    fontName="Helvetica-Bold", fontSize=22,
    textColor=WHITE, alignment=TA_CENTER, spaceAfter=2)

subtitle_style = S("subtitle",
    fontName="Helvetica", fontSize=10,
    textColor=WHITE, alignment=TA_CENTER)

sec_head = S("sechead",
    fontName="Helvetica-Bold", fontSize=12,
    textColor=WHITE, alignment=TA_CENTER, leading=16)

col_head = S("colhead",
    fontName="Helvetica-Bold", fontSize=9,
    textColor=WHITE, alignment=TA_CENTER, leading=12)

body = S("body",
    fontName="Helvetica", fontSize=8,
    textColor=BLACK, leading=11, spaceAfter=2)

body_b = S("bodyb",
    fontName="Helvetica-Bold", fontSize=8,
    textColor=BLACK, leading=11)

small = S("small",
    fontName="Helvetica", fontSize=7.5,
    textColor=BLACK, leading=10)

small_b = S("smallb",
    fontName="Helvetica-Bold", fontSize=7.5,
    textColor=BLACK, leading=10)

bullet = S("bullet",
    fontName="Helvetica", fontSize=7.5,
    textColor=BLACK, leading=10, leftIndent=8, bulletIndent=0)

warn = S("warn",
    fontName="Helvetica-Bold", fontSize=7.5,
    textColor=RED_DARK, leading=10)

# ── Helpers ──────────────────────────────────────────────────────────────────
def hdr_cell(text, style=sec_head):
    return Paragraph(text, style)

def bc(text, sty=body):
    return Paragraph(text, sty)

def bb(text):
    return Paragraph(text, body_b)

def bl(items, color=None):
    """Bullet list as a single Paragraph string."""
    lines = []
    for it in items:
        lines.append(f"• {it}")
    return Paragraph("<br/>".join(lines), small)

def colored_table(data, col_widths, hdr_bg, alt_bg=GREY_LT):
    """Build a styled table with a coloured header row."""
    ts = TableStyle([
        ("BACKGROUND", (0,0), (-1,0), hdr_bg),
        ("TEXTCOLOR",  (0,0), (-1,0), WHITE),
        ("FONTNAME",   (0,0), (-1,0), "Helvetica-Bold"),
        ("FONTSIZE",   (0,0), (-1,0), 8),
        ("ALIGN",      (0,0), (-1,0), "CENTER"),
        ("VALIGN",     (0,0), (-1,-1), "TOP"),
        ("FONTNAME",   (0,1), (-1,-1), "Helvetica"),
        ("FONTSIZE",   (0,1), (-1,-1), 7.5),
        ("ROWBACKGROUNDS", (0,1), (-1,-1), [WHITE, alt_bg]),
        ("GRID",       (0,0), (-1,-1), 0.4, colors.grey),
        ("LEFTPADDING",  (0,0), (-1,-1), 4),
        ("RIGHTPADDING", (0,0), (-1,-1), 4),
        ("TOPPADDING",   (0,0), (-1,-1), 3),
        ("BOTTOMPADDING",(0,0), (-1,-1), 3),
    ])
    t = Table(data, colWidths=col_widths)
    t.setStyle(ts)
    return t

def section_banner(text, bg):
    t = Table([[Paragraph(text, sec_head)]], colWidths=[178*mm])
    t.setStyle(TableStyle([
        ("BACKGROUND", (0,0), (-1,-1), bg),
        ("LEFTPADDING",  (0,0), (-1,-1), 6),
        ("RIGHTPADDING", (0,0), (-1,-1), 6),
        ("TOPPADDING",   (0,0), (-1,-1), 4),
        ("BOTTOMPADDING",(0,0), (-1,-1), 4),
    ]))
    return t

# ── Document ─────────────────────────────────────────────────────────────────
doc = SimpleDocTemplate(
    OUTPUT, pagesize=A4,
    leftMargin=16*mm, rightMargin=16*mm,
    topMargin=14*mm, bottomMargin=14*mm)

story = []
W = 178*mm   # usable width

# ════════════════════════════════════════════════════════════════════
# TITLE BANNER
# ════════════════════════════════════════════════════════════════════
title_tbl = Table(
    [[Paragraph("SHOCK", title_style)],
     [Paragraph("Types · Pathophysiology · Management  |  SRB's Manual of Surgery – Ch. 5", subtitle_style)]],
    colWidths=[W])
title_tbl.setStyle(TableStyle([
    ("BACKGROUND", (0,0), (-1,-1), NAVY),
    ("LEFTPADDING",  (0,0), (-1,-1), 8),
    ("RIGHTPADDING", (0,0), (-1,-1), 8),
    ("TOPPADDING",   (0,0), (-1,-1), 6),
    ("BOTTOMPADDING",(0,0), (-1,-1), 6),
]))
story.append(title_tbl)
story.append(Spacer(1, 4*mm))

