"""
Tareas Celery para importacion CSV de Conductores.
Flujo: scan_file (validacion) -> insert_valid_rows (commit).
"""
import os
import base64
import csv
import json
import logging
import re
import unicodedata
from typing import Dict, Any, Optional, List

from core.celery_app import celery_app
from core.database import CoreSessionLocal
from core.paths import layout_path

from .template_config import row_from_template

logger = logging.getLogger(__name__)

DRV_IMPORT_FILE_PREFIX = "drv_import_file:"
DRV_IMPORT_META_PREFIX = "drv_import_meta:"
DRV_IMPORT_ERROR_LINES_PREFIX = "drv_import_error_lines:"
DRV_IMPORT_STATUS_PREFIX = "drv_import_status:"
DRV_IMPORT_REDIS_TTL = 3600


def _get_redis():
    import redis
    url = os.getenv("VALKEY_URL", os.getenv("REDIS_URL", "redis://valkey:6379/0"))
    return redis.Redis.from_url(url, decode_responses=False)


def _worker_upload_dir() -> str:
    return layout_path("imports", "temp")


def _ensure_worker_has_file_from_redis(job_id: str) -> Optional[str]:
    r = _get_redis()
    data = r.get(f"{DRV_IMPORT_FILE_PREFIX}{job_id}")
    if not data:
        return None
    try:
        raw = base64.b64decode(data)
    except Exception as e:
        logger.warning(f"Drivers import: failed to decode file from Redis: {e}")
        return None
    upload_dir = _worker_upload_dir()
    os.makedirs(upload_dir, exist_ok=True)
    file_path = os.path.join(upload_dir, f"drv_{job_id}.csv")
    with open(file_path, "wb") as f:
        f.write(raw)
    return file_path


def _ensure_worker_has_meta_from_redis(job_id: str, file_path: str) -> bool:
    r = _get_redis()
    data = r.get(f"{DRV_IMPORT_META_PREFIX}{job_id}")
    if not data:
        return False
    try:
        meta = json.loads(data.decode("utf-8"))
    except Exception as e:
        logger.warning(f"Drivers import: failed to decode meta from Redis: {e}")
        return False
    meta_path = file_path.replace(".csv", ".meta.json")
    with open(meta_path, "w", encoding="utf-8") as f:
        json.dump(meta, f)
    return True


def _delete_import_from_redis(job_id: str) -> None:
    try:
        r = _get_redis()
        r.delete(
            f"{DRV_IMPORT_FILE_PREFIX}{job_id}",
            f"{DRV_IMPORT_META_PREFIX}{job_id}",
            f"{DRV_IMPORT_ERROR_LINES_PREFIX}{job_id}",
            f"{DRV_IMPORT_STATUS_PREFIX}{job_id}",
        )
    except Exception as e:
        logger.warning(f"Drivers import: failed to delete Redis keys: {e}")


def normalize_header(name: Optional[str]) -> str:
    if not name:
        return ""
    name = unicodedata.normalize("NFKD", str(name)).upper()
    name = "".join(ch for ch in name if not unicodedata.combining(ch))
    name = re.sub(r"[^A-Z0-9]+", " ", name)
    return re.sub(r"\s+", " ", name).strip()


_MAX = {
    "transporter_key": 5,
    "driver_name": 80,
    "license_number": 29,
    "express_line_id": 17,
    "ace_id": 20,
    "gender": 1,
    "birth_country": 3,
    "hazardous_material_auth": 2,
    "hazardous_material_state": 30,
    "first_name": 20,
    "last_name": 20,
    "id_key1": 40,
    "id_number1": 20,
    "id_state1": 30,
    "id_country1": 3,
    "id_key2": 40,
    "id_number2": 20,
    "id_state2": 30,
    "id_country2": 3,
    "badge_number": 20,
    "class_type": 1,
    "unique_badge_number": 100,
}


