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, PageBreak
)
from reportlab.lib.enums import TA_CENTER, TA_LEFT, TA_JUSTIFY
from reportlab.platypus import KeepTogether

OUTPUT = "/home/daytona/workspace/epidemiology-pdf/Epidemiology_Important_Questions.pdf"

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=2*cm,
    leftMargin=2*cm,
    topMargin=2.5*cm,
    bottomMargin=2.5*cm,
    title="Important Questions - Epidemiology",
    author="Orris Medical Education"
)

styles = getSampleStyleSheet()

# Custom styles
title_style = ParagraphStyle(
    'CustomTitle',
    parent=styles['Title'],
    fontSize=22,
    textColor=colors.HexColor('#1a3c6e'),
    spaceAfter=6,
    alignment=TA_CENTER,
    fontName='Helvetica-Bold'
)

subtitle_style = ParagraphStyle(
    'Subtitle',
    parent=styles['Normal'],
    fontSize=11,
    textColor=colors.HexColor('#4a6fa5'),
    spaceAfter=4,
    alignment=TA_CENTER,
    fontName='Helvetica'
)

section_style = ParagraphStyle(
    'SectionHeading',
    parent=styles['Heading1'],
    fontSize=13,
    textColor=colors.white,
    backColor=colors.HexColor('#1a3c6e'),
    spaceBefore=14,
    spaceAfter=6,
    leftIndent=-10,
    rightIndent=-10,
    borderPad=6,
    fontName='Helvetica-Bold'
)

subsection_style = ParagraphStyle(
    'SubSection',
    parent=styles['Heading2'],
    fontSize=11,
    textColor=colors.HexColor('#1a3c6e'),
    spaceBefore=8,
    spaceAfter=4,
    fontName='Helvetica-Bold',
    borderPad=2,
)

body_style = ParagraphStyle(
    'Body',
    parent=styles['Normal'],
    fontSize=10,
    leading=16,
    spaceAfter=2,
    fontName='Helvetica',
    textColor=colors.HexColor('#2d2d2d')
)

bullet_style = ParagraphStyle(
    'Bullet',
    parent=styles['Normal'],
    fontSize=10,
    leading=15,
    leftIndent=16,
    spaceAfter=2,
    fontName='Helvetica',
    textColor=colors.HexColor('#2d2d2d'),
    bulletIndent=4
)

note_style = ParagraphStyle(
    'Note',
    parent=styles['Normal'],
    fontSize=9,
    textColor=colors.HexColor('#555555'),
    fontName='Helvetica-Oblique',
    alignment=TA_CENTER,
    spaceBefore=8,
    spaceAfter=4
)

def section(title):
    return [
        Spacer(1, 0.2*cm),
        Paragraph(f"  {title}", section_style),
        Spacer(1, 0.1*cm)
    ]

def subsection(title):
    return Paragraph(title, subsection_style)

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

def bullet(text):
    return Paragraph(f"• {text}", bullet_style)

def space(h=0.2):
    return Spacer(1, h*cm)

story = []

# ── TITLE PAGE ──
story.append(space(1.5))
story.append(Paragraph("EPIDEMIOLOGY", title_style))
story.append(Paragraph("Important University Exam Questions", subtitle_style))
story.append(Paragraph("Based on Park's Textbook of Preventive and Social Medicine", subtitle_style))
story.append(space(0.3))
story.append(HRFlowable(width="100%", thickness=2, color=colors.HexColor('#1a3c6e')))
story.append(space(0.3))
story.append(Paragraph("Community Medicine | Preventive & Social Medicine", note_style))
story.append(space(2))

# ── SECTION 1: DEFINITIONS ──
story += section("1. DEFINITIONS & CONCEPTS")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Define epidemiology. Describe the aims and uses of epidemiology.",
    "Explain the concept of natural history of disease and the levels of prevention.",
    "Describe the differences between epidemiology and clinical medicine."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Define: Incidence, Prevalence, Attack rate, Secondary attack rate",
    "Difference between Incidence and Prevalence",
    "Herd immunity — definition and significance",
    "Define: Epidemic, Endemic, Pandemic, Sporadic",
    "Difference between Rate, Ratio, and Proportion",
    "Epidemiology vs. Clinical medicine — key differences"
]:
    story.append(bullet(q))

