package tui

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

	"gitgud.io/mike/mpv-manager/pkg/config"
	"gitgud.io/mike/mpv-manager/pkg/constants"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func isolateLanguageConfig(t *testing.T) string {
	t.Helper()
	// Register this before Setenv so it reloads from the original environment
	// after Setenv's cleanup restores it.
	t.Cleanup(func() { _, _ = config.Reload() })
	home := t.TempDir()
	for _, key := range []string{"HOME", "USERPROFILE", "APPDATA", "LOCALAPPDATA"} {
		t.Setenv(key, home)
	}
	t.Setenv("XDG_CONFIG_HOME", filepath.Join(home, ".config"))
	_, err := config.Reload()
	require.NoError(t, err)
	return config.GetConfigPath()
}

func TestApplyLanguagePreferencesCopiesBackupAndPreservesLiveConfig(t *testing.T) {
	configPath := isolateLanguageConfig(t)
	require.NoError(t, os.MkdirAll(filepath.Dir(configPath), constants.DirPermission))
	original := "profile=high-quality\nalang=en\nslang=fr\n"
	require.NoError(t, os.WriteFile(configPath, []byte(original), constants.FilePermission))

	m := NewModel()
	m.langPreferenceType = "audio"
	m.selectedLanguageCodes = []string{"ja", "en"}
	require.NoError(t, m.applyLanguagePreferences())

	live, err := os.ReadFile(configPath)
	require.NoError(t, err)
	assert.Contains(t, string(live), "profile=high-quality")
	assert.Contains(t, string(live), "alang=ja,en")
	assert.Contains(t, string(live), "slang=fr")

	backupDir, err := config.GetMPVConfigBackupDir()
	require.NoError(t, err)
	entries, err := os.ReadDir(backupDir)
	require.NoError(t, err)
	require.Len(t, entries, 1)
	backup, err := os.ReadFile(filepath.Join(backupDir, entries[0].Name()))
	require.NoError(t, err)
	assert.Equal(t, original, string(backup))
}

func TestApplyLanguagePreferencesAbortsWhenBackupFails(t *testing.T) {
	configPath := isolateLanguageConfig(t)
	configDir := filepath.Dir(configPath)
	require.NoError(t, os.MkdirAll(configDir, constants.DirPermission))
	original := "profile=high-quality\nalang=en\n"
	require.NoError(t, os.WriteFile(configPath, []byte(original), constants.FilePermission))
	require.NoError(t, os.WriteFile(filepath.Join(configDir, constants.ConfigBackupsDir), []byte("block"), 0600))

	m := NewModel()
	m.langPreferenceType = "audio"
	m.selectedLanguageCodes = []string{"ja"}
	require.Error(t, m.applyLanguagePreferences())

	live, err := os.ReadFile(configPath)
	require.NoError(t, err)
	assert.Equal(t, original, string(live))
}