import { useEffect, useState, useRef, HTMLAttributes } from "react"
import {
    Sheet,
    SheetTrigger,
    SheetContent,
    SheetHeader,
    SheetTitle,
    SheetDescription,
} from "./xui/overlayless-sheet"
import { IconButton } from "./xui/icon-button"
import { createFM } from "@/api/fm"
import { ModelCreateFMResponse, FMEntry, FMOpcode, FMIdentifier, FMWorkerData, FMWorkerOpcode } from "@/types"
import useWebSocket from "react-use-websocket"
import { toast } from "sonner"
import { ColumnDef } from "@tanstack/react-table"
import { Folder, File } from "lucide-react"
import { fm, formatPath, fmWorker as worker } from "@/lib/utils"
import {
    AlertDialog,
    AlertDialogContent,
    AlertDialogDescription,
    AlertDialogHeader,
    AlertDialogTitle,
    AlertDialogTrigger,
    AlertDialogFooter,
    AlertDialogCancel,
    AlertDialogAction,
} from "@/components/ui/alert-dialog"
import {
    DropdownMenu,
    DropdownMenuContent,
    DropdownMenuItem,
    DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu"
import { Row, flexRender } from "@tanstack/react-table"
import { TableRow, TableCell } from "./ui/table"
import { DataTable } from "./xui/virtulized-data-table"
import { Input } from "@/components/ui/input"
import { Filepath } from "./xui/filepath"

interface FMProps {
    wsUrl: string;
}

const arraysEqual = (a: Uint8Array, b: Uint8Array) => {
    if (a.length !== b.length) return false;
    for (let i = 0; i < a.length; i++) {
        if (a[i] !== b[i]) return false;
    }
    return true;
}

const FMComponent: React.FC<FMProps & JSX.IntrinsicElements["div"]> = ({ wsUrl, ...props }) => {
    const fmRef = useRef<HTMLDivElement>(null);

    const [dOpen, setdOpen] = useState(false);
    const [uOpen, setuOpen] = useState(false);

    const columns: ColumnDef<FMEntry>[] = [
        {
            id: "type",
            header: () => <span>Type</span>,
            accessorFn: row => row.type,
            cell: ({ row }) => (
                row.original.type == 0 ? <File size={24} /> : <Folder size={24} />
            ),
        },
        {
            header: () => <span>Name</span>,
            id: "name",
            accessorFn: row => row.name,
            cell: ({ row }) => (
                <div className="max-w-48 text-sm whitespace-normal break-words">
                    {row.original.name}
                </div>
            ),
            size: 5000,
        },
        {
            header: () => <span>Action</span>,
            id: "download",
            cell: ({ row }) => {
                return (
                    <IconButton variant="ghost" icon="download" onClick={
                        () => {
                            if (!dOpen) setdOpen(true);
                            downloadFile(row.original.name);
                        }
                    } />
                )
            },
        }
    ]

    const tableRowComponent = (rows: Row<FMEntry>[]) =>
        function getTableRow(props: HTMLAttributes<HTMLTableRowElement>) {
            // @ts-expect-error data-index is a valid attribute
            const index = props["data-index"];
            const row = rows[index];

            if (!row) return null;

            return (
                <TableRow
                    key={row.id}
                    data-state={row.getIsSelected() && "selected"}
                    onClick={() => {
                        if (row.original.type === 1) {
                            setPath(`${currentPath}/${row.original.name}`);
                        }
                    }}
                    className={row.original.type === 1 ? "cursor-pointer" : "cursor-default"}
                    {...props}
                >
                    {row.getVisibleCells().map((cell) => (
                        <TableCell key={cell.id}>
                            {flexRender(cell.column.columnDef.cell, cell.getContext())}
                        </TableCell>
                    ))}
                </TableRow>
            );
        };

    const [fmEntires, setFMEntries] = useState<FMEntry[]>([]);

    const firstChunk = useRef(true);
    const handleReady = useRef(false);
    const currentBasename = useRef('temp');

    const waitForHandleReady = async () => {
        while (!handleReady.current) {
            await new Promise(resolve => setTimeout(resolve, 10));
        }
    };

