import {
  FC,
  ReactNode,
  useEffect,
  useId,
  useLayoutEffect,
  useState,
} from "react";
import {
  Table,
  Alert,
  Skeleton,
  Box,
  LoadingOverlay,
  SegmentedControl,
  ScrollArea,
  Group,
  Stack,
  Text,
  Anchor,
} from "@mantine/core";
import { IconAlertTriangle, IconInfoCircle } from "@tabler/icons-react";
import {
  InstantQueryResult,
  InstantSample,
  RangeSamples,
} from "../../api/responseTypes/query";
import SeriesName from "./SeriesName";
import { useAPIQuery } from "../../api/api";
import classes from "./DataTable.module.css";
import dayjs from "dayjs";
import timezone from "dayjs/plugin/timezone";
import { formatTimestamp } from "../../lib/formatTime";
import HistogramChart from "./HistogramChart";
import { Histogram } from "../../types/types";
import { bucketRangeString } from "./HistogramHelpers";
import { useSettings } from "../../state/settingsSlice";
import { useAppDispatch, useAppSelector } from "../../state/hooks";
import { setVisualizer } from "../../state/queryPageSlice";
import TimeInput from "./TimeInput";
dayjs.extend(timezone);

const maxFormattableSeries = 1000;
const maxDisplayableSeries = 10000;

const limitSeries = <S extends InstantSample | RangeSamples>(
  series: S[],
  limit: boolean
): S[] => {
  if (limit && series.length > maxDisplayableSeries) {
    return series.slice(0, maxDisplayableSeries);
  }
  return series;
};

export interface DataTableProps {
  panelIdx: number;
  retriggerIdx: number;
}

const DataTable: FC<DataTableProps> = ({ panelIdx, retriggerIdx }) => {
  const [scale, setScale] = useState<string>("exponential");
  const [limitResults, setLimitResults] = useState<boolean>(true);
  const [responseTime, setResponseTime] = useState<number>(0);

  const { expr, visualizer } = useAppSelector(
    (state) => state.queryPage.panels[panelIdx]
  );
  const dispatch = useAppDispatch();

  const { endTime, range } = visualizer;

  const { data, error, isFetching, isLoading, refetch } =
    useAPIQuery<InstantQueryResult>({
      key: useId(),
      path: "/query",
      params: {
        query: expr,
        time: `${(endTime !== null ? endTime : Date.now()) / 1000}`,
      },
      enabled: expr !== "",
      recordResponseTime: setResponseTime,
    });

  useEffect(() => {
    expr !== "" && refetch();
  }, [retriggerIdx, refetch, expr, endTime]);

  useLayoutEffect(() => {
    setLimitResults(true);
  }, [data, isFetching]);

  const { useLocalTime } = useSettings();

  // Show a skeleton only on the first load, not on subsequent ones.
  if (isLoading) {
    return (
      <Box>
        {Array.from(Array(5), (_, i) => (
          <Skeleton key={i} height={30} mb={15} />
        ))}
      </Box>
    );
  }

  if (error) {
    return (
      <Alert
        color="red"
        title="Error executing query"
        icon={<IconAlertTriangle size={14} />}
      >
        {error.message}
      </Alert>
    );
  }

  if (data === undefined) {
    return <Alert variant="transparent">No data queried yet</Alert>;
  }

  const { result, resultType } = data.data;

  if (result.length === 0) {
    return (
      <Alert title="Empty query result" icon={<IconInfoCircle size={14} />}>
        This query returned no data.
      </Alert>
    );
  }

  const doFormat = result.length <= maxFormattableSeries;

  return (
    <Stack gap="lg" mt="sm">
      {isLoading ? (
        <Box>
          {Array.from(Array(5), (_, i) => (
            <Skeleton key={i} height={30} mb={15} />
          ))}
        </Box>
      ) : data === undefined ? (
        <Alert variant="transparent">No data queried yet</Alert>
      ) : result.length === 0 ? (
        <Alert title="Empty query result" icon={<IconInfoCircle size={14} />}>
          This query returned no data.
        </Alert>
      ) : (
        <>
          <Group justify="space-between">
            <TimeInput
              time={endTime}
              range={range}
              description="Evaluation time"
              onChangeTime={(time) =>
                dispatch(
                  setVisualizer({
                    idx: panelIdx,
                    visualizer: { ...visualizer, endTime: time },
                  })
                )
              }
            />
            <Text size="xs" c="gray">
              Load time: {responseTime}ms &ensp; Result series: {result.length}
            </Text>
          </Group>

