// warning: experimental, incomplete and likely to change in the future
// if you find problems, please send a pull request

/**
 * The type for images as a file, loaded asynchronously.
 *
 * Files with `async: true` and `use_parts: false` are downloaded using HTTP
 * Range requests. Note that not all web servers support this header correctly,
 * and it inherently disables HTTP compression. The `url` fields points
 * directly to the disk images.
 */
type V86AsyncFileImage =
    {
        /** The URL to the image */
        url: string;

        /**
         * Async loading.
         *
         * If true, the file is downloaded completely, otherwise in chunks
         * (see {@link V86AsyncFileImage.use_parts} for the chunking method).
         */
        async: true;

        /** Image size, required for async loading */
        size: number;

        /**
         * Use parts instead of Range header, useful for static hostings.
         *
         * If true, v86 expects the image to be split in files of `fixed_chunk_size`
         * bytes. You can use [split-image.py](https://github.com/copy/v86/blob/master/tools/split-image.py)
         * to split an image. V86 appends `-<start-byte>-<end-byte>` to the url.
         */
        use_parts?: boolean;

        /**
         * Fixed chunk size, useful with `use_parts: true` for GitHub Pages users.
         */
        fixed_chunk_size?: number;
    };

/**
 * The type for images as a file, loaded synchronously.
 */
type V86SyncFileImage =
    {
        /** The URL to the image */
        url: string;

        /** @ignore */
        async?: false;
    };

/**
 * The type for images as a buffer.
 */
type V86BufferImage =
    {
        /** Image buffer */
        buffer: ArrayBuffer
    };
    //| { buffer: File; async?: boolean; }; // only in browsers: https://developer.mozilla.org/en-US/docs/Web/API/File

/**
 * The type of disk/bios/state images.
 *
 * Note that bios, initial state, bzimage, initrd, multiboot and floppy disk
 * images are always loaded synchronously.
 *
 * State images and fixed-size chunks (but not other image types) that end with
 * .zst are automatically decompressed using a built-in zstd decompressor. This
 * has a performance overhead compared to HTTP compression, but will result in
 * better compression ration.
 */
export type V86Image = V86AsyncFileImage | V86SyncFileImage | V86BufferImage;

/**
 * Config for virtio/serial console.
 */
export type ConsoleConfig =
    {
        /**
         * Console type
         *
         * Available types:
         *  - `textarea` - using TextArea HTML element, doesn't support ESC codes
         *  - `xtermjs` - using XtermJS-compatible terminal
         */
        type: "textarea" | "xtermjs" | "none";

        /** XtermJS constructor, useful for ESM users. When not set, `window["Terminal"]` is used */
        xterm_lib?: Function;

        /** HTML container for console */
        container?: HTMLElement | HTMLTextAreaElement;
    };

/**
 * Config for emulator screen.
 */
export type ScreenConfig =
    {
        /**
         * HTML container for emulator screen. This should have a certain structure.
         * @see {@link https://github.com/copy/v86/blob/master/examples/basic.html} for example
         */
        container?: HTMLElement | null;

        /**
         * Encoding for text mode screen
         * @default "cp437"
         */
        encoding?: "ascii" | "cp437" | "cp858";

        /**
         * Screen scaling
         * @default 1
         */
        scaling?: number;

        /**
         * Use canvas for text mode (browser only) with VGA fonts.
         * @default false
         */
        use_graphical_text?: boolean;

        /**
         * Use ANSI Truecolor codes for text mode output.
         * @default false
         */
        ansi?: boolean;
    };