# ════════════════════════════════════════════════════════════════════
# 1. TYPES OF SHOCK – 4-column overview table
# ════════════════════════════════════════════════════════════════════
story.append(section_banner("1.  TYPES OF SHOCK", TEAL))
story.append(Spacer(1, 2*mm))

types_data = [
    [Paragraph("TYPE", col_head), Paragraph("CAUSE", col_head),
     Paragraph("KEY FEATURES", col_head), Paragraph("MANAGEMENT", col_head)],

    [bb("Vasovagal"),
     bc("Sudden dilatation of peripheral & splanchnic vessels"),
     bc("Reduced cardiac output; may be life-threatening due to hypoxia"),
     bc("Lay flat, O2, IV fluids; treat underlying cause")],

    [bb("Neurogenic"),
     bc("Spinal cord injury → splanchnic vessel dilatation"),
     bl(["Bradycardia", "Hypotension", "Arrhythmias", "Decreased cardiac output"]),
     bl(["BP & O2 control", "IV fluids + airway", "Vasoconstrictors (dopamine, phenylephrine – α agonist)", "Methylprednisolone"])],

    [bb("Hypovolaemic\n(Haemorrhagic)"),
     bl(["Haemorrhage (liver, spleen, bone fractures, vascular injury)", "Vomiting / diarrhoea (Na⁺ & water loss)", "Burns (extravascular fluid sequestration)"]),
     bl(["Mild <15%: no significant change in HR/CO", "Moderate 15-40%: cold periphery, tachycardia, hypotension (postural), metabolic acidosis", "Severe >40%: hypotension, tachycardia, sweating, oliguria, drowsiness → SIRS → MODS"]),
     bl(["Stop haemorrhage", "IV fluid resuscitation (crystalloids/colloids/blood)", "Treat underlying cause", "Monitor urine output"])],

    [bb("Cardiogenic"),
     bl(["Acute MI (≥50% LV wall damage)", "Aortic dissection", "Mitral/aortic stenosis", "Congestive cardiac failure", "Massive pulmonary embolism"]),
     bl(["Circulatory failure → tissue hypoxia", "SBP <90 mmHg for ≥30 min", "Cardiac index <2.2 L/min/m²", "PCWP >15 mmHg", "Pulmonary oedema + severe hypoxia", "Mortality >50%"]),
     bl(["ECG, echocardiography", "ABG, cardiac enzymes, PCWP, electrolytes", "Inotropic support", "Revascularisation (PCI/CABG)", "Correct hypokalaemia & hypomagnesaemia"])],
]

cw = [28*mm, 42*mm, 60*mm, 48*mm]
types_tbl = colored_table(types_data, cw, TEAL, TEAL_LT)
story.append(types_tbl)
story.append(Spacer(1, 4*mm))

# ════════════════════════════════════════════════════════════════════
# 2. STAGES OF SHOCK
# ════════════════════════════════════════════════════════════════════
story.append(section_banner("2.  STAGES OF SHOCK", AMBER))
story.append(Spacer(1, 2*mm))

stages_data = [
    [Paragraph("STAGE", col_head), Paragraph("MECHANISM", col_head), Paragraph("FEATURES", col_head)],
    [bb("Compensatory\n(Early)"),
     bc("Sympathetic activation; ADH, ACTH, prostaglandins, histamine released; blood flow redirected to heart, brain, lungs"),
     bc("Tachycardia, vasoconstriction, oliguria; normal or slightly low BP")],
    [bb("Decompensatory\n(Progressive)"),
     bc("Compensatory mechanisms fail; cell perfusion decreases; raised intracellular Na⁺, low intracellular K⁺"),
     bc("Kidney, liver & lung failure begin; microcirculation failure; capillary dysfunction")],
    [bb("Irreversible\n(Refractory)"),
     bc("Cellular ATP metabolism lost completely"),
     Paragraph("MODS (Multi-Organ Dysfunction Syndrome) and MOF (Multi-Organ Failure) – death if untreated", warn)],
]

stages_tbl = colored_table(stages_data, [35*mm, 80*mm, 63*mm], AMBER, AMBER_LT)
story.append(stages_tbl)
story.append(Spacer(1, 4*mm))

# ════════════════════════════════════════════════════════════════════
# 3. EFFECTS OF SHOCK – organ by organ
# ════════════════════════════════════════════════════════════════════
story.append(section_banner("3.  EFFECTS OF SHOCK – Organ Systems", RED_DARK))
story.append(Spacer(1, 2*mm))