def _parse_int(val: Any) -> Optional[int]:
    if val is None or (isinstance(val, str) and not val.strip()):
        return None
    s = str(val).strip()
    if re.match(r"^\d+$", s):
        return int(s)
    if re.match(r"^\d+\.0+$", s):
        try:
            return int(float(s))
        except ValueError:
            return None
    return None


def _parse_birth_date(val: Any) -> Optional[int]:
    if val is None or (isinstance(val, str) and not val.strip()):
        return None
    s = str(val).strip()
    if re.match(r"^\d{8}$", s):
        try:
            return int(s)
        except ValueError:
            return None
    if re.match(r"^\d+\.0+$", s):
        try:
            return int(float(s))
        except ValueError:
            return None
    for sep in ["/", "-", "."]:
        if sep in s:
            parts = s.split(sep)
            if len(parts) == 3:
                try:
                    a, b, c = [p.strip() for p in parts]
                    if len(c) == 4 and len(a) <= 2 and len(b) <= 2:
                        return int(c) * 10000 + int(b) * 100 + int(a)
                    if len(a) == 4 and len(b) <= 2 and len(c) <= 2:
                        return int(a) * 10000 + int(b) * 100 + int(c)
                except (ValueError, TypeError):
                    return None
            break
    return None


def _str_or_none(val: Any, max_len: Optional[int] = None) -> Optional[str]:
    if val is None:
        return None
    s = str(val).strip()
    if not s:
        return None
    if max_len and len(s) > max_len:
        return s[:max_len]
    return s


def _dedupe_headers(headers: List[str]) -> List[str]:
    counts: Dict[str, int] = {}
    unique: List[str] = []
    for header in headers:
        name = str(header or "").strip() or "COL"
        count = counts.get(name, 0) + 1
        counts[name] = count
        if count == 1:
            unique.append(name)
        else:
            unique.append(f"{name} {count}")
    return unique


def _validate_row_driver(row: Dict[str, Any], line_num: int) -> Optional[Dict[str, Any]]:
    transporter_key = (row.get("TRANSPORTISTA") or "").strip()
    if not transporter_key:
        return {"line": line_num, "col": "TRANSPORTISTA", "msg": "Requerido"}
    if len(transporter_key) > _MAX["transporter_key"]:
        return {"line": line_num, "col": "TRANSPORTISTA", "msg": f"Maximo {_MAX['transporter_key']} caracteres"}

    line_val = _parse_int(row.get("LINEA"))
    if line_val is None:
        return {"line": line_num, "col": "LINEA", "msg": "Debe ser numerico"}
    if line_val <= 0:
        return {"line": line_num, "col": "LINEA", "msg": "Debe ser mayor a 0"}

    driver_name = (row.get("CLAVE CONDUCTOR") or "").strip()
    if driver_name and len(driver_name) > _MAX["driver_name"]:
        return {"line": line_num, "col": "CLAVE CONDUCTOR", "msg": f"Maximo {_MAX['driver_name']} caracteres"}

    for col, max_len in [
        ("LICENCIA", _MAX["license_number"]),
        ("PERMISO LINEA EXPRESS", _MAX["express_line_id"]),
        ("IDENTIFICACION ACE", _MAX["ace_id"]),
        ("SEXO", _MAX["gender"]),
        ("PAIS NACIMIENTO", _MAX["birth_country"]),
        ("TRANSPORTA MAT. PELIGROSO?", _MAX["hazardous_material_auth"]),
        ("PERMISO MAT. PELIGROSO", _MAX["hazardous_material_state"]),
        ("NOMBRE(S)", _MAX["first_name"]),
        ("APELLIDO PATERNO", _MAX["last_name"]),
        ("FORMA IDENTIFICACION 1", _MAX["id_key1"]),
        ("NUM. IDENTIFICACION 1", _MAX["id_number1"]),
        ("ESTADO", _MAX["id_state1"]),
        ("PAIS", _MAX["id_country1"]),
        ("FORMA IDENTIFICACION 2", _MAX["id_key2"]),
        ("NUM. IDENTIFICACION 2", _MAX["id_number2"]),
        ("ESTADO 2", _MAX["id_state2"]),
        ("PAIS 2", _MAX["id_country2"]),
    ]:
        val = (row.get(col) or "").strip()
        if val and len(val) > max_len:
            return {"line": line_num, "col": col, "msg": f"Maximo {max_len} caracteres"}

