"""
ClaimSense — Agent 7: FNOL Intake Agent
========================================
First Notice of Loss parser and validator.
- Extracts and normalises incident fields from raw FNOL payload
- Validates required fields are present
- Checks policy_number format and incident_date is not future
- Determines FNOL completeness score
- No ML model needed — pure logic/rules
"""

import os, sys, json, logging
from datetime import datetime, date

log = logging.getLogger(__name__)


# ── Field validation helpers ──────────────────────────────────
VALID_INCIDENT_TYPES = {
    'FIRE', 'WATER', 'WIND', 'HAIL', 'THEFT', 'VANDALISM',
    'LIABILITY', 'EARTHQUAKE', 'FLOOD', 'VEHICLE_IMPACT',
    'STRUCTURAL', 'OTHER'
}

REQUIRED_FIELDS = [
    'policy_number', 'claimant_name', 'incident_date', 'incident_type'
]


def _parse_date(val):
    if not val:
        return None
    for fmt in ('%Y-%m-%d', '%m/%d/%Y', '%d-%m-%Y', '%Y/%m/%d'):
        try:
            return datetime.strptime(str(val).strip(), fmt).date()
        except ValueError:
            continue
    return None


def _days_to_report(incident_dt, reported_dt=None):
    """Days between incident and FNOL submission — key fraud signal."""
    if not incident_dt:
        return 0
    ref = reported_dt or date.today()
    if isinstance(ref, datetime):
        ref = ref.date()
    delta = (ref - incident_dt).days
    return max(0, delta)


def _completeness_score(fnol: dict) -> int:
    """0–100 completeness score based on fields present."""
    bonus_fields = [
        'incident_description', 'incident_address', 'incident_city',
        'claimant_email', 'claimant_phone', 'has_police_report',
        'has_photos', 'estimated_damage'
    ]
    base = len([f for f in REQUIRED_FIELDS if fnol.get(f)]) / len(REQUIRED_FIELDS)
    bonus = sum(1 for f in bonus_fields if fnol.get(f)) / len(bonus_fields)
    return int((base * 70) + (bonus * 30))


# ── Main agent function ───────────────────────────────────────
def run_fnol_intake_agent(fnol_payload: dict) -> dict:
    """
    Agent 7 — FNOL Intake.

    Args:
        fnol_payload: Raw FNOL submission dict

    Returns:
        result dict with status, normalised fields, validation issues
    """
    claim_id = fnol_payload.get('claim_id', '')
    log.info(f"[FNOL] Agent 7 running for {claim_id}")

    issues       = []
    normalised   = {}

    # ── Required field checks ─────────────────────────────────
    for field in REQUIRED_FIELDS:
        if not fnol_payload.get(field):
            issues.append(f"Missing required field: {field}")

    # ── Policy number ─────────────────────────────────────────
    policy_number = str(fnol_payload.get('policy_number', '')).strip()
    normalised['policy_number'] = policy_number

    # ── Claimant ──────────────────────────────────────────────
    normalised['claimant_name']     = str(fnol_payload.get('claimant_name', '')).strip()
    normalised['claimant_email']    = fnol_payload.get('claimant_email')
    normalised['claimant_phone']    = fnol_payload.get('claimant_phone')
    normalised['claimant_relation'] = fnol_payload.get('claimant_relation', 'Named Insured')

    # ── Incident type ─────────────────────────────────────────
    raw_type = str(fnol_payload.get('incident_type', '')).upper().strip()
    if raw_type and raw_type not in VALID_INCIDENT_TYPES:
        # Try to map common synonyms
        synonyms = {
            'FLOOD': 'WATER', 'BURST PIPE': 'WATER', 'LEAK': 'WATER',
            'BREAK-IN': 'THEFT', 'BURGLARY': 'THEFT', 'ROBBERY': 'THEFT',
            'STORM': 'WIND', 'HURRICANE': 'WIND', 'TORNADO': 'WIND',
            'ACCIDENT': 'LIABILITY', 'INJURY': 'LIABILITY',
        }
        mapped = synonyms.get(raw_type)
        if mapped:
            raw_type = mapped
        else:
            raw_type = 'OTHER'
    normalised['incident_type'] = raw_type or 'OTHER'

    # ── Incident date ─────────────────────────────────────────
    incident_dt = _parse_date(fnol_payload.get('incident_date'))
    if incident_dt:
        if incident_dt > date.today():
            issues.append("incident_date is in the future")
            incident_dt = None
        elif (date.today() - incident_dt).days > 1825:  # 5 years
            issues.append("incident_date is more than 5 years ago — verify")
    else:
        if fnol_payload.get('incident_date'):
            issues.append(f"Could not parse incident_date: {fnol_payload.get('incident_date')}")

    normalised['incident_date']   = incident_dt.isoformat() if incident_dt else None
    normalised['days_to_report']  = _days_to_report(incident_dt)

    # ── Late reporting flag ───────────────────────────────────
    late_report = normalised['days_to_report'] > 30
    if normalised['days_to_report'] > 90:
        issues.append(
            f"Very late FNOL: {normalised['days_to_report']} days after incident — fraud signal"
        )

    # ── Incident details ──────────────────────────────────────
    normalised['incident_description'] = fnol_payload.get('incident_description')
    normalised['incident_address']     = fnol_payload.get('incident_address')
    normalised['incident_city']        = fnol_payload.get('incident_city')
    normalised['incident_state']       = fnol_payload.get('incident_state')
    normalised['estimated_damage']     = fnol_payload.get('estimated_damage')
    normalised['has_police_report']    = bool(fnol_payload.get('has_police_report', False))
    normalised['has_photos']           = bool(fnol_payload.get('has_photos', False))

    # ── Completeness ─────────────────────────────────────────
    completeness = _completeness_score({**fnol_payload, **normalised})

    # ── Status determination ──────────────────────────────────
    critical_issues = [i for i in issues if 'Missing required' in i]
    if critical_issues:
        status = 'FNOL_INVALID'
    elif issues:
        status = 'FNOL_PARTIAL'
    else:
        status = 'FNOL_ACCEPTED'

    result = {
        'claim_id':            claim_id,
        'status':              status,
        'normalised_fields':   normalised,
        'completeness_score':  completeness,
        'late_report':         late_report,
        'days_to_report':      normalised['days_to_report'],
        'validation_issues':   issues,
        'incident_type':       normalised['incident_type'],
        'incident_date':       normalised['incident_date'],
        'policy_number':       policy_number,
        'claimant_name':       normalised['claimant_name'],
    }

    log.info(
        f"[FNOL] {claim_id}: {status} | "
        f"completeness={completeness} | "
        f"days_to_report={normalised['days_to_report']} | "
        f"issues={len(issues)}"
    )
    return result