import matplotlib
matplotlib.use('Agg')
import matplotlib.pyplot as plt
import matplotlib.patches as mpatches
from matplotlib.patches import FancyBboxPatch, FancyArrowPatch
import matplotlib.patheffects as pe
import numpy as np

fig = plt.figure(figsize=(28, 48))
ax = fig.add_axes([0, 0, 1, 1])
ax.set_xlim(0, 28)
ax.set_ylim(0, 48)
ax.axis('off')
fig.patch.set_facecolor('#F8F9FA')

# ── colour palette ──────────────────────────────────────────────────────────
C_TITLE   = '#1A237E'   # deep navy
C_DIAG    = '#283593'   # dark blue  – diagnosis / assessment boxes
C_SEVER   = '#1565C0'   # mid blue   – severity classification
C_STEP1   = '#2E7D32'   # dark green – step 1
C_STEP2   = '#388E3C'
C_STEP3   = '#F57F17'   # amber      – step 3
C_STEP4   = '#E65100'   # deep orange– step 4
C_STEP5   = '#B71C1C'   # dark red   – step 5/6
C_ACUTE   = '#880E4F'   # deep purple– acute exacerbation
C_CTRL    = '#00695C'   # teal       – control assessment
C_ARROW   = '#37474F'
C_WHITE   = 'white'
C_LIGHT   = '#E3F2FD'
C_WARN    = '#FFF9C4'
C_BIO     = '#4A148C'   # violet     – biologics

def box(ax, x, y, w, h, text, facecolor, textcolor='white', fontsize=9,
        bold=False, radius=0.3, alpha=1.0, style='round,pad=0.1',
        ha='center', va='center', wrap=True, border=None):
    bp = FancyBboxPatch((x - w/2, y - h/2), w, h,
                        boxstyle=f"round,pad=0.15",
                        linewidth=1.4,
                        edgecolor=border if border else facecolor,
                        facecolor=facecolor, alpha=alpha, zorder=3)
    ax.add_patch(bp)
    weight = 'bold' if bold else 'normal'
    ax.text(x, y, text, ha=ha, va=va, fontsize=fontsize,
            color=textcolor, fontweight=weight,
            wrap=True, zorder=4,
            multialignment='center',
            linespacing=1.35)

def diamond(ax, x, y, w, h, text, facecolor, textcolor='white', fontsize=8.5):
    dx, dy = w/2, h/2
    xs = [x, x+dx, x, x-dx, x]
    ys = [y+dy, y, y-dy, y, y+dy]
    poly = plt.Polygon(list(zip(xs, ys)), closed=True,
                       facecolor=facecolor, edgecolor=facecolor,
                       linewidth=1.4, zorder=3)
    ax.add_patch(poly)
    ax.text(x, y, text, ha='center', va='center', fontsize=fontsize,
            color=textcolor, fontweight='bold', zorder=4, multialignment='center')

def arrow(ax, x1, y1, x2, y2, label='', color=C_ARROW, lw=2.0):
    ax.annotate('', xy=(x2, y2), xytext=(x1, y1),
                arrowprops=dict(arrowstyle='->', color=color,
                                lw=lw, connectionstyle='arc3,rad=0.0'),
                zorder=5)
    if label:
        mx, my = (x1+x2)/2, (y1+y2)/2
        ax.text(mx+0.15, my, label, fontsize=7.5, color=color, va='center')

def harrow(ax, x1, y1, x2, y2, label='', color=C_ARROW, lw=1.8):
    """Horizontal or bent arrow."""
    ax.annotate('', xy=(x2, y2), xytext=(x1, y1),
                arrowprops=dict(arrowstyle='->', color=color, lw=lw,
                                connectionstyle='angle,angleA=0,angleB=90'),
                zorder=5)
    if label:
        ax.text((x1+x2)/2, (y1+y2)/2+0.15, label, fontsize=7.5,
                color=color, ha='center')

