"""
批量导入 API

端点:
  GET  /api/v1/import/template?type=material|bom   → 下载Excel模板
  POST /api/v1/import/preview                       → Dry-Run预览+验证
  POST /api/v1/import/execute                       → 确认导入执行
"""
from flask import Blueprint, request, jsonify, send_file, current_app
from flask_jwt_extended import jwt_required
from app.utils.decorators import permission_required
from app.services.import_service import (
    generate_template,
    preview_material, preview_bom,
    execute_material_import, execute_bom_import,
)
import traceback

import_bp = Blueprint('import_bp', __name__, url_prefix='/api/v1/import')


@import_bp.route('/template', methods=['GET'])
@jwt_required()
@permission_required('material_list')
def download_template():
    """下载导入模板"""
    try:
        import_type = request.args.get('type', 'material').strip()
        if import_type not in ('material', 'bom'):
            return jsonify({'code': 400, 'msg': 'type 必须为 material 或 bom'}), 400

        file_stream = generate_template(import_type)
        filename = f"{'基础信息' if import_type == 'material' else 'BOM表'}_导入模板.xlsx"

        return send_file(
            file_stream,
            mimetype='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
            as_attachment=True,
            download_name=filename
        )
    except Exception as e:
        current_app.logger.error(f'下载模板失败: {str(e)}')
        return jsonify({'code': 500, 'msg': str(e)}), 500


@import_bp.route('/preview', methods=['POST'])
@jwt_required()
@permission_required('material_list:operation')
def preview_import():
    """Dry-Run 预览 + 验证（不写入数据库）"""
    try:
        import_type = request.form.get('type', 'material').strip()
        file = request.files.get('file')
        if not file:
            return jsonify({'code': 400, 'msg': '请上传文件'}), 400
        if import_type not in ('material', 'bom'):
            return jsonify({'code': 400, 'msg': 'type 必须为 material 或 bom'}), 400

        file_stream = file.read()
        from io import BytesIO

        if import_type == 'material':
            results = preview_material(BytesIO(file_stream))
        else:
            results = preview_bom(BytesIO(file_stream))

        success_count = sum(1 for r in results if r['status'] == 'success')
        error_count = sum(1 for r in results if r['status'] == 'error')

        return jsonify({
            'code': 200, 'msg': '预览完成',
            'data': {
                'rows': results,
                'total': len(results),
                'success_count': success_count,
                'error_count': error_count,
            }
        })
    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'预览失败: {str(e)}'}), 500


@import_bp.route('/execute', methods=['POST'])
@jwt_required()
@permission_required('material_list:operation')
def execute_import():
    """确认导入执行（事务保护）"""
    try:
        data = request.get_json() or {}
        import_type = data.get('type', 'material').strip()
        rows = data.get('rows', [])

        if not rows:
            return jsonify({'code': 400, 'msg': '导入数据不能为空'}), 400
        if import_type not in ('material', 'bom'):
            return jsonify({'code': 400, 'msg': 'type 必须为 material 或 bom'}), 400

        # 仅导入状态为 success 的行
        valid_rows = [r for r in rows if r.get('status') == 'success']
        if not valid_rows:
            return jsonify({'code': 400, 'msg': '没有可导入的有效数据（全部为error状态）'}), 400

        if import_type == 'material':
            result = execute_material_import(valid_rows)
        else:
            result = execute_bom_import(valid_rows)

        code = 200 if result['success'] else 400
        return jsonify({'code': code, 'msg': result['msg'], 'data': result})

    except Exception as e:
        traceback.print_exc()
        return jsonify({'code': 500, 'msg': f'导入失败: {str(e)}'}), 500