"""Import API routes for XLSX file import operations."""
from flask import request, send_file
from flask_restx import Namespace, Resource, fields
from werkzeug.datastructures import FileStorage
from app.services.import_service import ImportService
from app.utils.auth_decorator import require_auth

import_ns = Namespace('import', description='数据导入接口')

# File upload parser
upload_parser = import_ns.parser()
upload_parser.add_argument(
    'file',
    location='files',
    type=FileStorage,
    required=True,
    help='XLSX文件'
)

# Response models for Swagger documentation
error_response = import_ns.model('ImportErrorResponse', {
    'success': fields.Boolean(description='操作是否成功'),
    'error': fields.String(description='错误信息'),
    'errors': fields.List(fields.String, description='错误信息列表'),
    'code': fields.String(description='错误代码')
})

success_response = import_ns.model('ImportSuccessResponse', {
    'success': fields.Boolean(description='操作是否成功'),
    'count': fields.Integer(description='成功导入的记录数')
})


@import_ns.route('/template')
class ImportTemplate(Resource):
    """Resource for downloading import template."""
    
    @import_ns.doc('download_template')
    @import_ns.response(200, 'XLSX模板文件下载')
    @import_ns.response(500, '服务器错误', error_response)
    @import_ns.produces(['application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'])
    @require_auth
    def get(self):
        """下载导入模板
        
        下载包含以下列的XLSX模板文件:
        - 人员姓名
        - 物品名称
        - 工作日期 (格式: YYYY-MM-DD)
        - 数量
        
        Requirements: 3.6
        """
        try:
            template_file = ImportService.generate_template()
            
            return send_file(
                template_file,
                mimetype='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
                as_attachment=True,
                download_name='import_template.xlsx'
            )
        except Exception as e:
            return {
                'success': False,
                'error': f'生成模板失败: {str(e)}',
                'code': 'SERVER_ERROR'
            }, 500


@import_ns.route('/upload')
class ImportUpload(Resource):
    """Resource for uploading and importing XLSX files."""
    
    @import_ns.doc('upload_import')
    @import_ns.expect(upload_parser)
    @import_ns.response(200, '导入成功', success_response)
    @import_ns.response(400, '验证错误', error_response)
    @import_ns.response(500, '服务器错误', error_response)
    @require_auth
    def post(self):
        """上传并导入XLSX文件
        
        上传XLSX文件并批量创建工作记录。
        文件大小限制: 5MB
        
        验证规则:
        - 文件必须是XLSX格式
        - 必须包含所有必需列
        - 人员姓名必须匹配系统中已存在的人员
        - 物品名称必须匹配系统中已存在的物品
        - 工作日期格式必须为 YYYY-MM-DD
        - 数量必须为正数
        
        Requirements: 4.9, 4.11, 4.12
        """
        # Check if file is present
        if 'file' not in request.files:
            return {
                'success': False,
                'error': '请选择要上传的文件',
                'code': 'VALIDATION_ERROR'
            }, 400
        
        file = request.files['file']
        
        # Check if file is selected
        if file.filename == '':
            return {
                'success': False,
                'error': '请选择要上传的文件',
                'code': 'VALIDATION_ERROR'
            }, 400
        
        # Check file extension
        if not file.filename.lower().endswith('.xlsx'):
            return {
                'success': False,
                'error': '文件格式错误，请上传XLSX文件',
                'code': 'VALIDATION_ERROR'
            }, 400
        
        # Read file content and check size
        file_content = file.read()
        
        # Validate file size (5MB limit)
        if len(file_content) > ImportService.MAX_FILE_SIZE:
            return {
                'success': False,
                'error': '文件大小超过限制(最大5MB)',
                'code': 'VALIDATION_ERROR'
            }, 400
        
        try:
            # Parse and validate file content
            valid_records, errors = ImportService.parse_and_validate(file_content)
            
            # If there are validation errors, return them (atomic operation - no records created)
            if errors:
                return {
                    'success': False,
                    'errors': errors,
                    'code': 'VALIDATION_ERROR'
                }, 400
            
            # If no valid records found
            if not valid_records:
                return {
                    'success': False,
                    'error': '文件中没有有效的数据行',
                    'code': 'VALIDATION_ERROR'
                }, 400
            
            # Import the validated records
            count = ImportService.import_records(valid_records)
            
            return {
                'success': True,
                'count': count
            }, 200
            
        except Exception as e:
            return {
                'success': False,
                'error': f'导入失败: {str(e)}',
                'code': 'SERVER_ERROR'
            }, 500