    fecha = row.get("FECHA NACIMIENTO")
    if fecha is not None and str(fecha).strip():
        if _parse_birth_date(fecha) is None:
            return {
                "line": line_num,
                "col": "FECHA NACIMIENTO",
                "msg": "Formato de fecha invalido (use YYYYMMDD o DD/MM/YYYY)",
            }

    return None


def _row_to_driver_dto(row: Dict[str, Any], tenant_id: int, company_id: int) -> Dict[str, Any]:
    transporter_key = _str_or_none(row.get("TRANSPORTISTA"), _MAX["transporter_key"])
    line = _parse_int(row.get("LINEA"))
    if not transporter_key or line is None:
        return {}
    data = {
        "transporter_key": transporter_key,
        "line": line,
        "driver_name": _str_or_none(row.get("CLAVE CONDUCTOR"), _MAX["driver_name"]),
        "license_number": _str_or_none(row.get("LICENCIA"), _MAX["license_number"]),
        "express_line_id": _str_or_none(row.get("PERMISO LINEA EXPRESS"), _MAX["express_line_id"]),
        "ace_id": _str_or_none(row.get("IDENTIFICACION ACE"), _MAX["ace_id"]),
        "birth_date": _parse_birth_date(row.get("FECHA NACIMIENTO")),
        "gender": _str_or_none(row.get("SEXO"), _MAX["gender"]),
        "birth_country": _str_or_none(row.get("PAIS NACIMIENTO"), _MAX["birth_country"]),
        "hazardous_material_auth": _str_or_none(
            row.get("TRANSPORTA MAT. PELIGROSO?"), _MAX["hazardous_material_auth"]
        ),
        "hazardous_material_state": _str_or_none(
            row.get("PERMISO MAT. PELIGROSO"), _MAX["hazardous_material_state"]
        ),
        "first_name": _str_or_none(row.get("NOMBRE(S)"), _MAX["first_name"]),
        "last_name": _str_or_none(row.get("APELLIDO PATERNO"), _MAX["last_name"]),
        "id_key1": _str_or_none(row.get("FORMA IDENTIFICACION 1"), _MAX["id_key1"]),
        "id_number1": _str_or_none(row.get("NUM. IDENTIFICACION 1"), _MAX["id_number1"]),
        "id_state1": _str_or_none(row.get("ESTADO"), _MAX["id_state1"]),
        "id_country1": _str_or_none(row.get("PAIS"), _MAX["id_country1"]),
        "id_key2": _str_or_none(row.get("FORMA IDENTIFICACION 2"), _MAX["id_key2"]),
        "id_number2": _str_or_none(row.get("NUM. IDENTIFICACION 2"), _MAX["id_number2"]),
        "id_state2": _str_or_none(row.get("ESTADO 2"), _MAX["id_state2"]),
        "id_country2": _str_or_none(row.get("PAIS 2"), _MAX["id_country2"]),
        "company_id": company_id,
        "tenant_id": tenant_id,
    }
    return data


def _do_scan(job_id: str, progress_callback: Optional[Any] = None) -> Dict[str, Any]:
    file_path = _ensure_worker_has_file_from_redis(job_id)
    if not file_path:
        return {"status": "failed", "error": "Archivo no encontrado (expirado o no subido). Sube de nuevo."}
    _ensure_worker_has_meta_from_redis(job_id, file_path)

    error_dir = layout_path("imports", "errors")
    os.makedirs(error_dir, exist_ok=True)
    error_path = os.path.join(error_dir, f"drv_{job_id}.jsonl")