# ── SECTION 2: MEASUREMENTS ──
story += section("2. MEASUREMENTS IN EPIDEMIOLOGY")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Describe the basic measurements in epidemiology — mortality and morbidity indicators.",
    "Explain Crude Death Rate, Specific Death Rate, Standardized Mortality Ratio (SMR) and their uses.",
    "Write about measurement of morbidity. Describe incidence and prevalence with formulas and examples."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Incidence rate — definition and formula",
    "Prevalence rate (point vs. period) — definitions and formulas",
    "Attack rate and secondary attack rate with formulas",
    "Proportional Mortality Rate (PMR)",
    "Case Fatality Rate — definition and use",
    "Standardized Mortality Ratio (SMR)"
]:
    story.append(bullet(q))

# ── SECTION 3: CAUSATION ──
story += section("3. CONCEPT OF CAUSATION")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Describe the concept of causation in epidemiology. Discuss the Epidemiological Triad, Web of Causation, and Koch's Postulates.",
    "Write about Henle-Koch's postulates and their limitations. What are Bradford Hill's criteria of causation?",
    "Describe the multifactorial causation model with examples."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Epidemiological triad — Agent, Host, Environment",
    "Web of causation (MacMahon's model)",
    "Koch's / Henle-Koch's postulates",
    "Bradford Hill's criteria for causation (all 9 criteria)",
    "Multifactorial causation",
    "Germ theory of disease and its limitations"
]:
    story.append(bullet(q))

# ── SECTION 4: STUDY DESIGNS ──
story += section("4. EPIDEMIOLOGICAL STUDY DESIGNS")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Classify epidemiological study designs. Compare and contrast Case-Control and Cohort studies.",
    "Describe the design, methodology, uses, advantages, and disadvantages of a Case-Control study.",
    "Describe the design, methodology, types, uses, advantages, and disadvantages of a Cohort study.",
    "Write a note on Randomized Controlled Trials (RCTs) — design, advantages, limitations.",
    "Describe cross-sectional study — design, uses, and limitations."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Cross-sectional (prevalence) study — uses and limitations",
    "Ecological/Correlational study",
    "Prospective vs. Retrospective cohort studies",
    "Odds Ratio — definition, formula, and when it is used",
    "Relative Risk (Risk Ratio) — definition and formula",
    "Attributable risk — definition and significance",
    "Double-blind trial",
    "Community trial vs. Field trial"
]:
    story.append(bullet(q))

# ── SECTION 5: DESCRIPTIVE EPIDEMIOLOGY ──
story += section("5. DESCRIPTIVE EPIDEMIOLOGY")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Describe descriptive epidemiology. Explain the variables of Person, Place, and Time.",
    "Write about the epidemiological approach to disease investigation."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Person, Place, Time variables in epidemiology",
    "Spot map and epidemic curve — significance",
    "Age-standardization — direct and indirect methods",
    "Secular trend in disease"
]:
    story.append(bullet(q))

# ── SECTION 6: BIAS & CONFOUNDING ──
story += section("6. BIAS AND CONFOUNDING")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Define bias. Describe the types of bias in epidemiological studies and how to minimize them.",
    "What is confounding? How is it controlled in epidemiological studies?"
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Selection bias vs. Information bias",
    "Recall bias",
    "Berkson's bias",
    "Confounding variable — definition and methods of control",
    "Neyman's bias (prevalence-incidence bias)",
    "Methods to control confounding: matching, stratification, randomization, multivariate analysis"
]:
    story.append(bullet(q))

# ── SECTION 7: SCREENING ──
story += section("7. SCREENING")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Define screening. Describe the criteria for a good screening test and the principles of screening.",
    "Explain sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with formulas and a 2×2 table.",
    "Describe Wilson and Jungner criteria for screening."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Sensitivity and Specificity — definitions, formulas, and trade-off",
    "Positive Predictive Value (PPV) and Negative Predictive Value (NPV)",
    "Wilson and Jungner criteria for screening",
    "Mass screening vs. Selective screening",
    "Lead time bias in screening",
    "ROC curve — interpretation"
]:
    story.append(bullet(q))