# ════════════════════════════════════════════════════════════════════════════
# TITLE
# ════════════════════════════════════════════════════════════════════════════
ax.add_patch(FancyBboxPatch((0.3, 46.2), 27.4, 1.5,
             boxstyle="round,pad=0.15", facecolor=C_TITLE,
             edgecolor=C_TITLE, linewidth=2, zorder=3))
ax.text(14, 47.15, 'ASTHMA PHARMACOTHERAPY — TREATMENT ALGORITHM',
        ha='center', va='center', fontsize=16, color='white',
        fontweight='bold', zorder=4)
ax.text(14, 46.65,
        'Based on NAEPP 2020 Focused Updates | NAEPP EPR-3 | Harriet Lane Handbook 23rd ed. | Textbook of Family Medicine 9th ed.',
        ha='center', va='center', fontsize=8.5, color='#BBDEFB', zorder=4)

# ════════════════════════════════════════════════════════════════════════════
# BLOCK 1 — PATIENT PRESENTATION
# ════════════════════════════════════════════════════════════════════════════
box(ax, 14, 45.3, 9, 0.75,
    'PATIENT PRESENTS WITH SUSPECTED ASTHMA',
    C_DIAG, fontsize=10, bold=True)
arrow(ax, 14, 44.92, 14, 44.3)

# ════════════════════════════════════════════════════════════════════════════
# BLOCK 2 — DIAGNOSIS
# ════════════════════════════════════════════════════════════════════════════
box(ax, 14, 43.85, 18, 0.8,
    'DIAGNOSIS\n'
    'History (wheeze, cough, dyspnoea, chest tightness) + Spirometry (FEV₁/FVC <0.70, ≥12% reversibility)\n'
    'R/O: COPD, CHF, foreign body, GERD, vocal cord dysfunction',
    C_DIAG, fontsize=8.2, bold=False)

arrow(ax, 14, 43.45, 14, 42.85)

# ════════════════════════════════════════════════════════════════════════════
# BLOCK 3 — SEVERITY CLASSIFICATION (diamond + table)
# ════════════════════════════════════════════════════════════════════════════
box(ax, 14, 42.55, 18, 0.7,
    'CLASSIFY SEVERITY (before starting treatment) — by Impairment & Risk',
    C_SEVER, fontsize=9, bold=True)

# four severity boxes side by side
sev_data = [
    ('INTERMITTENT\n'
     '≤2 days/wk symptoms\n'
     'Nighttime ≤2×/month\n'
     'SABA ≤2 d/wk\n'
     'FEV₁ >80% pred\n'
     '→ Start: Step 1', C_STEP1, 4.0),
    ('MILD PERSISTENT\n'
     '>2 d/wk but not daily\n'
     'Nighttime 3–4×/month\n'
     'Minor activity limit\n'
     'FEV₁ >80% pred\n'
     '→ Start: Step 2', C_STEP2, 10.0),
    ('MODERATE PERSISTENT\n'
     'Daily symptoms\n'
     'Nighttime >1×/wk\n'
     'Some activity limit\n'
     'FEV₁ 60–80% pred\n'
     '→ Start: Step 3', C_STEP3, '#5D4037', 16.0),
    ('SEVERE PERSISTENT\n'
     'Continuous symptoms\n'
     'Nighttime often 7×/wk\n'
     'Extreme limitation\n'
     'FEV₁ <60% pred\n'
     '→ Start: Step 4–5', C_STEP5, 22.0),
]