    worker.onmessage = async (event: MessageEvent<FMWorkerData>) => {
        switch (event.data.type) {
            case FMWorkerOpcode.Error: {
                console.error('Error from worker', event.data.error);
                break;
            }
            case FMWorkerOpcode.Progress: {
                handleReady.current = true;
                break;
            }
            case FMWorkerOpcode.Result: {
                handleReady.current = false;

                if (event.data.blob && event.data.fileName) {
                    const url = URL.createObjectURL(event.data.blob);
                    const anchor = document.createElement('a');
                    anchor.href = url;
                    anchor.download = event.data.fileName;
                    anchor.click();
                    URL.revokeObjectURL(url);
                }

                firstChunk.current = true;
                if (dOpen) setdOpen(false);
                break;
            }
        }
    }

    const { sendMessage, getWebSocket } = useWebSocket(wsUrl, {
        share: false,
        onOpen: () => {
            listFile();
        },
        onClose: (e) => {
            console.log('WebSocket connection closed:', e);
        },
        onError: (e) => {
            console.error(e);
            toast("Websocket error", {
                description: "View console for details.",
            })
        },
        onMessage: async (e) => {
            try {
                const buf: ArrayBufferLike = e.data;

                if (firstChunk.current) {
                    const identifier = new Uint8Array(buf, 0, 4);
                    if (arraysEqual(identifier, FMIdentifier.file)) {
                        worker.postMessage({ operation: 1, arrayBuffer: buf, fileName: currentBasename.current });
                        firstChunk.current = false;
                    } else if (arraysEqual(identifier, FMIdentifier.fileName)) {
                        const { path, fmList } = await fm.parseFMList(buf);
                        setPath(path);
                        setFMEntries(fmList);
                    } else if (arraysEqual(identifier, FMIdentifier.error)) {
                        const errBytes = buf.slice(4);
                        const errMsg = new TextDecoder('utf-8').decode(errBytes);
                        throw new Error(errMsg);
                    } else if (arraysEqual(identifier, FMIdentifier.complete)) {
                        // Upload completed
                        if (uOpen) setuOpen(false);
                        listFile();
                    } else {
                        throw new Error("Unknown identifier");
                    }
                } else {
                    await waitForHandleReady();
                    worker.postMessage({ operation: 2, arrayBuffer: buf, fileName: currentBasename.current });
                }
            } catch (error) {
                console.error('Error processing received data:', error);
                toast("FM error", {
                    description: "View console for details.",
                })
                if (dOpen) setdOpen(false);
                if (uOpen) setuOpen(false);
            }
        }
    });

    const socket = getWebSocket();
    useEffect(() => {
        if (socket && 'binaryType' in socket)
            socket.binaryType = 'arraybuffer';
    }, [socket])

    const [currentPath, setPath] = useState('');
    useEffect(() => {
        listFile();
    }, [currentPath])

    const listFile = () => {
        const prefix = new Int8Array([FMOpcode.List]);
        const pathMsg = new TextEncoder().encode(currentPath);

        const msg = new Int8Array(prefix.length + pathMsg.length);
        msg.set(prefix);
        msg.set(pathMsg, prefix.length);

        sendMessage(msg);
    }

    const downloadFile = (basename: string) => {
        currentBasename.current = basename;
        const prefix = new Int8Array([FMOpcode.Download]);
        const filePathMessage = new TextEncoder().encode(`${currentPath}/${basename}`);

        const msg = new Int8Array(prefix.length + filePathMessage.length);
        msg.set(prefix);
        msg.set(filePathMessage, prefix.length);

        sendMessage(msg);
    }

    const uploadFile = async (file: File) => {
        const chunkSize = 1048576; // 1MB chunk
        let offset = 0;

        // Send header
        const header = fm.buildUploadHeader({ path: currentPath, file: file });
        sendMessage(header);