# ── SECTION 8: EPIDEMICS ──
story += section("8. EPIDEMICS AND OUTBREAK INVESTIGATION")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Describe the steps in investigation of an epidemic (outbreak investigation).",
    "Classify epidemics. Describe common-source and propagated epidemics with examples and epidemic curves.",
    "Describe the investigation of a food-borne disease outbreak."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Point source vs. propagated epidemic — differences and epidemic curves",
    "Steps in epidemic investigation (10 steps)",
    "Herd immunity threshold",
    "Epidemic curve — types and interpretation",
    "Mixed epidemic"
]:
    story.append(bullet(q))

# ── SECTION 9: SURVEILLANCE ──
story += section("9. SURVEILLANCE")
story.append(subsection("Long Answer Questions (10 marks)"))
for q in [
    "Define epidemiological surveillance. Describe the types and uses of surveillance systems.",
    "Describe the National Disease Surveillance system in India."
]:
    story.append(bullet(q))

story.append(space())
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Sentinel surveillance",
    "Active vs. passive surveillance",
    "Disease notification system in India",
    "Uses of surveillance data",
    "Syndromic surveillance"
]:
    story.append(bullet(q))

# ── SECTION 10: APPLIED MEASURES ──
story += section("10. ASSOCIATION AND CAUSATION (Applied)")
story.append(subsection("Short Answer Questions (5 marks)"))
for q in [
    "Odds Ratio vs. Relative Risk — when each is used",
    "Number Needed to Treat (NNT) and Number Needed to Harm (NNH)",
    "Absolute Risk Reduction vs. Relative Risk Reduction",
    "Population Attributable Risk and Population Attributable Risk Percent",
    "P-value and confidence interval — interpretation",
    "Type I and Type II errors"
]:
    story.append(bullet(q))

# ── FORMULAS TABLE ──
story += section("KEY FORMULAS TO MEMORIZE")
story.append(space(0.3))

formula_data = [
    ["Measure", "Formula"],
    ["Incidence Rate", "New cases / Population at risk × 1000"],
    ["Prevalence", "All existing cases / Total population × 1000"],
    ["Attack Rate", "Cases / Population exposed × 100"],
    ["Secondary Attack Rate", "New cases in contacts / Total contacts × 100"],
    ["Case Fatality Rate", "Deaths from disease / Cases of disease × 100"],
    ["Odds Ratio (case-control)", "ad / bc"],
    ["Relative Risk (cohort)", "Incidence in exposed / Incidence in unexposed"],
    ["Attributable Risk", "Incidence exposed − Incidence unexposed"],
    ["Sensitivity", "TP / (TP + FN) × 100"],
    ["Specificity", "TN / (TN + FP) × 100"],
    ["PPV", "TP / (TP + FP) × 100"],
    ["NPV", "TN / (TN + FN) × 100"],
]

table = Table(formula_data, colWidths=[6.5*cm, 10*cm])
table.setStyle(TableStyle([
    ('BACKGROUND', (0, 0), (-1, 0), colors.HexColor('#1a3c6e')),
    ('TEXTCOLOR', (0, 0), (-1, 0), colors.white),
    ('FONTNAME', (0, 0), (-1, 0), 'Helvetica-Bold'),
    ('FONTSIZE', (0, 0), (-1, 0), 10),
    ('ALIGN', (0, 0), (-1, -1), 'LEFT'),
    ('VALIGN', (0, 0), (-1, -1), 'MIDDLE'),
    ('FONTNAME', (0, 1), (-1, -1), 'Helvetica'),
    ('FONTSIZE', (0, 1), (-1, -1), 9.5),
    ('ROWBACKGROUNDS', (0, 1), (-1, -1), [colors.HexColor('#f0f4fa'), colors.white]),
    ('GRID', (0, 0), (-1, -1), 0.5, colors.HexColor('#c0cce0')),
    ('TOPPADDING', (0, 0), (-1, -1), 6),
    ('BOTTOMPADDING', (0, 0), (-1, -1), 6),
    ('LEFTPADDING', (0, 0), (-1, -1), 8),
]))
story.append(table)

