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

OUTPUT = "/home/daytona/workspace/anemia-pregnancy/Anaemia_in_Pregnancy_MD_Anaesthesia.pdf"

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=2*cm, leftMargin=2*cm,
    topMargin=2*cm, bottomMargin=2*cm
)

styles = getSampleStyleSheet()

# Custom styles
title_style = ParagraphStyle(
    'CustomTitle',
    parent=styles['Title'],
    fontSize=18,
    textColor=colors.HexColor('#1a3c5e'),
    spaceAfter=4,
    spaceBefore=0,
    alignment=TA_CENTER,
    fontName='Helvetica-Bold'
)

subtitle_style = ParagraphStyle(
    'Subtitle',
    parent=styles['Normal'],
    fontSize=11,
    textColor=colors.HexColor('#2d6a9f'),
    spaceAfter=2,
    alignment=TA_CENTER,
    fontName='Helvetica-Oblique'
)

h1_style = ParagraphStyle(
    'H1',
    parent=styles['Heading1'],
    fontSize=13,
    textColor=colors.white,
    backColor=colors.HexColor('#1a3c5e'),
    spaceBefore=14,
    spaceAfter=6,
    leftIndent=-0.3*cm,
    rightIndent=-0.3*cm,
    borderPadding=(4, 6, 4, 6),
    fontName='Helvetica-Bold'
)

h2_style = ParagraphStyle(
    'H2',
    parent=styles['Heading2'],
    fontSize=11,
    textColor=colors.HexColor('#1a3c5e'),
    spaceBefore=10,
    spaceAfter=4,
    fontName='Helvetica-Bold',
    borderPadding=(2, 0, 2, 0),
)

h3_style = ParagraphStyle(
    'H3',
    parent=styles['Heading3'],
    fontSize=10,
    textColor=colors.HexColor('#2d6a9f'),
    spaceBefore=7,
    spaceAfter=3,
    fontName='Helvetica-Bold',
)

body_style = ParagraphStyle(
    'Body',
    parent=styles['Normal'],
    fontSize=9.5,
    leading=14,
    spaceAfter=4,
    alignment=TA_JUSTIFY,
    fontName='Helvetica'
)

bullet_style = ParagraphStyle(
    'Bullet',
    parent=styles['Normal'],
    fontSize=9.5,
    leading=13,
    spaceAfter=2,
    leftIndent=16,
    bulletIndent=4,
    fontName='Helvetica'
)

sub_bullet_style = ParagraphStyle(
    'SubBullet',
    parent=styles['Normal'],
    fontSize=9,
    leading=12,
    spaceAfter=2,
    leftIndent=30,
    bulletIndent=18,
    fontName='Helvetica'
)

note_style = ParagraphStyle(
    'Note',
    parent=styles['Normal'],
    fontSize=8.5,
    leading=12,
    spaceAfter=4,
    leftIndent=12,
    textColor=colors.HexColor('#444444'),
    fontName='Helvetica-Oblique'
)

source_style = ParagraphStyle(
    'Source',
    parent=styles['Normal'],
    fontSize=8,
    leading=11,
    textColor=colors.HexColor('#555555'),
    fontName='Helvetica-Oblique',
    alignment=TA_CENTER
)

def h1(text):
    return Paragraph(f"  {text}", h1_style)

def h2(text):
    return Paragraph(text, h2_style)

def h3(text):
    return Paragraph(text, h3_style)

def body(text):
    return Paragraph(text, body_style)

def bullet(text, level=1):
    if level == 1:
        return Paragraph(f"•  {text}", bullet_style)
    else:
        return Paragraph(f"–  {text}", sub_bullet_style)

def note(text):
    return Paragraph(f'<i>"{text}"</i>', note_style)

def sp(h=4):
    return Spacer(1, h)

def hr():
    return HRFlowable(width="100%", thickness=0.5, color=colors.HexColor('#2d6a9f'), spaceAfter=4, spaceBefore=4)

