package windsurf

import (
	"path/filepath"
	"reflect"
	"strings"
	"testing"
)

func stubDataDirStat(t *testing.T, present map[string]dataDirStat) {
	t.Helper()
	orig := dataDirStatFn
	dataDirStatFn = func(path string) dataDirStat {
		return present[path]
	}
	t.Cleanup(func() { dataDirStatFn = orig })
}

func stubUserConfigDir(t *testing.T, dir string) {
	t.Helper()
	orig := userConfigDirFn
	userConfigDirFn = func() string { return dir }
	t.Cleanup(func() { userConfigDirFn = orig })
}

func TestResolveDataDir_ExplicitCfgWins(t *testing.T) {
	stubUserConfigDir(t, "/home/test/.config")
	got := resolveDataDirFor("/explicit/path", "", "linux")
	if got != "/explicit/path" {
		t.Errorf("explicit cfg should win, got %q", got)
	}
}

func TestResolveDataDir_EnvWinsOverDefaults(t *testing.T) {
	stubUserConfigDir(t, "/home/test/.config")
	got := resolveDataDirFor("", "/env/path", "linux")
	if got != "/env/path" {
		t.Errorf("env var should win over defaults, got %q", got)
	}
}

func TestResolveDataDir_LinuxLegacyKeptWhenWritable(t *testing.T) {
	stubDataDirStat(t, map[string]dataDirStat{
		LegacyLinuxDataDir: {Exists: true, Writable: true},
	})
	stubUserConfigDir(t, "/home/test/.config")
	got := resolveDataDirFor("", "", "linux")
	if got != LegacyLinuxDataDir {
		t.Errorf("linux with writable /opt/windsurf/data should keep legacy path, got %q", got)
	}
}

func TestResolveDataDir_LinuxLegacyNotWritableFallsBack(t *testing.T) {
	stubDataDirStat(t, map[string]dataDirStat{
		LegacyLinuxDataDir: {Exists: true, Writable: false}, // root-owned
	})
	stubUserConfigDir(t, "/home/test/.config")
	got := resolveDataDirFor("", "", "linux")
	want := filepath.Join("/home/test/.config", "windsurf", "data")
	if got != want {
		t.Errorf("unwritable legacy should fall back to UserConfigDir, got %q want %q", got, want)
	}
}

func TestResolveDataDir_DarwinIgnoresLinuxLegacy(t *testing.T) {
	stubDataDirStat(t, map[string]dataDirStat{
		LegacyLinuxDataDir: {Exists: true, Writable: true},
	})
	stubUserConfigDir(t, "/Users/test/Library/Application Support")
	got := resolveDataDirFor("", "", "darwin")
	want := filepath.Join("/Users/test/Library/Application Support", "windsurf", "data")
	if got != want {
		t.Errorf("darwin should ignore /opt/windsurf/data, got %q want %q", got, want)
	}
}

func TestResolveDataDir_WindowsUsesUserConfigDir(t *testing.T) {
	stubUserConfigDir(t, `C:\Users\test\AppData\Roaming`)
	got := resolveDataDirFor("", "", "windows")
	want := filepath.Join(`C:\Users\test\AppData\Roaming`, "windsurf", "data")
	if got != want {
		t.Errorf("windows should use UserConfigDir, got %q want %q", got, want)
	}
}

func TestResolveDataDir_EmptyUserConfigFallsBackToTemp(t *testing.T) {
	stubUserConfigDir(t, "")
	got := resolveDataDirFor("", "", "linux")
	if !strings.Contains(got, "windsurf-data") {
		t.Errorf("fallback should contain windsurf-data, got %q", got)
	}
}

func TestInstanceHomeDir(t *testing.T) {
	got := instanceHomeDir("/var/lib/windsurf/key1")
	want := filepath.Join("/var/lib/windsurf/key1", "home")
	if got != want {
		t.Errorf("got %q, want %q", got, want)
	}
}

func TestHomeEnvForPlatform(t *testing.T) {
	tests := []struct {
		goos string
		want []string
	}{
		{"linux", []string{"HOME=/sandbox"}},
		{"darwin", []string{"HOME=/sandbox"}},
		{"windows", []string{"HOME=/sandbox", "USERPROFILE=/sandbox"}},
	}
	for _, tt := range tests {
		t.Run(tt.goos, func(t *testing.T) {
			got := homeEnvForPlatform("/sandbox", tt.goos)
			if !reflect.DeepEqual(got, tt.want) {
				t.Errorf("goos=%s: got %v, want %v", tt.goos, got, tt.want)
			}
		})
	}
}