    total_rows = 0
    try:
        with open(file_path, "r", encoding="utf-8-sig") as f:
            total_rows = sum(1 for _ in f) - 1
    except Exception as e:
        return {"status": "failed", "error": str(e)}

    meta_path = file_path.replace(".csv", ".meta.json")
    meta = {}
    if os.path.exists(meta_path):
        try:
            with open(meta_path, "r", encoding="utf-8") as f:
                meta = json.load(f) or {}
        except Exception as e:
            logger.warning(f"Drivers import: failed to read meta: {e}")

    tenant_id = meta.get("tenant_id")
    company_id = meta.get("company_id")
    if not tenant_id or not company_id:
        return {"status": "failed", "error": "Falta contexto (tenant/company)"}

    error_count = 0
    processed_rows = 0
    errors_detail: List[Dict[str, Any]] = []

    try:
        with open(file_path, "r", encoding="utf-8-sig") as f_in, open(
            error_path, "w", encoding="utf-8"
        ) as f_err:
            sample = f_in.read(2048)
            f_in.seek(0)
            try:
                dialect = csv.Sniffer().sniff(sample, delimiters=",;\t")
            except Exception:
                dialect = "excel"
            reader = csv.reader(f_in, dialect=dialect)
            try:
                headers = next(reader)
            except StopIteration:
                headers = []
            headers = _dedupe_headers(headers)
            dict_reader = csv.DictReader(f_in, fieldnames=headers, dialect=dialect)

            for i, row in enumerate(dict_reader, start=1):
                if progress_callback and i % 500 == 0:
                    progress_callback(i, total_rows, error_count)

                row_norm = row_from_template(row, normalize_header)
                err = _validate_row_driver(row_norm, i)
                if err:
                    error_count += 1
                    f_err.write(json.dumps(err) + "\n")
                    if len(errors_detail) < 500:
                        errors_detail.append(
                            {"line": err["line"], "col": err.get("col", ""), "msg": err.get("msg", "")}
                        )
                processed_rows += 1

    except Exception as e:
        logger.error(f"Drivers import scan failed: {e}")
        return {"status": "failed", "error": str(e)}

    error_lines_list = []
    try:
        if os.path.exists(error_path):
            with open(error_path, "r", encoding="utf-8") as f:
                for line in f:
                    try:
                        err = json.loads(line)
                        if "line" in err:
                            error_lines_list.append(err["line"])
                    except Exception:
                        pass
        if error_lines_list:
            r = _get_redis()
            r.set(
                f"{DRV_IMPORT_ERROR_LINES_PREFIX}{job_id}",
                json.dumps(error_lines_list).encode("utf-8"),
                ex=DRV_IMPORT_REDIS_TTL,
            )
    except Exception as e:
        logger.warning(f"Drivers import: failed to store error lines: {e}")

    result = {
        "status": "waiting_confirmation",
        "job_id": job_id,
        "total_rows": processed_rows,
        "error_count": error_count,
        "valid_rows": processed_rows - error_count,
        "errors": errors_detail,
    }
    return result


def run_scan_sync(job_id: str) -> Dict[str, Any]:
    result = _do_scan(job_id, progress_callback=None)
    try:
        r = _get_redis()
        r.set(
            f"{DRV_IMPORT_STATUS_PREFIX}{job_id}",
            json.dumps(result).encode("utf-8"),
            ex=DRV_IMPORT_REDIS_TTL,
        )
    except Exception as e:
        logger.warning(f"Drivers import: failed to store scan status in Redis: {e}")
    return result