# ── TOP QUESTIONS ──
story += section("MOST LIKELY EXAM QUESTIONS")

story.append(space(0.2))
story.append(subsection("Long Essay (10 marks) — Top 8"))
for i, q in enumerate([
    "Case-Control study — design, methodology, advantages, disadvantages",
    "Cohort study — design, types, advantages, disadvantages",
    "Screening — criteria, sensitivity, specificity, PPV, NPV",
    "Epidemic investigation — steps",
    "Bradford Hill's criteria for causation",
    "Measurements in epidemiology (incidence, prevalence, mortality rates)",
    "Bias in epidemiological studies",
    "Randomized Controlled Trial"
], 1):
    story.append(bullet(f"{i}. {q}"))

story.append(space(0.3))
story.append(subsection("Short Notes (5 marks) — Top 10"))
for i, q in enumerate([
    "Odds Ratio",
    "Herd immunity",
    "Sentinel surveillance",
    "Attack rate and secondary attack rate",
    "Web of causation",
    "Epidemic curve",
    "Confounding and its control",
    "Sensitivity and Specificity",
    "Standardized Mortality Ratio",
    "Cross-sectional study"
], 1):
    story.append(bullet(f"{i}. {q}"))

# ── FOOTER NOTE ──
story.append(space(0.8))
story.append(HRFlowable(width="100%", thickness=1, color=colors.HexColor('#c0cce0')))
story.append(space(0.2))
story.append(Paragraph(
    "Source: Park's Textbook of Preventive and Social Medicine | Prepared by Orris Medical Education",
    note_style
))

doc.build(story)
print(f"PDF created: {OUTPUT}")

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/epidemiology-pdf/Uses_of_Epidemiology_Exam_Prep.pdf"

doc = SimpleDocTemplate(
    OUTPUT,
    pagesize=A4,
    rightMargin=2*cm,
    leftMargin=2*cm,
    topMargin=2.5*cm,
    bottomMargin=2.5*cm,
    title="Uses of Epidemiology - Exam Prep",
    author="Orris Medical Education"
)

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

# ── STYLES ──
styles = getSampleStyleSheet()

title_style = ParagraphStyle('T', parent=styles['Title'],
    fontSize=24, textColor=colors.HexColor('#1a3c6e'),
    spaceAfter=4, alignment=TA_CENTER, fontName='Helvetica-Bold')

subtitle_style = ParagraphStyle('Sub', parent=styles['Normal'],
    fontSize=11, textColor=colors.HexColor('#4a6fa5'),
    spaceAfter=3, alignment=TA_CENTER, fontName='Helvetica-Oblique')

section_style = ParagraphStyle('Sec', parent=styles['Normal'],
    fontSize=12, textColor=colors.white,
    fontName='Helvetica-Bold', alignment=TA_LEFT,
    leftIndent=8, rightIndent=8, spaceBefore=10, spaceAfter=4)

use_num_style = ParagraphStyle('UseNum', parent=styles['Normal'],
    fontSize=13, textColor=colors.HexColor('#1a3c6e'),
    fontName='Helvetica-Bold', spaceBefore=8, spaceAfter=2)

body_style = ParagraphStyle('Body', parent=styles['Normal'],
    fontSize=10, leading=15, spaceAfter=3,
    fontName='Helvetica', textColor=colors.HexColor('#2d2d2d'),
    alignment=TA_JUSTIFY)

bullet_style = ParagraphStyle('Bul', parent=styles['Normal'],
    fontSize=10, leading=14, leftIndent=14, spaceAfter=2,
    fontName='Helvetica', textColor=colors.HexColor('#2d2d2d'),
    bulletIndent=4)

example_style = ParagraphStyle('Ex', parent=styles['Normal'],
    fontSize=9.5, leading=14, leftIndent=14, spaceAfter=2,
    fontName='Helvetica-Oblique', textColor=colors.HexColor('#555555'))

note_style = ParagraphStyle('Note', parent=styles['Normal'],
    fontSize=9, textColor=colors.HexColor('#666666'),
    fontName='Helvetica-Oblique', alignment=TA_CENTER,
    spaceBefore=6, spaceAfter=4)

quote_style = ParagraphStyle('Quote', parent=styles['Normal'],
    fontSize=10.5, leading=15, leftIndent=20, rightIndent=20,
    fontName='Helvetica-Oblique', textColor=colors.HexColor('#1a3c6e'),
    spaceBefore=4, spaceAfter=4)

def sp(h=0.25): return Spacer(1, h*cm)
def hr(color='#c0cce0', t=0.7): return HRFlowable(width="100%", thickness=t, color=colors.HexColor(color))

