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

package config

import (
	"bytes"
	"os"
	"path/filepath"
	"testing"
)

func TestStartupSaveDestinationAndLegacySettingsIgnored(t *testing.T) {
	for _, scenario := range []string{"defaults", "system fallback", "personal", "explicit", "root"} {
		t.Run(scenario, func(t *testing.T) {
			root := t.TempDir()
			paths := Paths(root, 1000)
			userPath := paths[0]
			// Substitute an isolated system directory without touching /etc.
			systemPath := filepath.Join(root, "etc", "settings.toml")
			paths[1] = systemPath
			legacyPath := filepath.Join(filepath.Dir(userPath), "settings.conf")
			legacy := []byte("[speech]\nrate = 19\n")
			if err := os.MkdirAll(filepath.Dir(userPath), 0700); err != nil {
				t.Fatal(err)
			}
			if err := os.WriteFile(legacyPath, legacy, 0600); err != nil {
				t.Fatal(err)
			}
			requested, destination, rate := "", userPath, 0
			if scenario != "defaults" {
				system := Defaults()
				system.Presentation.Speech.Rate = 30
				if err := Save(systemPath, system); err != nil {
					t.Fatal(err)
				}
				rate = 30
			}
			switch scenario {
			case "personal":
				personal := Defaults()
				personal.Presentation.Speech.Rate = 40
				if err := Save(userPath, personal); err != nil {
					t.Fatal(err)
				}
				rate = 40
			case "explicit":
				requested, destination = systemPath, systemPath
			case "root":
				paths, destination = []string{systemPath}, systemPath
			}
			systemBefore, _ := os.ReadFile(systemPath)
			settings, path, err := Load_startup(requested, paths)
			if err != nil || path != destination || settings.Presentation.Speech.Rate != rate {
				t.Fatalf("startup: destination=%q rate=%d err=%v", path, settings.Presentation.Speech.Rate, err)
			}
			// Follow the settings menu's document save workflow, then restart.
			doc, err := Open_document(path, settings)
			if err != nil || doc.Settings.Presentation.Speech.Rate != rate {
				t.Fatalf("open settings: %+v %v", doc, err)
			}
			settings.Presentation.Speech.Rate = 55
			if err := doc.Save(settings); err != nil {
				t.Fatal(err)
			}
			restarted, path, err := Load_startup(requested, paths)
			if err != nil || path != destination || restarted.Presentation.Speech.Rate != 55 {
				t.Fatalf("restart: destination=%q rate=%d err=%v", path, restarted.Presentation.Speech.Rate, err)
			}
			if destination != systemPath {
				systemAfter, _ := os.ReadFile(systemPath)
				if !bytes.Equal(systemBefore, systemAfter) {
					t.Fatal("personal save modified the system file")
				}
			}
			if data, err := os.ReadFile(legacyPath); err != nil || !bytes.Equal(data, legacy) {
				t.Fatal("legacy settings changed", err)
			}
		})
	}
}

func TestStartupErrorsIdentifySource(t *testing.T) {
	root := t.TempDir()
	userPath, systemPath := filepath.Join(root, "user.toml"), filepath.Join(root, "system.toml")
	if err := os.WriteFile(systemPath, []byte("invalid=true"), 0600); err != nil {
		t.Fatal(err)
	}
	if _, path, err := Load_startup("", []string{userPath, systemPath}); err == nil || path != systemPath {
		t.Fatal("invalid fallback did not identify source", path, err)
	}
	if _, path, err := Load_startup(userPath, []string{systemPath}); err == nil || path != userPath {
		t.Fatal("explicit missing file did not identify source", path, err)
	}
}