# --- TABLE HELPER ---
def make_table(data, col_widths=None, header=True):
    t = Table(data, colWidths=col_widths, repeatRows=1 if header else 0)
    style_cmds = [
        ('BACKGROUND', (0, 0), (-1, 0), colors.HexColor('#1a3c5e')),
        ('TEXTCOLOR', (0, 0), (-1, 0), colors.white),
        ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
        ('FONTSIZE', (0, 0), (-1, 0), 9),
        ('ALIGN', (0, 0), (-1, -1), 'LEFT'),
        ('VALIGN', (0, 0), (-1, -1), 'MIDDLE'),
        ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
        ('FONTSIZE', (0, 1), (-1, -1), 9),
        ('ROWBACKGROUNDS', (0, 1), (-1, -1), [colors.white, colors.HexColor('#eef4fb')]),
        ('GRID', (0, 0), (-1, -1), 0.4, colors.HexColor('#9bbbd4')),
        ('TOPPADDING', (0, 0), (-1, -1), 4),
        ('BOTTOMPADDING', (0, 0), (-1, -1), 4),
        ('LEFTPADDING', (0, 0), (-1, -1), 6),
        ('RIGHTPADDING', (0, 0), (-1, -1), 6),
    ]
    t.setStyle(TableStyle(style_cmds))
    return t

# ===================== CONTENT =====================
story = []

# Title block
story.append(sp(8))
story.append(Paragraph("ANAEMIA IN PREGNANCY", title_style))
story.append(Paragraph("MD Anaesthesia Examination — 10 Marks", subtitle_style))
story.append(sp(4))
story.append(hr())
story.append(sp(6))

# I. DEFINITION
story.append(h1("I.  DEFINITION"))
story.append(sp(4))
story.append(body("Anaemia in pregnancy is defined by the <b>WHO</b> as a haemoglobin (Hb) concentration below accepted thresholds for each trimester:"))
story.append(sp(4))

def_data = [
    ["Trimester", "Hb Threshold"],
    ["1st Trimester", "< 11 g/dL"],
    ["2nd Trimester", "< 10.5 g/dL"],
    ["3rd Trimester", "< 11 g/dL"],
]
story.append(make_table(def_data, col_widths=[9*cm, 8*cm]))
story.append(sp(6))

story.append(body("<b>Severity Grading:</b>"))
story.append(sp(4))
sev_data = [
    ["Grade", "Hb (g/dL)"],
    ["Mild", "10.0 – 10.9"],
    ["Moderate", "7.0 – 9.9"],
    ["Severe", "< 7.0"],
    ["Very Severe", "< 4.0"],
]
story.append(make_table(sev_data, col_widths=[9*cm, 8*cm]))
story.append(sp(8))

# II. PHYSIOLOGICAL BASIS
story.append(h1("II.  PHYSIOLOGICAL BASIS — WHY ANAEMIA OCCURS IN NORMAL PREGNANCY"))
story.append(sp(4))
story.append(body("During pregnancy, haemodilutional changes occur in a disproportionate fashion:"))
story.append(sp(3))
story.append(bullet("Blood volume increases <b>40–45%</b> (maximum at 34 weeks)"))
story.append(bullet("Plasma volume increases <b>47%</b>"))
story.append(bullet("RBC mass increases only <b>17–20%</b> (maximum at term)"))
story.append(sp(4))
story.append(body("This disproportionate expansion produces <b>physiological (dilutional) anaemia</b>, peaking at 28–34 weeks. "
                  "Crucially, <b>MCV and MCHC do not change</b> in pure dilutional anaemia — the key differentiating feature from pathological anaemia."))
story.append(sp(4))
story.append(note("Normocytic anaemia with Hb >11 g/dL in the late first trimester or >10 g/dL in the second and third "
                  "trimesters of an uncomplicated pregnancy can be attributed to physiologic anaemia of pregnancy without further testing. "
                  "Lower Hb concentrations or microcytic/macrocytic anaemia require evaluation. — Goldman-Cecil Medicine"))
story.append(sp(8))

# III. CLASSIFICATION
story.append(h1("III.  CLASSIFICATION"))
story.append(sp(4))

story.append(h2("A. By Pathophysiologic Mechanism"))
story.append(sp(3))
story.append(bullet("<b>Dilutional</b> — plasma volume expansion of pregnancy"))
story.append(bullet("<b>Decreased RBC Production</b>"))
story.append(bullet("Nutritional: iron deficiency (most common), folate deficiency, vitamin B12 deficiency", level=2))
story.append(bullet("Bone marrow suppression: aplastic anaemia, chronic renal disease, chronic inflammation", level=2))
story.append(bullet("<b>Increased RBC Loss / Destruction</b>"))
story.append(bullet("Haemolysis: hereditary spherocytosis, G6PD deficiency, sickle cell disease, thalassaemia", level=2))
story.append(bullet("Immune: autoimmune haemolytic anaemia, HELLP syndrome", level=2))
story.append(bullet("Haemorrhage: antepartum haemorrhage, placenta praevia", level=2))
story.append(sp(6))

story.append(h2("B. By Morphology (MCV)"))
story.append(sp(4))
morph_data = [
    ["Type", "MCV", "Key Causes"],
    ["Microcytic", "< 80 fL", "Iron deficiency, thalassaemia, sideroblastic anaemia"],
    ["Normocytic", "80–100 fL", "Physiologic dilutional, aplastic, haemolytic"],
    ["Macrocytic", "> 100 fL", "Folate deficiency, B12 deficiency (megaloblastic)"],
]
story.append(make_table(morph_data, col_widths=[4.5*cm, 3.5*cm, 9*cm]))
story.append(sp(8))

