import React, { useEffect, useState } from 'react';
import { Button, Form, Label, Pagination, Popup, Table } from 'semantic-ui-react';
import { Link } from 'react-router-dom';
import { API, showError, showInfo, showSuccess, timestamp2string } from '../helpers';

import { CHANNEL_OPTIONS, ITEMS_PER_PAGE } from '../constants';

function renderTimestamp(timestamp) {
  return (
    <>
      {timestamp2string(timestamp)}
    </>
  );
}

let type2label = undefined;

function renderType(type) {
  if (!type2label) {
    type2label = new Map;
    for (let i = 0; i < CHANNEL_OPTIONS.length; i++) {
      type2label[CHANNEL_OPTIONS[i].value] = CHANNEL_OPTIONS[i];
    }
    type2label[0] = { value: 0, text: '未知类型', color: 'grey' };
  }
  return <Label basic color={type2label[type].color}>{type2label[type].text}</Label>;
}

const ChannelsTable = () => {
  const [channels, setChannels] = useState([]);
  const [loading, setLoading] = useState(true);
  const [activePage, setActivePage] = useState(1);
  const [searchKeyword, setSearchKeyword] = useState('');
  const [searching, setSearching] = useState(false);

  const loadChannels = async (startIdx) => {
    const res = await API.get(`/api/channel/?p=${startIdx}`);
    const { success, message, data } = res.data;
    if (success) {
      if (startIdx === 0) {
        setChannels(data);
      } else {
        let newChannels = channels;
        newChannels.push(...data);
        setChannels(newChannels);
      }
    } else {
      showError(message);
    }
    setLoading(false);
  };

  const onPaginationChange = (e, { activePage }) => {
    (async () => {
      if (activePage === Math.ceil(channels.length / ITEMS_PER_PAGE) + 1) {
        // In this case we have to load more data and then append them.
        await loadChannels(activePage - 1);
      }
      setActivePage(activePage);
    })();
  };

  useEffect(() => {
    loadChannels(0)
      .then()
      .catch((reason) => {
        showError(reason);
      });
  }, []);

  const manageChannel = async (id, action, idx) => {
    let data = { id };
    let res;
    switch (action) {
      case 'delete':
        res = await API.delete(`/api/channel/${id}/`);
        break;
      case 'enable':
        data.status = 1;
        res = await API.put('/api/channel/', data);
        break;
      case 'disable':
        data.status = 2;
        res = await API.put('/api/channel/', data);
        break;
    }
    const { success, message } = res.data;
    if (success) {
      showSuccess('操作成功完成！');
      let channel = res.data.data;
      let newChannels = [...channels];
      let realIdx = (activePage - 1) * ITEMS_PER_PAGE + idx;
      if (action === 'delete') {
        newChannels[realIdx].deleted = true;
      } else {
        newChannels[realIdx].status = channel.status;
      }
      setChannels(newChannels);
    } else {
      showError(message);
    }
  };

  const renderStatus = (status) => {
    switch (status) {
      case 1:
        return <Label basic color='green'>已启用</Label>;
      case 2:
        return (
          <Label basic color='red'>
            已禁用
          </Label>
        );
      default:
        return (
          <Label basic color='grey'>
            未知状态
          </Label>
        );
    }
  };

  const renderResponseTime = (responseTime) => {
    let time = responseTime / 1000;
    time = time.toFixed(2) + " 秒";
    if (responseTime === 0) {
      return <Label basic color='grey'>未测试</Label>;
    } else if (responseTime <= 1000) {
      return <Label basic color='green'>{time}</Label>;
    } else if (responseTime <= 3000) {
      return <Label basic color='olive'>{time}</Label>;
    } else if (responseTime <= 5000) {
      return <Label basic color='yellow'>{time}</Label>;
    } else {
      return <Label basic color='red'>{time}</Label>;
    }
  };

  const searchChannels = async () => {
    if (searchKeyword === '') {
      // if keyword is blank, load files instead.
      await loadChannels(0);
      setActivePage(1);
      return;
    }
    setSearching(true);
    const res = await API.get(`/api/channel/search?keyword=${searchKeyword}`);
    const { success, message, data } = res.data;
    if (success) {
      setChannels(data);
      setActivePage(1);
    } else {
      showError(message);
    }
    setSearching(false);
  };

  const testChannel = async (id, name, idx) => {
    const res = await API.get(`/api/channel/test/${id}/`);
    const { success, message, time } = res.data;
    if (success) {
      let newChannels = [...channels];
      let realIdx = (activePage - 1) * ITEMS_PER_PAGE + idx;
      newChannels[realIdx].response_time = time * 1000;
      newChannels[realIdx].test_time = Date.now() / 1000;
      setChannels(newChannels);
      showInfo(`通道 ${name} 测试成功，耗时 ${time} 秒。`);
    } else {
      showError(message);
    }
  };

  const testAllChannels = async () => {
    const res = await API.get(`/api/channel/test`);
    const { success, message } = res.data;
    if (success) {
      showSuccess("已成功开始测试所有已启用通道，请刷新页面查看结果。");
    } else {
      showError(message);
    }
  }