/**
 * Debug log levels.
 */
export enum LogLevel {
    LOG_ALL = -1,
    LOG_NONE = 0,
    LOG_OTHER = 0x000001,
    LOG_CPU = 0x000002,
    LOG_FPU = 0x000004,
    LOG_MEM = 0x000008,
    LOG_DMA = 0x000010,
    LOG_IO = 0x000020,
    LOG_PS2 = 0x000040,
    LOG_PIC = 0x000080,
    LOG_VGA = 0x000100,
    LOG_PIT = 0x000200,
    LOG_MOUSE = 0x000400,
    LOG_PCI = 0x000800,
    LOG_BIOS = 0x001000,
    LOG_FLOPPY = 0x002000,
    LOG_SERIAL = 0x004000,
    LOG_DISK = 0x008000,
    LOG_RTC = 0x010000,
    LOG_HPET = 0x020000,
    LOG_ACPI = 0x040000,
    LOG_APIC = 0x080000,
    LOG_NET = 0x100000,
    LOG_VIRTIO = 0x200000,
    LOG_9P = 0x400000,
    LOG_SB16 = 0x800000,
    LOG_FETCH = 0x1000000,
    LOG_MODEM = 0x2000000,
}

/**
 * Boot order.
 */
export enum BootOrder {
    AUTO = 0,
    CD_FLOPPY_HARDDISK = 0x213,
    CD_HARDDISK_FLOPPY = 0x123,
    FLOPPY_CD_HARDDISK = 0x231,
    FLOPPY_HARDDISK_CD = 0x321,
    HARDDISK_CD_FLOPPY = 0x132,
}

/**
 * Emulator events.
 */
export interface Event {
    "9p-attach": void;
    "9p-read-end": [filename: string, byte_count: number];
    "9p-read-start": [filename: string];
    "9p-write-end": [filename: string, byte_count: number];
    "download-error": {
        file_index: number,
        file_count: number,
        file_name: string,
        request: any,
    };
    "download-progress": {
        file_index: number,
        file_count: number,
        file_name: string,
        lengthComputable: boolean,
        total: number,
        loaded: number,
    };
    "emulator-loaded": void;
    "emulator-ready": void;
    "emulator-started": void;
    "emulator-stopped": void;
    "eth-receive-end": [byte_count: number];
    "eth-transmit-end": [byte_count: number];
    "ide-read-end": [channel_nr: number, byte_count: number, sector_count: number];
    "ide-read-start": void;
    "ide-write-end": [channel_nr: number, byte_count: number, sector_count: number];
    "mouse-enable": boolean;
    "net0-send": Uint8Array;
    "screen-put-char": [row: number, col: number, chr: number];
    "screen-set-size": [width: number, height: number, bpp: number];
    "serial0-input": number;
    "serial0-output-byte": number;
    "serial1-input": number;
    "serial1-output-byte": number;
    "serial2-input": number;
    "serial2-output-byte": number;
    "serial3-input": number;
    "serial3-output-byte": number;
    "virtio-console0-output-bytes": Uint8Array;
    "virtio-console0-input-bytes": Uint8Array;
    "virtio-console0-resize": [cols: number, rows: number];
    "vmware-absolute-mouse": boolean;
}

/**
 * @ignore
 * @constructor
 *
 * @param {string=} message
 */
declare class FileExistsError extends Error {
    constructor(message: string);
}

/**
 * @ignore
 * @constructor
 *
 * @param {string=} message
 */
declare class FileNotFoundError extends Error {
    constructor(message: string);
}

/**
 * Network device configuration.
 * @see {@link https://github.com/copy/v86/blob/master/docs/networking.md} for more infos
 */
type V86NetworkDevice =
    {
        /**
         * The type of emulated NIC provided to the guest OS.
         * Recommended to use `ne2k` for old OSes and `virtio` for modern Linux.
         * @default "ne2k"
         */
        type?: "ne2k" | "virtio";

        /**
         * The network backend URL.
         * Note that the CORS proxy server of the fetch backend is defined in field `cors_proxy` below.
         * @see {@link https://github.com/copy/v86/blob/master/docs/networking.md#backend-url-schemes} for backend URL schemes
         */
        relay_url?: string;

        /**
         * Network id, all v86 network instances with the same id share the same network namespace.
         * @todo class NetworkAdapter should also get options.net_device as an argument, at least options.net_device.id.
         * @default 0
         */
        id?: number;

