package installer

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

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

// installFakeTools creates executable POSIX shell scripts that print canned
// command output and prepends their directory to PATH, so the version-probe
// parsing loops can be exercised deterministically without real package
// managers. Each value is the script body (without the shebang).
func installFakeTools(t *testing.T, tools map[string]string) {
	t.Helper()
	if runtime.GOOS == "windows" {
		t.Skip("fake tool scripts require a POSIX shell")
	}
	dir := t.TempDir()
	for name, body := range tools {
		require.NoError(t, os.WriteFile(filepath.Join(dir, name), []byte("#!/bin/sh\n"+body), 0755))
	}
	t.Setenv("PATH", dir+string(os.PathListSeparator)+os.Getenv("PATH"))
}

func fakeToolScripts() map[string]string {
	return map[string]string{
		"flatpak": "cat <<'MPV_FAKE_EOF'\nID: io.mpv.Mpv\nVersion: 0.39.0\nMPV_FAKE_EOF\n",
		"apt-get": "exit 0\n",
		// GetPackageVersion matches "Installed:" at line start, so no indent here.
		"apt-cache": "cat <<'MPV_FAKE_EOF'\nmpv:\nInstalled: 0.39.0\nCandidate: 0.39.0\nMPV_FAKE_EOF\n",
		"dnf":       "cat <<'MPV_FAKE_EOF'\nInstalled Packages\nName         : mpv\nVersion      : 7.0.1\nMPV_FAKE_EOF\n",
		"rpm":       "echo '1.2-3'\n",
		"brew":      "echo 'mpv 0.39.0'\n",
		// pacman fails for "celluloid" itself so the alternative-name loop runs.
		"pacman": "case \"$2\" in\n celluloid) echo \"error: package 'celluloid' was not found\" >&2; exit 1;;\nesac\ncat <<'MPV_FAKE_EOF'\nName            : mpv\nVersion         : 1:0.41.0-2\nMPV_FAKE_EOF\n",
	}
}

func TestFlatpakDetectionWithFakeTool(t *testing.T) {
	installFakeTools(t, fakeToolScripts())

	assert.Equal(t, "0.39.0", getFlatpakAppVersion("io.mpv.Mpv"))

	apps := detectFlatpakApps()
	require.Len(t, apps, 2, "the fake flatpak reports every app as installed")
	assert.Equal(t, "MPV", apps[0].AppName)
	assert.Equal(t, "flatpak", apps[0].InstallType)
	assert.Equal(t, "0.39.0", apps[0].Version)
}

func TestPackageVersionProbesWithFakeTools(t *testing.T) {
	installFakeTools(t, fakeToolScripts())

	version, _ := getPackageAppVersion(constants.PMFamilyDebian, "mpv")
	assert.Equal(t, "0.39.0", version)

	version, _ = getPackageAppVersion(constants.PMFamilyRHEL, "mpv")
	assert.Equal(t, "7.0.1", version)

	version, _ = getPackageAppVersion(constants.PMFamilySUSE, "mpv")
	assert.Equal(t, "1.2-3", version)

	// Discovery retains the package epoch, matching canonical version checks.
	version, _ = getPackageAppVersion(constants.PMFamilyArch, "mpv")
	assert.Equal(t, "1:0.41.0-2", version)

	// celluloid itself is "not installed"; the alternative names are tried.
	version, _ = getPackageAppVersion(constants.PMFamilyArch, "celluloid")
	assert.Equal(t, "1:0.41.0-2", version)
}

func TestDetectPackageAppsWithFakeTools(t *testing.T) {
	installFakeTools(t, fakeToolScripts())

	apps := detectPackageApps()
	require.NotEmpty(t, apps)
	byMethod := map[string]DetectedApp{}
	for _, app := range apps {
		byMethod[app.MethodID] = app
		assert.Equal(t, "package", app.InstallType)
		assert.NotEmpty(t, app.Version)
	}
	assert.Contains(t, byMethod, "mpv-package")
}