package packagequery

import (
	"context"
	"errors"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"time"

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

// The copied test executable acts as a native package-manager fixture. Its
// normal package arguments do not pass through the Go test flag parser.
func init() {
	mode := os.Getenv("MPV_MANAGER_PACKAGE_PROBE_TEST_HELPER")
	if mode == "" {
		return
	}
	if os.Getenv("LC_ALL") != "C" {
		fmt.Fprintln(os.Stderr, "fixture expected LC_ALL=C")
		os.Exit(2)
	}
	switch mode {
	case "installed":
		fmt.Println("Version: 0.41.0")
		os.Exit(0)
	case "missing":
		fmt.Fprintln(os.Stderr, "error: application is not installed")
		os.Exit(1)
	case "hang":
		fmt.Fprintln(os.Stderr, "not installed")
		time.Sleep(time.Minute)
	case "oversize":
		fmt.Fprintln(os.Stderr, "not installed"+strings.Repeat("x", 2<<20))
		os.Exit(1)
	}
	os.Exit(2)
}

func installProbeFixture(t *testing.T) {
	t.Helper()
	path, err := os.Executable()
	require.NoError(t, err)
	source, err := os.Open(path)
	require.NoError(t, err)
	defer source.Close()
	dir := t.TempDir()
	name := "flatpak"
	if runtime.GOOS == "windows" {
		name += ".exe"
	}
	dest, err := os.OpenFile(filepath.Join(dir, name), os.O_CREATE|os.O_WRONLY, 0755)
	require.NoError(t, err)
	_, err = io.Copy(dest, source)
	require.NoError(t, err)
	require.NoError(t, dest.Close())
	t.Setenv("PATH", dir+string(os.PathListSeparator)+os.Getenv("PATH"))
	t.Setenv("LC_ALL", "fr_FR.UTF-8")
}

func TestNativePackageProbeOutcomes(t *testing.T) {
	installProbeFixture(t)
	t.Run("locale and parsed installed version", func(t *testing.T) {
		t.Setenv("MPV_MANAGER_PACKAGE_PROBE_TEST_HELPER", "installed")
		value, err := Installed(context.Background(), constants.MethodMPVFlatpak)
		require.NoError(t, err)
		assert.Equal(t, "0.41.0", value)
	})
	t.Run("definitive stderr absence", func(t *testing.T) {
		t.Setenv("MPV_MANAGER_PACKAGE_PROBE_TEST_HELPER", "missing")
		_, err := Installed(context.Background(), constants.MethodMPVFlatpak)
		require.ErrorIs(t, err, ErrNotInstalled)
	})
	t.Run("partial timeout output stays unknown", func(t *testing.T) {
		t.Setenv("MPV_MANAGER_PACKAGE_PROBE_TEST_HELPER", "hang")
		ctx, cancel := context.WithTimeout(context.Background(), 150*time.Millisecond)
		defer cancel()
		start := time.Now()
		_, err := Installed(ctx, constants.MethodMPVFlatpak)
		require.ErrorIs(t, err, context.DeadlineExceeded)
		assert.False(t, errors.Is(err, ErrNotInstalled))
		assert.Less(t, time.Since(start), 3*time.Second)
	})
	t.Run("oversized diagnostic stays unknown", func(t *testing.T) {
		t.Setenv("MPV_MANAGER_PACKAGE_PROBE_TEST_HELPER", "oversize")
		_, err := Installed(context.Background(), constants.MethodMPVFlatpak)
		require.ErrorIs(t, err, process.ErrOutputLimit)
		assert.False(t, errors.Is(err, ErrNotInstalled))
	})
}