"""
Rutas de importacion CSV para Conductores.
Flujo: upload -> scan -> status (polling) -> commit.
"""
import json
import logging
import os
import threading
from uuid import uuid4

from fastapi import APIRouter, File, HTTPException, Query, UploadFile, Depends
from sqlalchemy.orm import Session
from typing import Dict, Any

from core.celery_app import celery_app
from core.database import get_core_db
from core.security import get_current_user, validate_access_to_resource

from .schemas import ImportJobResponse
from .tasks import (
    run_scan_sync,
    run_commit_sync,
    JOB_TYPE,
    DRV_IMPORT_STATUS_PREFIX,
    DRV_IMPORT_REDIS_TTL,
)
from ..common import storage as common_storage
from ..common.error_csv import download_scan_errors_csv_stream
from ..common.responses import normalize_commit_status_payload

router = APIRouter()
logger = logging.getLogger(__name__)


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)


@router.post("/upload", response_model=ImportJobResponse)
async def upload_import_file(
    file: UploadFile = File(...),
    company_id: int = Query(..., description="Company ID"),
    db: Session = Depends(get_core_db),
    current_user: Dict[str, Any] = Depends(get_current_user),
):
    try:
        tenant_id = validate_access_to_resource(db, company_id, current_user, ["csv_upload.process"])
    except Exception as e:
        logger.error(f"Drivers import: access validation failed: {e}")
        raise HTTPException(status_code=403, detail="Invalid company access")

    if not file.filename or not file.filename.lower().endswith(".csv"):
        raise HTTPException(status_code=400, detail="Solo se permiten archivos .csv")

    job_id = str(uuid4())
    contents = await file.read()

    meta_data = {
        "tenant_id": tenant_id,
        "company_id": company_id,
        "user_id": current_user.get("id"),
        "template_id": "drivers",
    }

    try:
        common_storage.store_import_file(
            JOB_TYPE,
            job_id,
            contents,
            meta_data,
            tenant_id=int(tenant_id),
            company_id=company_id,
            ttl=DRV_IMPORT_REDIS_TTL,
            log_label="Drivers import",
        )
    except common_storage.ImportStoreError as e:
        logger.error(f"Drivers import: store error: {e}")
        raise HTTPException(status_code=500, detail="No se pudo encolar el archivo.")
    except Exception as e:
        logger.error(f"Drivers import: Redis store error: {e}")
        raise HTTPException(status_code=500, detail="No se pudo encolar el archivo.")

    def run_scan_background():
        try:
            run_scan_sync(job_id)
        except Exception as e:
            logger.exception(f"Drivers import: background scan failed: {e}")

    threading.Thread(target=run_scan_background, daemon=True).start()

    return ImportJobResponse(
        job_id=job_id,
        status="queued",
        message="Archivo subido. Escaneo iniciado.",
    )


@router.get("/{job_id}/status")
async def get_import_status(job_id: str):
    try:
        r = _get_redis()
        raw = r.get(f"{DRV_IMPORT_STATUS_PREFIX}{job_id}")
        if raw:
            data = json.loads(raw.decode("utf-8"))
            if isinstance(data, dict) and data.get("status") in ("finished", "warning"):
                return normalize_commit_status_payload(data)
            return data
    except Exception as e:
        logger.debug(f"Drivers import: could not read status from Redis: {e}")

    task_result = celery_app.AsyncResult(job_id)

    if task_result.state == "PENDING":
        return {"status": "processing", "progress": 0}
    if task_result.state == "PROGRESS":
        info = (task_result.info or {})
        return {
            "status": "processing",
            "progress": info.get("current", 0),
            "total": info.get("total", 0),
        }
    if task_result.state == "SUCCESS":
        result = task_result.result
        if isinstance(result, dict) and "status" in result:
            return normalize_commit_status_payload(result)
        return {"status": "finished", "result": result}

    result = getattr(task_result, "result", None)
    if isinstance(result, dict) and result.get("status") in ("finished", "warning"):
        return normalize_commit_status_payload(result)

    logger.warning("Drivers import task %s failed: state=%s", job_id, task_result.state)
    err_msg = None
    tb = getattr(task_result, "traceback", None)
    if tb and isinstance(tb, str):
        lines = [l.strip() for l in tb.strip().split("\n") if l.strip()]
        if lines:
            err_msg = lines[-1]
    if not err_msg:
        try:
            exc = task_result.get(propagate=False)
            if exc is not None:
                err_msg = str(exc)
        except Exception:
            pass
    if not err_msg and result is not None:
        if not isinstance(result, dict):
            err_msg = str(result)
        elif result.get("error") or result.get("message"):
            err_msg = result.get("error") or result.get("message")
    return {"status": "failed", "error": err_msg or "Task failed"}


@router.post("/{job_id}/commit")
async def commit_import_job(job_id: str):
    try:
        r = _get_redis()
        r.set(
            f"{DRV_IMPORT_STATUS_PREFIX}{job_id}",
            json.dumps({"status": "processing", "message": "Insertando..."}).encode("utf-8"),
            ex=DRV_IMPORT_REDIS_TTL,
        )
    except Exception as e:
        logger.debug(f"Drivers import: could not write processing status: {e}")

    def run_commit_background():
        try:
            run_commit_sync(job_id)
        except Exception as e:
            logger.exception(f"Drivers import: background commit failed: {e}")

    threading.Thread(target=run_commit_background, daemon=True).start()

    return {
        "status": "committing",
        "message": "Insercion iniciada.",
        "commit_job_id": job_id,
    }


@router.get("/{job_id}/errors/scan-csv")
async def download_scan_errors_csv(job_id: str):
    return download_scan_errors_csv_stream("drv", job_id)