# IV. CAUSES IN ORDER OF FREQUENCY
story.append(h1("IV.  CAUSES IN ORDER OF FREQUENCY"))
story.append(sp(4))
causes = [
    "Iron Deficiency Anaemia (IDA) — 75–95% of anaemia in pregnancy",
    "Folate deficiency (megaloblastic anaemia)",
    "Haemoglobinopathies (sickle cell disease, thalassaemia)",
    "Physiologic dilutional anaemia",
    "Aplastic anaemia",
    "HELLP syndrome",
]
for i, c in enumerate(causes, 1):
    story.append(Paragraph(f"<b>{i}.</b> &nbsp;{c}", bullet_style))
story.append(sp(8))

# V. IRON DEFICIENCY ANAEMIA
story.append(h1("V.  IRON DEFICIENCY ANAEMIA — KEY PHYSIOLOGY"))
story.append(sp(4))
story.append(body("Iron requirements during pregnancy are substantial, totalling approximately <b>1130 mg</b>:"))
story.append(sp(4))

iron_data = [
    ["Requirement", "Average (mg)", "Range (mg)"],
    ["External iron loss", "170", "150–200"],
    ["Expansion of RBC mass", "450", "200–600"],
    ["Fetal iron", "270", "200–370"],
    ["Iron in placenta and cord", "90", "30–170"],
    ["Blood loss at delivery", "150", "90–310"],
    ["Total requirement", "~1130", "580–1340"],
]
story.append(make_table(iron_data, col_widths=[8*cm, 4.5*cm, 4.5*cm]))
story.append(sp(6))

story.append(body("<b>Key points about iron kinetics in pregnancy:</b>"))
story.append(bullet("~Two-thirds of women enter pregnancy with <b>minimal iron stores</b>"))
story.append(bullet("Iron deficiency increases from <b>8% in 1st trimester to 62% in 3rd trimester</b> without supplementation"))
story.append(bullet("<b>Serum ferritin</b> is the most sensitive early indicator (falls before Hb drops)"))
story.append(bullet("Iron supplementation reduces the incidence of anaemia by up to <b>73%</b>"))
story.append(bullet("Fetal compartment preferentially obtains iron at the expense of the mother"))
story.append(sp(6))

story.append(h3("Three Stages of Iron Deficiency:"))
story.append(bullet("<b>Stage 1 – Prelatent:</b> ↓ serum ferritin only; Hb, MCV, serum iron all normal"))
story.append(bullet("<b>Stage 2 – Latent:</b> ↓ serum iron, ↑ TIBC, ↓ % saturation; Hb still normal"))
story.append(bullet("<b>Stage 3 – Frank IDA:</b> ↓ Hb, ↓ MCV; microcytic hypochromic picture"))
story.append(sp(8))

# VI. IMPLICATIONS FOR ANAESTHESIA
story.append(h1("VI.  IMPLICATIONS FOR ANAESTHESIA"))
story.append(sp(4))

story.append(h2("A. Preoperative Assessment"))
story.append(bullet("Full blood count, reticulocyte count, MCV"))
story.append(bullet("Serum ferritin, serum iron, TIBC, transferrin saturation"))
story.append(bullet("Peripheral blood smear — morphology to identify type"))
story.append(bullet("Identify type: nutritional vs haemolytic vs aplastic"))
story.append(bullet("Target Hb: ideally <b>>10 g/dL</b> before elective surgery; ≥8 g/dL for emergency"))
story.append(bullet("Type and crossmatch; group and screen for all anaemic obstetric patients"))
story.append(bullet("Coagulation profile (especially in haemolytic anaemias, HELLP)"))
story.append(bullet("Placental localisation to assess risk of perioperative haemorrhage"))
story.append(sp(6))

story.append(h2("B. Pathophysiological Concerns"))
story.append(sp(3))
story.append(h3("Cardiovascular Compensation:"))
story.append(bullet("Chronic anaemia → compensatory ↑ cardiac output, tachycardia, ↓ SVR"))
story.append(bullet("Pre-existing high CO means <b>reduced haemodynamic reserve</b> during acute blood loss"))
story.append(bullet("Patients with Hb <7 g/dL tolerate haemorrhage poorly"))
story.append(sp(4))