  const handleKeywordChange = async (e, { value }) => {
    setSearchKeyword(value.trim());
  };

  const sortChannel = (key) => {
    if (channels.length === 0) return;
    setLoading(true);
    let sortedChannels = [...channels];
    sortedChannels.sort((a, b) => {
      return ('' + a[key]).localeCompare(b[key]);
    });
    if (sortedChannels[0].id === channels[0].id) {
      sortedChannels.reverse();
    }
    setChannels(sortedChannels);
    setLoading(false);
  };

  return (
    <>
      <Form onSubmit={searchChannels}>
        <Form.Input
          icon='search'
          fluid
          iconPosition='left'
          placeholder='搜索渠道的 ID 和名称 ...'
          value={searchKeyword}
          loading={searching}
          onChange={handleKeywordChange}
        />
      </Form>

      <Table basic>
        <Table.Header>
          <Table.Row>
            <Table.HeaderCell
              style={{ cursor: 'pointer' }}
              onClick={() => {
                sortChannel('id');
              }}
            >
              ID
            </Table.HeaderCell>
            <Table.HeaderCell
              style={{ cursor: 'pointer' }}
              onClick={() => {
                sortChannel('name');
              }}
            >
              名称
            </Table.HeaderCell>
            <Table.HeaderCell
              style={{ cursor: 'pointer' }}
              onClick={() => {
                sortChannel('type');
              }}
            >
              类型
            </Table.HeaderCell>
            <Table.HeaderCell
              style={{ cursor: 'pointer' }}
              onClick={() => {
                sortChannel('status');
              }}
            >
              状态
            </Table.HeaderCell>
            <Table.HeaderCell
              style={{ cursor: 'pointer' }}
              onClick={() => {
                sortChannel('response_time');
              }}
            >
              响应时间
            </Table.HeaderCell>
            <Table.HeaderCell
              style={{ cursor: 'pointer' }}
              onClick={() => {
                sortChannel('test_time');
              }}
            >
              测试时间
            </Table.HeaderCell>
            <Table.HeaderCell>操作</Table.HeaderCell>
          </Table.Row>
        </Table.Header>

        <Table.Body>
          {channels
            .slice(
              (activePage - 1) * ITEMS_PER_PAGE,
              activePage * ITEMS_PER_PAGE
            )
            .map((channel, idx) => {
              if (channel.deleted) return <></>;
              return (
                <Table.Row key={channel.id}>
                  <Table.Cell>{channel.id}</Table.Cell>
                  <Table.Cell>{channel.name ? channel.name : '无'}</Table.Cell>
                  <Table.Cell>{renderType(channel.type)}</Table.Cell>
                  <Table.Cell>{renderStatus(channel.status)}</Table.Cell>
                  <Table.Cell>{renderResponseTime(channel.response_time)}</Table.Cell>
                  <Table.Cell>{channel.test_time ? renderTimestamp(channel.test_time) : "未测试"}</Table.Cell>
                  <Table.Cell>
                    <div>
                      <Button
                        size={'small'}
                        positive
                        onClick={() => {
                          testChannel(channel.id, channel.name, idx);
                        }}
                      >
                        测试
                      </Button>
                      <Popup
                        trigger={
                          <Button size='small' negative>
                            删除
                          </Button>
                        }
                        on='click'
                        flowing
                        hoverable
                      >
                        <Button
                          negative
                          onClick={() => {
                            manageChannel(channel.id, 'delete', idx);
                          }}
                        >
                          删除渠道 {channel.name}
                        </Button>
                      </Popup>
                      <Button
                        size={'small'}
                        onClick={() => {
                          manageChannel(
                            channel.id,
                            channel.status === 1 ? 'disable' : 'enable',
                            idx
                          );
                        }}
                      >
                        {channel.status === 1 ? '禁用' : '启用'}
                      </Button>
                      <Button
                        size={'small'}
                        as={Link}
                        to={'/channel/edit/' + channel.id}
                      >
                        编辑
                      </Button>
                    </div>
                  </Table.Cell>
                </Table.Row>
              );
            })}
        </Table.Body>

        <Table.Footer>
          <Table.Row>
            <Table.HeaderCell colSpan='7'>
              <Button size='small' as={Link} to='/channel/add' loading={loading}>
                添加新的渠道
              </Button>
              <Button size='small' loading={loading} onClick={testAllChannels}>
                测试所有已启用通道
              </Button>
              <Pagination
                floated='right'
                activePage={activePage}
                onPageChange={onPaginationChange}
                size='small'
                siblingRange={1}
                totalPages={
                  Math.ceil(channels.length / ITEMS_PER_PAGE) +
                  (channels.length % ITEMS_PER_PAGE === 0 ? 1 : 0)
                }
              />
            </Table.HeaderCell>
          </Table.Row>
        </Table.Footer>
      </Table>
    </>
  );
};

export default ChannelsTable;