"""B21/E4: отправка приоритетных зон в КОНТУР (контракт B20, outbound).

POST /api/v1/operations/{id}/send-to-contour:
  анализ кейса → SearchZones[] (GeoJSON-сектора направлений) →
  POST {CONTOUR_API_URL}/api/v1/vector/zones?operation_id=<contour_operation_id>

Требуется: у операции задан contour_operation_id (UUID операции в КОНТУРе),
env CONTOUR_API_URL и CONTOUR_TOKEN (межсервисный, в secrets).
"""
from __future__ import annotations

import math
import os
import uuid as uuid_mod
from datetime import datetime, timezone
from typing import Any, Optional

import httpx
from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel

from backend.audit import audit_log, can_access_unit
from backend.database import get_db
from backend.models import SearchOperation, User
from backend.routers.auth import get_current_user, require_permission

router = APIRouter(prefix='/api/v1/operations', tags=['operations-contour'])

def _contour_url() -> str:
    return os.getenv('CONTOUR_API_URL', 'http://192.168.0.130:8000')


def _contour_token() -> str:
    return os.getenv('CONTOUR_TOKEN', '')
SCHEMA_VERSION = '1.0'

_DIRECTIONS = {
    'N': 0, 'NE': 45, 'E': 90, 'SE': 135,
    'S': 180, 'SW': 225, 'W': 270, 'NW': 315,
}


class SendResult(BaseModel):
    sent_zones: int
    contour_operation_id: str
    contour_response: dict[str, Any]


def _sector_polygon(lat: float, lon: float, radius_km: float, direction: str,
                    segments: int = 24) -> dict:
    """GeoJSON Polygon сектора ±22.5° вокруг направления (для контракта B20)."""
    az = _DIRECTIONS.get(direction, 0)
    half = 22.5
    ring: list[list[float]] = [[lon, lat]]
    for i in range(segments + 1):
        bearing = math.radians(az - half + (2 * half) * i / segments)
        dlat = (radius_km / 111.0) * math.cos(bearing)
        dlon = (radius_km / (111.0 * math.cos(math.radians(lat)))) * math.sin(bearing)
        ring.append([round(lon + dlon, 7), round(lat + dlat, 7)])
    ring.append([lon, lat])
    return {'type': 'Polygon', 'coordinates': [ring]}


def _probability_from_priority(priority: int, total: int) -> float:
    """Градация: топ-зона → наибольшая вероятность (0..1)."""
    if total <= 1:
        return 0.8
    return round(max(0.1, 0.9 - 0.7 * (priority - 1) / max(1, total - 1)), 3)


def _load_analysis(db, case_id) -> dict:
    """Последний анализ кейса: search_models (B15) или analysis_log (legacy)."""
    from sqlalchemy import text as sa_text
    row = db.execute(
        sa_text("SELECT model_json FROM search_models "
                "WHERE case_id = :cid ORDER BY version DESC LIMIT 1"),
        {'cid': str(case_id)},
    ).first()
    if row and row[0]:
        return dict(row[0])
    from backend.models import Case
    case = db.get(__import__('backend.models', fromlist=['Case']).Case, case_id)
    if case and case.analysis_log and isinstance(case.analysis_log, dict):
        return dict(case.analysis_log)
    raise HTTPException(status_code=400, detail='У карточки нет анализа — запустите анализ сначала')


def _build_b20_payload(op: SearchOperation, analysis: dict) -> dict:
    """SearchZones[] из primary_zones анализа (полигоны направлений)."""
    lat = analysis.get('lat') or analysis.get('tnp_lat')
    lon = analysis.get('lon') or analysis.get('tnp_lon')
    if lat is None or lon is None:
        raise HTTPException(status_code=400,
                            detail='В анализе нет координат ТНП — невозможны геометрии зон')
    max_distance = float(analysis.get('max_distance_km') or 3.0)
    zones_in = analysis.get('primary_zones') or []
    if not zones_in:
        raise HTTPException(status_code=400, detail='В анализе нет приоритетных зон')

