import { NextApiResponse } from 'next';
import { methodNotAllowed, ok, unauthorized } from 'next-basics';
import { WebsiteMetric, NextApiRequestQueryBody } from 'lib/types';
import { canViewWebsite } from 'lib/auth';
import { useAuth, useCors } from 'lib/middleware';
import { SESSION_COLUMNS, EVENT_COLUMNS, FILTER_COLUMNS } from 'lib/constants';
import { getPageviewMetrics, getSessionMetrics } from 'queries';

export interface WebsiteMetricsRequestQuery {
  id: string;
  type: string;
  startAt: number;
  endAt: number;
  url: string;
  referrer: string;
  title: string;
  query: string;
  event: string;
  os: string;
  browser: string;
  device: string;
  country: string;
  subdivision1: string;
  subdivision2: string;
  city: string;
}

export default async (
  req: NextApiRequestQueryBody<WebsiteMetricsRequestQuery>,
  res: NextApiResponse<WebsiteMetric[]>,
) => {
  await useCors(req, res);
  await useAuth(req, res);

  const {
    id: websiteId,
    type,
    startAt,
    endAt,
    url,
    referrer,
    title,
    query,
    event,
    os,
    browser,
    device,
    country,
    subdivision1,
    subdivision2,
    city,
  } = req.query;

  if (req.method === 'GET') {
    if (!(await canViewWebsite(req.auth, websiteId))) {
      return unauthorized(res);
    }

    const startDate = new Date(+startAt);
    const endDate = new Date(+endAt);

    if (SESSION_COLUMNS.includes(type)) {
      const column = FILTER_COLUMNS[type] || type;
      const filters = {
        os,
        browser,
        device,
        country,
        subdivision1,
        subdivision2,
        city,
      };

      filters[type] = undefined;

      let data = await getSessionMetrics(websiteId, {
        startDate,
        endDate,
        column,
        filters,
      });

      if (type === 'language') {
        const combined = {};

        for (const { x, y } of data) {
          const key = String(x).toLowerCase().split('-')[0];

          if (combined[key] === undefined) {
            combined[key] = { x: key, y };
          } else {
            combined[key].y += y;
          }
        }

        data = Object.values(combined);
      }

      return ok(res, data);
    }

    if (EVENT_COLUMNS.includes(type)) {
      const column = FILTER_COLUMNS[type] || type;
      const filters = {
        url,
        referrer,
        title,
        query,
        event,
        os,
        browser,
        device,
        country,
        subdivision1,
        subdivision2,
        city,
      };

      filters[type] = undefined;

      const data = await getPageviewMetrics(websiteId, {
        startDate,
        endDate,
        column,
        filters,
      });

      return ok(res, data);
    }
  }

  return methodNotAllowed(res);
};