package version

import (
	"bytes"
	"context"
	"errors"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"

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

func TestSelectManagerAssetPlatforms(t *testing.T) {
	newRelease := func() *ReleaseInfo {
		release := &ReleaseInfo{Version: "9.9.9"}
		release.Components = map[string]releasemanifest.Component{
			ComponentID: {
				Version: "9.9.9",
				Assets: []releasemanifest.Asset{
					{GOOS: "linux", GOARCH: "amd64", URL: "https://example.com/linux-amd64", BLAKE3: "blake3:linux-amd64"},
					{GOOS: "linux", GOARCH: "arm64", URL: "https://example.com/linux-arm64", BLAKE3: "blake3:linux-arm64"},
					{GOOS: "windows", GOARCH: "amd64", URL: "https://example.com/win-x86_64.exe", BLAKE3: "blake3:win-x86_64"},
					{GOOS: "windows", GOARCH: "arm64", URL: "https://example.com/win-arm64.exe", BLAKE3: "blake3:win-arm64"},
					{GOOS: "darwin", GOARCH: "amd64", URL: "https://example.com/macos-intel", BLAKE3: "blake3:macos-intel"},
					{GOOS: "darwin", GOARCH: "arm64", URL: "https://example.com/macos-arm", BLAKE3: "blake3:macos-arm"},
				},
			},
		}
		return release
	}

	tests := []struct {
		name     string
		goos     string
		goarch   string
		wantURL  string
		wantHash string
	}{
		{"linux/amd64", "linux", "amd64", "https://example.com/linux-amd64", "blake3:linux-amd64"},
		{"linux/arm64", "linux", "arm64", "https://example.com/linux-arm64", "blake3:linux-arm64"},
		{"windows/amd64", "windows", "amd64", "https://example.com/win-x86_64.exe", "blake3:win-x86_64"},
		{"windows/arm64", "windows", "arm64", "https://example.com/win-arm64.exe", "blake3:win-arm64"},
		{"darwin/amd64", "darwin", "amd64", "https://example.com/macos-intel", "blake3:macos-intel"},
		{"darwin/arm64", "darwin", "arm64", "https://example.com/macos-arm", "blake3:macos-arm"},
		{"unsupported combo", "freebsd", "amd64", "", ""},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := &VersionCheckResult{}
			err := selectManagerAsset(result, newRelease(), tt.goos, tt.goarch)

			assert.Equal(t, tt.wantURL, result.URL)
			assert.Equal(t, tt.wantHash, result.BLAKE3)
			assert.Equal(t, tt.wantURL != "", result.UpdateAvailable)
			if tt.wantURL == "" {
				assert.Error(t, err)
			} else {
				assert.NoError(t, err)
			}
		})
	}
}

func TestVerifyBLAKE3OpenFailure(t *testing.T) {
	err := VerifyBLAKE3(filepath.Join(t.TempDir(), "does-not-exist"), "blake3:whatever")
	require.Error(t, err)
	assert.Contains(t, err.Error(), "failed to open file")
}

// errAfterReader yields its data once and then fails, simulating a connection
// that dies mid-download.
type errAfterReader struct {
	data []byte
	err  error
}

func (r *errAfterReader) Read(p []byte) (int, error) {
	if len(r.data) == 0 {
		return 0, r.err
	}
	n := copy(p, r.data)
	r.data = r.data[n:]
	return n, nil
}

func (r *errAfterReader) Close() error { return nil }

func TestDownloadFileWithProgressMidStreamError(t *testing.T) {
	payload := []byte("partial content that never completes")
	previousClient := selfUpdateHTTPClient
	selfUpdateHTTPClient = &http.Client{Transport: roundTripFunc(func(*http.Request) (*http.Response, error) {
		return &http.Response{
			StatusCode:    http.StatusOK,
			Body:          &errAfterReader{data: bytes.Clone(payload), err: errors.New("connection reset")},
			ContentLength: int64(len(payload)) * 4,
		}, nil
	})}
	t.Cleanup(func() { selfUpdateHTTPClient = previousClient })

	dest := filepath.Join(t.TempDir(), "partial.bin")
	err := downloadFileWithProgressContext(context.Background(), "https://example.invalid/update", dest, func(written, total int64) {}, 2)

	require.Error(t, err)
	assert.Contains(t, err.Error(), "download failed after 2 attempts")
	assert.NoFileExists(t, dest, "partial downloads are removed on failure")
}

func TestDownloadFileWithProgressUnwritableDirectory(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("content"))
	}))
	defer server.Close()

	// A regular file as the parent path makes MkdirAll fail deterministically.
	parent := filepath.Join(t.TempDir(), "a-file")
	require.NoError(t, os.WriteFile(parent, []byte("x"), 0644))

	err := downloadFileWithProgressContext(context.Background(), server.URL, filepath.Join(parent, "nested", "dest.bin"), nil, 1)
	require.Error(t, err)
}