'use client';

import { CodeSnippet } from "@/app/components/codeSnippet";
import { KeyboardShortcutHint } from "@/app/components/keyboardShortcutHint";
import { useToast } from "@/components/hooks/use-toast";
import { AnimatedResizableHandle } from "@/components/ui/animatedResizableHandle";
import { Button } from "@/components/ui/button";
import {
    ResizablePanel,
    ResizablePanelGroup,
} from "@/components/ui/resizable";
import { Separator } from "@/components/ui/separator";
import { Tooltip, TooltipContent, TooltipTrigger } from "@/components/ui/tooltip";
import { RepositoryInfo, SearchResultFile, SearchStats } from "@/features/search/types";
import useCaptureEvent from "@/hooks/useCaptureEvent";
import { useDomain } from "@/hooks/useDomain";
import { useNonEmptyQueryParam } from "@/hooks/useNonEmptyQueryParam";
import { useSearchHistory } from "@/hooks/useSearchHistory";
import { SearchQueryParams } from "@/lib/types";
import { createPathWithQueryParams, measure, unwrapServiceError } from "@/lib/utils";
import { InfoCircledIcon, SymbolIcon } from "@radix-ui/react-icons";
import { useQuery } from "@tanstack/react-query";
import { useLocalStorage } from "@uidotdev/usehooks";
import { AlertTriangleIcon, BugIcon, FilterIcon } from "lucide-react";
import { useRouter } from "next/navigation";
import { useCallback, useEffect, useMemo, useRef, useState } from "react";
import { useHotkeys } from "react-hotkeys-hook";
import { ImperativePanelHandle } from "react-resizable-panels";
import { search } from "../../../api/(client)/client";
import { CopyIconButton } from "../../components/copyIconButton";
import { SearchBar } from "../../components/searchBar";
import { TopBar } from "../../components/topBar";
import { CodePreviewPanel } from "./codePreviewPanel";
import { FilterPanel } from "./filterPanel";
import { useFilteredMatches } from "./filterPanel/useFilterMatches";
import { SearchResultsPanel } from "./searchResultsPanel";

const DEFAULT_MAX_MATCH_COUNT = 5000;

interface SearchResultsPageProps {
    searchQuery: string;
}

export const SearchResultsPage = ({
    searchQuery,
}: SearchResultsPageProps) => {
    const router = useRouter();
    const { setSearchHistory } = useSearchHistory();
    const captureEvent = useCaptureEvent();
    const domain = useDomain();
    const { toast } = useToast();

    // Encodes the number of matches to return in the search response.
    const _maxMatchCount = parseInt(useNonEmptyQueryParam(SearchQueryParams.matches) ?? `${DEFAULT_MAX_MATCH_COUNT}`);
    const maxMatchCount = isNaN(_maxMatchCount) ? DEFAULT_MAX_MATCH_COUNT : _maxMatchCount;

    const {
        data: searchResponse,
        isPending: isSearchPending,
        isFetching: isFetching,
        error
    } = useQuery({
        queryKey: ["search", searchQuery, maxMatchCount],
        queryFn: () => measure(() => unwrapServiceError(search({
            query: searchQuery,
            matches: maxMatchCount,
            contextLines: 3,
            whole: false,
        }, domain)), "client.search"),
        select: ({ data, durationMs }) => ({
            ...data,
            totalClientSearchDurationMs: durationMs,
        }),
        enabled: searchQuery.length > 0,
        refetchOnWindowFocus: false,
        retry: false,
        staleTime: 0,
    });

    useEffect(() => {
        if (error) {
            toast({
                description: `❌ Search failed. Reason: ${error.message}`,
            });
        }
    }, [error, toast]);


    // Write the query to the search history
    useEffect(() => {
        if (searchQuery.length === 0) {
            return;
        }

        const now = new Date().toUTCString();
        setSearchHistory((searchHistory) => [
            {
                query: searchQuery,
                date: now,
            },
            ...searchHistory.filter(search => search.query !== searchQuery),
        ])
    }, [searchQuery, setSearchHistory]);

    useEffect(() => {
        if (!searchResponse) {
            return;
        }

        const fileLanguages = searchResponse.files?.map(file => file.language) || [];

