/*
Copyright 2020 The Matrix.org Foundation C.I.C.

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 * as React from "react";
import classNames from "classnames";

import * as sdk from "../index";
import Modal from "../Modal";
import { _t, _td } from "../languageHandler";
import {isMac, Key} from "../Keyboard";

// TS: once languageHandler is TS we can probably inline this into the enum
_td("Navigation");
_td("Calls");
_td("Composer");
_td("Room List");
_td("Autocomplete");

export enum Categories {
    NAVIGATION="Navigation",
    CALLS="Calls",
    COMPOSER="Composer",
    ROOM_LIST="Room List",
    AUTOCOMPLETE="Autocomplete",
}

// TS: once languageHandler is TS we can probably inline this into the enum
_td("Alt");
_td("Alt Gr");
_td("Shift");
_td("Super");
_td("Ctrl");

export enum Modifiers {
    ALT="Alt",
    OPTION="Option", // This gets displayed as an Icon
    ALT_GR="Alt Gr",
    SHIFT="Shift",
    SUPER="Super", // should this be "Windows"?
    // Instead of using below, consider CMD_OR_CTRL
    COMMAND="Command", // This gets displayed as an Icon
    CONTROL="Ctrl",
}

// Meta-modifier: isMac ? CMD : CONTROL
export const CMD_OR_CTRL = isMac ? Modifiers.COMMAND : Modifiers.CONTROL;

interface IKeybind {
    modifiers?: Modifiers[];
    key: string; // TS: fix this once Key is an enum
}

interface IShortcut {
    keybinds: IKeybind[];
    description: string;
}

const shortcuts: Record<Categories, IShortcut[]> = {
    [Categories.COMPOSER]: [
        {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.B,
            }],
            description: _td("Toggle Bold"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.I,
            }],
            description: _td("Toggle Italics"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.GREATER_THAN,
            }],
            description: _td("Toggle Quote"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.M,
            }],
            description: _td("Toggle Markdown"),
        }, {
            keybinds: [{
                modifiers: [Modifiers.SHIFT],
                key: Key.ENTER,
            }],
            description: _td("New line"),
        }, {
            keybinds: [{
                key: Key.ARROW_UP,
            }, {
                key: Key.ARROW_DOWN,
            }],
            description: _td("Navigate recent messages to edit"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.HOME,
            }, {
                modifiers: [CMD_OR_CTRL],
                key: Key.END,
            }],
            description: _td("Jump to start/end of the composer"),
        },
    ],

    [Categories.CALLS]: [
        {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.D,
            }],
            description: _td("Toggle microphone mute"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.E,
            }],
            description: _td("Toggle video on/off"),
        },
    ],

    [Categories.ROOM_LIST]: [
        {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.K,
            }],
            description: _td("Jump to room search"),
        }, {
            keybinds: [{
                key: Key.ARROW_UP,
            }, {
                key: Key.ARROW_DOWN,
            }],
            description: _td("Navigate up/down in the room list"),
        }, {
            keybinds: [{
                key: Key.ENTER,
            }],
            description: _td("Select room from the room list"),
        }, {
            keybinds: [{
                key: Key.ARROW_LEFT,
            }],
            description: _td("Collapse room list section"),
        }, {
            keybinds: [{
                key: Key.ARROW_RIGHT,
            }],
            description: _td("Expand room list section"),
        }, {
            keybinds: [{
                key: Key.ESCAPE,
            }],
            description: _td("Clear room list filter field"),
        },
    ],

    [Categories.NAVIGATION]: [
        {
            keybinds: [{
                key: Key.PAGE_UP,
            }, {
                key: Key.PAGE_DOWN,
            }],
            description: _td("Scroll up/down in the timeline"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.BACKTICK,
            }],
            description: _td("Toggle the top left menu"),
        }, {
            keybinds: [{
                key: Key.ESCAPE,
            }],
            description: _td("Close dialog or context menu"),
        }, {
            keybinds: [{
                key: Key.ENTER,
            }, {
                key: Key.SPACE,
            }],
            description: _td("Activate selected button"),
        }, {
            keybinds: [{
                modifiers: [CMD_OR_CTRL],
                key: Key.SLASH,
            }],
            description: _td("Toggle this dialog"),
        },
    ],

    [Categories.AUTOCOMPLETE]: [
        {
            keybinds: [{
                key: Key.ARROW_UP,
            }, {
                key: Key.ARROW_DOWN,
            }],
            description: _td("Move autocomplete selection up/down"),
        }, {
            keybinds: [{
                key: Key.ESCAPE,
            }],
            description: _td("Cancel autocomplete"),
        },
    ],
};

interface IModal {
    close: () => void;
    finished: Promise<any[]>;
}

const modifierIcon: Record<Modifiers, string> = {
    [Modifiers.COMMAND]: "⌘",
    [Modifiers.OPTION]: "⌥",
};

const alternateKeyName: Record<string, string> = { // TS: fix this once Key is an enum
    [Key.PAGE_UP]: _td("Page Up"),
    [Key.PAGE_DOWN]: _td("Page Down"),
    [Key.ESCAPE]: _td("Esc"),
    [Key.ENTER]: _td("Enter"),
    [Key.SPACE]: _td("Space"),
    [Key.HOME]: _td("Home"),
    [Key.END]: _td("End"),
};
const keyIcon: Record<string, string> = { // TS: fix this once Key is an enum
    [Key.ARROW_UP]: "↑",
    [Key.ARROW_DOWN]: "↓",
    [Key.ARROW_LEFT]: "←",
    [Key.ARROW_RIGHT]: "→",
};

const Shortcut: React.FC<{
    shortcut: IShortcut;
}> = ({shortcut}) => {
    const classes = classNames({
        "mx_KeyboardShortcutsDialog_inline": shortcut.keybinds.every(k => !k.modifiers || k.modifiers.length === 0),
    });

    return <div className={classes}>
        <h5>{ _t(shortcut.description) }</h5>
        { shortcut.keybinds.map(s => {
            let text = s.key;
            if (alternateKeyName[s.key]) {
                text = _t(alternateKeyName[s.key]);
            } else if (keyIcon[s.key]) {
                text = keyIcon[s.key];
            }

            return <div key={s.key}>
                { s.modifiers && s.modifiers.map(m => {
                    return <React.Fragment key={m}>
                        <kbd>{ modifierIcon[m] || _t(m) }</kbd>+
                    </React.Fragment>;
                }) }
                <kbd>{ text }</kbd>
            </div>;
        }) }
    </div>;
};

let activeModal: IModal = null;
export const toggleDialog = () => {
    if (activeModal) {
        activeModal.close();
        activeModal = null;
        return;
    }

    const sections = Object.entries(shortcuts).map(([category, list]) => {
        return <div className="mx_KeyboardShortcutsDialog_category" key={category}>
            <h3>{_t(category)}</h3>
            <div>{list.map(shortcut => <Shortcut key={shortcut.description} shortcut={shortcut} />)}</div>
        </div>;
    });

    const InfoDialog = sdk.getComponent('dialogs.InfoDialog');
    activeModal = Modal.createTrackedDialog("Keyboard Shortcuts", "", InfoDialog, {
        className: "mx_KeyboardShortcutsDialog",
        title: _t("Keyboard Shortcuts"),
        description: sections,
        hasCloseButton: true,
        onKeyDown: (ev) => {
            if (ev.ctrlKey && !ev.shiftKey && !ev.altKey && !ev.metaKey && ev.key === Key.SLASH) { // Ctrl + /
                ev.stopPropagation();
                activeModal.close();
            }
        },
        onFinished: () => {
            activeModal = null;
        },
    });
};