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

package app

import (
	"fmt"
	"os"
	"strings"

	"git.stormux.org/storm/fenrir/internal/config"
	"git.stormux.org/storm/fenrir/internal/control"
	"git.stormux.org/storm/fenrir/internal/i18n"
)

// These operations run only after the shared credential and settings gates.
// A save keeps its reply pending until the worker reports the actual disk result.
func (a *application) remote_settings_request(text string, request control.Request) (string, bool) {
	verb, parameter, _ := strings.Cut(text, " ")
	verb, parameter = strings.ToUpper(verb), strings.TrimSpace(parameter)
	if a.saves_unavailable() && (verb == "SAVE" || verb == "SAVEAS") {
		return "Save unavailable.", false
	}
	if a.overrideTransition {
		return "Settings are busy; try again after the current operation", false
	}
	if a.speechPending {
		return "Settings are busy; try again after the current operation", false
	}
	if verb == "SET" {
		if err := a.check_application_remote(text); err != nil {
			return err.Error(), false
		}
		updated, err := remote_settings(a.effective_settings(), text)
		if err != nil {
			return err.Error(), false
		}
		if !same_speech_selection(updated.Presentation.Speech, a.settings.live.Presentation.Speech) {
			if a.saver.busy || a.ui.active {
				return "Settings are busy; try again after the current operation", false
			}
			a.change_speech(updated.Presentation.Speech, func(err error) {
				response := ""
				if err != nil {
					response = err.Error()
				} else {
					response = a.apply_remote_settings(resolved_remote_selection(text, updated))
				}
				remote_reply(request.Reply, response)
			})
			return "", true
		}
	}
	switch verb {
	case "SAVE", "SAVEAS", "RESET":
		if a.saver.busy || a.ui.active {
			return "Settings are busy; try again after the current operation", false
		}
	default:
		return a.apply_remote_settings(text), false
	}
	if verb != "SAVEAS" && parameter != "" {
		return verb + " does not accept parameters", false
	}
	if verb == "RESET" {
		updated, _, err := a.remote_reset_state()
		if err != nil {
			return err.Error(), false
		}
		if !same_speech_selection(updated.Presentation.Speech, a.settings.live.Presentation.Speech) {
			a.change_speech(updated.Presentation.Speech, func(err error) {
				response := ""
				if err != nil {
					response = err.Error()
				} else {
					response = a.reset_remote_settings()
				}
				remote_reply(request.Reply, response)
			})
			return "", true
		}
		return a.reset_remote_settings(), false
	}
	path := a.settings_path()
	if verb == "SAVEAS" {
		if a.overrideCurrent != nil {
			return "SAVEAS is unavailable in application settings", false
		}
		// A root TTY reader also admits its active console user for ordinary
		// commands. That must not grant arbitrary root-owned file writes.
		if request.UID != 0 && request.UID != os.Geteuid() {
			return "SAVEAS requires the reader owner or root", false
		}
		path = parameter
	}
	if path == "" || strings.ContainsAny(path, "\x00\r\n") {
		return "A valid settings destination is required", false
	}
	if !a.start_settings_save(path, a.settings_to_save()) {
		return "Settings are busy; try again after the current operation", false
	}
	a.saver.revision = a.settings.remoteRevision
	a.saver.reply = request.Reply
	return "", true
}

func (a *application) settings_save_result(err error) {
	if !a.saver.busy {
		return
	}
	if settings_committed(err) {
		a.settings.resetBase = a.saver.snapshot
		for path, revision := range a.settings.remoteFields {
			if revision <= a.saver.revision {
				delete(a.settings.remoteFields, path)
			}
		}
	}
	if done := a.saver.menuDone; done != nil {
		a.saver.busy, a.saver.menuDone = false, nil
		done(err)
	} else if reply := a.saver.reply; reply != nil {
		a.saver.busy, a.saver.reply = false, nil
		response := ""
		if err != nil {
			response = "Could not save settings: " + err.Error()
		}
		remote_reply(reply, response)
	} else if a.overrideCurrent != nil && err == nil {
		a.saver.busy = false
		a.voice.Say(i18n.Format("{0} application settings saved.", i18n.T(a.overrideCurrent.adapter.Name())))
	} else {
		a.saver.result(err, a.voice)
	}
}

