from django.shortcuts import render
from apps.utils.viewsets import CustomModelViewSet
from rest_framework.decorators import action
from rest_framework.response import Response
from apps.bi.models import Dataset, Report
from apps.bi.serializers import DatasetSerializer, DatasetCreateUpdateSerializer, ReportCreateUpdateSerializer, ReportSerializer, ReportExecSerializer
import concurrent.futures
from django.core.cache import cache
from apps.utils.sql import execute_raw_sql
from apps.bi.services import check_sql_safe
# Create your views here.

class DatasetViewSet(CustomModelViewSet):
    queryset = Dataset.objects.all()
    serializer_class = DatasetSerializer
    create_serializer_class = DatasetCreateUpdateSerializer
    update_serializer_class = DatasetCreateUpdateSerializer
    search_fields = ['name']


class ReportViewSet(CustomModelViewSet):
    queryset = Report.objects.all()
    serializer_class = ReportSerializer
    create_serializer_class = ReportCreateUpdateSerializer
    update_serializer_class = ReportCreateUpdateSerializer
    search_fields = ['name', 'code']

    @action(methods=['post'], detail=True, perms_map={'post': '*'}, serializer_class=ReportExecSerializer)
    def exec(self, request, pk=None):
        """执行报表查询

        执行报表查询并用于返回前端渲染
        """
        report = self.get_object()
        rdata = ReportSerializer(instance=report).data
        query = request.data.get('query', {})
        query['r_user'] = request.user.id
        query['r_dept'] = request.user.belong_dept.id if request.user.belong_dept else ''
        datasets = report.datasets.all()
        results = {}
        seconds = 10   # 缓存秒数

        with concurrent.futures.ThreadPoolExecutor(max_workers=6) as executor:   # 多线程运行并返回字典结果
            fun_ps = []
            for ds in datasets:
                sql_query = ds.sql_query
                if sql_query:
                    sql_f = check_sql_safe(sql_query.format(**query))  # 有风险先这样处理一下
                    res = cache.get(sql_f, None)
                    if isinstance(res, list):
                        results[ds.name] = res
                    else:
                        fun_ps.append((ds.name, execute_raw_sql, sql_f, seconds))
            # 生成执行函数
            futures = {executor.submit(i[1], i[2]): i for i in fun_ps}
            for future in concurrent.futures.as_completed(futures):
                name, *_, sql_f, seconds = futures[future]  # 获取对应的键
                try:
                    r = future.result()
                    results[name] = r
                    if seconds:
                        cache.set(sql_f, r, seconds)
                except Exception as e:
                    results[name] = 'error: ' + str(e)

        rdata['data'] = results
        return Response(rdata)