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

package app

import (
	"context"
	"fmt"
	"math"
	"sort"
	"strings"
	"time"

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

// Use the settings worker's bounded mailbox, keeping discovery, disk writes,
// and speech connection replacement off the input and focus paths.
func (worker *preferencesWorker) SpeechCommand(command input.Command) {
	worker.TrySpeechCommand(command)
}

func (worker *preferencesWorker) TrySpeechCommand(command input.Command) bool {
	select {
	case worker.speechCommands <- command:
		return true
	default:
		return false
	}
}

func (worker *preferencesWorker) announceSpeechSetting(message string) {
	if worker.announce != nil {
		worker.announce(message)
	}
}

func (worker *preferencesWorker) handleSpeechCommand(ctx context.Context, command input.Command) {
	if command == input.CycleProgressBarOutput {
		worker.cycle_progress_output()
		return
	}
	ctx, cancel := context.WithTimeout(ctx, 6*time.Second)
	defer cancel()
	if command == input.SaveSpeechSettings {
		store, err := config.NewStore(worker.globalSettings.Path)
		if err == nil {
			err = store.Save(worker.globalSettings)
		}
		if err != nil {
			worker.logger.Warn("save speech settings", "error", err)
			worker.announceSpeechSetting("Speech settings could not be saved")
		} else {
			worker.announceSpeechSetting("Speech settings saved")
		}
		return
	}
	worker.sync_extensions(ctx)
	quickSettings := worker.quick_settings()
	settingIndex := worker.speechSetting
	if worker.quickSettingKey != "" {
		settingIndex = 4
		found := false
		for index, setting := range quickSettings {
			if setting.key == worker.quickSettingKey {
				settingIndex = 5 + index
				found = true
				break
			}
		}
		if !found && (command == input.IncreaseSpeechSetting || command == input.DecreaseSpeechSetting) {
			worker.quickSettingKey, worker.speechSetting = "", 4
			worker.announceSpeechSetting("The selected speech setting is no longer available")
			return
		}
	}
	switch command {
	case input.SelectPreviousSpeechSetting:
		settingIndex = max(0, settingIndex-1)
	case input.SelectNextSpeechSetting:
		settingIndex = min(4+len(quickSettings), settingIndex+1)
	}
	worker.quickSettingKey = ""
	if settingIndex >= 5 {
		worker.quickSettingKey = quickSettings[settingIndex-5].key
	} else {
		worker.speechSetting = settingIndex
	}
	next := worker.effective_settings(worker.settings)
	adjust := command == input.IncreaseSpeechSetting || command == input.DecreaseSpeechSetting
	delta := 1
	if command == input.DecreaseSpeechSetting {
		delta = -1
	}
	if settingIndex >= 5 {
		worker.handle_extension_quick(ctx, quickSettings[settingIndex-5], adjust, delta)
		return
	}
	message := ""
	switch worker.speechSetting {
	case 0, 1, 2:
		names := []string{"Rate", "Pitch", "Volume"}
		fields := []**float64{&next.DefaultVoice.Rate, &next.DefaultVoice.AveragePitch, &next.DefaultVoice.Gain}
		defaults := []float64{50, 5, 9}
		limits := []float64{99, 9, 9}
		steps := []float64{1, 0.1, 0.1}
		field := fields[worker.speechSetting]
		value := defaults[worker.speechSetting]
		if *field != nil {
			value = math.Round(**field*10) / 10
		}
		if adjust {
			value = math.Round((value+float64(delta)*steps[worker.speechSetting])*10) / 10
			value = math.Max(0, math.Min(limits[worker.speechSetting], value))
			*field = &value
		}
		message = fmt.Sprintf("%s %g", names[worker.speechSetting], value)
		if *field == nil {
			message = names[worker.speechSetting] + " server default"
		}
	case 3, 4:
		if next.SpeechServerFactory == "hardwarefactory" {
			if worker.speechSetting == 4 {
				worker.announceSpeechSetting("Hardware speech has no selectable voices")
				return
			}
			modules := []string{"litetalk", "doubletalk", "tripletalk", "dectalk"}
			if adjust {
				for index, module := range modules {
					if module == next.SpeechOutputModule {
						next.SpeechOutputModule = modules[max(0, min(len(modules)-1, index+delta))]
						break
					}
				}
			}
			message = "Hardware synthesizer " + next.SpeechOutputModule
			break
		}
		if worker.catalog == nil {
			catalog, err := worker.discover(ctx, worker.socket)
			if err != nil {
				worker.announceSpeechSetting("Speech settings unavailable")
				return
			}
			worker.catalog = catalog
		}
		if worker.speechSetting == 3 {
			modules := []string{}
			for module := range worker.catalog {
				if module != "" {
					modules = append(modules, module)
				}
			}
			sort.Strings(modules)
			if len(modules) == 0 {
				worker.announceSpeechSetting("No speech-dispatcher modules available")
				return
			}
			if adjust {
				index := 0
				for i, module := range modules {
					if module == next.SpeechOutputModule {
						index = i
						break
					}
				}
				// An unspecified module is a server default, not a known list position.
				if next.SpeechOutputModule != "" {
					index = max(0, min(len(modules)-1, index+delta))
				}
				next.SpeechOutputModule = modules[index]
				next.DefaultVoice.Family = nil
				if voices := quickSpeechVoices(next.SpeechOutputModule, worker.catalog[next.SpeechOutputModule]); len(voices) > 0 {
					next.DefaultVoice.Family = &config.VoiceFamily{Name: voices[0].Name, Lang: voices[0].Language, Variant: voices[0].Variant}
				}
			}
			name := next.SpeechOutputModule
			if name == "" {
				name = "server default"
			}
			message = "Speech-dispatcher module " + name
		} else {
			voices := quickSpeechVoices(next.SpeechOutputModule, worker.catalog[next.SpeechOutputModule])
			if len(voices) == 0 {
				worker.announceSpeechSetting("No speech-dispatcher voices available")
				return
			}
			name := "server default"
			if family := next.DefaultVoice.Family; family != nil && family.Name != "" {
				name = family.Name
			}
			if adjust {
				index := 0
				for i, voice := range voices {
					if voice.Name == name {
						index = max(0, min(len(voices)-1, i+delta))
						break
					}
				}
				voice := voices[index]
				next.DefaultVoice.Family = &config.VoiceFamily{Name: voice.Name, Lang: voice.Language, Variant: voice.Variant}
				name = voice.Name
			}
			message = "Speech-dispatcher voice " + name
		}
	}
	if adjust {
		err := config.Validate(next)
		if err == nil {
			err = worker.updateSpeech(ctx, next)
		}
		if err != nil {
			worker.logger.Warn("adjust speech setting", "error", err)
			worker.catalog = nil
			worker.announceSpeechSetting("Speech settings were not applied")
			return
		}
		if worker.speechOverride != nil {
			value := tentaclewire.SpeechFromSettings(next)
			worker.speechOverride = &value
		} else {
			worker.quickSpeech.settings = next
			worker.quickSpeech.adjusted[worker.speechSetting] = true
			global := copyQuickSpeechSetting(worker.globalSettings, next, worker.speechSetting)
			for application, settings := range worker.appSettings {
				worker.appSettings[application] = config.RebaseApplicationSettings(worker.globalSettings, global, settings)
			}
			worker.globalSettings = global
			worker.settings = next
		}
		if worker.live != nil {
			worker.live.Store(next)
		}
	}
	worker.announceSpeechSetting(message)
}