# 3-element tuples for first three, 2-element for last → fix
sev_fixed = [
    ('INTERMITTENT\n≤2 days/wk symptoms\nNighttime ≤2×/month\nSABA ≤2 d/wk\nFEV₁ >80% pred\n→ Start: Step 1',
     C_STEP1, 'white', 4.0),
    ('MILD PERSISTENT\n>2 d/wk but not daily\nNighttime 3–4×/month\nMinor activity limit\nFEV₁ >80% pred\n→ Start: Step 2',
     C_STEP2, 'white', 10.0),
    ('MODERATE PERSISTENT\nDaily symptoms\nNighttime >1×/wk\nSome activity limit\nFEV₁ 60–80% pred\n→ Start: Step 3',
     C_STEP3, '#1A0000', 16.0),
    ('SEVERE PERSISTENT\nContinuous symptoms\nNighttime often 7×/wk\nExtreme limitation\nFEV₁ <60% pred\n→ Start: Step 4–5',
     C_STEP5, 'white', 22.0),
]

for txt, fc, tc, xpos in sev_fixed:
    box(ax, xpos, 41.3, 5.2, 1.8, txt, fc, textcolor=tc, fontsize=7.6)

# arrows from severity bar to boxes
for xpos in [4.0, 10.0, 16.0, 22.0]:
    arrow(ax, xpos, 42.2, xpos, 42.2, color=C_ARROW, lw=0)
    ax.annotate('', xy=(xpos, 42.22), xytext=(14, 42.2),
                arrowprops=dict(arrowstyle='->', color=C_ARROW, lw=1.6,
                                connectionstyle='arc3,rad=0.0'), zorder=5)

# ── central down arrow from severity boxes to stepwise ───────────────────
for xpos in [4.0, 10.0, 16.0, 22.0]:
    arrow(ax, xpos, 40.4, xpos, 39.9, color=C_ARROW)
# converge
ax.annotate('', xy=(14, 39.55), xytext=(14, 39.9),
            arrowprops=dict(arrowstyle='->', color=C_ARROW, lw=2),
            zorder=5)
ax.plot([4.0, 22.0], [39.9, 39.9], color=C_ARROW, lw=1.8, zorder=5)
ax.plot([4.0, 4.0],  [40.4, 39.9], color=C_ARROW, lw=1.8, zorder=5)
ax.plot([22.0, 22.0],[40.4, 39.9], color=C_ARROW, lw=1.8, zorder=5)

# ════════════════════════════════════════════════════════════════════════════
# STEPWISE SECTION HEADER
# ════════════════════════════════════════════════════════════════════════════
box(ax, 14, 39.25, 20, 0.6,
    'STEPWISE PHARMACOTHERAPY (Ages ≥12 years — Adults & Adolescents)',
    C_TITLE, fontsize=10, bold=True)

# ════════════════════════════════════════════════════════════════════════════
# STEPS 1–6
# ════════════════════════════════════════════════════════════════════════════

