"""Tier 3 QA verification: hand-compute readiness per demo persona and compare
to `compute_gap_report`.

Run via: ./venv/Scripts/python.exe manage.py shell < scripts/qa_verify_personas.py
"""
import os, sys, django  # noqa
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'config.settings')
django.setup()

from apps.accounts.models import User
from apps.roles.models import UserTargetRole, RoleSkill
from apps.skills.models import UserSkill
from apps.analysis.services import compute_gap_report, LEVEL_THRESHOLDS, MANDATORY_CAP


def hand_compute(user, role):
    """Independent re-derivation from the design doc §Module 4."""
    role_skills = list(RoleSkill.objects.filter(role=role).select_related('skill'))
    if not role_skills:
        return {'readiness': 100.0, 'no_requirements': True, 'cap': False}

    user_prof = {
        us.skill_id: us.proficiency
        for us in UserSkill.objects.filter(user=user)
    }

    sat_sum = 0.0
    weight_sum = 0.0
    mandatory_short = False
    gap_rows = []
    for rs in role_skills:
        T = LEVEL_THRESHOLDS[rs.required_level]
        U = user_prof.get(rs.skill_id, 0)
        S = min(U / T, 1.0)
        sat_sum += S * rs.weight
        weight_sum += rs.weight
        if rs.is_mandatory and S < 1.0:
            mandatory_short = True
        # severity
        gap = max(T - U, 0)
        if U >= T:
            gt, sev = 'MET', None
        elif U == 0:
            gt, sev = 'MISSING', ('CRITICAL' if rs.is_mandatory else 'MEDIUM')
        else:
            ratio = gap / T
            if rs.is_mandatory or ratio >= 0.5:
                sev = 'HIGH'
            elif ratio >= 0.25:
                sev = 'MEDIUM'
            else:
                sev = 'LOW'
            gt = 'INSUFFICIENT'
        gap_rows.append((rs.skill.skill_name, rs.required_level, U, S, rs.weight,
                         rs.is_mandatory, gt, sev))

    if weight_sum == 0:
        return {'readiness': 100.0, 'no_requirements': True, 'cap': False,
                'raw': None, 'gaps': gap_rows}

    raw = sat_sum / weight_sum * 100.0
    cap = mandatory_short and raw > MANDATORY_CAP
    final = MANDATORY_CAP if cap else raw
    return {'readiness': final, 'no_requirements': False, 'cap': cap,
            'raw': raw, 'gaps': gap_rows}


DEMO_EMAILS = [
    'demo.weak@gapguide.test',
    'demo.partial@gapguide.test',
    'demo.ready@gapguide.test',
    'demo.closedloop@gapguide.test',
]

mismatches = []
for email in DEMO_EMAILS:
    try:
        u = User.objects.get(email=email)
    except User.DoesNotExist:
        print(f'[MISS] {email} not in DB')
        continue
    target = UserTargetRole.objects.filter(user=u, is_active=True).select_related('role').first()
    if not target:
        print(f'[MISS] {email} has no active target')
        continue
    role = target.role
    expected = hand_compute(u, role)
    actual = compute_gap_report(u, role)

    exp_r = round(expected['readiness'], 2)
    act_r = round(actual.readiness, 2)
    ok = abs(exp_r - act_r) <= 0.1 and expected['cap'] == actual.mandatory_cap_applied

    print(f'\n=== {email} -> {role.role_name} ===')
    print(f'  expected readiness: {exp_r} (raw={expected["raw"]}, cap={expected["cap"]})')
    print(f'  actual   readiness: {act_r} (band={actual.band}, cap={actual.mandatory_cap_applied})')
    print(f'  match: {ok}')
    if not ok:
        mismatches.append((email, expected, actual))
    # Also spot-check one severity vs hand-computed
    actual_severities = {(g.skill_name, g.severity) for g in actual.gaps}
    expected_severities = {(row[0], row[7]) for row in expected['gaps']}
    diff = actual_severities ^ expected_severities
    if diff:
        print(f'  severity diff: {diff}')

if mismatches:
    print(f'\n*** {len(mismatches)} persona readiness mismatches ***')
    sys.exit(1)
else:
    print('\n*** All persona readiness values match hand computation ***')