        // Send data chunks
        while (offset < file.size) {
            const chunk = file.slice(offset, offset + chunkSize);
            const arrayBuffer = await fm.readFileAsArrayBuffer(chunk);
            if (arrayBuffer) sendMessage(arrayBuffer);
            offset += chunkSize;
        }
    }

    const fileInputRef = useRef<HTMLInputElement>(null);

    const [gotoPath, setGotoPath] = useState('');
    return (
        <div ref={fmRef} {...props}>
            <div className="flex justify-center items-center gap-4">
                <AlertDialog>
                    <DropdownMenu>
                        <DropdownMenuTrigger asChild>
                            <IconButton variant="ghost" icon="menu" />
                        </DropdownMenuTrigger>
                        <DropdownMenuContent>
                            <DropdownMenuItem onClick={listFile}>Refresh</DropdownMenuItem>
                            <DropdownMenuItem onClick={
                                async () => {
                                    await navigator.clipboard.writeText(formatPath(currentPath));
                                }
                            }>Copy path</DropdownMenuItem>
                            <AlertDialogTrigger asChild>
                                <DropdownMenuItem>Goto</DropdownMenuItem>
                            </AlertDialogTrigger>
                        </DropdownMenuContent>
                    </DropdownMenu>
                    <AlertDialogContent>
                        <AlertDialogHeader>
                            <AlertDialogTitle>Goto</AlertDialogTitle>
                            <AlertDialogDescription />
                        </AlertDialogHeader>
                        <Input className="mb-1" placeholder="Path" value={gotoPath} onChange={(e) => { setGotoPath(e.target.value) }} />
                        <AlertDialogFooter>
                            <AlertDialogCancel>Cancel</AlertDialogCancel>
                            <AlertDialogAction onClick={() => { setPath(gotoPath) }}>Confirm</AlertDialogAction>
                        </AlertDialogFooter>
                    </AlertDialogContent>
                </AlertDialog>
                <h1 className="text-base">Pseudo File Manager</h1>
                <div className="ml-auto">
                    <input ref={fileInputRef} type="file" className="hidden" onChange={
                        async (e) => {
                            const files = e.target.files;
                            if (files && files.length > 0) {
                                if (!uOpen) setuOpen(true);
                                await uploadFile(files[0]);
                            }
                        }
                    } />
                    <IconButton icon="upload" variant="ghost" onClick={
                        () => {
                            if (fileInputRef.current) fileInputRef.current.click();
                        }
                    } />
                </div>
            </div>
            <Filepath path={currentPath} setPath={setPath} />
            <AlertDialog open={dOpen}>
                <AlertDialogContent>
                    <AlertDialogHeader>
                        <AlertDialogTitle>Downloading...</AlertDialogTitle>
                        <AlertDialogDescription />
                    </AlertDialogHeader>
                </AlertDialogContent>
            </AlertDialog>
            <AlertDialog open={uOpen}>
                <AlertDialogContent>
                    <AlertDialogHeader>
                        <AlertDialogTitle>Uploading...</AlertDialogTitle>
                        <AlertDialogDescription />
                    </AlertDialogHeader>
                </AlertDialogContent>
            </AlertDialog>
            <DataTable columns={columns} data={fmEntires} rowComponent={tableRowComponent} />
        </div>
    );
}

export const FMCard = ({ id }: { id?: string }) => {
    const [open, setOpen] = useState(false);
    const [fm, setFM] = useState<ModelCreateFMResponse | null>(null);
    const [init, setInit] = useState(false);

    const fetchFM = async () => {
        if (id) {
            try {
                setInit(false);
                const createdFM = await createFM(id);
                setFM(createdFM);
            } catch (e) {
                toast("FM API Error", {
                    description: "View console for details.",
                })
                console.error("fetch error", e);
                return;
            }
            setInit(true);
        }
    }

    return (
        <Sheet modal={false} open={open} onOpenChange={(isOpen) => { if (isOpen) setOpen(true); }}>
            <SheetTrigger asChild>
                <IconButton icon="folder-closed" onClick={fetchFM} />
            </SheetTrigger>
            <SheetContent setOpen={setOpen} className="sm:min-w-[35%]">
                <div className="overflow-auto">
                    <SheetTitle />
                    <SheetHeader className="pb-2">
                        <SheetDescription />
                    </SheetHeader>
                    {fm?.session_id && init
                        ?
                        <FMComponent className="p-1 space-y-5" wsUrl={`/api/v1/ws/file/${fm.session_id}`} />
                        :
                        <p>The server does not exist, or have not been connected yet.</p>
                    }
                </div>
            </SheetContent>
        </Sheet>
    )
}