story.append(h3("Oxygen Delivery:"))
story.append(bullet("DO₂ = CO × CaO₂ = CO × (Hb × 1.34 × SaO₂ + 0.003 × PaO₂)"))
story.append(bullet("Low Hb significantly reduces oxygen-carrying capacity"))
story.append(bullet("Regional anaesthesia may be preferable — reduces oxygen demand vs general anaesthesia"))
story.append(sp(6))

story.append(h2("C. Regional Anaesthesia (Neuraxial)"))
story.append(bullet("<b>Preferred technique</b> for caesarean section in anaemic parturients (if coagulation normal)"))
story.append(bullet("Avoids general anaesthetic risks: difficult airway, aspiration, volatile agent depression"))
story.append(bullet("<b>Risk:</b> sympathetic block + vasodilation in a haemo-compensated patient → severe hypotension"))
story.append(bullet("Treat aggressively with vasopressors (phenylephrine, noradrenaline) and IV crystalloid"))
story.append(bullet("Epidural allows titration — preferred in severely compromised patients"))
story.append(bullet("<b>Contraindications to neuraxial:</b> platelets <70–80 × 10⁹/L, coagulopathy, active DIC"))
story.append(sp(6))

story.append(h2("D. General Anaesthesia (if required)"))
story.append(bullet("Higher risk of difficult intubation (airway oedema in pregnancy)"))
story.append(bullet("<b>Avoid N₂O</b> in folate/B12 deficiency — inactivates methionine synthase, worsens megaloblastic state"))
story.append(bullet("Ensure adequate pre-oxygenation (reduced FRC + increased O₂ consumption in pregnancy)"))
story.append(bullet("Volatile agents: maintain adequate depth without excessive myocardial depression"))
story.append(sp(6))

story.append(h2("E. Intraoperative Management"))
story.append(bullet("Invasive arterial monitoring if Hb <8 g/dL or major haemorrhage anticipated"))
story.append(bullet("Cell salvage with leuco-depleted filters (mandatory in obstetrics)"))
story.append(bullet("Transfusion trigger: Hb <7 g/dL (or <8 g/dL in symptomatic/cardiac compromise)"))
story.append(bullet("Transfuse to Hb ~8–9 g/dL (restrictive strategy — not to 'normal' levels)"))
story.append(bullet("Uterotonics: oxytocin, ergometrine, misoprostol — to reduce intraoperative blood loss and prevent PPH"))
story.append(sp(6))

story.append(h2("F. Postoperative Care"))
story.append(bullet("Supplemental oxygen in recovery period"))
story.append(bullet("Continue iron supplementation postoperatively"))
story.append(bullet("Monitor vigilantly for PPH — anaemia reduces tolerance to blood loss"))
story.append(bullet("IV iron (ferric carboxymaltose or iron sucrose) for moderate-severe IDA postoperatively"))
story.append(bullet("Erythropoietin may be considered in aplastic anaemia cases"))
story.append(sp(8))

# VII. TREATMENT
story.append(h1("VII.  TREATMENT OF ANAEMIA IN PREGNANCY"))
story.append(sp(4))
treat_data = [
    ["Condition", "Treatment"],
    ["Mild IDA (Hb 10–10.9, ferritin <20 µg/L)", "Oral ferrous sulphate 200 mg TDS"],
    ["Moderate IDA / poor oral tolerance", "IV iron (ferric carboxymaltose, iron sucrose)\nPreferred in 3rd trimester"],
    ["Severe IDA, <34 weeks", "IV iron; consider erythropoietin"],
    ["Severe with Hb <7 g/dL or near term", "Blood transfusion"],
    ["Folate deficiency", "Folic acid 5 mg/day"],
    ["B12 deficiency", "Hydroxocobalamin IM"],
    ["Aplastic anaemia", "Supportive: keep Hb >8 g/dL, platelets >20×10⁹/L\nCyclosporine, steroids; BMT post-delivery"],
]
story.append(make_table(treat_data, col_widths=[8.5*cm, 8.5*cm]))
story.append(sp(6))
story.append(note("IV iron vs oral iron: IV iron achieves faster haemoglobin response and is the treatment of choice for "
                  "moderate-severe IDA in the 2nd and 3rd trimesters and when oral iron is not tolerated. — Creasy & Resnik's Maternal-Fetal Medicine"))
story.append(sp(8))

