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

package app

import (
	"context"
	"errors"
	"reflect"
	"sync"
	"unicode"
	"unicode/utf8"

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

// echoSpeaker prepares all voices before publishing any. Speech and
// cancellation remain available while a preferences change is prepared.
type echoSpeaker struct {
	socket  string
	initial config.Settings
	mu      sync.RWMutex
	update  sync.Mutex
	voices  map[string]*speech.Client
	closed  bool
}

func newEchoSpeaker(socket string, settings config.Settings) *echoSpeaker {
	return &echoSpeaker{socket: socket, initial: settings}
}
func (speaker *echoSpeaker) Connect(ctx context.Context) error {
	return speaker.UpdateConfiguration(ctx, speaker.initial)
}
func (speaker *echoSpeaker) UpdateConfiguration(ctx context.Context, settings config.Settings) error {
	if !speaker.update.TryLock() {
		return errors.New("speech settings update already in progress")
	}
	defer speaker.update.Unlock()
	candidates := make(map[string]*speech.Client)
	closeClients := func(clients map[string]*speech.Client) error {
		var result error
		for _, client := range clients {
			result = errors.Join(result, client.Close(context.Background()))
		}
		return result
	}
	voiceSettings := map[string]speech.Settings{"default": speechSettingsFromConfig(settings)}
	for _, kind := range []string{"uppercase", "hyperlink", "system"} {
		if kind == "hyperlink" && reflect.DeepEqual(settings.HyperlinkVoice, config.Voice{}) || kind == "system" && reflect.DeepEqual(settings.SystemVoice, config.Voice{}) {
			continue
		}
		candidate := settings
		candidate.DefaultVoice = config.EffectiveVoice(settings, kind)
		voiceSettings[kind] = speechSettingsFromConfig(candidate)
	}
	if settings.UseCustomEchoVoice {
		voiceSettings["echo"] = echoSpeechSettings(settings)
		echoSettings := settings
		echoSettings.DefaultVoice = config.EffectiveVoice(settings, "default")
		merge_echo_voice(&echoSettings.DefaultVoice, settings.EchoVoice)
		echoSettings.DefaultVoice = config.EffectiveVoice(echoSettings, "uppercase")
		if settings.UseCustomEchoSpeechServer {
			echoSettings.SpeechOutputModule = settings.EchoSpeechServer
		}
		// Echo endpoints allow 100/10/10; use the existing clamping mapper.
		echoSettings.EchoVoice = echoSettings.DefaultVoice
		voiceSettings["uppercase-echo"] = echoSpeechSettings(echoSettings)
	}
	for _, kind := range []string{"default", "echo", "uppercase", "uppercase-echo", "hyperlink", "system"} {
		values, exists := voiceSettings[kind]
		if !exists {
			continue
		}
		client := speech.NewWithSettings(speaker.socket, values)
		candidates[kind] = client
		if err := client.Connect(ctx); err != nil {
			closeClients(candidates)
			return err
		}
	}
	speaker.mu.Lock()
	defer speaker.mu.Unlock()
	if speaker.closed {
		closeClients(candidates)
		return errors.New("speech is closed")
	}
	if err := ctx.Err(); err != nil {
		closeClients(candidates)
		return err
	}
	for _, client := range speaker.voices {
		if err := client.Cancel(ctx); err != nil {
			closeClients(candidates)
			return err
		}
	}
	retired := speaker.voices
	speaker.voices = candidates
	_ = closeClients(retired)
	return nil
}
func (speaker *echoSpeaker) client(kind string) *speech.Client {
	if client := speaker.voices[kind]; client != nil {
		return client
	}
	return speaker.voices["default"]
}
func (speaker *echoSpeaker) Speak(ctx context.Context, text string) error {
	return speaker.SpeakVoice(ctx, text, "default")
}
func (speaker *echoSpeaker) SpeakVoice(ctx context.Context, text, kind string) error {
	speaker.mu.RLock()
	defer speaker.mu.RUnlock()
	client := speaker.client(kind)
	if client == nil {
		return errors.New("speech is not connected")
	}
	return client.Speak(ctx, text)
}
func (speaker *echoSpeaker) SpeakCharacter(ctx context.Context, text string) error {
	return speaker.speak_character(ctx, text, false)
}
func (speaker *echoSpeaker) SpeakEchoCharacter(ctx context.Context, text string) error {
	return speaker.speak_character(ctx, text, true)
}
func (speaker *echoSpeaker) speak_character(ctx context.Context, text string, custom bool) error {
	speaker.mu.RLock()
	defer speaker.mu.RUnlock()
	kind := "default"
	if custom {
		kind = "echo"
	}
	r, size := utf8.DecodeRuneInString(text)
	if size == len(text) && unicode.IsUpper(r) {
		kind = "uppercase"
		if custom && speaker.voices["uppercase-echo"] != nil {
			kind = "uppercase-echo"
		}
	}
	client := speaker.client(kind)
	if client == nil {
		return errors.New("speech is not connected")
	}
	return client.SpeakCharacter(ctx, text)
}
func (speaker *echoSpeaker) SpeakEcho(ctx context.Context, text string) error {
	return speaker.SpeakVoice(ctx, text, "echo")
}
func (speaker *echoSpeaker) SpeakAndWait(ctx context.Context, text string, began func()) error {
	return speaker.SpeakVoiceAndWait(ctx, text, "default", began)
}

