"""
Upload Blueprint
Handles file upload and processing initiation endpoints.
"""

import uuid
import threading
from pathlib import Path
from flask import Blueprint, request, current_app
from werkzeug.utils import secure_filename
import yaml
from io import BytesIO


from ..app import process_data_async
from ..shared import _format_response, log_performance, logger, ALLOWED_DATA_EXTENSIONS, ALLOWED_CONFIG_EXTENSIONS, allowed_file, update_task_status, TASK_STATUS_PENDING, TASK_STATUS_FAILED
from ..auth import require_api_key

# Create blueprint
upload_bp = Blueprint('upload', __name__, url_prefix='/upload')


@upload_bp.route('', methods=['POST'])
@require_api_key
@log_performance
def upload_file():
    logger.info("Received upload request")
    logger.info(f"Request content length: {request.content_length} bytes")

    # Check if data file is present
    if 'file' not in request.files:
        logger.warning("Upload failed: No data file part in request")
        return _format_response(400, "未找到数据文件部分")

    data_file = request.files['file']
    config_file = request.files.get('config')

    # Log file details
    logger.info(f"Data file: {data_file.filename} (size: {getattr(data_file, 'content_length', 'unknown')} bytes)")
    if config_file:
        logger.info(f"Config file: {config_file.filename} (size: {getattr(config_file, 'content_length', 'unknown')} bytes)")
    else:
        logger.info("No custom config file provided, will use default")

    if data_file.filename == '':
        logger.warning("Upload failed: No data file selected (empty filename)")
        return _format_response(400, "未选择数据文件")

    if not allowed_file(data_file.filename, ALLOWED_DATA_EXTENSIONS):
        logger.warning(f"Upload failed: Invalid data file type {data_file.filename} - allowed: {ALLOWED_DATA_EXTENSIONS}")
        return _format_response(400, "无效的数据文件类型。只允许 .xlsx 和 .xls 格式。")

    # Generate unique job ID
    task_id = str(uuid.uuid4())
    logger.info(f"Generated job ID: {task_id}")

    # 1) Parse config content (parse in memory without saving first)
    if config_file and config_file.filename != '':
        if not allowed_file(config_file.filename, ALLOWED_CONFIG_EXTENSIONS):
            return _format_response(400, "无效的配置文件类型。只允许 .yaml 和 .yml 格式。")
        config_file.stream.seek(0)
        config_text = config_file.read().decode('utf-8', errors='ignore')
        try:
            active_config = yaml.safe_load(config_text)
        except Exception:
            return _format_response(400, "配置文件解析失败")
        # Reset stream for saving
        config_file.stream = BytesIO(config_text.encode('utf-8'))
    else:
        default_config_path = Path(__file__).parent.parent / "gasflux_config.yaml"
        with open(default_config_path, 'r', encoding='utf-8') as f:
            active_config = yaml.safe_load(f)

    # 2) Create job directories based on INI configuration
    upload_base = Path(current_app.config['UPLOAD_FOLDER'])
    output_base = Path(current_app.config['OUTPUT_FOLDER'])
    job_upload_dir = upload_base / task_id
    job_output_dir = output_base / task_id
    job_upload_dir.mkdir(parents=True, exist_ok=True)
    job_output_dir.mkdir(parents=True, exist_ok=True)
    logger.info(f"Job {task_id}: Created directories - Upload: {job_upload_dir}, Output: {job_output_dir}")

    # 3) Save data file to job_upload_dir
    data_filename = secure_filename(data_file.filename)
    data_path = job_upload_dir / data_filename
    try:
        data_file.seek(0)
        data_file.save(str(data_path))
        logger.info(f"Job {task_id}: Data file saved successfully - Path: {data_path}")
    except Exception as e:
        logger.error(f"Job {task_id}: Failed to save data file {data_filename}: {str(e)}")
        return _format_response(500, "保存数据文件失败")

    # 4) Save config file to job_upload_dir
    if config_file and config_file.filename != '':
        config_filename = secure_filename(config_file.filename)
        config_path = job_upload_dir / config_filename
        try:
            config_file.seek(0)
            config_file.save(str(config_path))
            active_config_path = config_path
            logger.info(f"Job {task_id}: Custom config saved successfully - Path: {config_path}")
        except Exception as e:
            logger.error(f"Job {task_id}: Failed to save config file {config_filename}: {str(e)}")
            return _format_response(500, "保存配置文件失败")
    else:
        # Copy default config for record keeping
        config_path = job_upload_dir / "config.yaml"
        with open(config_path, 'w', encoding='utf-8') as f:
            yaml.safe_dump(active_config, f, allow_unicode=True)
        active_config_path = config_path
        logger.info(f"Job {task_id}: Default config saved for record - Path: {config_path}")

    # Initialize task status
    update_task_status(task_id, TASK_STATUS_PENDING, "任务已加入处理队列", output_dir=str(job_output_dir))
    logger.info(f"Job {task_id}: Task status initialized as PENDING")

    # Start background processing
    try:
        thread = threading.Thread(
            target=process_data_async,
            args=(task_id, data_path, active_config_path, job_output_dir)
        )
        thread.daemon = True
        thread.start()
        logger.info(f"Job {task_id}: Background processing thread started successfully")
    except Exception as e:
        logger.error(f"Job {task_id}: Failed to start background processing thread: {str(e)}")
        update_task_status(task_id, TASK_STATUS_FAILED, error=str(e))
        return _format_response(500, "启动处理失败")

    logger.info(f"Job {task_id}: Upload process completed successfully, returning job ID to client")
    return _format_response(202, "任务已接受并加入处理队列", {
        "status": "accepted",
        "task_id": task_id,
        "task_status_url": f"/task/{task_id}"
    })