steps = [
    # (step_label, preferred_text, alternative_text, y_centre, pref_color, alt_color)
    (
        'STEP 1\nIntermittent',
        '● PRN SABA (albuterol)\n'
        '● PRN concomitant ICS + SABA▲\n'
        '  (new NAEPP 2020 option)',
        '— No daily controller needed —',
        38.1, C_STEP1, '#A5D6A7'
    ),
    (
        'STEP 2\nMild Persistent',
        '● Daily LOW-DOSE ICS + PRN SABA\n'
        '  (e.g. fluticasone 88–264 μg/d)',
        '● Daily LTRA* (montelukast⚠) + PRN SABA\n'
        '● Cromolyn* / Nedocromil* / Theophylline* + PRN SABA\n'
        '  [*Limited availability; ⚠ FDA Black Box Warning]',
        36.3, C_STEP2, '#C8E6C9'
    ),
    (
        'STEP 3\nModerate',
        '● Daily + PRN LOW-DOSE ICS–formoterol▲\n'
        '  (SMART regimen; max 12 puffs/day)',
        '● Daily MEDIUM-DOSE ICS + PRN SABA\n'
        '● Daily low-dose ICS–LABA + PRN SABA\n'
        '● Daily low-dose ICS + LAMA▲ + PRN SABA\n'
        '● Daily low-dose ICS + LTRA* or Theophylline* + PRN SABA',
        34.2, C_STEP3, '#FFF9C4'
    ),
    (
        'STEP 4\nModerate–Severe',
        '● Daily + PRN MEDIUM-DOSE ICS–formoterol▲\n'
        '  (SMART; max 12 puffs/day)',
        '● Daily medium-dose ICS–LABA + PRN SABA\n'
        '● Daily medium-dose ICS + LAMA▲ + PRN SABA\n'
        '● Daily medium-dose ICS + LTRA* + PRN SABA\n'
        '● Daily medium-dose ICS + Zileuton* or Theophylline* + PRN SABA',
        31.9, C_STEP4, '#FFE0B2'
    ),
    (
        'STEP 5\nSevere Persistent',
        '● Daily MEDIUM–HIGH dose ICS–LABA\n'
        '  + LAMA (triple therapy) + PRN SABA▲\n'
        '  Consider BIOLOGICS:',
        '● Daily medium–high dose ICS–LABA\n'
        '● Daily HIGH-DOSE ICS + LTRA* + PRN SABA\n'
        'Biologics: anti-IgE (Omalizumab) | anti-IL5 (Mepolizumab,\n'
        'Reslizumab) | anti-IL5Rα (Benralizumab) | anti-IL4/13 (Dupilumab)',
        29.4, C_STEP5, '#FFCDD2'
    ),
    (
        'STEP 6\nVery Severe',
        '● Daily HIGH-DOSE ICS–LABA\n'
        '  + Oral systemic corticosteroid (prednisone)\n'
        '  + PRN SABA\n'
        '  Continue biologics if applicable',
        '● High-dose ICS + LTRA* + oral CS + PRN SABA\n'
        '● High-dose ICS + Theophylline* + oral CS + PRN SABA\n'
        '  Refer to Pulmonologist / Allergist',
        27.0, '#7B1FA2', '#E1BEE7'
    ),
]

for step_lbl, pref, alt, yc, pc, ac in steps:
    box_h = 1.55
    # step label (left)
    box(ax, 2.0, yc, 2.8, box_h, step_lbl, pc, fontsize=8.5, bold=True)
    # preferred (centre)
    box(ax, 10.5, yc, 10.5, box_h, '✔ PREFERRED\n' + pref,
        C_LIGHT, textcolor='#0D47A1', fontsize=7.8,
        border=pc)
    # alternative (right)
    box(ax, 22.5, yc, 9.5, box_h, '◈ ALTERNATIVE\n' + alt,
        C_WARN, textcolor='#4E342E', fontsize=7.4,
        border='#FFA000')
    # connect step→preferred, step→alternative
    arrow(ax, 3.4, yc, 5.25, yc, color=pc, lw=1.8)
    arrow(ax, 15.75, yc, 17.75, yc, color='#78909C', lw=1.4)

# down arrows between steps
step_ycs = [s[3] for s in steps]
for i in range(len(step_ycs)-1):
    y_top = step_ycs[i] - 0.78
    y_bot = step_ycs[i+1] + 0.78
    arrow(ax, 2.0, y_top, 2.0, y_bot, color='#263238', lw=2.2)
    ax.text(2.75, (y_top+y_bot)/2, 'Step\nUp', fontsize=7,
            color='#263238', ha='left', va='center', fontweight='bold')

# up arrows (step down)
for i in range(1, len(step_ycs)):
    y_bot = step_ycs[i] + 0.78
    y_top = step_ycs[i-1] - 0.78
    ax.annotate('', xy=(1.1, y_top), xytext=(1.1, y_bot),
                arrowprops=dict(arrowstyle='->', color='#2E7D32',
                                lw=1.5), zorder=5)

ax.text(0.55, (step_ycs[0]+step_ycs[-1])/2, 'Step\nDown\n(if ≥3 mo\ncontrolled)',
        fontsize=6.8, color='#2E7D32', ha='center', va='center',
        fontweight='bold', rotation=90)