# VIII. SPECIAL SITUATIONS
story.append(h1("VIII.  SPECIAL ANAESTHETIC SITUATIONS"))
story.append(sp(4))

story.append(h2("A. Sickle Cell Disease"))
story.append(bullet("Risk of vaso-occlusive crisis, acute chest syndrome, stroke perioperatively"))
story.append(bullet("<b>Avoid:</b> hypoxia, hypothermia, dehydration, acidosis, infection"))
story.append(bullet("Consider exchange transfusion to keep HbS <30–40% preoperatively"))
story.append(bullet("Regional anaesthesia preferred; avoid vasoconstrictors in subarachnoid space"))
story.append(sp(6))

story.append(h2("B. Thalassaemia"))
story.append(bullet("Beta-thalassaemia major: chronic transfusion-dependent; haemosiderosis affects cardiac and hepatic function"))
story.append(bullet("Assess cardiac function (echocardiography) preoperatively in transfusion-dependent patients"))
story.append(bullet("Beta-thalassaemia trait: usually mild microcytic anaemia; generally manageable"))
story.append(sp(6))

story.append(h2("C. HELLP Syndrome"))
story.append(bullet("Microangiopathic haemolytic anaemia + thrombocytopenia + hepatic dysfunction"))
story.append(bullet("<b>Epidural/spinal contraindicated if platelets <70–80 × 10⁹/L</b>"))
story.append(bullet("Thrombocytopenia is the primary anaesthetic concern"))
story.append(bullet("General anaesthesia often required; be prepared for difficult airway"))
story.append(sp(6))

story.append(h2("D. Aplastic Anaemia in Pregnancy"))
story.append(bullet("Supportive therapy is the main objective: keep Hb >8 g/dL, platelets >20 × 10⁹/L"))
story.append(bullet("Treat infections aggressively"))
story.append(bullet("Cyclosporine, G-CSF, IVIG, corticosteroids used in selected cases"))
story.append(bullet("Multidisciplinary team: haematologist + MFM specialist + anaesthesiologist"))
story.append(sp(8))

# IX. LABORATORY EVALUATION
story.append(h1("IX.  KEY LABORATORY PARAMETERS IN PREGNANCY"))
story.append(sp(4))
lab_data = [
    ["Laboratory Study", "Reference Range"],
    ["Haemoglobin (Hb)", ">11 g/dL (1st/3rd); >10.5 g/dL (2nd trimester)"],
    ["MCV", "81–99 fL (varies by trimester)"],
    ["MCHC", "32–35 g/dL"],
    ["Serum ferritin", ">20 µg/L (early pregnancy)"],
    ["Serum iron (1st trimester)", "72–143 µg/dL"],
    ["TIBC (3rd trimester)", "580–597 µg/dL (rises significantly)"],
    ["Transferrin saturation", "16–60%"],
    ["Reticulocyte count", "0.5%–1.5%"],
    ["Direct Coombs test", "Negative"],
]
story.append(make_table(lab_data, col_widths=[8*cm, 9*cm]))
story.append(sp(8))

# X. SUMMARY
story.append(h1("X.  SUMMARY"))
story.append(sp(4))
story.append(body("Anaemia in pregnancy is the most common medical complication of pregnancy. From the anaesthetist's perspective, the key concerns are:"))
story.append(sp(4))
summary_pts = [
    "Identify and classify the type and severity of anaemia pre-procedure",
    "Optimise Hb preoperatively — especially in elective settings (target >10 g/dL)",
    "Anticipate haemodynamic instability — reduced reserve, exaggerated response to sympathetic block",
    "Choose appropriate anaesthetic technique (regional preferred when coagulation permits)",
    "Active blood conservation and rational transfusion strategy intraoperatively",
    "Vigilance for PPH, as anaemia reduces tolerance to blood loss",
    "Avoid N₂O in megaloblastic anaemia; avoid triggers in sickle cell disease",
    "Postoperative iron supplementation and monitoring"
]
for i, pt in enumerate(summary_pts, 1):
    story.append(Paragraph(f"<b>{i}.</b> &nbsp;{pt}", bullet_style))

story.append(sp(10))
story.append(hr())
story.append(sp(4))
story.append(Paragraph(
    "Sources: Creasy &amp; Resnik's Maternal-Fetal Medicine, 8e (Ch. 55) &nbsp;|&nbsp; "
    "Goldman-Cecil Medicine, Int'l Ed. &nbsp;|&nbsp; "
    "Rosen's Emergency Medicine &nbsp;|&nbsp; "
    "Miller's Anesthesia, 10e",
    source_style
))

# Build
doc.build(story)
print(f"PDF saved to: {OUTPUT}")