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

package app

import (
	"context"
	"log/slog"
	"strings"
	"sync"

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

type speechSettingsUpdater interface {
	UpdateSettings(context.Context, speech.Settings) error
}

type brailleSettingsUpdater interface {
	Configure(context.Context, bool) error
}

// preferencesWorker owns session settings and at most one UI child. Open has a
// capacity-one, coalescing mailbox: repeated commands cannot queue windows or
// block input. The child permits one outstanding apply; messages are capped at
// 512 KiB. Shutdown cancels backend I/O, terminates the child, and joins the worker.
type preferencesWorker struct {
	tentacles           *tentacleRuntime
	logger              *slog.Logger
	settings            config.Settings
	globalSettings      config.Settings
	appSettings         map[string]config.Settings
	activeApp           string
	editApp             string
	editing             config.Settings
	editingActive       bool
	choosingApplication bool
	updater             any
	open                chan string
	applicationChanges  chan string
	done                chan struct{}
	cancel              context.CancelFunc
	once                sync.Once
	live                *liveSettings
	history             *speechHistory
	speechWorker        *speechWorker
	refreshHistory      func()
	sound               soundSettingsUpdater
	geometry            soundGeometryCaptureConfigurer
	textAttributes      textAttributeCaptureConfigurer
	bindings            interface {
		SetKeyBindings(context.Context, []input.BindingOverride) error
	}
	braille        brailleSettingsUpdater
	documentReview *review.Worker
	socket         string
	speechCommands chan input.Command
	remoteChanges  chan remoteSettingsChange
	speechSetting  int
	announce       func(string)
	announceApply  func(string)
	catalog        speech.Catalog
	discover       func(context.Context, string) (speech.Catalog, error)
}

func newPreferencesWorker(logger *slog.Logger, settings config.Settings, updater any) *preferencesWorker {
	return &preferencesWorker{logger: logger, settings: settings, globalSettings: settings, appSettings: make(map[string]config.Settings), updater: updater,
		speechCommands: make(chan input.Command, 16), remoteChanges: make(chan remoteSettingsChange, 16), discover: speech.Discover, open: make(chan string, 1), applicationChanges: make(chan string, 1), done: make(chan struct{})}
}

func (worker *preferencesWorker) Start(ctx context.Context) error {
	ctx, worker.cancel = context.WithCancel(ctx)
	go func() {
		defer close(worker.done)
		for {
			select {
			case <-ctx.Done():
				return
			case command := <-worker.speechCommands:
				worker.handleSpeechCommand(ctx, command)
			case change := <-worker.remoteChanges:
				change.result <- worker.applyRemoteChange(ctx, change)
			case application := <-worker.applicationChanges:
				worker.switchApplication(ctx, application)
			case application := <-worker.open:
				worker.choosingApplication = application == "\x01"
				if application != "\x01" && !worker.beginEdit(ctx, application) {
					continue
				}
				if err := worker.window(ctx); err != nil && ctx.Err() == nil {
					worker.logger.Error("preferences window", "error", err)
				}
				worker.editingActive = false
				worker.choosingApplication = false
				select {
				case application := <-worker.applicationChanges:
					worker.switchApplication(ctx, application)
				default:
				}
			}
		}
	}()
	return nil
}

func (worker *preferencesWorker) Open() {
	select {
	case worker.open <- "":
	default:
	}
}

func (worker *preferencesWorker) OpenApplication() {
	select {
	case worker.open <- "\x00":
	default:
	}
}

func (worker *preferencesWorker) ChooseApplication() {
	select {
	case worker.open <- "\x01":
	default:
	}
}

// Focus handling only publishes the latest foreground application and never
// waits for settings I/O on the native event loop.
func (worker *preferencesWorker) SetApplication(application string) {
	application = strings.TrimSpace(application)
	if application == "" || strings.HasPrefix(strings.ToLower(application), "cthulhu") {
		return
	}
	if worker.live != nil {
		worker.live.requestedApplication.Store(&application)
		worker.live.notify_clipboard()
	}
	select {
	case worker.applicationChanges <- application:
	default:
		select {
		case <-worker.applicationChanges:
		default:
		}
		select {
		case worker.applicationChanges <- application:
		default:
		}
	}
}

func (worker *preferencesWorker) Stop(ctx context.Context) error {
	worker.once.Do(func() {
		if worker.cancel != nil {
			worker.cancel()
		}
	})
	select {
	case <-worker.done:
		return nil
	case <-ctx.Done():
		return ctx.Err()
	}
}