// The preferences worker owns these session-only choices. Apply them after
// resolving an application profile so window switches cannot undo a shortcut.
// Explicit preferences Apply or reader exit ends this override; saving does not.
type quickSpeechSettings struct {
	settings config.Settings
	adjusted [5]bool
}

func (quick quickSpeechSettings) apply(settings config.Settings) config.Settings {
	for index, adjusted := range quick.adjusted {
		if adjusted {
			settings = copyQuickSpeechSetting(settings, quick.settings, index)
		}
	}
	return settings
}

func copyQuickSpeechSetting(target, source config.Settings, index int) config.Settings {
	switch index {
	case 0:
		target.DefaultVoice.Rate = source.DefaultVoice.Rate
	case 1:
		target.DefaultVoice.AveragePitch = source.DefaultVoice.AveragePitch
	case 2:
		target.DefaultVoice.Gain = source.DefaultVoice.Gain
	case 3, 4:
		// A voice belongs to its synthesizer, and a hardware synthesizer also
		// needs its transport. Keep this selection valid across app profiles.
		target.SpeechServerFactory = source.SpeechServerFactory
		target.SpeechOutputModule = source.SpeechOutputModule
		target.HardwareSpeechDevice = source.HardwareSpeechDevice
		target.HardwareSpeechBaudRate = source.HardwareSpeechBaudRate
		target.DefaultVoice.Family = source.DefaultVoice.Family
	}
	return target
}

// Keep eSpeak NG's language/variant cross product manageable in quick settings.
// Prefer an exact dialect, then a language-only voice if that dialect is absent.
// Unknown languages retain the catalog so the user can still select a voice.
func quickSpeechVoices(module string, voices []speech.Voice) []speech.Voice {
	if !strings.Contains(strings.ToLower(module), "espeak-ng") {
		return voices
	}
	return speech.LocaleVoices(voices)
}