effects_data = [
    [Paragraph("ORGAN", col_head), Paragraph("PATHOPHYSIOLOGY & CONSEQUENCES", col_head)],
    [bb("Heart"),
     bc("Low perfusion → ↓ venous return → ↓ cardiac output → hypotension → tachycardia → myocardial depressants released → worsening cardiac damage")],
    [bb("Lungs"),
     bc("Interstitial oedema → ↓ gaseous exchange → pulmonary A-V shunting → tachypnoea → ARDS + pulmonary oedema")],
    [bb("Metabolic"),
     bc("Hypoxia → anaerobic metabolism → lactic acidosis. ADH released → ↑ water reabsorption from renal tubules. Also: ACTH, prostaglandins, histamine, bradykinin, serotonin released.")],
    [bb("Cellular"),
     bc("Lysosomal enzymes released in persistent shock → altered cell membrane permeability → cell death (sick cell syndrome). Sympathetic overactivity alters microcirculation → capillary dysfunction.")],
    [bb("Brain"),
     bc("Last organ to be underperfused. Decreased perfusion → drowsiness. Severe: loss of consciousness.")],
    [bb("Kidneys"),
     bc("GFR decreases + tubular reabsorption ↑ (compensatory). Severe: acute tubular necrosis → irreversible renal damage.")],
    [bb("Blood"),
     bc("Platelet & cellular alterations → DIC (Disseminated Intravascular Coagulation) → bleeding from all organs.")],
    [bb("GI Tract"),
     bc("Mucosal ischaemia → haematemesis & malaena (aggravated by DIC). Hepatic ischaemia → ↑ liver enzymes.")],
]

effects_tbl = colored_table(effects_data, [28*mm, 150*mm], RED_DARK, RED_LT)
story.append(effects_tbl)
story.append(Spacer(1, 4*mm))

# ════════════════════════════════════════════════════════════════════
# 4. HYPOVOLAEMIA SEVERITY GRADING
# ════════════════════════════════════════════════════════════════════
story.append(section_banner("4.  HYPOVOLAEMIC SHOCK – Severity Grading", GREEN_DK))
story.append(Spacer(1, 2*mm))

hv_data = [
    [Paragraph("GRADE", col_head), Paragraph("BLOOD LOSS", col_head),
     Paragraph("HEART RATE", col_head), Paragraph("BP", col_head),
     Paragraph("FEATURES", col_head)],
    [bb("Mild\n(Covert Compensated)"),   bc("<15%"),
     bc("No significant change"), bc("Normal"), bc("Cardiac output & splanchnic blood compensate; no significant clinical change")],
    [bb("Moderate\n(Overt Compensated)"),bc("15–40%"),
     bc("Tachycardia"), bc("Systolic well-maintained\n(postural drop)"),
     bc("Cold periphery, tachycardia, confusion, hyponatraemia, metabolic acidosis")],
    [bb("Severe\n(Decompensated)"),      bc(">40%"),
     bc("Tachycardia"), Paragraph("Hypotension", warn),
     Paragraph("Sweating, tachypnoea, oliguria, drowsiness, SIRS → MODS → Irreversible shock", warn)],
]

hv_tbl = colored_table(hv_data, [32*mm, 22*mm, 28*mm, 34*mm, 62*mm], GREEN_DK, GREEN_LT)
story.append(hv_tbl)
story.append(Spacer(1, 4*mm))

# ════════════════════════════════════════════════════════════════════
# 5. QUICK NOTES
# ════════════════════════════════════════════════════════════════════
story.append(section_banner("5.  QUICK NOTES", PURPLE))
story.append(Spacer(1, 2*mm))

notes_data = [
    [Paragraph("CONCEPT", col_head), Paragraph("DEFINITION / NOTES", col_head)],
    [bb("Distributive Shock"),
     bc("Vasodilatation + ↓ vascular resistance + altered microvascular perfusion. Seen in septic shock, spinal trauma, adrenal crisis, anaphylaxis.")],
    [bb("Obstructive Shock"),
     bc("Mechanical impediment to circulation: pulmonary embolism, tension pneumothorax, cardiac tamponade, aortic stenosis.")],
    [bb("Cardiogenic – Diagnosis"),
     bc("ECG + Echocardiography + ABG + Cardiac enzymes + PCWP + Electrolytes (hypokalaemia & hypomagnesaemia common).")],
    [bb("Neurogenic – Key Drug"),
     bc("Dopamine and Phenylephrine (α-agonist) – used to bring up blood pressure by vasoconstriction.")],
    [bb("DIC"),
     bc("Disseminated Intravascular Coagulation: complication of persistent shock. Platelets and coagulation factors consumed → bleeding from all organs.")],
    [bb("Sick Cell Syndrome"),
     bc("Lysosomal enzyme release in persistent shock alters cell membrane permeability → irreversible cell death.")],
]

notes_tbl = colored_table(notes_data, [40*mm, 138*mm], PURPLE, PURPLE_LT)
story.append(notes_tbl)
story.append(Spacer(1, 4*mm))

# ── Footer ────────────────────────────────────────────────────────────────────
story.append(HRFlowable(width=W, thickness=0.5, color=colors.grey))
story.append(Spacer(1, 1*mm))
footer = Paragraph(
    "Reference: SRB's Manual of Surgery, Chapter 5 – Shock  |  For educational purposes only  |  Always follow current institutional protocols",
    S("footer", fontName="Helvetica-Oblique", fontSize=7, textColor=colors.grey, alignment=TA_CENTER))
story.append(footer)

# ── Build ─────────────────────────────────────────────────────────────────────
doc.build(story)
print("PDF created:", OUTPUT)