        /**
         * MAC address of virtual network peers (ARP, PING, DHCP, DNS, NTP, UDP echo and TCP peers) in common MAC
         * address notation (fetch/wisp only).
         * @default "52:54:0:1:2:3"
         */
        router_mac?: string;

        /**
         * IP address of virtual network peers (ARP, PING, DHCP, DNS and TCP peers) in dotted IP notation (fetch/wisp only).
         * @default "192.168.86.1"
         */
        router_ip?: string;

        /**
         * IP address to be assigned to the guest by DHCP in dotted IP notation (fetch/wisp only).
         * @default "192.168.86.100"
         */
        vm_ip?: string;

        /**
         * Network masquerade (fetch/wisp only).
         *
         * If true, announce `router_ip` as the router's and DNS server's IP addresses in generated
         * DHCP replies, and also generate ARP replies to IPs outside the router's subnet `255.255.255.0`.
         * @default true
         */
        masquerade?: boolean;

        /**
         * DNS method to use (fetch/wisp only).
         *
         * Available methods:
         * - `static`: use built-in DNS server
         * - `doh`: use DNS-over-HTTPS (DoH)
         * @default `static` for `fetch` or `doh` for `wisp` backend
         * @see {@link https://en.wikipedia.org/wiki/DNS_over_HTTPS} about DNS over HTTPS
         */
        dns_method?: "static" | "doh";

        /**
         * Host name or IP address (and optional port number) of the DoH server if `dns_method` is `doh`.
         *
         * The value is expanded to the URL `https://DOH_SERVER/dns-query`.
         * @default "cloudflare-dns.com"
         */
        doh_server?: string;

        /**
         * CORS proxy server URL, do not use a proxy if undefined (`fetch` backend only).
         */
        cors_proxy?: string;

        /**
         * The MTU used for the virtual network. Increasing it can improve performance. This only works if the NIC type is `virtio`.
         * @default 1500
         */
        mtu?: number;
    };

/**
 * Emulator instance constructor options.
 */
export interface V86Options {
    /**
     * Reference to the v86 wasm exported function.
     */
    wasm_fn?: (options: WebAssembly.Imports) => Promise<WebAssembly.Exports>;

    /**
     * Path to v86 wasm artifact
     * @default "build/v86.wasm" or "build/v86-debug.wasm" when debug mode enabled
     */
    wasm_path?: string;

    /**
     * The memory size in bytes, should be a power of 2.
     * @example 16 * 1024 * 1024
     * @default 64 * 1024 * 1024
     */
    memory_size?: number;

    /**
     * VGA memory size in bytes.
     * @example 8 * 1024 * 1024
     * @default 8 * 1024 * 1024
     */
    vga_memory_size?: number;

    /**
     * If emulation should be started when emulator is ready.
     * @default false
     */
    autostart?: boolean;

    /**
     * If keyboard should be disabled (only browsers).
     */
    disable_keyboard?: boolean;

    /**
     * If mouse should be disabled (only browsers).
     */
    disable_mouse?: boolean;

    /**
     * If speaker should be disabled (only browsers).
     */
    disable_speaker?: boolean;

    /**
     * BIOS image (supported SeaBIOS and Bochs BIOS)
     * @see {@link https://github.com/copy/v86/tree/master/bios} for BIOS images
     */
    bios?: V86Image;

    /**
     * VGA BIOS image
     * @see {@link https://github.com/copy/v86/tree/master/bios} for BIOS images
     */
    vga_bios?: V86Image;

    /**
     * First hard disk
     */
    hda?: V86Image;

    /**
     * Second hard disk
     */
    hdb?: V86Image;

    /**
     * First floppy disk
     */
    fda?: V86Image;

    /**
     * Second floppy disk
     */
    fdb?: V86Image;

    /**
     * CD-ROM
     * By default, an ejected CD-ROM drive is emulated
     */
    cdrom?: V86Image;

    /**
     * A Linux kernel image to boot (only bzimage format)
     */
    bzimage?: V86Image;