func (speaker *echoSpeaker) speak_uninterruptible(ctx context.Context, text string) error {
	return speaker.SpeakVoiceAndWait(ctx, text, "system", nil)
}

func (speaker *echoSpeaker) SpeakVoiceAndWait(ctx context.Context, text, kind string, began func()) error {
	speaker.mu.RLock()
	client := speaker.client(kind)
	speaker.mu.RUnlock()
	if client == nil {
		return errors.New("speech is not connected")
	}
	return client.SpeakAndWait(ctx, text, began)
}
func (speaker *echoSpeaker) Cancel(ctx context.Context) error {
	speaker.mu.RLock()
	defer speaker.mu.RUnlock()
	var result error
	for _, client := range speaker.voices {
		result = errors.Join(result, client.Cancel(ctx))
	}
	return result
}
func (speaker *echoSpeaker) Close(ctx context.Context) error {
	speaker.update.Lock()
	defer speaker.update.Unlock()
	speaker.mu.Lock()
	defer speaker.mu.Unlock()
	speaker.closed = true
	var result error
	for _, client := range speaker.voices {
		result = errors.Join(result, client.Close(ctx))
	}
	speaker.voices = nil
	return result
}
func merge_echo_voice(voice *config.Voice, echo config.Voice) {
	if echo.Rate != nil {
		voice.Rate = echo.Rate
	}
	if echo.AveragePitch != nil {
		voice.AveragePitch = echo.AveragePitch
	}
	if echo.Gain != nil {
		voice.Gain = echo.Gain
	}
	if echo.Family != nil {
		voice.Family = echo.Family
	}
}
func echoSpeechSettings(settings config.Settings) speech.Settings {
	voice := settings.DefaultVoice
	if v := settings.EchoVoice.Rate; v != nil {
		voice.Rate = v
	}
	if v := settings.EchoVoice.AveragePitch; v != nil {
		voice.AveragePitch = v
	}
	if v := settings.EchoVoice.Gain; v != nil {
		voice.Gain = v
	}
	if v := settings.EchoVoice.Family; v != nil {
		voice.Family = v
	}
	// Cthulhu accepts UI endpoints 100/10/10 and clamps for SSIP.
	for _, field := range []struct {
		value **float64
		max   float64
	}{{&voice.Rate, 99}, {&voice.AveragePitch, 9}, {&voice.Gain, 9}} {
		if *field.value != nil {
			value := min(**field.value, field.max)
			*field.value = &value
		}
	}
	settings.DefaultVoice = voice
	result := speechSettingsFromConfig(settings)
	if settings.UseCustomEchoSpeechServer {
		result.OutputModule = settings.EchoSpeechServer
	}
	return result
}
func customEcho(settings config.Settings, kind string) bool {
	if !settings.EnableKeyEcho || !settings.UseCustomEchoVoice {
		return false
	}
	switch kind {
	case "key":
		return settings.UseCustomEchoForKey
	case "character":
		return settings.UseCustomEchoForCharacter
	case "word":
		return settings.UseCustomEchoForWord
	case "sentence":
		return settings.UseCustomEchoForSentence
	}
	return false
}