# ════════════════════════════════════════════════════════════════════════════
# CONTROL ASSESSMENT BOX (between steps and acute)
# ════════════════════════════════════════════════════════════════════════════
arrow(ax, 14, 26.22, 14, 25.55)

box(ax, 14, 25.1, 22, 0.85,
    'ASSESS CONTROL AT EVERY VISIT  ▸  Check: adherence | inhaler technique | environmental triggers | comorbidities (rhinitis, GERD, obesity, OSA)\n'
    'Step UP if needed (reassess in 2–6 weeks)  |  Step DOWN if well-controlled ≥3 consecutive months  |  Consult specialist if Step 4+ required',
    C_CTRL, fontsize=8, bold=False)

# ════════════════════════════════════════════════════════════════════════════
# QUICK-RELIEF / RESCUE (below stepwise)
# ════════════════════════════════════════════════════════════════════════════
arrow(ax, 14, 24.67, 14, 24.05)

box(ax, 14, 23.65, 22, 0.75,
    'QUICK-RELIEF (all steps): SABA PRN  ▸  Up to 3 treatments q20 min for acute symptoms\n'
    'SABA use >2 days/week for relief (not EIB prevention) = inadequate control → Step Up',
    '#1565C0', fontsize=8.2)

# ════════════════════════════════════════════════════════════════════════════
# ACUTE EXACERBATION PANEL
# ════════════════════════════════════════════════════════════════════════════
arrow(ax, 14, 23.27, 14, 22.65)

box(ax, 14, 22.35, 26, 0.65,
    'ACUTE EXACERBATION MANAGEMENT  (Home → ED → Hospital)',
    C_ACUTE, fontsize=10, bold=True)

acute_steps = [
    ('① MILD–MODERATE\n(Home / Clinic)',
     '● SABA 2–4 puffs MDI q20 min × 3\n'
     '● Short-course oral prednisone\n'
     '  (0.5–1 mg/kg/d, max 40 mg × 5–7 d)\n'
     '● Continue controller medications\n'
     '● Review action plan',
     5.0, 21.1),
    ('② MODERATE–SEVERE\n(Emergency Dept)',
     '● Nebulised albuterol q20 min × 3\n'
     '● Add ipratropium (SOR: A)\n'
     '● IV/oral methylprednisolone\n'
     '● Supplemental O₂ (SpO₂ ≥92%)\n'
     '● Peak flow / spirometry monitoring',
     12.5, 21.1),
    ('③ SEVERE / REFRACTORY\n(ICU / Admit)',
     '● Continuous SABA nebulisation\n'
     '● IV magnesium sulfate (2 g over 20 min)\n'
     '● Heliox-driven albuterol (if available)\n'
     '● IV corticosteroids (high-dose)\n'
     '● Consider intubation / mechanical ventilation\n'
     '● NO aminophylline in acute setting',
     20.5, 21.1),
    ('④ RESPONSE?\nDischarge Planning',
     '● Good response: discharge with\n'
     '  3–5 day oral prednisone burst\n'
     '  + controller step review\n'
     '  + written action plan\n'
     '● Poor response: admit / ICU',
     26.5, 21.1),
]

for title, content, xpos, ypos in acute_steps:
    box(ax, xpos, ypos, 6.2, 2.0,
        title + '\n' + content,
        C_ACUTE, fontsize=7.4, alpha=0.88,
        border='#AD1457')