    /**
     * Kernel boot cmdline
     */
    cmdline?: string;

    /**
     * A Linux ramdisk image
     */
    initrd?: V86Image;

    /**
     * Automatically fetch bzimage and initrd from the 9p filesystem
     */
    bzimage_initrd_from_filesystem?: boolean;

    /**
     * Multiboot image
     */
    multiboot?: V86Image;

    /**
     * An initial state to load
     * @see {@link V86.prototype.save_state}
     */
    initial_state?: V86Image;

    /**
     * Should the MAC address be preserved from the state image, for operating systems that
     * don't allow you to reload the network card driver
     * @default false
     * @see {@link https://github.com/copy/v86/blob/master/docs/networking.md#v86-run-time-state-images}
     */
    preserve_mac_from_state_image?: boolean;

    /**
     * A 9p filesystem is supported by the emulator, using a virtio transport. Using it, files can be exchanged with the guest OS
     * If `basefs` and `baseurl` are omitted, an empty 9p filesystem is created.
     */
    filesystem?: {
        /**
         * A URL to a JSON file created using [fs2json](https://github.com/copy/v86/blob/master/tools/fs2json.py).
         */
        baseurl?: string;

        /**
         * A directory of 9p files, as created by [copy-to-sha256.py](https://github.com/copy/v86/blob/master/tools/copy-to-sha256.py).
         * @see {@link https://github.com/copy/v86/blob/master/docs/filesystem.md} for more details
         */
        basefs?: string;

        /**
         * A function that will be called for each 9p request.
         * If specified, this will back Virtio9p instead of a filesystem.
         * Use this to build or connect to a custom 9p server.
         */
        handle9p?: (reqbuf: Uint8Array, reply: (replybuf: Uint8Array) => void) => void;

        /**
         * A URL to a websocket proxy for 9p.
         * If specified, this will back Virtio9p instead of a filesystem.
         * Use this to connect to a custom 9p server over websocket.
         */
        proxy_url?: string;
    };

    /**
     * A textarea that will receive and send data to the emulated serial terminal (only browsers).
     * Alternatively the serial terminal can also be accessed programatically, see
     * [examples/serial.html](https://github.com/copy/v86/blob/master/examples/serial.html) for example.
     * Deprecated in favor of {@link V86Options.serial_console}.
     * @deprecated
     * @see {@link V86Options.serial_console}
     */
    serial_container?: HTMLTextAreaElement;

    /**
     * Xtermjs serial terminal container (only browsers). When set, serial_container option is ignored.
     * Deprecated in favor of {@link V86Options.serial_console}.
     * @deprecated
     * @see {@link V86Options.serial_console}
     */
    serial_container_xtermjs?: HTMLElement;

    /**
     * Console adapter for serial console
     */
    serial_console?: ConsoleConfig;

    /**
     * Console adapter for virtio console.
     * Setting to true, creates virtio console device without adapter
     */
    virtio_console?: ConsoleConfig;

    /**
     * Emulator screen element (only browsers).
     * Only provided for backwards compatibility, use {@link V86Options.screen} instead.
     * @deprecated
     * @see {@link https://github.com/copy/v86/blob/master/examples/basic.html} for example
     */
    screen_container?: HTMLElement | null;

    /**
     * Emulator screen config
     */
    screen?: ScreenConfig;

    /**
     * Enable ACPI (also enables APIC). Experimental and only partially implemented.
     * @default false
     */
    acpi?: boolean;

    /**
     * Log level (for debug builds)
     * @default LogLevel.LOG_NONE
     */
    log_level?: LogLevel;

    /**
     * Boot order
     * @default BootOrder.AUTO
     */
    boot_order?: BootOrder;

    /**
     * Fast boot, skips boot menu in bochs bios
     * @default false
     */
    fastboot?: boolean;

    /**
     * Create a virtio balloon device
     * @default false
     */
    virtio_balloon?: boolean;

    /**
     * Override the maximum supported cpuid level
     * Used for some versions of Windows, see [docs/windows-nt.md](https://github.com/copy/v86/blob/master/docs/windows-nt.md)
     */
    cpuid_level?: number;

