package fileops

import (
	"os"
	"path/filepath"
	"runtime"
	"testing"
	"time"
)

func TestPruneBackupsPreservesNewestAndNonRegularEntries(t *testing.T) {
	dir := t.TempDir()
	for index, name := range []string{"old.bak", "new.bak"} {
		path := filepath.Join(dir, name)
		if err := os.WriteFile(path, []byte(name), 0o600); err != nil {
			t.Fatal(err)
		}
		stamp := time.Unix(int64(index), 0)
		if err := os.Chtimes(path, stamp, stamp); err != nil {
			t.Fatal(err)
		}
	}
	if err := os.Mkdir(filepath.Join(dir, "directory.bak"), 0o700); err != nil {
		t.Fatal(err)
	}
	if runtime.GOOS != "windows" {
		if err := os.Symlink("old.bak", filepath.Join(dir, "symlink.bak")); err != nil {
			t.Fatal(err)
		}
	}
	if err := PruneBackups(dir, "*.bak", 1); err != nil {
		t.Fatal(err)
	}
	if _, err := os.Lstat(filepath.Join(dir, "old.bak")); !os.IsNotExist(err) {
		t.Fatalf("old backup survived: %v", err)
	}
	for _, name := range []string{"new.bak", "directory.bak"} {
		if _, err := os.Lstat(filepath.Join(dir, name)); err != nil {
			t.Fatal(err)
		}
	}
	if runtime.GOOS != "windows" {
		if _, err := os.Lstat(filepath.Join(dir, "symlink.bak")); err != nil {
			t.Fatal(err)
		}
	}
	if err := PruneBackups(dir, "*.bak", -1); err == nil {
		t.Fatal("negative retention accepted")
	}
}

func TestPruneBackupsTreatsBracketDirectoriesLiterally(t *testing.T) {
	for _, name := range []string{"MPV [test", "MPV [test]"} {
		t.Run(name, func(t *testing.T) {
			dir := filepath.Join(t.TempDir(), name)
			if err := os.Mkdir(dir, 0o700); err != nil {
				t.Fatal(err)
			}
			for index, name := range []string{"first.bak", "second.bak"} {
				path := filepath.Join(dir, name)
				if err := os.WriteFile(path, []byte(name), 0o600); err != nil {
					t.Fatal(err)
				}
				stamp := time.Unix(int64(index), 0)
				if err := os.Chtimes(path, stamp, stamp); err != nil {
					t.Fatal(err)
				}
			}
			if err := PruneBackups(dir, "*.bak", 1); err != nil {
				t.Fatal(err)
			}
			if _, err := os.Lstat(filepath.Join(dir, "first.bak")); !os.IsNotExist(err) {
				t.Fatalf("first retained: %v", err)
			}
			if _, err := os.Lstat(filepath.Join(dir, "second.bak")); err != nil {
				t.Fatal(err)
			}
		})
	}
}