# ════════════════════════════════════════════════════════════════════════════
# BIOLOGICS REFERENCE BOX
# ════════════════════════════════════════════════════════════════════════════
arrow(ax, 14, 20.1, 14, 19.5)

box(ax, 14, 19.05, 26, 0.8,
    'BIOLOGICS (Steps 5–6)  |  For severe persistent allergic / eosinophilic asthma',
    C_BIO, fontsize=9.5, bold=True)

bio_data = [
    ('OMALIZUMAB\n(anti-IgE)\n'
     'Mechanism: Binds free IgE\n'
     '↓98–99% circulating IgE\n'
     'Dose: SC q2–4wk\n'
     'Age: ≥6 years\n'
     'Indication: Allergic asthma',
     4.0, '#7B1FA2'),
    ('MEPOLIZUMAB\nRESLIZUMAB\n(anti-IL-5)\n'
     'Mechanism: Block IL-5\n'
     '↓ eosinophil survival\n'
     'Indication: Eosinophilic\n'
     'severe asthma\n'
     'Age: ≥6 years (mepo)',
     9.5, '#512DA8'),
    ('BENRALIZUMAB\n(anti-IL-5Rα)\n'
     'Mechanism: Binds IL-5Rα\n'
     'Direct eosinophil depletion\n'
     'via ADCC\n'
     'Indication: Eosinophilic\n'
     'severe asthma ≥12 yr',
     15.0, '#4527A0'),
    ('DUPILUMAB\n(anti-IL-4Rα)\n'
     'Mechanism: Blocks shared\n'
     'IL-4/IL-13 receptor\n'
     'Indication: Moderate–severe\n'
     'uncontrolled, T2 asthma\n'
     'Age: ≥6 years',
     20.5, '#311B92'),
    ('TEZEPELUMAB\n(anti-TSLP)\n'
     'Mechanism: Blocks TSLP\n'
     '(upstream alarmin)\n'
     'Indication: Severe uncontrolled\n'
     'regardless of phenotype\n'
     'Age: ≥12 years',
     26.0, '#1A237E'),
]

for bio_txt, xpos, fc in bio_data:
    box(ax, xpos, 17.85, 5.2, 2.1, bio_txt, fc, fontsize=7.5, alpha=0.92)

# ════════════════════════════════════════════════════════════════════════════
# ICS DOSE TABLE
# ════════════════════════════════════════════════════════════════════════════
arrow(ax, 14, 16.8, 14, 16.25)

box(ax, 14, 15.95, 26, 0.6,
    'ICS COMPARATIVE DAILY DOSE TABLE (Adults ≥12 years)  — NAEPP EPR-3 / Family Medicine 9e, Table 16-4',
    '#0D47A1', fontsize=9, bold=True)

dose_headers = ['Drug', 'Formulation', 'Low Dose', 'Medium Dose', 'High Dose']
dose_data = [
    ['Beclomethasone HFA', '40 or 80 μg/puff', '80–240 μg', '>240–480 μg', '>480 μg'],
    ['Budesonide DPI',     '90/180/200 μg/inh','180–600 μg','>600–1200 μg','>1200 μg'],
    ['Fluticasone HFA/MDI','44/110/220 μg/puff','88–264 μg', '>264–440 μg', '>440 μg'],
    ['Fluticasone DPI',    '50/100/250 μg/inh','100–300 μg','>300–500 μg', '>500 μg'],
    ['Mometasone DPI',     '200 μg/inh',        '200 μg',    '400 μg',       '>400 μg'],
    ['Flunisolide',        '250 μg/puff',        '500–1000 μg','>1000–2000 μg','>2000 μg'],
]

col_xs = [3.2, 8.0, 13.0, 18.5, 23.5]
col_ws = [4.8, 4.8, 4.8, 4.8, 4.8]

# header row
y_tbl = 15.35
for i, (hdr, cx) in enumerate(zip(dose_headers, col_xs)):
    box(ax, cx, y_tbl, col_ws[i]-0.15, 0.45, hdr, '#0D47A1',
        fontsize=8, bold=True)

for row_i, row in enumerate(dose_data):
    y_row = y_tbl - 0.48*(row_i+1)
    for col_i, (val, cx) in enumerate(zip(row, col_xs)):
        fc = '#E3F2FD' if row_i % 2 == 0 else 'white'
        box(ax, cx, y_row, col_ws[col_i]-0.15, 0.42, val,
            fc, textcolor='#1A237E', fontsize=7.5, border='#90CAF9')