        captureEvent("search_finished", {
            durationMs: searchResponse.totalClientSearchDurationMs,
            fileCount: searchResponse.stats.fileCount,
            matchCount: searchResponse.stats.totalMatchCount,
            actualMatchCount: searchResponse.stats.actualMatchCount,
            filesSkipped: searchResponse.stats.filesSkipped,
            contentBytesLoaded: searchResponse.stats.contentBytesLoaded,
            indexBytesLoaded: searchResponse.stats.indexBytesLoaded,
            crashes: searchResponse.stats.crashes,
            shardFilesConsidered: searchResponse.stats.shardFilesConsidered,
            filesConsidered: searchResponse.stats.filesConsidered,
            filesLoaded: searchResponse.stats.filesLoaded,
            shardsScanned: searchResponse.stats.shardsScanned,
            shardsSkipped: searchResponse.stats.shardsSkipped,
            shardsSkippedFilter: searchResponse.stats.shardsSkippedFilter,
            ngramMatches: searchResponse.stats.ngramMatches,
            ngramLookups: searchResponse.stats.ngramLookups,
            wait: searchResponse.stats.wait,
            matchTreeConstruction: searchResponse.stats.matchTreeConstruction,
            matchTreeSearch: searchResponse.stats.matchTreeSearch,
            regexpsConsidered: searchResponse.stats.regexpsConsidered,
            flushReason: searchResponse.stats.flushReason,
            fileLanguages,
        });
    }, [captureEvent, searchQuery, searchResponse]);


    const onLoadMoreResults = useCallback(() => {
        const url = createPathWithQueryParams(`/${domain}/search`,
            [SearchQueryParams.query, searchQuery],
            [SearchQueryParams.matches, `${maxMatchCount * 2}`],
        )
        router.push(url);
    }, [maxMatchCount, router, searchQuery, domain]);

    return (
        <div className="flex flex-col h-screen overflow-clip">
            {/* TopBar */}
            <TopBar
                domain={domain}
            >
                <SearchBar
                    size="sm"
                    defaultQuery={searchQuery}
                    className="w-full"
                />
            </TopBar>

            {(isSearchPending || isFetching) ? (
                <div className="flex flex-col items-center justify-center h-full gap-2">
                    <SymbolIcon className="h-6 w-6 animate-spin" />
                    <p className="font-semibold text-center">Searching...</p>
                </div>
            ) : error ? (
                <div className="flex flex-col items-center justify-center h-full gap-2">
                    <AlertTriangleIcon className="h-6 w-6" />
                    <p className="font-semibold text-center">Failed to search</p>
                    <p className="text-sm text-center">{error.message}</p>
                </div>
            ) : (
                <PanelGroup
                    fileMatches={searchResponse.files}
                    isMoreResultsButtonVisible={searchResponse.isSearchExhaustive === false}
                    onLoadMoreResults={onLoadMoreResults}
                    isBranchFilteringEnabled={searchResponse.isBranchFilteringEnabled}
                    repoInfo={searchResponse.repositoryInfo}
                    searchDurationMs={searchResponse.totalClientSearchDurationMs}
                    numMatches={searchResponse.stats.actualMatchCount}
                    searchStats={searchResponse.stats}
                />
            )}
        </div>
    );
}

interface PanelGroupProps {
    fileMatches: SearchResultFile[];
    isMoreResultsButtonVisible?: boolean;
    onLoadMoreResults: () => void;
    isBranchFilteringEnabled: boolean;
    repoInfo: RepositoryInfo[];
    searchDurationMs: number;
    numMatches: number;
    searchStats?: SearchStats;
}

const PanelGroup = ({
    fileMatches,
    isMoreResultsButtonVisible,
    onLoadMoreResults,
    isBranchFilteringEnabled,
    repoInfo: _repoInfo,
    searchDurationMs: _searchDurationMs,
    numMatches,
    searchStats,
}: PanelGroupProps) => {
    const [previewedFile, setPreviewedFile] = useState<SearchResultFile | undefined>(undefined);
    const filteredFileMatches = useFilteredMatches(fileMatches);
    const filterPanelRef = useRef<ImperativePanelHandle>(null);
    const [selectedMatchIndex, setSelectedMatchIndex] = useState(0);

    const [isFilterPanelCollapsed, setIsFilterPanelCollapsed] = useLocalStorage('isFilterPanelCollapsed', false);

    useHotkeys("mod+b", () => {
        if (isFilterPanelCollapsed) {
            filterPanelRef.current?.expand();
        } else {
            filterPanelRef.current?.collapse();
        }
    }, {
        enableOnFormTags: true,
        enableOnContentEditable: true,
        description: "Toggle filter panel",
    });

    const searchDurationMs = useMemo(() => {
        return Math.round(_searchDurationMs);
    }, [_searchDurationMs]);

    const repoInfo = useMemo(() => {
        return _repoInfo.reduce((acc, repo) => {
            acc[repo.id] = repo;
            return acc;
        }, {} as Record<number, RepositoryInfo>);
    }, [_repoInfo]);