    /**
     * Turn off the x86-to-wasm jit
     * @default false
     */
    disable_jit?: boolean;

    /**
     * The URL of a server running network relay.
     * Deprecated in favor of {@link V86Options.net_device}.
     * @deprecated
     * @see {@link V86Options.net_device}
     */
    network_relay_url?: string;

    /**
     * Network device configuration.
     */
    net_device?: V86NetworkDevice;

    /**
     * Enable serial port 1
     * @default false
     */
    uart1?: boolean;

    /**
     * Enable serial port 2
     * @default false
     */
    uart2?: boolean;

    /**
     * Enable serial port 3
     * @default false
     */
    uart3?: boolean;
}

export class V86 {
    constructor(options: V86Options);

    /**
     * Start emulation. Do nothing if emulator is running already. Can be asynchronous.
     */
    run(): Promise<void>;

    /**
     * Stop emulation. Do nothing if emulator is not running. Can be asynchronous.
     */
    stop(): Promise<void>;

    /**
     * Free resources associated with this instance
     */
    destroy(): Promise<void>;

    /**
     * Restart (force a reboot).
     */
    restart(): void;

    /**
     * Add an event listener (the emulator is an event emitter).
     *
     * The callback function gets a single argument which depends on the event.
     *
     * @param event Name of the event.
     * @param listener The callback function.
     */
    add_listener<T extends keyof Event>(event: T, listener: (argument: Event[T]) => void): void;

    /**
     * Remove an event listener.
     *
     * The callback function gets a single argument which depends on the event.
     *
     * @param event Name of the event.
     * @param listener The callback function.
     */
    remove_listener<T extends keyof Event>(event: T, listener: (argument: Event[T]) => void): void;

    /**
     * Restore the emulator state from the given state, which must be an
     * ArrayBuffer returned by {@link V86.prototype.save_state}.
     *
     * Note that the state can only be restored correctly if this constructor has
     * been created with the same options as the original instance (e.g., same disk
     * images, memory size, etc.).
     *
     * Different versions of the emulator might use a different format for the
     * state buffer.
     *
     * @param state
     */
    restore_state(state: ArrayBuffer): Promise<void>;

    /**
     * Asynchronously save the current state of the emulator.
     */
    save_state(): Promise<ArrayBuffer>;

    /**
     * Get current instruction counter
     */
    get_instruction_counter(): number;

    /**
     * Get emulator running status
     */
    is_running(): boolean;

    /**
     * Set the image inserted in the first floppy drive. Can be changed at runtime,
     * as when physically changing the floppy disk.
     */
    set_fda(image: V86Image): Promise<void>;

    /**
     * Eject the first floppy drive.
     */
    eject_fda(): void;

    /**
     * Set the image inserted in the second floppy drive. Can be changed at runtime,
     * as when physically changing the floppy disk.
     */
    set_fdb(image: V86Image): Promise<void>;

    /**
     * Eject the second floppy drive.
     */
    eject_fdb(): void;

    /**
     * Set the image inserted in the CD-ROM drive. Can be changed at runtime, as
     * when physically changing the CD-ROM.
     */
    set_cdrom(image: V86Image): Promise<void>;

    /**
     * Eject the CD-ROM.
     */
    eject_cdrom(): void;

    /**
     * Send a sequence of scan codes to the emulated PS2 controller. A list of
     * codes can be found at http://stanislavs.org/helppc/make_codes.html.
     * Do nothing if there is no keyboard controller.
     *
     * @param codes
     */
    keyboard_send_scancodes(codes: number[]): void;

    /**
     * Send translated keys
     */
    keyboard_send_keys(codes: number[]): void;

    /**
     * Send text, assuming the guest OS uses a US keyboard layout
     */
    keyboard_send_text(string: string): void;

    /**
     * Download a screenshot (returns an <img> element, only works in browsers)
     */
    screen_make_screenshot(): HTMLElement;