// RESET clears temporary quick/remote overrides, as in Python's
// reset_setting_arg_dict. It never reloads a file or installs factory defaults.
func (a *application) remote_reset_state() (config.Settings, config.Settings, error) {
	updated, persisted := a.effective_settings(), a.settings.saveDraft
	for _, target := range []*config.Settings{&updated, &persisted} {
		copy_quick_settings(target, a.settings.resetBase)
		if a.quick.selectionChanged {
			copy_speech_selection(&target.Presentation.Speech, a.settings.resetBase.Presentation.Speech)
		}
		copy_remote_settings(target, a.settings.resetBase, a.settings.remoteFields)
		if err := target.Validate(); err != nil {
			return updated, persisted, err
		}
	}
	if updated.Presentation.Speech.Enabled && !a.settings.speechAvailable {
		return updated, persisted, fmt.Errorf("Speech was disabled at startup; enable it in settings and relaunch")
	}
	return updated, persisted, nil
}

func (a *application) reset_remote_settings() string {
	updated, persisted, err := a.remote_reset_state()
	if err != nil {
		return err.Error()
	}
	a.settings.saveDraft = persisted
	_, speechOverridden := a.settings.remoteFields["speech#enabled"]
	a.apply_remote_state(updated, speechOverridden)
	clear(a.settings.remoteFields)
	a.quick.changed = false
	a.quick.selectionChanged = false
	return ""
}

// Copy only remotely overridden fields; unrelated session mute/AutoRead,
// next-launch menu choices, reading regions and keyboard routing survive.
func copy_remote_settings(target *config.Settings, source config.Settings, fields map[string]uint64) {
	for path := range fields {
		switch path {
		case "reading#mode", "focus#cursor", "focus#highlight":
			target.Reading.Mode = source.Reading.Mode
		case "speech#enabled":
			target.Presentation.Speech.Enabled = source.Presentation.Speech.Enabled
		case "speech#module", "speech#language", "speech#voice":
			copy_speech_selection(&target.Presentation.Speech, source.Presentation.Speech)
		case "speech#rate":
			target.Presentation.Speech.Rate = source.Presentation.Speech.Rate
		case "speech#pitch":
			target.Presentation.Speech.Pitch = source.Presentation.Speech.Pitch
		case "speech#volume":
			target.Presentation.Speech.Volume = source.Presentation.Speech.Volume
		case "sound#enabled":
			target.Presentation.Sound.Enabled = source.Presentation.Sound.Enabled
		case "sound#volume":
			target.Presentation.Sound.Volume = source.Presentation.Sound.Volume
		case "sound#progress_monitoring":
			target.Presentation.Progress.Enabled = source.Presentation.Progress.Enabled
		case "general#punctuation_level":
			target.Reading.PunctuationLevel = source.Reading.PunctuationLevel
		case "speech#auto_read_incoming", "reading#automatic":
			target.Reading.Automatic = source.Reading.Automatic
		case "reading#cursor_echo":
			target.Reading.CursorEcho = source.Reading.CursorEcho
		case "keyboard#char_echo_mode":
			target.Keyboard.CharacterEcho = source.Keyboard.CharacterEcho
			target.Keyboard.EchoOnCapsLock = source.Keyboard.EchoOnCapsLock
		case "keyboard#word_echo":
			target.Keyboard.WordEcho = source.Keyboard.WordEcho
		case "keyboard#echo_on_capslock":
			target.Keyboard.EchoOnCapsLock = source.Keyboard.EchoOnCapsLock
		case "screen#ignore_screen":
			target.Screen.IgnoredVTs = append([]int{}, source.Screen.IgnoredVTs...)
		}
	}
}

// Screen routing is global and has no application-profile counterpart.
func (a *application) check_application_remote(text string) error {
	if a.overrideCurrent == nil {
		return nil
	}
	_, parameters, _ := strings.Cut(text, " ")
	for _, assignment := range remote_assignments(parameters) {
		path, _, _ := strings.Cut(assignment, "=")
		if strings.EqualFold(strings.TrimSpace(path), "screen#ignore_screen") {
			return fmt.Errorf("screen#ignore_screen is unavailable in application settings")
		}
	}
	return nil
}