// Copyright 2022 The Parca Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import React, {useCallback, useEffect, useMemo} from 'react';

import {tableFromIPC} from '@uwdata/flechette';
import {AnimatePresence, motion} from 'framer-motion';
import {useQueryState} from 'nuqs';
import {Item, Menu, useContextMenu} from 'react-contexify';

import {Source} from '@parca/client';
import {SourceSkeleton, useParcaContext, type ProfileData} from '@parca/components';

import {ExpandOnHover} from '../GraphTooltipArrow/ExpandOnHoverValue';
import {stringParam} from '../hooks/urlParsers';
import {alignedUint8Array, truncateStringReverse} from '../utils';
import {Highlighter, profileAwareRenderer, type LineDataLookup} from './Highlighter';
import useLineRange from './useSelectedLineRange';

interface SourceViewProps {
  loading: boolean;
  data?: Source;
  total: bigint;
  filtered: bigint;
  setActionButtons?: (buttons: JSX.Element) => void;
}

const MENU_ID = 'source-view-context-menu';

export const SourceView = React.memo(function SourceView({
  data,
  loading,
  total,
  filtered,
  setActionButtons,
}: SourceViewProps): JSX.Element {
  const [sourceFileName] = useQueryState('source_filename', stringParam);
  const {isDarkMode, sourceViewContextMenuItems = []} = useParcaContext();

  const sourceCode = useMemo(() => {
    if (data === undefined) {
      return [''];
    }
    // To use the array index as line number
    return ['', ...data.source.split('\n')];
  }, [data]);

  const {show} = useContextMenu({
    id: MENU_ID,
  });

  const {startLine, endLine} = useLineRange();

  const sourceTable = useMemo(() => {
    if (data === undefined) {
      return null;
    }
    const table = tableFromIPC(alignedUint8Array(data.record), {useBigInt: true});
    return {
      numRows: table.numRows,
      lineNumbers: table.getChild('line_number'),
      cumulative: table.getChild('cumulative'),
      flat: table.getChild('flat'),
    };
  }, [data]);

  const getLineData: LineDataLookup = useCallback(
    (lineNumber: number) => {
      if (sourceTable === null || sourceTable.lineNumbers === null) {
        return undefined;
      }
      const {numRows, lineNumbers, cumulative, flat} = sourceTable;

      let lo = 0;
      let hi = numRows - 1;
      while (lo <= hi) {
        const mid = (lo + hi) >>> 1;
        const midVal = Number(lineNumbers.get(mid));
        if (midVal === lineNumber) {
          return {
            cumulative: (cumulative?.get(mid) as bigint) ?? 0n,
            flat: (flat?.get(mid) as bigint) ?? 0n,
          };
        }
        if (midVal < lineNumber) {
          lo = mid + 1;
        } else {
          hi = mid - 1;
        }
      }
      return undefined;
    },
    [sourceTable]
  );

  const getProfileDataForLine = useCallback(
    (line: number): ProfileData | undefined => {
      const data = getLineData(line);
      if (data === undefined) {
        return undefined;
      }
      if (data.cumulative === 0n && data.flat === 0n) {
        return undefined;
      }
      return {
        line,
        cumulative: Number(data.cumulative),
        flat: Number(data.flat),
      };
    },
    [getLineData]
  );

  const [selectedCode, profileData] = useMemo(() => {
    if (startLine === -1 && endLine === -1) {
      return ['', []];
    }
    if (startLine === endLine) {
      const profileData: ProfileData[] = [];
      const profileDataForLine = getProfileDataForLine(startLine);
      if (profileDataForLine != null) {
        profileData.push(profileDataForLine);
      }

      return [sourceCode[startLine - 1], profileData];
    }
    let code = '';
    const profileData: ProfileData[] = [];
    for (let i = startLine; i <= endLine; i++) {
      code += sourceCode[i] + '\n';
      const profileDataForLine = getProfileDataForLine(i);
      if (profileDataForLine != null) {
        profileData.push(profileDataForLine);
      }
    }
    return [code, profileData];
  }, [startLine, endLine, sourceCode, getProfileDataForLine]);

  useEffect(() => {
    setActionButtons?.(
      <div className="px-2">
        <ExpandOnHover
          value={sourceFileName as string}
          displayValue={truncateStringReverse(sourceFileName as string, 50)}
        />
      </div>
    );
  }, [sourceFileName, setActionButtons]);

  if (loading) {
    return (
      <div className="h-auto overflow-clip">
        <SourceSkeleton isDarkMode={isDarkMode} />
      </div>
    );
  }

  if (data === undefined) {
    return <>Source code not uploaded for this build.</>;
  }

  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const onContextMenu = (event: any): void => {
    show({
      event,
    });
  };

  return (
    <AnimatePresence>
      <motion.div
        className="h-full w-full"
        key="source-view-loaded"
        initial={{display: 'none', opacity: 0}}
        animate={{display: 'block', opacity: 1}}
        transition={{duration: 0.5}}
      >
        <Highlighter
          file={sourceFileName as string}
          content={data.source}
          renderer={profileAwareRenderer(getLineData, total, filtered, onContextMenu)}
        />
        {sourceViewContextMenuItems.length > 0 ? (
          <Menu id={MENU_ID}>
            {sourceViewContextMenuItems.map(item => (
              <Item key={item.id} onClick={() => item.action(selectedCode, profileData)}>
                {item.label}
              </Item>
            ))}
          </Menu>
        ) : null}
      </motion.div>
    </AnimatePresence>
  );
});

export default SourceView;