@celery_app.task(bind=True)
def scan_file(self, job_id: str, config: str = None):
    logger.info(f"Drivers import: starting scan for job {job_id}")

    def on_progress(current: int, total: int, errors: int) -> None:
        self.update_state(
            state="PROGRESS",
            meta={"current": current, "total": total, "errors": errors},
        )

    result = _do_scan(job_id, progress_callback=on_progress)
    try:
        r = _get_redis()
        r.set(
            f"{DRV_IMPORT_STATUS_PREFIX}{job_id}",
            json.dumps(result).encode("utf-8"),
            ex=DRV_IMPORT_REDIS_TTL,
        )
    except Exception as e:
        logger.warning(f"Drivers import: failed to store scan status in Redis: {e}")
    return result


def _do_commit(job_id: str) -> Dict[str, Any]:
    file_path = _ensure_worker_has_file_from_redis(job_id)
    if not file_path:
        alt_path = os.path.join(_worker_upload_dir(), f"drv_{job_id}.csv")
        if not os.path.exists(alt_path):
            return {
                "status": "failed",
                "error": "Archivo no encontrado (expirado). Sube y confirma de nuevo.",
            }
        file_path = alt_path
    else:
        _ensure_worker_has_meta_from_redis(job_id, file_path)

    error_dir = layout_path("imports", "errors")
    error_path = os.path.join(error_dir, f"drv_{job_id}.jsonl")

    error_lines = set()
    try:
        r = _get_redis()
        raw = r.get(f"{DRV_IMPORT_ERROR_LINES_PREFIX}{job_id}")
        if raw:
            error_lines = set(json.loads(raw.decode("utf-8")))
    except Exception as e:
        logger.debug(f"Drivers import: could not load error lines from Redis: {e}")
    if not error_lines and os.path.exists(error_path):
        with open(error_path, "r", encoding="utf-8") as f:
            for line in f:
                try:
                    err = json.loads(line)
                    error_lines.add(err["line"])
                except Exception:
                    pass

    meta_path = file_path.replace(".csv", ".meta.json")
    tenant_id = None
    company_id = None
    meta = {}
    if os.path.exists(meta_path):
        try:
            with open(meta_path, "r", encoding="utf-8") as f:
                meta = json.load(f) or {}
                tenant_id = meta.get("tenant_id")
                company_id = meta.get("company_id")
        except Exception:
            pass

    if not tenant_id or not company_id:
        return {"status": "failed", "error": "Falta contexto (tenant/company)"}

    from api.v1.modules.a76.transportation.drivers.services import DriverService
    from api.v1.modules.a76.transportation.drivers.dto import DriverCreateDTO

    inserted_count = 0
    updated_count = 0
    skipped_invalid = 0
    skipped_duplicate = 0
    skipped_details: List[Dict[str, Any]] = []
    seen_keys_in_file: Dict[str, int] = {}

    try:
        with CoreSessionLocal() as session:
            with open(file_path, "r", encoding="utf-8-sig") as f:
                sample = f.read(2048)
                f.seek(0)
                try:
                    dialect = csv.Sniffer().sniff(sample, delimiters=",;\t")
                except Exception:
                    dialect = "excel"
                reader = csv.reader(f, dialect=dialect)
                try:
                    headers = next(reader)
                except StopIteration:
                    headers = []
                headers = _dedupe_headers(headers)
                dict_reader = csv.DictReader(f, fieldnames=headers, dialect=dialect)

                for i, row in enumerate(dict_reader, start=1):
                    if i in error_lines:
                        continue

                    row_norm = row_from_template(row, normalize_header)
                    err = _validate_row_driver(row_norm, i)
                    if err:
                        skipped_invalid += 1
                        skipped_details.append(
                            {
                                "line": i,
                                "driver_key": (row_norm.get("CLAVE CONDUCTOR") or "").strip()[:80] or "-",
                                "invoice": (row_norm.get("CLAVE CONDUCTOR") or "").strip()[:80] or "-",
                                "reason": f"{err.get('col', '')}: {err.get('msg', '')}",
                            }
                        )
                        continue

                    data = _row_to_driver_dto(row_norm, tenant_id, company_id)
                    if not data or not data.get("transporter_key") or data.get("line") is None:
                        skipped_invalid += 1
                        continue