def section_bar(text):
    data = [[Paragraph(f"  {text}", section_style)]]
    t = Table(data, colWidths=[W])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), colors.HexColor('#1a3c6e')),
        ('TOPPADDING', (0,0), (-1,-1), 6),
        ('BOTTOMPADDING', (0,0), (-1,-1), 6),
        ('LEFTPADDING', (0,0), (-1,-1), 0),
    ]))
    return t

def use_block(num, title, color_hex):
    data = [[Paragraph(f"  USE {num} — {title}", ParagraphStyle('UB',
        parent=styles['Normal'],
        fontSize=11.5, textColor=colors.white,
        fontName='Helvetica-Bold',
        leftIndent=6))]]
    t = Table(data, colWidths=[W])
    t.setStyle(TableStyle([
        ('BACKGROUND', (0,0), (-1,-1), colors.HexColor(color_hex)),
        ('TOPPADDING', (0,0), (-1,-1), 7),
        ('BOTTOMPADDING', (0,0), (-1,-1), 7),
        ('LEFTPADDING', (0,0), (-1,-1), 0),
        ('RIGHTPADDING', (0,0), (-1,-1), 4),
    ]))
    return t

def bullet(text): return Paragraph(f"• {text}", bullet_style)
def example(text): return Paragraph(f"  ✦ {text}", example_style)
def body(text): return Paragraph(text, body_style)
def quote(text): return Paragraph(f'"{text}"', quote_style)

story = []

# ══════════════════════════════════════════════
# TITLE
# ══════════════════════════════════════════════
story.append(sp(0.5))
story.append(Paragraph("USES OF EPIDEMIOLOGY", title_style))
story.append(Paragraph("Exam Preparation Summary", subtitle_style))
story.append(Paragraph("Based on Park's Textbook of Preventive and Social Medicine", subtitle_style))
story.append(sp(0.3))
story.append(hr('#1a3c6e', 2))
story.append(sp(0.2))

# Definition box
def_data = [[Paragraph(
    '<b>Definition:</b> Epidemiology has been defined as <i>"a means of learning, '
    'or asking questions and getting answers that lead to further questions."</i>',
    ParagraphStyle('Def', parent=styles['Normal'], fontSize=10.5, leading=16,
        fontName='Helvetica', textColor=colors.HexColor('#1a3c6e'),
        leftIndent=6, rightIndent=6))]]
def_table = Table(def_data, colWidths=[W])
def_table.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,-1), colors.HexColor('#eef3fb')),
    ('BOX', (0,0), (-1,-1), 1, colors.HexColor('#4a6fa5')),
    ('TOPPADDING', (0,0), (-1,-1), 10),
    ('BOTTOMPADDING', (0,0), (-1,-1), 10),
    ('LEFTPADDING', (0,0), (-1,-1), 12),
    ('RIGHTPADDING', (0,0), (-1,-1), 12),
]))
story.append(def_table)
story.append(sp(0.3))

# IEA Aims
story.append(section_bar("AIMS OF EPIDEMIOLOGY (IEA) — 3 Main Aims"))
story.append(sp(0.15))
for a in [
    "Describe the <b>distribution and magnitude</b> of health and disease in human populations",
    "Identify <b>aetiological factors (risk factors)</b> in the pathogenesis of disease",
    "Provide data for <b>planning, implementation, and evaluation</b> of health services and setting priorities"
]:
    story.append(bullet(a))
story.append(sp(0.1))
story.append(quote("The ultimate aim is to eliminate or reduce health problems and promote the health and well-being of society as a whole."))
story.append(sp(0.2))

# ══════════════════════════════════════════════
# 7 USES
# ══════════════════════════════════════════════
story.append(section_bar("7 USES OF EPIDEMIOLOGY — MORRIS (1957)"))
story.append(sp(0.2))

# Color palette for 7 uses
colors_list = ['#1a3c6e','#2e6da4','#3a7fc1','#2980b9','#1f618d','#154360','#1b4f72']

# ── USE 1 ──
story.append(use_block(1, "To Study the Historical Rise and Fall of Disease", colors_list[0]))
story.append(sp(0.1))
story.append(body('Epidemiology tracks how disease patterns change over time — both over short and long periods. By studying history, we can project into the future.'))
story.append(bullet('Winston Churchill: <i>"The farther back you look, the farther forward you can see."</i>'))
story.append(bullet('Coronary heart disease was first recognised as an <b>"epidemic"</b> through epidemiology'))
story.append(bullet('As old diseases (smallpox) are conquered, new ones (AIDS, Legionnaire\'s disease, Lassa fever) are identified — epidemiology plays a key role each time'))
story.append(bullet('Epidemiology provides a means to study <b>disease profiles, time trends</b> and identify <b>emerging health problems</b>'))
story.append(sp(0.15))

