package com.ts3client.ui;

import com.ts3client.hotkey.GlobalInputHook;
import com.ts3client.hotkey.Hotkey;
import com.ts3client.hotkey.HotkeyAction;
import com.ts3client.hotkey.HotkeyCombo;
import com.ts3client.hotkey.HotkeyEngine;
import com.ts3client.hotkey.HotkeyKey;
import com.ts3client.hotkey.Hotkeys;
import com.ts3client.hotkey.desktop.DesktopInputHooks;

import java.util.List;

/**
 * Owns the hotkey machinery for the UI: the stored bindings, the matching engine and
 * the platform input hook they are fed from. Everything the dialogs need — recording a
 * combination, naming keys, telling the user why hotkeys are dead — goes through here.
 */
final class HotkeyService {

    private final Hotkeys hotkeys = Hotkeys.load();
    private final HotkeyEngine engine;
    private final GlobalInputHook hook;
    private final HotkeyArguments arguments;

    HotkeyService(HotkeyEngine.Handler handler, HotkeyArguments arguments) {
        this.arguments = arguments;
        engine = new HotkeyEngine(hotkeys, handler);
        hook = DesktopInputHooks.start(engine);
    }

    /** The values this action's parameter can take right now, for the action tree. */
    List<String> argumentChoices(HotkeyAction action) {
        if (arguments == null || action.argument() == HotkeyAction.Argument.NONE) return List.of();
        try {
            return arguments.choices(action);
        } catch (RuntimeException e) {
            return List.of();
        }
    }

    List<Hotkey> all() {
        return hotkeys.all();
    }

    void replaceAll(List<Hotkey> updated) {
        engine.releaseAll();
        hotkeys.replaceAll(updated);
        hotkeys.save();
    }

    /** The binding for an action with no argument, or {@code null} when unbound. */
    Hotkey find(HotkeyAction action) {
        synchronized (hotkeys.all()) {
            for (Hotkey h : hotkeys.all()) {
                if (h.action == action) return h;
            }
        }
        return null;
    }

    boolean isRunning() {
        return hook.isRunning();
    }

    /** One line for the options dialog: either working, or why it is not. */
    String status() {
        return hook.isRunning()
                ? "Global hotkeys are active."
                : "Global hotkeys are unavailable (" + hook.unavailableReason() + ").";
    }

    String display(HotkeyCombo combo) {
        return combo == null ? "No hotkey assigned" : combo.display(this::keyName);
    }

    private String keyName(HotkeyKey key) {
        return hook.keyName(key);
    }

    /** Captures the next combination instead of firing bindings; see {@link #stopRecording()}. */
    void record(HotkeyEngine.Recorder recorder) {
        engine.record(recorder);
    }

    void stopRecording() {
        engine.stopRecording();
    }

    void dispose() {
        engine.releaseAll();
        hook.close();
    }
}