# ════════════════════════════════════════════════════════════════════════════
# SPECIAL POPULATIONS & KEY WARNINGS
# ════════════════════════════════════════════════════════════════════════════
y_sp = 12.1
box(ax, 14, y_sp + 0.4, 26, 0.5,
    'SPECIAL POPULATIONS & KEY WARNINGS', '#37474F', fontsize=9.5, bold=True)

sp_boxes = [
    ('PREGNANCY\n'
     '● Albuterol (SABA) and ICS: Safe\n'
     '● Monitor PEFR ≥80% personal best\n'
     '● Uncontrolled asthma → ↑ preterm\n'
     '  labour, LBW, preeclampsia\n'
     '● Treat same as non-pregnant',
     4.0, '#1565C0'),
    ('PAEDIATRICS (0–4 yrs)\n'
     '● Step 1: PRN SABA ± short-course ICS at RTI\n'
     '● Step 2: Low-dose ICS\n'
     '● Steps 4–6: Medium→high ICS+LABA\n'
     '● Montelukast: FDA Boxed Warning\n'
     '  (neuropsychiatric events) ⚠',
     10.5, '#1B5E20'),
    ('EIB (Exercise-Induced)\n'
     '● SABA 15–30 min pre-exercise\n'
     '● Regular ICS reduces EIB frequency\n'
     '● ICS-formoterol covers rescue + EIB\n'
     '● Warm-up before exercise helps',
     17.0, '#E65100'),
    ('KEY DRUG WARNINGS\n'
     '● LABA alone: FDA BLACK BOX (↑ death)\n'
     '● Montelukast: Neuropsychiatric ⚠\n'
     '● Theophylline: Narrow window;\n'
     '  NOT for acute ED use\n'
     '● Oral CS: Taper if prolonged use',
     23.5, '#B71C1C'),
]

for sp_txt, xpos, fc in sp_boxes:
    box(ax, xpos, y_sp - 0.55, 5.8, 1.8, sp_txt, fc, fontsize=7.5, alpha=0.9)

# ════════════════════════════════════════════════════════════════════════════
# MONITORING BOX
# ════════════════════════════════════════════════════════════════════════════
y_mon = 9.35
box(ax, 14, y_mon, 26, 0.5,
    'MONITORING & FOLLOW-UP', '#004D40', fontsize=9.5, bold=True)

mon_txt = ('FEV₁ (spirometry): Gold standard for obstruction severity  |  '
           'PEFR: Portable monitoring (≥80% personal best = well controlled)  |  '
           'FeNO: Conditionally recommended for ICS titration in allergic asthma ≥5 yrs\n'
           'Reassess in 2–6 weeks after any step change  |  '
           'Asthma control: Well-controlled (Step Down possible) | Not well-controlled (Step Up) | Very poorly controlled (Step Up 1–2 steps or oral CS)\n'
           'Written Asthma Action Plan (MAP: Management | Action | Prevention)  |  '
           'Inhaler technique check at every visit  |  Allergen avoidance counselling')
box(ax, 14, y_mon - 0.75, 26, 1.2, mon_txt,
    '#E0F2F1', textcolor='#004D40', fontsize=8.0, border='#004D40')

# ════════════════════════════════════════════════════════════════════════════
# REFERENCES FOOTER
# ════════════════════════════════════════════════════════════════════════════
y_ref = 7.15
box(ax, 14, y_ref, 26, 0.4,
    'REFERENCES', '#263238', fontsize=9, bold=True)