# ── USE 2 ──
story.append(use_block(2, "Community Diagnosis", colors_list[1]))
story.append(sp(0.1))
story.append(body('Identification and quantification of health problems in a community in terms of mortality and morbidity rates; identifies groups at risk or those in need of health care.'))
story.append(bullet('<b>Three purposes of community diagnosis:</b>'))
story.append(example('(a) Lays down priorities in disease control and prevention'))
story.append(example('(b) Serves as a benchmark for evaluation of health services later'))
story.append(example('(c) Source of new knowledge about disease distribution, causation, and prevention'))
story.append(bullet('Extends beyond illness profiles to include <b>social, cultural, and environmental</b> characteristics'))
story.append(bullet('Epidemiology is called the <b>"diagnostic tool of community medicine"</b>'))
story.append(sp(0.15))

# ── USE 3 ──
story.append(use_block(3, "Planning and Evaluation of Health Services", colors_list[2]))
story.append(sp(0.1))
story.append(body('Epidemiological data provides the fundamental basis for planning and developing health services and for assessing their impact.'))
story.append(bullet('<b>Planning includes:</b>'))
story.append(example('• Medical care: number of hospital beds, health manpower planning'))
story.append(example('• Preventive services: screening programmes, immunization campaigns, sanitary services'))
story.append(example('• Research planning'))
story.append(bullet('<b>Evaluation:</b> Any disease control measure must be evaluated for <b>effectiveness AND cost-effectiveness</b>'))
story.append(bullet('Application of epidemiological principles to health care = <b>"New Epidemiology"</b>'))
story.append(sp(0.15))

# ── USE 4 ──
story.append(use_block(4, "Evaluation of Individual Risks and Chances", colors_list[3]))
story.append(sp(0.1))
story.append(body('Epidemiologists quantify the degree of risk in a population and translate that into individual risk assessment.'))
story.append(bullet('Measures used: <b>Incidence rate</b> (absolute risk), <b>Relative risk</b>, <b>Attributable risk</b>'))
story.append(bullet('<b>Examples:</b>'))
story.append(example('• Risk of bearing a Down syndrome child with advancing maternal age'))
story.append(example('• Risk of hereditary disorders'))
story.append(example('• Smokers vs. non-smokers: risk for lung cancer and coronary heart disease (CHD)'))
story.append(bullet('Helps in <b>individual counselling</b> and <b>targeted prevention</b>'))
story.append(sp(0.15))

# ── USE 5 ──
story.append(use_block(5, "Syndrome Identification", colors_list[4]))
story.append(sp(0.1))
story.append(body('Epidemiological investigations can define and refine medical syndromes, and correct misconceptions — something impossible from individual patient observations alone.'))
story.append(bullet('Of ~3,000 syndromes described in paediatric literature, primary defect is known in only <b>~20%</b>'))
story.append(bullet('<b>Examples:</b>'))
story.append(example('• Gastric vs. duodenal ulcer differentiation: "poverty gradient" seen in gastric ulcer but not duodenal — identified by epidemiology (1920s)'))
story.append(example('• Patterson-Kelly syndrome (dysphagia + iron-deficiency anaemia): when tested epidemiologically, the association was NOT confirmed'))
story.append(example('• Essential hypertension: epidemiology suggested aetiologically distinct subtypes based on plasma renin levels'))
story.append(sp(0.15))

# ── USE 6 ──
story.append(use_block(6, "Completing the Natural History of Disease", colors_list[5]))
story.append(sp(0.1))
story.append(body('Epidemiology covers the entire disease spectrum in a population — clinical and sub-clinical — filling gaps that hospital-based studies cannot.'))
story.append(bullet('Hospital studies give an <b>incomplete and biased picture</b> of disease'))
story.append(bullet('The epidemiologist studies disease patterns in the community (agent-host-environment) and fills gaps in natural history'))
story.append(bullet('<b>Classic example:</b>'))
story.append(example('• Ischaemic Heart Disease (IHD): Epidemiology revealed that 1/3 to 2/3 of all IHD deaths are SUDDEN (occur within <1 hour). Hospital studies could never have discovered this — because these patients never reach the hospital!'))
story.append(sp(0.15))