                    key = f"{data['transporter_key']}:{data['line']}"
                    if key in seen_keys_in_file:
                        skipped_duplicate += 1
                        skipped_details.append(
                            {
                                "line": i,
                                "driver_key": key,
                                "invoice": key,
                                "reason": "Clave duplicada en el archivo (se usa la primera)",
                            }
                        )
                        continue
                    seen_keys_in_file[key] = i

                    existing = DriverService.get_driver_by_key_and_line(
                        session, data["transporter_key"], data["line"], str(company_id), tenant_id
                    )
                    try:
                        if existing:
                            update_fields = {k: v for k, v in data.items() if k not in ("transporter_key", "line", "company_id", "tenant_id")}
                            for field, value in update_fields.items():
                                setattr(existing, field, value)
                            session.add(existing)
                            updated_count += 1
                        else:
                            create_data = DriverCreateDTO(**data)
                            DriverService.create_driver(session, create_data)
                            inserted_count += 1
                    except Exception as db_err:
                        session.rollback()
                        skipped_invalid += 1
                        skipped_details.append(
                            {"line": i, "driver_key": key, "invoice": key, "reason": str(db_err)}
                        )
                        continue

            try:
                session.commit()
            except Exception as db_err:
                session.rollback()
                logger.error(f"Drivers import DB error: {db_err}")
                return {"status": "failed", "error": str(db_err)}

    except Exception as e:
        logger.error(f"Drivers import task failed: {e}")
        import traceback
        logger.error(traceback.format_exc())
        return {"status": "failed", "error": str(e)}

    try:
        if file_path and os.path.exists(file_path):
            os.remove(file_path)
        if os.path.exists(error_path):
            os.remove(error_path)
        if os.path.exists(meta_path):
            os.remove(meta_path)
        _delete_import_from_redis(job_id)
    except Exception as cleanup_err:
        logger.warning(f"Drivers import cleanup failed: {cleanup_err}")

    total_ok = inserted_count + updated_count
    if total_ok == 0 and (skipped_invalid + skipped_duplicate) > 0:
        return {
            "status": "warning",
            "inserted": inserted_count,
            "updated": updated_count,
            "skipped_invalid": skipped_invalid,
            "skipped_duplicate": skipped_duplicate,
            "skipped_missing_fk": 0,
            "skipped_details": skipped_details,
            "message": f"No se insertaron registros. {skipped_invalid + skipped_duplicate} rechazados.",
        }
    if total_ok == 0:
        return {
            "status": "failed",
            "error": "No hay registros validos en el archivo CSV",
            "inserted": 0,
            "updated": 0,
            "skipped_invalid": skipped_invalid,
            "skipped_duplicate": skipped_duplicate,
            "skipped_missing_fk": 0,
            "skipped_details": skipped_details,
        }
    return {
        "status": "finished",
        "inserted": inserted_count,
        "updated": updated_count,
        "skipped_invalid": skipped_invalid,
        "skipped_duplicate": skipped_duplicate,
        "skipped_missing_fk": 0,
        "skipped_details": skipped_details,
    }


def run_commit_sync(job_id: str) -> Dict[str, Any]:
    result = _do_commit(job_id)
    try:
        r = _get_redis()
        r.set(
            f"{DRV_IMPORT_STATUS_PREFIX}{job_id}",
            json.dumps(result).encode("utf-8"),
            ex=DRV_IMPORT_REDIS_TTL,
        )
    except Exception as e:
        logger.warning(f"Drivers import: failed to store commit status in Redis: {e}")
    return result


@celery_app.task(bind=True)
def insert_valid_rows(self, job_id: str):
    logger.info(f"Drivers import: starting commit for job {job_id}")
    result = _do_commit(job_id)
    try:
        r = _get_redis()
        r.set(
            f"{DRV_IMPORT_STATUS_PREFIX}{job_id}",
            json.dumps(result).encode("utf-8"),
            ex=DRV_IMPORT_REDIS_TTL,
        )
    except Exception as e:
        logger.warning(f"Drivers import: failed to store commit status in Redis: {e}")
    return result