package uiconfig

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

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

func sandboxUIConfig(t *testing.T, uiType, confName, confContent string) string {
	t.Helper()
	home := t.TempDir()
	for _, key := range []string{"HOME", "USERPROFILE", "APPDATA", "LOCALAPPDATA", "XDG_CONFIG_HOME"} {
		t.Setenv(key, home)
	}
	_, err := config.Reload()
	require.NoError(t, err)

	configDir := config.GetMPVConfigPath()
	require.NoError(t, os.MkdirAll(filepath.Join(configDir, constants.ScriptsDir), 0755))
	require.NoError(t, os.MkdirAll(filepath.Join(configDir, constants.ScriptOptsDir), 0755))
	scriptName := "modernz.lua"
	if uiType == constants.UITypeUOSC {
		scriptName = "uosc.lua"
	}
	require.NoError(t, os.WriteFile(filepath.Join(configDir, constants.ScriptsDir, scriptName), []byte("-- test"), 0644))
	if confName != "" {
		require.NoError(t, os.WriteFile(filepath.Join(configDir, constants.ScriptOptsDir, confName), []byte(confContent), 0644))
	}
	return configDir
}

func TestModernZScalingMigrationApplyIsPersistent(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=auto\nscalewindowed=1.5\n")

	status, err := Inspect()
	require.NoError(t, err)
	require.NotNil(t, status.Migration)
	require.Equal(t, MigrationModernZScalingV1, status.Migration.ID)

	require.NoError(t, ResolveMigration(MigrationModernZScalingV1, MigrationActionApply, ""))
	conf, err := modernzconf.ParseModernZConf(filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf"))
	require.NoError(t, err)
	require.Equal(t, modernzconf.ManagedVidscaleDefault, conf.GetValue("vidscale"))
	require.Equal(t, "1.5", conf.GetValue("scalewindowed"), "migration must not replace custom size multipliers")
	require.Equal(t, MigrationActionApply, config.GetUIConfigMigrationResolution(MigrationModernZScalingV1))

	status, err = Inspect()
	require.NoError(t, err)
	require.Nil(t, status.Migration)
}

func TestModernZScalingMigrationKeepDoesNotRewriteConfig(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "# custom\nvidscale=auto\n")
	path := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
	before, err := os.ReadFile(path)
	require.NoError(t, err)

	require.NoError(t, ResolveMigration(MigrationModernZScalingV1, MigrationActionKeep, ""))
	after, err := os.ReadFile(path)
	require.NoError(t, err)
	require.Equal(t, before, after)
	require.Equal(t, MigrationActionKeep, config.GetUIConfigMigrationResolution(MigrationModernZScalingV1))
}

func TestInspectReportsInvalidUOSCValues(t *testing.T) {
	sandboxUIConfig(t, constants.UITypeUOSC, "uosc.conf", "timeline_size=999\n")

	status, err := Inspect()
	require.NoError(t, err)
	require.Equal(t, constants.UITypeUOSC, status.UI)
	require.Len(t, status.Warnings, 1)
	require.Equal(t, "timeline_size", status.Warnings[0].Key)
	require.Nil(t, status.Migration)
}

func TestInspectRepresentsTwoInstalledOverlayScriptsAsAmbiguous(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=yes\n")
	require.NoError(t, os.WriteFile(
		filepath.Join(configDir, constants.ScriptsDir, "uosc.lua"),
		[]byte("-- second overlay"),
		0644,
	))

	require.Equal(t, constants.UITypeAmbiguous, DetectInstalledUI())
	status, err := Inspect()
	require.NoError(t, err)
	require.Equal(t, constants.UITypeAmbiguous, status.UI)
	require.Len(t, status.Warnings, 1)
	require.Equal(t, "ui", status.Warnings[0].Key)
	require.Contains(t, status.Warnings[0].Message, "Both ModernZ and uOSC")
}

func TestMigrationDoesNotOverrideExplicitWindowScaling(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=yes\n")
	status, err := Inspect()
	require.NoError(t, err)
	require.Nil(t, status.Migration)
	require.Error(t, ResolveMigration(MigrationModernZScalingV1, MigrationActionApply, ""))

	conf, err := modernzconf.ParseModernZConf(filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf"))
	require.NoError(t, err)
	require.Equal(t, "yes", conf.GetValue("vidscale"))
}

func TestMigrationRollsBackScriptWhenManagerPersistenceFails(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "# exact\nvidscale=auto\nscalewindowed=1.5\n")
	require.NoError(t, config.Save())
	confPath := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
	before, err := os.ReadFile(confPath)
	require.NoError(t, err)
	managerPath := filepath.Join(config.GetConfigDir(), constants.ConfigFileName)
	managerBefore, err := os.ReadFile(managerPath)
	require.NoError(t, err)
	require.NoError(t, os.Remove(managerPath))
	require.NoError(t, os.Mkdir(managerPath, 0o755))

	err = ResolveMigration(MigrationModernZScalingV1, MigrationActionApply, "")
	require.Error(t, err)
	after, readErr := os.ReadFile(confPath)
	require.NoError(t, readErr)
	require.Equal(t, before, after)
	require.NoFileExists(t, migrationJournalPath(confPath))

	require.NoError(t, os.Remove(managerPath))
	require.NoError(t, os.WriteFile(managerPath, managerBefore, 0o644))
	_, err = config.Reload()
	require.NoError(t, err)
}