# ── USE 7 ──
story.append(use_block(7, "Searching for Causes and Risk Factors", colors_list[6]))
story.append(sp(0.1))
story.append(body('Epidemiology identifies causes by relating disease to inter-population differences and population attributes. The concept of "risk factors" gave renewed impetus to epidemiological research.'))
story.append(bullet('<b>Major discoveries through epidemiology:</b>'))
story.append(example('• Rubella → congenital defects in newborns'))
story.append(example('• Thalidomide → teratogenic agent'))
story.append(example('• Cigarette smoking → lung cancer'))
story.append(example('• Oxygen exposure in premature babies → retrolental fibroplasia'))
story.append(bullet('For chronic diseases: concept of <b>"risk factors"</b> used instead of single cause'))
story.append(bullet('The search for causes and risk factors is a <b>ceaseless effort</b> — especially for chronic and "new" diseases'))
story.append(sp(0.3))

# ══════════════════════════════════════════════
# SUMMARY TABLE
# ══════════════════════════════════════════════
story.append(section_bar("QUICK REVISION TABLE"))
story.append(sp(0.2))

table_data = [
    [Paragraph('<b>#</b>', ParagraphStyle('th', parent=styles['Normal'], fontSize=10, fontName='Helvetica-Bold', textColor=colors.white, alignment=TA_CENTER)),
     Paragraph('<b>Use</b>', ParagraphStyle('th', parent=styles['Normal'], fontSize=10, fontName='Helvetica-Bold', textColor=colors.white)),
     Paragraph('<b>Key Point / Example</b>', ParagraphStyle('th', parent=styles['Normal'], fontSize=10, fontName='Helvetica-Bold', textColor=colors.white))],
    ['1', 'Historical study', 'Rise/fall of diseases; forecast future trends (Churchill quote)'],
    ['2', 'Community diagnosis', '"Diagnostic tool of community medicine"; quantify morbidity & mortality'],
    ['3', 'Planning & evaluation', 'Hospital beds, manpower, immunization; cost-effectiveness evaluation'],
    ['4', 'Individual risk evaluation', 'Relative risk, attributable risk; Down syndrome, smoking-cancer risk'],
    ['5', 'Syndrome identification', 'Gastric vs. duodenal ulcer; Patterson-Kelly syndrome correction'],
    ['6', 'Natural history of disease', 'IHD: 1/3–2/3 deaths sudden — missed by hospital studies'],
    ['7', 'Search for causes/risk factors', 'Rubella, thalidomide, smoking, oxygen; concept of risk factors'],
]

cell_style = ParagraphStyle('cell', parent=styles['Normal'], fontSize=9.5, fontName='Helvetica', leading=13)

formatted_data = [table_data[0]]
for row in table_data[1:]:
    formatted_data.append([
        Paragraph(f'<b>{row[0]}</b>', ParagraphStyle('n', parent=styles['Normal'], fontSize=10, fontName='Helvetica-Bold', alignment=TA_CENTER, textColor=colors.HexColor('#1a3c6e'))),
        Paragraph(f'<b>{row[1]}</b>', ParagraphStyle('n', parent=styles['Normal'], fontSize=9.5, fontName='Helvetica-Bold', textColor=colors.HexColor('#1a3c6e'))),
        Paragraph(row[2], cell_style),
    ])

summary_table = Table(formatted_data, colWidths=[1.2*cm, 4.8*cm, 10.5*cm])
summary_table.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#1a3c6e')),
    ('TEXTCOLOR', (0,0), (-1,0), colors.white),
    ('FONTNAME', (0,0), (-1,0), 'Helvetica-Bold'),
    ('FONTSIZE', (0,0), (-1,0), 10),
    ('ALIGN', (0,0), (0,-1), 'CENTER'),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('ROWBACKGROUNDS', (0,1), (-1,-1), [colors.HexColor('#f0f4fa'), colors.white]),
    ('GRID', (0,0), (-1,-1), 0.5, colors.HexColor('#c0cce0')),
    ('TOPPADDING', (0,0), (-1,-1), 6),
    ('BOTTOMPADDING', (0,0), (-1,-1), 6),
    ('LEFTPADDING', (0,0), (-1,-1), 8),
    ('RIGHTPADDING', (0,0), (-1,-1), 6),
]))
story.append(summary_table)
story.append(sp(0.3))

