package version

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

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"lukechampine.com/blake3"
)

// blake3HashOf computes the "blake3:<hex>" hash used by the release JSON.
func blake3HashOf(data []byte) string {
	sum := blake3.Sum256(data)
	return "blake3:" + hex.EncodeToString(sum[:])
}

func TestVerifySelfUpdate(t *testing.T) {
	content := []byte("mpv-manager self-update test vector")

	writeBinary := func(t *testing.T) string {
		t.Helper()
		path := filepath.Join(t.TempDir(), "mpv-manager.new")
		require.NoError(t, os.WriteFile(path, content, 0755))
		return path
	}

	t.Run("correct hash passes", func(t *testing.T) {
		path := writeBinary(t)
		assert.NoError(t, verifySelfUpdate(path, blake3HashOf(content)))
	})

	t.Run("wrong hash fails", func(t *testing.T) {
		path := writeBinary(t)
		err := verifySelfUpdate(path, blake3HashOf([]byte("tampered")))
		require.Error(t, err)
		assert.Contains(t, err.Error(), "BLAKE3 hash mismatch")
	})

	t.Run("missing hash aborts the update (fail-closed)", func(t *testing.T) {
		path := writeBinary(t)
		err := verifySelfUpdate(path, "")
		require.Error(t, err)
		assert.Contains(t, err.Error(), "no BLAKE3 hash available")
	})
}

func TestVerifyBLAKE3(t *testing.T) {
	content := []byte("mpv-manager verify test vector")

	t.Run("correct hash passes", func(t *testing.T) {
		path := filepath.Join(t.TempDir(), "artifact.bin")
		require.NoError(t, os.WriteFile(path, content, 0644))
		assert.NoError(t, VerifyBLAKE3(path, blake3HashOf(content)))
	})

	t.Run("wrong hash fails", func(t *testing.T) {
		path := filepath.Join(t.TempDir(), "artifact.bin")
		require.NoError(t, os.WriteFile(path, content, 0644))
		err := VerifyBLAKE3(path, blake3HashOf([]byte("other content")))
		require.Error(t, err)
		assert.Contains(t, err.Error(), "BLAKE3 hash mismatch")
	})
}