refs = [
    '1. National Asthma Education and Prevention Program (NAEPP). Expert Panel Report 3 (EPR-3). NHLBI, 2007.',
    '2. NAEPP. 2020 Focused Updates to the Asthma Management Guidelines. National Heart, Lung and Blood Institute, December 2020.',
    '3. The Harriet Lane Handbook, 23rd ed. (Johns Hopkins Hospital). Elsevier, 2021. — Chapter 25, Figures 25.4–25.8.',
    '4. Textbook of Family Medicine, 9th ed. (Rakel RE). Elsevier Saunders, 2015. — Chapters 16 & 19, Tables 16-3, 16-4.',
    '5. Murray & Nadel\'s Textbook of Respiratory Medicine, 2-Volume, 7th ed. Elsevier, 2022. — Chapter 35.',
    '6. Murphy KR & Solis J. NAEPP 2020 Guidelines: What\'s Important for Primary Care. J Fam Pract. 2021. PMID: 34432620.',
    '7. Laitano R et al. Asthma management with triple ICS/LABA/LAMA. Expert Opin Pharmacother. 2024. PMID: 38864834.',
    '8. GINA. Global Strategy for Asthma Management and Prevention. 2023 Update. ginasthma.org.',
]

ref_y_start = y_ref - 0.45
for i, ref in enumerate(refs):
    ax.text(1.0, ref_y_start - i * 0.43, ref, fontsize=7.2,
            color='#263238', va='top', ha='left')

# ════════════════════════════════════════════════════════════════════════════
# LEGEND / ABBREVIATIONS
# ════════════════════════════════════════════════════════════════════════════
legend_txt = ('Abbreviations: ICS = Inhaled Corticosteroid  |  LABA = Long-Acting β₂-Agonist  |  LAMA = Long-Acting Muscarinic Antagonist  |  '
              'SABA = Short-Acting β₂-Agonist  |  LTRA = Leukotriene Receptor Antagonist\n'
              'SMART = Single Maintenance And Reliever Therapy  |  EIB = Exercise-Induced Bronchoconstriction  |  '
              'PRN = as needed  |  OCS = Oral Corticosteroid  |  FeNO = Fractional exhaled Nitric Oxide\n'
              '▲ = New/updated recommendation in NAEPP 2020  |  * = Limited availability / increased monitoring required  |  '
              '⚠ = FDA Boxed Warning  |  SOR = Strength of Recommendation')
box(ax, 14, 3.55, 26, 0.95, legend_txt,
    '#ECEFF1', textcolor='#263238', fontsize=7.5, border='#90A4AE')

# ════════════════════════════════════════════════════════════════════════════
# COLOUR LEGEND
# ════════════════════════════════════════════════════════════════════════════
legend_items = [
    (C_STEP1, 'Step 1'),
    (C_STEP2, 'Step 2'),
    (C_STEP3, 'Step 3'),
    (C_STEP4, 'Step 4'),
    (C_STEP5, 'Step 5'),
    ('#7B1FA2', 'Step 6'),
    (C_ACUTE, 'Acute Exacerbation'),
    (C_BIO,   'Biologics'),
    (C_CTRL,  'Control Assessment'),
]
for i, (fc, lbl) in enumerate(legend_items):
    xp = 1.3 + i * 3.0
    ax.add_patch(FancyBboxPatch((xp - 0.35, 2.7), 0.7, 0.35,
                                boxstyle="round,pad=0.05",
                                facecolor=fc, edgecolor='none', zorder=3))
    ax.text(xp + 0.45, 2.875, lbl, fontsize=7, color='#263238',
            va='center', ha='left')

ax.text(14, 2.35, 'Colour Legend', ha='center', fontsize=7.8,
        color='#37474F', fontweight='bold')

plt.tight_layout(pad=0)
plt.savefig('/home/daytona/workspace/asthma-flowchart/asthma_treatment_algorithm.png',
            dpi=180, bbox_inches='tight', facecolor=fig.get_facecolor())
plt.savefig('/home/daytona/workspace/asthma-flowchart/asthma_treatment_algorithm_hires.png',
            dpi=300, bbox_inches='tight', facecolor=fig.get_facecolor())
print("Saved successfully.")