import json
import os
import urllib.parse

import openpyxl
from openpyxl.utils import get_column_letter
from openpyxl.worksheet.datavalidation import DataValidation
from django.apps import apps
from django.core.exceptions import ValidationError
from openpyxl import load_workbook

from django.conf import settings
from django.contrib.auth.decorators import login_required
from django.contrib.staticfiles import finders
from django.core.files.storage import default_storage
from django.http import FileResponse, HttpResponseNotFound, JsonResponse
from django.views.decorators.csrf import csrf_exempt, csrf_protect
from rest_framework.decorators import api_view
from rest_framework.serializers import ModelSerializer


@login_required
def download_excel_template(request, template_name, fields):
    """
    该视图提供下载指定的Excel模板文件。

    参数:
        request: HttpRequest对象。
        template_name: 请求下载的Excel模板文件的名称，期望是一个字符串。
        fields: 包含字段信息的字典，用于生成Excel文件的表头和格式。

    返回:
        FileResponse对象，允许用户下载生成的Excel文件。
        如果文件未找到，则返回一个HttpResponseNotFound响应。
    """
    fields = json.loads(urllib.parse.unquote(fields).replace("'", '"'))

    # 创建一个新的工作簿
    wb = openpyxl.Workbook()
    ws = wb.active

    # 设置表头行
    headers = [config['label'] for field, config in fields.items()]
    ws.append(headers)

    # 保存生成的Excel文件到指定路径
    static_dir = os.path.join(settings.BASE_DIR, 'static', 'excels')
    if not os.path.exists(static_dir):
        os.makedirs(static_dir)
    temp_file_path = os.path.join(static_dir, template_name)
    wb.save(temp_file_path)

    # 创建FileResponse对象，设置为以附件形式下载，设置MIME类型为Excel文件
    response = FileResponse(open(temp_file_path, 'rb'),
                            content_type='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet')

    response['Content-Disposition'] = f'attachment; filename="{urllib.parse.quote(template_name)}"'

    return response


@csrf_protect
@login_required
def common_excel_parse(request):
    """
    该函数用于解析上传的Excel文件并返回数据。

    Args:
        request: HTTP请求对象，包含上传的Excel文件。

    Returns:
        JsonResponse: 包含解析后的Excel数据的JSON响应，或包含错误消息的JSON响应。

    Raises:
        N/A
    """

    # 如果是POST请求并且有上传的文件
    if request.method == 'POST' and request.FILES:
        # 获取上传的Excel文件
        excel_file = request.FILES.get('excel_file')

        # 如果没有提供文件，返回错误响应
        if not excel_file:
            return JsonResponse({'error': '请先选择文件。'}, status=400)

        # 获取fields_map和model_config
        fields_map = json.loads(request.POST.get('fields_map', '{}'))
        model_config = json.loads(request.POST.get('model_config', '{}'))

        # 动态获取模型
        try:
            model = apps.get_model(model_config['app_label'], model_config['model_name'])
        except (LookupError, KeyError):
            return JsonResponse({'error': '模型配置错误。'}, status=400)

        columns = list(fields_map.values())
        fields = list(fields_map.keys())

        # 保存文件到服务器
        file_name = default_storage.save(excel_file.name, excel_file)
        file_path = os.path.join(settings.MEDIA_ROOT, file_name)

        def create_dynamic_serializer(mod):
            class DynamicSerializer(ModelSerializer):
                class Meta:
                    model = mod
                    fields = '__all__'

            return DynamicSerializer

        try:
            # 打开并解析Excel文件
            workbook = load_workbook(file_path, data_only=True)
            sheet = workbook.active
            data = []

            # 读取第一行作为表头
            header_row = [cell.value for cell in sheet[1]]

            # 检查表头是否与fields_map的values对应
            if header_row != columns:
                return JsonResponse({'error': '表头不匹配，请使用正确的Excel上传模板。'}, status=400)

            for row in sheet.iter_rows(min_row=2, values_only=True):
                if not all(value is None for value in row):
                    instance_data = dict(zip(fields, row))
                    instance = model(**instance_data)
                    try:
                        instance.full_clean()
                        data.append(instance)
                    except ValidationError as e:
                        return JsonResponse({'error': f'数据校验错误: {e.message_dict}'}, status=400)

            # 动态获取序列化器
            serializer_class = create_dynamic_serializer(model)

            serializer = serializer_class(data, many=True)

            # 清理，删除上传的文件
            os.remove(file_path)
            return JsonResponse(serializer.data, safe=False)
        except Exception as e:
            # 清理，删除上传的文件
            os.remove(file_path)
            return JsonResponse({'error': f'解析文件时出错: {str(e)}'}, status=500)

    return JsonResponse({'error': '请求错误'}, status=400)


@csrf_protect
@login_required
def save_excel_table_data(request):
    if request.method == 'POST':
        try:
            data = json.loads(request.body)
            app_label = data.get('app_label')
            model_name = data.get('model_name')
            table_data = data.get('table_data')

            if not app_label or not model_name or not table_data:
                return JsonResponse({'error': '缺少必要的参数'}, status=400)

            Model = apps.get_model(app_label, model_name)

            for row_data in table_data:
                try:
                    instance = Model(**row_data)
                    instance.full_clean()  # 验证数据
                    instance.save()
                except ValidationError as e:
                    return JsonResponse({'error': f'数据校验错误: {e.message_dict}'}, status=400)
                except Exception as e:
                    return JsonResponse({'error': f'保存数据时出错: {str(e)}'}, status=500)

            return JsonResponse({'message': '表格数据保存成功'}, status=200)
        except json.JSONDecodeError:
            return JsonResponse({'error': '无效的JSON格式'}, status=400)
        except Exception as e:
            return JsonResponse({'error': f'服务器内部错误: {str(e)}'}, status=500)
    return JsonResponse({'error': '无效的请求方法'}, status=400)