    out_zones = []
    for z in zones_in[:5]:
        direction = z.get('direction')
        distance = float(z.get('distance') or max_distance * 0.5)
        priority = int(z.get('priority') or 1)
        out_zones.append({
            'zone_id': f"vec:{direction}:{int(distance * 1000)}m",
            'geom': _sector_polygon(float(lat), float(lon), distance, direction),
            'priority': priority,
            'probability': _probability_from_priority(priority, len(zones_in[:5])),
            'reasoning': z.get('reason') or f'Приоритет {priority} по модели ВЕКТОРа',
        })

    return {
        'schema_version': SCHEMA_VERSION,
        'case_id': str(op.case_id),
        'model_version': f"vector:{(analysis.get('analyzed_at') or datetime.now(timezone.utc).isoformat())[:19]}",
        'generated_at': analysis.get('analyzed_at') or datetime.now(timezone.utc).isoformat(),
        'max_distance_km': max_distance,
        'zones': out_zones,
    }


@router.post('/{operation_id}/send-to-contour')
def send_to_contour(
    operation_id: str,
    request: Request,
    current_user: User = Depends(require_permission('update')),
    db = Depends(get_db),
) -> SendResult:
    op = _load_operation(db, current_user, operation_id)

    if not op.contour_operation_id:
        raise HTTPException(
            status_code=400,
            detail='У операции не задан contour_operation_id (UUID операции в КОНТУРе) — '
                   'укажите его в карточке операции (PATCH /operations/{id})',
        )
    if not _contour_token():
        raise HTTPException(status_code=503, detail='CONTOUR_TOKEN не настроен')

    analysis = _load_analysis(db, op.case_id)
    payload = _build_b20_payload(op, analysis)

    url = f"{_contour_url()}/api/v1/vector/zones?operation_id={op.contour_operation_id}"
    try:
        resp = httpx.post(url, json=payload,
                          headers={'Authorization': f'Bearer {_contour_token()}'},
                          timeout=30.0)
    except httpx.HTTPError as e:
        audit_log(db, current_user, 'contour_send_failed', object_type='operation',
                  object_id=str(op.id), request=request, details={'error': str(e)})
        raise HTTPException(status_code=502, detail=f'КОНТУР недоступен: {e}') from e

    if resp.status_code >= 400:
        audit_log(db, current_user, 'contour_send_failed', object_type='operation',
                  object_id=str(op.id), request=request,
                  details={'status': resp.status_code, 'body': resp.text[:500]})
        raise HTTPException(status_code=502,
                            detail=f'КОНТУР отклонил импорт: {resp.status_code} {resp.text[:300]}')

    result = resp.json()
    audit_log(db, current_user, 'contour_send_ok', object_type='operation',
              object_id=str(op.id), request=request,
              details={'zones': result.get('zones_total'), 'status': result.get('status')})
    return SendResult(
        sent_zones=payload['zones'].__len__(),
        contour_operation_id=str(op.contour_operation_id),
        contour_response=result,
    )


def _load_operation(db, user: User, operation_id: str) -> SearchOperation:
    op = db.get(SearchOperation, uuid_mod.UUID(operation_id)) if operation_id else None
    if not op:
        raise HTTPException(status_code=404, detail='Операция не найдена')
    if not can_access_unit(db, user, str(op.unit_id) if op.unit_id else None):
        raise HTTPException(status_code=403, detail='Операция вне вашего скоупа')
    return op


@router.get('/{operation_id}/areas-checked')
def areas_checked(
    operation_id: str,
    current_user: User = Depends(get_current_user),
    db = Depends(get_db),
) -> dict[str, Any]:
    """Прокси: проверенные квадраты операции из КОНТУРа (inbound B17-заготовка)."""
    op = _load_operation(db, current_user, operation_id)
    if not op.contour_operation_id:
        raise HTTPException(status_code=400, detail='contour_operation_id не задан')
    if not _contour_token():
        raise HTTPException(status_code=503, detail='CONTOUR_TOKEN не настроен')
    url = f"{_contour_url()}/api/v1/vector/areas-checked?operation_id={op.contour_operation_id}"
    try:
        resp = httpx.get(url, headers={'Authorization': f'Bearer {_contour_token()}'}, timeout=30.0)
    except httpx.HTTPError as e:
        raise HTTPException(status_code=502, detail=f'КОНТУР недоступен: {e}') from e
    if resp.status_code >= 400:
        raise HTTPException(status_code=502, detail=f'КОНТУР: {resp.status_code} {resp.text[:300]}')
    return resp.json()