func TestMigrationRecoveryRollsBackUncommittedScriptChange(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=auto\n")
	confPath := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
	before, err := os.ReadFile(confPath)
	require.NoError(t, err)
	journal, err := captureMigrationJournal(confPath, MigrationActionApply)
	require.NoError(t, err)
	require.NoError(t, writeMigrationJournal(confPath, journal))
	require.NoError(t, fileops.WithLock(confPath, func() error {
		return modernzconf.SetValueFileLocked(confPath, "vidscale", modernzconf.ManagedVidscaleDefault)
	}))

	require.NoError(t, RecoverMigrationTransactions())
	after, err := os.ReadFile(confPath)
	require.NoError(t, err)
	require.Equal(t, before, after)
	require.NoFileExists(t, migrationJournalPath(confPath))
}

func TestMigrationRecoveryKeepsCommittedScriptChange(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=auto\n")
	confPath := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
	journal, err := captureMigrationJournal(confPath, MigrationActionApply)
	require.NoError(t, err)
	require.NoError(t, writeMigrationJournal(confPath, journal))
	require.NoError(t, fileops.WithLock(confPath, func() error {
		return modernzconf.SetValueFileLocked(confPath, "vidscale", modernzconf.ManagedVidscaleDefault)
	}))
	require.NoError(t, config.SetUIConfigMigrationResolution(MigrationModernZScalingV1, MigrationActionApply))

	require.NoError(t, RecoverMigrationTransactions())
	conf, err := modernzconf.ParseModernZConf(confPath)
	require.NoError(t, err)
	require.Equal(t, modernzconf.ManagedVidscaleDefault, conf.GetValue("vidscale"))
	require.NoFileExists(t, migrationJournalPath(confPath))
}

func TestMigrationRecoveryRetainsConcurrentEditsAndJournal(t *testing.T) {
	for _, originalExists := range []bool{false, true} {
		t.Run(map[bool]string{false: "created after migration", true: "edited after migration"}[originalExists], func(t *testing.T) {
			configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=auto\nscalewindowed=1.5\n")
			path := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
			if !originalExists {
				require.NoError(t, os.Remove(path))
			}
			journal, err := captureMigrationJournal(path, MigrationActionApply)
			require.NoError(t, err)
			require.NoError(t, writeMigrationJournal(path, journal))
			require.NoError(t, modernzconf.SetValueFile(path, "vidscale", modernzconf.ManagedVidscaleDefault))
			require.NoError(t, modernzconf.SetValueFile(path, "scalewindowed", "2.5"))
			before, err := os.ReadFile(path)
			require.NoError(t, err)
			require.ErrorContains(t, RecoverMigrationTransactions(), "changed during migration")
			after, err := os.ReadFile(path)
			require.NoError(t, err)
			require.Equal(t, before, after)
			require.FileExists(t, migrationJournalPath(path))
		})
	}
}

func TestMigrationRecoveryReplaysAlreadyRestoredSnapshot(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "# original\nvidscale=auto\n")
	path := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
	journal, err := captureMigrationJournal(path, MigrationActionApply)
	require.NoError(t, err)
	require.NoError(t, writeMigrationJournal(path, journal))
	require.NoError(t, RecoverMigrationTransactions())
	require.NoError(t, RecoverMigrationTransactions())
	require.NoFileExists(t, migrationJournalPath(path))
}

func TestLegacyMigrationRecoveryRetainsAmbiguousSnapshot(t *testing.T) {
	configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "vidscale=auto\n")
	path := filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf")
	journal, err := captureMigrationJournal(path, MigrationActionApply)
	require.NoError(t, err)
	journal.Schema = 1
	journal.AppliedDigest = ""
	require.NoError(t, writeMigrationJournal(path, journal))
	require.NoError(t, modernzconf.SetValueFile(path, "vidscale", "no"))
	require.ErrorContains(t, RecoverMigrationTransactions(), "recovery requires review")
	require.FileExists(t, migrationJournalPath(path))
}

func TestQueuedMigrationMatchesLastPersistedValue(t *testing.T) {
	for _, otherEditor := range []bool{false, true} {
		t.Run(map[bool]string{false: "queued decision", true: "concurrent editor"}[otherEditor], func(t *testing.T) {
			configDir := sandboxUIConfig(t, constants.UITypeModernZ, "modernz.conf", "# retain\nvidscale=yes\nscalewindowed=1.5\n")
			expected := "yes"
			if otherEditor {
				expected = "auto"
			}
			err := ResolveMigration(MigrationModernZScalingV1, MigrationActionApply, expected)
			if otherEditor {
				require.ErrorContains(t, err, "scaling changed")
			} else {
				require.NoError(t, err)
			}
			conf, err := modernzconf.ParseModernZConf(filepath.Join(configDir, constants.ScriptOptsDir, "modernz.conf"))
			require.NoError(t, err)
			want := "no"
			if otherEditor {
				want = "yes"
			}
			require.Equal(t, want, conf.GetValue("vidscale"))
			require.Equal(t, "1.5", conf.GetValue("scalewindowed"))
		})
	}
}

func TestDetectUOSCDirectoryEntrypoint(t *testing.T) {
	dir := sandboxUIConfig(t, constants.UITypeUOSC, "", "")
	require.NoError(t, os.Remove(filepath.Join(dir, "scripts", "uosc.lua")))
	require.NoError(t, os.MkdirAll(filepath.Join(dir, "scripts", "uosc"), 0755))
	require.NoError(t, os.WriteFile(filepath.Join(dir, "scripts", "uosc", "main.lua"), []byte("-- uosc"), 0644))
	require.Equal(t, constants.UITypeUOSC, DetectInstalledUI())
	require.NoError(t, os.WriteFile(filepath.Join(dir, "scripts", "modernz.lua"), []byte("-- modernz"), 0644))
	require.Equal(t, constants.UITypeAmbiguous, DetectInstalledUI())
}