    return (
        <ResizablePanelGroup
            direction="horizontal"
            className="h-full"
        >
            {/* ~~ Filter panel ~~ */}
            <ResizablePanel
                ref={filterPanelRef}
                minSize={20}
                maxSize={30}
                defaultSize={isFilterPanelCollapsed ? 0 : 20}
                collapsible={true}
                id={'filter-panel'}
                order={1}
                onCollapse={() => setIsFilterPanelCollapsed(true)}
                onExpand={() => setIsFilterPanelCollapsed(false)}
            >
                <FilterPanel
                    matches={fileMatches}
                    repoInfo={repoInfo}
                />
            </ResizablePanel>
            {isFilterPanelCollapsed && (
                <div className="flex flex-col items-center h-full p-2">
                    <Tooltip
                        delayDuration={100}
                    >
                        <TooltipTrigger asChild>
                            <Button
                                variant="ghost"
                                size="icon"
                                className="h-8 w-8"
                                onClick={() => {
                                    filterPanelRef.current?.expand();
                                }}
                            >
                                <FilterIcon className="w-4 h-4" />
                            </Button>
                        </TooltipTrigger>
                        <TooltipContent side="right" className="flex flex-row items-center gap-2">
                            <KeyboardShortcutHint shortcut="⌘ B" />
                            <Separator orientation="vertical" className="h-4" />
                            <span>Open filter panel</span>
                        </TooltipContent>
                    </Tooltip>
                </div>
            )}
            <AnimatedResizableHandle />

            {/* ~~ Search results ~~ */}
            <ResizablePanel
                minSize={10}
                id={'search-results-panel'}
                order={2}
            >
                <div className="py-1 px-2 flex flex-row items-center">
                    <Tooltip>
                        <TooltipTrigger asChild>
                            <InfoCircledIcon className="w-4 h-4 mr-2" />
                        </TooltipTrigger>
                        <TooltipContent side="right" className="flex flex-col items-start gap-2 p-4">
                            <div className="flex flex-row items-center w-full">
                                <BugIcon className="w-4 h-4 mr-1.5" />
                                <p className="text-md font-medium">Search stats for nerds</p>
                                <CopyIconButton
                                    onCopy={() => {
                                        navigator.clipboard.writeText(JSON.stringify(searchStats, null, 2));
                                        return true;
                                    }}
                                    className="ml-auto"
                                />
                            </div>
                            <CodeSnippet renderNewlines>
                                {JSON.stringify(searchStats, null, 2)}
                            </CodeSnippet>
                        </TooltipContent>
                    </Tooltip>
                    {
                        fileMatches.length > 0 ? (
                            <p className="text-sm font-medium">{`[${searchDurationMs} ms] Found ${numMatches} matches in ${fileMatches.length} ${fileMatches.length > 1 ? 'files' : 'file'}`}</p>
                        ) : (
                            <p className="text-sm font-medium">No results</p>
                        )
                    }
                    {isMoreResultsButtonVisible && (
                        <div
                            className="cursor-pointer text-blue-500 text-sm hover:underline ml-4"
                            onClick={onLoadMoreResults}
                        >
                            (load more)
                        </div>
                    )}
                </div>
                {filteredFileMatches.length > 0 ? (
                    <SearchResultsPanel
                        fileMatches={filteredFileMatches}
                        onOpenFilePreview={(fileMatch, matchIndex) => {
                            setSelectedMatchIndex(matchIndex ?? 0);
                            setPreviewedFile(fileMatch);
                        }}
                        isLoadMoreButtonVisible={!!isMoreResultsButtonVisible}
                        onLoadMoreButtonClicked={onLoadMoreResults}
                        isBranchFilteringEnabled={isBranchFilteringEnabled}
                        repoInfo={repoInfo}
                    />
                ) : (
                    <div className="flex flex-col items-center justify-center h-full">
                        <p className="text-sm text-muted-foreground">No results found</p>
                    </div>
                )}
            </ResizablePanel>

            {previewedFile && (
                <>
                    <AnimatedResizableHandle />
                    {/* ~~ Code preview ~~ */}
                    <ResizablePanel
                        minSize={10}
                        collapsible={true}
                        id={'code-preview-panel'}
                        order={3}
                        onCollapse={() => setPreviewedFile(undefined)}
                    >
                        <CodePreviewPanel
                            previewedFile={previewedFile}
                            onClose={() => setPreviewedFile(undefined)}
                            selectedMatchIndex={selectedMatchIndex}
                            onSelectedMatchIndexChange={setSelectedMatchIndex}
                        />
                    </ResizablePanel>
                </>
            )}
        </ResizablePanelGroup>
    )
}