# ══════════════════════════════════════════════
# MEMORY AID
# ══════════════════════════════════════════════
story.append(section_bar("MEMORY AID"))
story.append(sp(0.2))

mem_data = [[
    Paragraph('<b>H</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#1a3c6e'), alignment=TA_CENTER)),
    Paragraph('<b>C</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#2e6da4'), alignment=TA_CENTER)),
    Paragraph('<b>P</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#3a7fc1'), alignment=TA_CENTER)),
    Paragraph('<b>E</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#2980b9'), alignment=TA_CENTER)),
    Paragraph('<b>S</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#1f618d'), alignment=TA_CENTER)),
    Paragraph('<b>N</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#154360'), alignment=TA_CENTER)),
    Paragraph('<b>S</b>', ParagraphStyle('m', parent=styles['Normal'], fontSize=22, fontName='Helvetica-Bold', textColor=colors.HexColor('#1b4f72'), alignment=TA_CENTER)),
],[
    Paragraph('History', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
    Paragraph('Community\nDiagnosis', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
    Paragraph('Planning &\nEvaluation', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
    Paragraph('Evaluation\nof Risk', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
    Paragraph('Syndrome\nID', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
    Paragraph('Natural\nHistory', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
    Paragraph('Search for\nCauses', ParagraphStyle('ms', parent=styles['Normal'], fontSize=8.5, fontName='Helvetica', alignment=TA_CENTER, textColor=colors.HexColor('#333333'))),
]]

col_w = W / 7
mem_table = Table(mem_data, colWidths=[col_w]*7)
mem_table.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,0), colors.HexColor('#eef3fb')),
    ('BACKGROUND', (0,1), (-1,1), colors.HexColor('#f8faff')),
    ('ALIGN', (0,0), (-1,-1), 'CENTER'),
    ('VALIGN', (0,0), (-1,-1), 'MIDDLE'),
    ('TOPPADDING', (0,0), (-1,-1), 8),
    ('BOTTOMPADDING', (0,0), (-1,-1), 8),
    ('BOX', (0,0), (-1,-1), 1, colors.HexColor('#c0cce0')),
    ('INNERGRID', (0,0), (-1,-1), 0.3, colors.HexColor('#d0daea')),
]))
story.append(mem_table)
story.append(sp(0.3))

# ══════════════════════════════════════════════
# EXAM TIPS BOX
# ══════════════════════════════════════════════
tips_data = [[Paragraph(
    '<b>EXAM TIPS</b><br/><br/>'
    '• Morris described 7 uses — always mention his name<br/>'
    '• IEA gave 3 aims — differentiate aims from uses<br/>'
    '• For Use 2: know the term "diagnostic tool of community medicine"<br/>'
    '• For Use 6: the IHD sudden death example is highly examinable<br/>'
    '• For Use 7: give 4 specific discoveries (rubella, thalidomide, smoking, oxygen-retrolental fibroplasia)<br/>'
    '• The ultimate aim is to "promote health and well-being of society as a whole"',
    ParagraphStyle('tip', parent=styles['Normal'], fontSize=10, leading=16,
        fontName='Helvetica', textColor=colors.HexColor('#1a3c6e'),
        leftIndent=6, rightIndent=6))]]
tips_table = Table(tips_data, colWidths=[W])
tips_table.setStyle(TableStyle([
    ('BACKGROUND', (0,0), (-1,-1), colors.HexColor('#fffbe6')),
    ('BOX', (0,0), (-1,-1), 1.5, colors.HexColor('#e6b800')),
    ('TOPPADDING', (0,0), (-1,-1), 12),
    ('BOTTOMPADDING', (0,0), (-1,-1), 12),
    ('LEFTPADDING', (0,0), (-1,-1), 14),
    ('RIGHTPADDING', (0,0), (-1,-1), 14),
]))
story.append(tips_table)
story.append(sp(0.4))

# Footer
story.append(hr())
story.append(Paragraph(
    "Source: Park's Textbook of Preventive and Social Medicine | Prepared by Orris Medical Education",
    note_style))

doc.build(story)
print(f"PDF created: {OUTPUT}")