from __future__ import annotations

from io import BytesIO
import re
import xml.etree.ElementTree as ET
import zipfile

from datetime import datetime, timezone
import logging

from fastapi import APIRouter, Depends, File, HTTPException, Query, UploadFile

from backend.database import db
from backend.routers.auth import require_roles
from backend.schemas import CaseListResponse, CaseResponse, CaseUpdate, DashboardResponse, ParseDocResponse

log = logging.getLogger('vector.admin')

router = APIRouter(prefix='/api/v1/admin', tags=['admin'], dependencies=[Depends(require_roles(['admin']))])


def _parse_bool(value: str | None) -> bool | None:
    if value is None:
        return None
    normalized = value.strip().lower()
    if normalized in {'1', 'true', 'yes', 'y', 'да'}:
        return True
    if normalized in {'0', 'false', 'no', 'n', 'нет'}:
        return False
    return None


def _extract_docx_text(content: bytes) -> str:
    try:
        with zipfile.ZipFile(BytesIO(content)) as archive:
            xml = archive.read('word/document.xml')
        root = ET.fromstring(xml)
    except (zipfile.BadZipFile, KeyError, ET.ParseError) as exc:
        raise ValueError('Не удалось прочитать .docx: файл повреждён или имеет неверный формат') from exc
    ns = {'w': 'http://schemas.openxmlformats.org/wordprocessingml/2006/main'}
    paragraphs: list[str] = []
    for paragraph in root.findall('.//w:body/w:p', ns):
        texts = [node.text for node in paragraph.findall('.//w:t', ns) if node.text]
        if texts:
            paragraphs.append(''.join(texts).strip())
    return '\n'.join(paragraphs).strip()


def _extract_kv_pairs(raw_text: str) -> dict[str, str]:
    parsed: dict[str, str] = {}
    for line in raw_text.splitlines():
        if ':' not in line:
            continue
        key, value = line.split(':', 1)
        parsed[key.strip().lower()] = value.strip()
    return parsed


def _coerce_preview(raw_text: str) -> dict:
    pairs = _extract_kv_pairs(raw_text)
    case: dict[str, object] = {}

    if 'age' in pairs:
        try:
            case['age'] = int(pairs['age'])
        except ValueError:
            pass
    if 'gender' in pairs:
        case['gender'] = pairs['gender']
    if 'status' in pairs:
        case['status'] = pairs['status']
    if 'found alive' in pairs:
        case['found_alive'] = _parse_bool(pairs['found alive'])
    if 'found distance km' in pairs:
        try:
            case['found_distance_km'] = float(pairs['found distance km'])
        except ValueError:
            pass
    if 'found lat' in pairs:
        try:
            case['found_lat'] = float(pairs['found lat'])
        except ValueError:
            pass
    if 'found lon' in pairs:
        try:
            case['found_lon'] = float(pairs['found lon'])
        except ValueError:
            pass
    if 'who found' in pairs:
        case['who_found'] = pairs['who found']
    if 'notes' in pairs:
        case['notes'] = pairs['notes']
    elif 'note' in pairs:
        case['notes'] = pairs['note']

    case_id = None
    if 'case id' in pairs:
        match = re.search(r'\d+', pairs['case id'])
        if match:
            case_id = match.group(0)

    return {'raw_text': raw_text, 'case_id': case_id, 'case': case}


@router.get('/cases', response_model=CaseListResponse)
def admin_cases(
    page: int = Query(default=1, ge=1),
    page_size: int = Query(default=20, ge=1, le=100),
    status: str | None = None,
    age_min: int | None = Query(default=None, ge=0),
    age_max: int | None = Query(default=None, ge=0),
) -> dict:
    cases = db.list_cases()
    if status:
        cases = [c for c in cases if c.status == status]
    if age_min is not None:
        cases = [c for c in cases if c.age is not None and c.age >= age_min]
    if age_max is not None:
        cases = [c for c in cases if c.age is not None and c.age <= age_max]
    start = (page - 1) * page_size
    end = start + page_size
    return {'items': [c.to_detail() for c in cases[start:end]], 'total': len(cases), 'page': page, 'page_size': page_size}


@router.patch('/cases/{case_id}', response_model=CaseResponse)
def admin_update_case(case_id: str, payload: CaseUpdate) -> dict:
    data = payload.model_dump(exclude_none=True)
    # default_factory-списки ([]) при exclude_none всё равно попадают в data и
    # ЗАТИРАЮТ реальные terrain/diagnosis_type — выкидываем пустые списки:
    data = {k: v for k, v in data.items() if not (isinstance(v, list) and not v)}
    note = data.pop('note', None)
    if note is not None and 'notes' not in data:
        data['notes'] = note
    case = db.update_case(case_id, **data)
    if not case:
        raise HTTPException(status_code=404, detail='Case not found')

    # B21-синхронизация: кейс закрыт вручную → его операция завершается автоматически
    if data.get('status') == 'closed':
        import uuid as _uuid
        from backend.models import SearchOperation as _Op
        from backend.database import SessionLocal as _SL
        case_uuid = _uuid.UUID(str(case.id)) if isinstance(case.id, str) else case.id
        with _SL() as session:
            ops = session.query(_Op).filter(_Op.case_id == case_uuid,
                                            _Op.status.in_(['planned', 'active', 'paused'])).all()
            for op in ops:
                op.status = 'completed'
                op.closed_at = datetime.now(timezone.utc)
            session.commit()
            closed_ops = len(ops)
        if closed_ops:
            log.info('admin closed case %s → %d операция(ий) завершены автоматически', case_id, closed_ops)
    return case.to_detail()


@router.get('/dashboard', response_model=DashboardResponse)
def admin_dashboard() -> dict:
    return db.stats()


@router.post('/parse-doc', response_model=ParseDocResponse)
async def admin_parse_doc(file: UploadFile = File(...)) -> dict:
    content = await file.read()
    try:
        raw_text = _extract_docx_text(content)
    except ValueError as exc:
        raise HTTPException(status_code=400, detail=str(exc)) from exc
    preview = _coerce_preview(raw_text)
    return {'filename': file.filename, 'parsed': True, 'preview': preview, 'raw_text': raw_text}