          {limitResults &&
            ["vector", "matrix"].includes(resultType) &&
            result.length > maxDisplayableSeries && (
              <Alert
                color="red"
                icon={<IconAlertTriangle size={14} />}
                title="Showing limited results"
              >
                Fetched {data.data.result.length} metrics, only displaying first{" "}
                {maxDisplayableSeries} for performance reasons.
                <Anchor ml="md" fz="1em" onClick={() => setLimitResults(false)}>
                  Show all results
                </Anchor>
              </Alert>
            )}

          {!doFormat && (
            <Alert
              title="Formatting turned off"
              icon={<IconInfoCircle size={14} />}
            >
              Showing more than {maxFormattableSeries} series, turning off label
              formatting for performance reasons.
            </Alert>
          )}

          <Box pos="relative" className={classes.tableWrapper}>
            <LoadingOverlay
              visible={isFetching}
              zIndex={1000}
              overlayProps={{ radius: "sm", blur: 1 }}
              loaderProps={{
                children: <Skeleton m={0} w="100%" h="100%" />,
              }}
              styles={{ loader: { width: "100%", height: "100%" } }}
            />

            <Table fz="xs">
              <Table.Tbody>
                {resultType === "vector" ? (
                  limitSeries<InstantSample>(result, limitResults).map(
                    (s, idx) => (
                      <Table.Tr key={idx}>
                        <Table.Td>
                          <SeriesName labels={s.metric} format={doFormat} />
                        </Table.Td>
                        <Table.Td className={classes.numberCell}>
                          {s.value && s.value[1]}
                          {s.histogram && (
                            <Stack>
                              <HistogramChart
                                histogram={s.histogram[1]}
                                index={idx}
                                scale={scale}
                              />
                              <Group
                                justify="space-between"
                                align="center"
                                p={10}
                              >
                                <Group align="center" gap="1rem">
                                  <span>
                                    <strong>Count:</strong>{" "}
                                    {s.histogram[1].count}
                                  </span>
                                  <span>
                                    <strong>Sum:</strong> {s.histogram[1].sum}
                                  </span>
                                </Group>
                                <Group align="center" gap="1rem">
                                  <span>x-axis scale:</span>
                                  <SegmentedControl
                                    size={"xs"}
                                    value={scale}
                                    onChange={setScale}
                                    data={["exponential", "linear"]}
                                  />
                                </Group>
                              </Group>
                              {histogramTable(s.histogram[1])}
                            </Stack>
                          )}
                        </Table.Td>
                      </Table.Tr>
                    )
                  )
                ) : resultType === "matrix" ? (
                  limitSeries<RangeSamples>(result, limitResults).map(
                    (s, idx) => (
                      <Table.Tr key={idx}>
                        <Table.Td>
                          <SeriesName labels={s.metric} format={doFormat} />
                        </Table.Td>
                        <Table.Td className={classes.numberCell}>
                          {s.values &&
                            s.values.map((v, idx) => (
                              <div key={idx}>
                                {v[1]}{" "}
                                <Text
                                  span
                                  c="gray.7"
                                  size="1em"
                                  title={formatTimestamp(v[0], useLocalTime)}
                                >
                                  @ {v[0]}
                                </Text>
                              </div>
                            ))}
                        </Table.Td>
                      </Table.Tr>
                    )
                  )
                ) : resultType === "scalar" ? (
                  <Table.Tr>
                    <Table.Td>Scalar value</Table.Td>
                    <Table.Td className={classes.numberCell}>
                      {result[1]}
                    </Table.Td>
                  </Table.Tr>
                ) : resultType === "string" ? (
                  <Table.Tr>
                    <Table.Td>String value</Table.Td>
                    <Table.Td>{result[1]}</Table.Td>
                  </Table.Tr>
                ) : (
                  <Alert
                    color="red"
                    title="Invalid query response"
                    icon={<IconAlertTriangle size={14} />}
                  >
                    Invalid result value type
                  </Alert>
                )}
              </Table.Tbody>
            </Table>
          </Box>
        </>
      )}
    </Stack>
  );
};

const histogramTable = (h: Histogram): ReactNode => (
  <Table withTableBorder fz="xs">
    <Table.Tbody
      style={{
        display: "flex",
        flexDirection: "column",
        justifyContent: "space-between",
      }}
    >
      <Table.Tr
        style={{
          display: "flex",
          flexDirection: "row",
          justifyContent: "space-between",
        }}
      >
        <Table.Th>Bucket range</Table.Th>
        <Table.Th>Count</Table.Th>
      </Table.Tr>
      <ScrollArea w={"100%"} h={265}>
        {h.buckets?.map((b, i) => (
          <Table.Tr key={i}>
            <Table.Td style={{ textAlign: "left" }}>
              {bucketRangeString(b)}
            </Table.Td>
            <Table.Td>{b[3]}</Table.Td>
          </Table.Tr>
        ))}
      </ScrollArea>
    </Table.Tbody>
  </Table>
);

export default DataTable;