"""
Tareas Celery para importación CSV de BOMs.
Flujo: scan_file (validación) → insert_valid_rows (commit).
Sin tabla BOM dedicada aún: insert_valid_rows solo valida y cuenta filas válidas.
Usa layouts_csv.common y common.fk_loader, validators.
"""
import json
import logging
import os
from typing import Dict, Any, List

from core.celery_app import celery_app

from ..common import storage as common_storage
from ..common import normalize as common_normalize
from ..common import csv_reader as common_csv
from ..common import meta as common_meta
from ..common import responses as common_responses
from .template_config import row_from_template
from .validators import validate_row_bom
from .common.fk_loader import load_boms_fk_sets

logger = logging.getLogger(__name__)

JOB_TYPE = "bom"

# Para routes.py
BOM_IMPORT_FILE_PREFIX = "bom_import_file:"
BOM_IMPORT_META_PREFIX = "bom_import_meta:"
BOM_IMPORT_ERROR_LINES_PREFIX = "bom_import_error_lines:"
BOM_IMPORT_REDIS_TTL = common_storage.IMPORT_REDIS_TTL


@celery_app.task(bind=True)
def scan_file(self, job_id: str, config: str = None):
    logger.info("BOMs import: starting scan for job %s", job_id)

    file_path = common_storage.ensure_file_from_redis(JOB_TYPE, job_id, "BOMs import")
    if not file_path:
        return {"status": "failed", "error": "Archivo no encontrado (expirado o no subido). Sube de nuevo."}
    common_storage.ensure_meta_from_redis(JOB_TYPE, job_id, file_path, "BOMs import")

    error_path = common_storage.error_path_for_job(JOB_TYPE, job_id)

    try:
        total_rows = common_csv.count_csv_rows(file_path)
    except Exception as e:
        return {"status": "failed", "error": str(e)}

    try:
        tenant_id, company_id = common_meta.require_tenant_context(file_path)
    except ValueError as e:
        return {"status": "failed", "error": str(e)}

    valid_part_numbers = load_boms_fk_sets(tenant_id, company_id)

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

    try:
        with open(error_path, "w", encoding="utf-8") as f_err:
            for i, row in common_csv.iter_csv_rows(file_path):
                if i % 500 == 0:
                    self.update_state(
                        state="PROGRESS",
                        meta={"current": i, "total": total_rows, "errors": error_count},
                    )
                row_norm = row_from_template(row, common_normalize.normalize_header)
                err = validate_row_bom(row_norm, i, valid_part_numbers=valid_part_numbers)
                if err:
                    error_count += 1
                    error_lines_list.append(err["line"])
                    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

        if error_lines_list:
            common_storage.store_error_lines(JOB_TYPE, job_id, error_lines_list)
    except Exception as e:
        logger.error("BOMs import scan failed: %s", e)
        return {"status": "failed", "error": str(e)}

    return common_responses.scan_result(
        job_id, processed_rows, error_count, errors_detail
    )


@celery_app.task(bind=True)
def insert_valid_rows(self, job_id: str):
    logger.info("BOMs import: starting commit for job %s", job_id)

    file_path = common_storage.ensure_file_from_redis(JOB_TYPE, job_id, "BOMs import")
    if not file_path:
        alt_path = common_storage.file_path_for_job(JOB_TYPE, job_id)
        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:
        common_storage.ensure_meta_from_redis(JOB_TYPE, job_id, file_path, "BOMs import")

    error_path = common_storage.error_path_for_job(JOB_TYPE, job_id)
    error_lines = common_storage.get_error_lines(JOB_TYPE, job_id, error_path)

    try:
        tenant_id, company_id = common_meta.require_tenant_context(file_path)
    except ValueError as e:
        return {"status": "failed", "error": str(e)}

    valid_part_numbers = load_boms_fk_sets(tenant_id, company_id)

    inserted_count = 0
    skipped_invalid = 0
    valid_count = 0
    skipped_details: List[Dict[str, Any]] = []
    response = None
    meta_path = common_meta.get_meta_path(file_path)

    try:
        for i, row in common_csv.iter_csv_rows(file_path):
            if i in error_lines:
                continue

            row_norm = row_from_template(row, common_normalize.normalize_header)
            err = validate_row_bom(row_norm, i, valid_part_numbers=valid_part_numbers)
            if err:
                skipped_invalid += 1
                skipped_details.append({
                    "line": i,
                    "reason": f"{err.get('col', '')}: {err.get('msg', '')}",
                })
                continue

            valid_count += 1
            # Sin tabla BOM dedicada: no se escribe en DB; solo se cuentan filas válidas.

        response = common_responses.commit_result(
            "finished", inserted_count, skipped_invalid, 0, 0, skipped_details,
        )
        if valid_count > 0 and inserted_count == 0:
            response["message"] = (
                f"WIP: {valid_count} filas válidas. "
                "La tabla BOM aún no existe en el sistema; no se insertó nada."
            )
    except Exception as e:
        logger.exception("BOMs import task failed")
        response = common_responses.commit_result(
            "failed", 0, skipped_invalid, 0, 0, skipped_details, error=str(e),
        )

    common_storage.cleanup_import_job(
        JOB_TYPE, job_id,
        file_path=file_path,
        error_path=error_path,
        meta_path=meta_path,
    )

    if response is None:
        response = common_responses.commit_result(
            "failed", 0, skipped_invalid, 0, 0, skipped_details, error="Error inesperado",
        )
    return response