    /**
     * Set the scaling level of the emulated screen.
     *
     * @param {number} sx
     * @param {number} sy
     */
    screen_set_scale(sx: number, sy: number): void;

    /**
     * Go fullscreen (only browsers)
     */
    screen_go_fullscreen(): void;

    /**
     * Lock the mouse cursor: It becomes invisble and is not moved out of the browser window (only browsers)
     */
    lock_mouse(): void;

    /**
     * Enable or disable sending mouse events to the emulated PS2 controller.
     */
    mouse_set_enabled(enabled: boolean): void;

    /**
     * Enable or disable sending keyboard events to the emulated PS2 controller.
     */
    keyboard_set_enabled(enabled: boolean): void;

    /**
     * Send a string to the first emulated serial terminal.
     *
     * @param data
     */
    serial0_send(data: string): void;

    /**
     * Send bytes to a serial port (to be received by the emulated PC).
     *
     * @param serial the index of the serial port
     * @param data
     */
    serial_send_bytes(serial: number, data: Uint8Array): void;

    /**
     * Set or clear the data carrier detect (DCD) status of a serial port.
     *
     * @param serial the index of the serial port
     * @param status the new DCD signal status
     */
    serial_set_carrier_detect(serial: number, status: boolean): void;

    /**
     * Set or clear the ring indicator (RING) status of a serial port.
     *
     * @param serial the index of the serial port
     * @param status the new RING signal status
     */
    serial_set_ring_indicator(serial: number, status: boolean): void;

    /**
     * Set or clear the data set ready (DSR) status of a serial port.
     *
     * @param serial the index of the serial port
     * @param status the new DSR signal status
     */
    serial_set_data_set_ready(serial: number, status: boolean): void;

    /**
     * Set or clear the clear to send (CTS) status of a serial port.
     *
     * @param serial the index of the serial port
     * @param status the new CTS signal status
     */
    serial_set_clear_to_send(serial: number, status: boolean): void;

    /**
     * Write to a file in the 9p filesystem. Nothing happens if no filesystem has
     * been initialized.
     *
     * @param file
     * @param data
     * @param callback
     * @throws {FileNotFoundError}
     */
    create_file(file: string, data: Uint8Array): Promise<void>;

    /**
     * Read a file in the 9p filesystem.
     *
     * @param {string} file
     * @throws {FileNotFoundError}
     */
    read_file(file: string): Promise<Uint8Array>;

    /**
     * Reads data from memory at specified offset.
     *
     * @param offset
     * @param length
     */
    read_memory(offset: number, length: number): Uint8Array;

    /**
     * Writes data to memory at specified offset.
     *
     * @param blob
     * @param offset
     */
    write_memory(blob: number[] | Uint8Array, offset: number): void;

    /**
     * Wait until expected text is present on the VGA text screen.
     *
     * Returns immediately if the expected text is already present on screen
     * at the time this function is called.
     *
     * @param expected
     * @param options
     */
    wait_until_vga_screen_contains(expected: string|RegExp|Array<string|RegExp>, options?: {timeout_msec?: number}): Promise<boolean>;

    /**
     * Set Xtermjs serial port console
     *
     * @param element
     * @param xterm_lib
     */
    set_serial_container_xtermjs(element: HTMLElement, xterm_lib?: Function): void;

    /**
     * Set Xtermjs virtio console
     *
     * @param element
     * @param xterm_lib
     */
    set_virtio_console_container_xtermjs(element: HTMLElement, xterm_lib?: Function): void;

    /**
     * Run steps automatically
     *
     * @param steps
     * @deprecated
     * @see {@link V86.prototype.wait_until_vga_screen_contains}
     */
    automatically(steps: Array<{ sleep?: number, vga_text?: string, keyboard_send?: string | number[], call?: Function }>): void;

    /**
     * Get instruction stats
     *
     * @see {@link https://github.com/copy/v86/blob/master/docs/profiling.md} for more infos
     */
    get_instruction_stats(): string;
}