// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package app

import (
	"context"
	"errors"

	"git.stormux.org/storm/cthulhu/internal/config"
	"git.stormux.org/storm/cthulhu/internal/preferences"
)

func (worker *preferencesWorker) preview(ctx context.Context, request preferences.Request) preferences.Response {
	next := worker.settings
	if worker.editingActive {
		next = worker.editing
	}
	next.DefaultVoice.Rate = request.Values.Rate
	next.DefaultVoice.AveragePitch = request.Values.Pitch
	next.DefaultVoice.Gain = request.Values.Volume
	next.SpeechServerFactory = request.Values.SpeechServerFactory
	next.HardwareSpeechDevice = request.Values.HardwareSpeechDevice
	next.HardwareSpeechBaudRate = request.Values.HardwareSpeechBaudRate
	next.SpeechOutputModule = request.Values.SpeechOutputModule
	next.DefaultVoice.Family = request.Values.SpeechVoiceFamily
	next.UppercaseVoice = request.Values.UppercaseVoice
	next.HyperlinkVoice = request.Values.HyperlinkVoice
	next.SystemVoice = request.Values.SystemVoice
	// GUI feedback auditions the selected type; Cancel restores the committed
	// configuration, while Apply receives the complete unmodified draft.
	if kind := request.Values.VoiceType; kind != "" && kind != "default" {
		next.DefaultVoice = config.EffectiveVoice(next, kind)
		next.SystemVoice = config.Voice{}
	}
	response := worker.response("Speech settings previewed.", false)
	response.Preview = true
	if err := config.Validate(next); err != nil {
		response.Message = "Speech settings were not previewed: " + err.Error()
		return response
	}
	if err := worker.updateSpeech(ctx, next); err != nil {
		response.Message = "Speech settings were not previewed: " + err.Error()
		return response
	}
	response.Accepted = true
	return response
}

func (worker *preferencesWorker) restorePreview(ctx context.Context) preferences.Response {
	response := worker.response("Speech settings restored.", false)
	if err := worker.updateSpeech(ctx, worker.settings); err != nil {
		response.Message = "Speech settings could not be restored: " + err.Error()
		return response
	}
	response.Accepted = true
	response.Close = true
	return response
}

func (worker *preferencesWorker) updateSpeech(ctx context.Context, next config.Settings) error {
	if worker.updater == nil {
		return errors.New("speech is disabled or this backend cannot change settings")
	}
	if updater, ok := worker.updater.(interface {
		UpdateConfiguration(context.Context, config.Settings) error
	}); ok {
		return updater.UpdateConfiguration(ctx, next)
	}
	if updater, ok := worker.updater.(speechSettingsUpdater); ok {
		if next.UseCustomEchoVoice {
			return errors.New("this speech backend cannot use a custom echo voice")
		}
		return updater.UpdateSettings(ctx, speechSettingsFromConfig(next))
	}
	return errors.New("this backend cannot change speech settings")
}