// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package fetch

import (
	"archive/zip"
	"context"
	"net/http"
	"os"
	"sort"
	"strings"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"github.com/google/safehtml"
	"golang.org/x/pkgsite/internal"
	"golang.org/x/pkgsite/internal/licenses"
	"golang.org/x/pkgsite/internal/log"
	"golang.org/x/pkgsite/internal/proxy"
	"golang.org/x/pkgsite/internal/source"
	"golang.org/x/pkgsite/internal/stdlib"
	"golang.org/x/pkgsite/internal/testing/sample"
	"golang.org/x/pkgsite/internal/testing/testhelper"
)

var testProxyCommitTime = time.Date(2019, 1, 30, 0, 0, 0, 0, time.UTC)

// cleanFetchResult adds missing information to a given FetchResult and returns
// it. It's meant to be used with test cases in fetchdata_test and should be called
// only once for each test case. The missing information is added here to avoid
// having to hardcode it into each test case.
func cleanFetchResult(t *testing.T, fr *FetchResult, detector *licenses.Detector) *FetchResult {
	t.Helper()

	fr.ModulePath = fr.Module.ModulePath
	if fr.GoModPath == "" {
		fr.GoModPath = fr.ModulePath
	}
	if fr.Status == 0 {
		fr.Status = 200
	}
	if fr.Module.Version == "" {
		fr.Module.Version = sample.VersionString
	}
	if fr.RequestedVersion == "" {
		fr.RequestedVersion = fr.Module.Version
	}
	fr.ResolvedVersion = fr.Module.Version
	if fr.Module.CommitTime.IsZero() {
		fr.Module.CommitTime = testProxyCommitTime
	}

	allLicenses := detector.AllLicenses()
	if len(allLicenses) > 0 {
		fr.Module.Licenses = allLicenses
		fr.Module.IsRedistributable = true
		for _, d := range fr.Module.Units {
			isRedist, lics := detector.PackageInfo(internal.Suffix(d.Path, fr.ModulePath))
			for _, l := range lics {
				d.Licenses = append(d.Licenses, l.Metadata)
			}
			d.IsRedistributable = isRedist
		}
	}

	shouldSetPVS := (fr.PackageVersionStates == nil)
	for _, u := range fr.Module.Units {
		u.UnitMeta = internal.UnitMeta{
			ModulePath:        fr.Module.ModulePath,
			Version:           fr.Module.Version,
			Path:              u.Path,
			Name:              u.Name,
			IsRedistributable: u.IsRedistributable,
			Licenses:          u.Licenses,
		}
		if u.Documentation != nil {
			if u.Documentation.GOOS == "" {
				u.Documentation.GOOS = "linux"
				u.Documentation.GOARCH = "amd64"
			}
		}
		if u.IsPackage() {
			fr.Module.LegacyPackages = append(fr.Module.LegacyPackages, &internal.LegacyPackage{
				Path:              u.Path,
				Licenses:          u.Licenses,
				V1Path:            internal.V1Path(u.Path, u.ModulePath),
				Name:              u.Name,
				Synopsis:          u.Documentation.Synopsis,
				DocumentationHTML: u.Documentation.HTML,
				Imports:           u.Imports,
				GOOS:              u.Documentation.GOOS,
				GOARCH:            u.Documentation.GOARCH,
				IsRedistributable: u.IsRedistributable,
			})
			if shouldSetPVS {
				fr.PackageVersionStates = append(
					fr.PackageVersionStates, &internal.PackageVersionState{
						PackagePath: u.Path,
						ModulePath:  fr.Module.ModulePath,
						Version:     fr.Module.Version,
						Status:      http.StatusOK,
					},
				)
			}
		}
	}
	return fr
}

// updateFetchResultVersions updates units' and package version states' version
// based on the type of fetching. Should be used for test cases in fetchdata_test.
func updateFetchResultVersions(t *testing.T, fr *FetchResult, local bool) *FetchResult {
	t.Helper()

	if local {
		for _, u := range fr.Module.Units {
			u.UnitMeta.Version = LocalVersion
		}
		for _, pvs := range fr.PackageVersionStates {
			pvs.Version = LocalVersion
		}
	} else {
		for _, u := range fr.Module.Units {
			u.UnitMeta.Version = fr.Module.Version
		}
		for _, pvs := range fr.PackageVersionStates {
			pvs.Version = fr.Module.Version
		}
	}
	return fr
}

// proxyFetcher is a test helper function that sets up a test proxy, fetches
// a module using FetchModule, and returns fetch result and a license detector.
func proxyFetcher(t *testing.T, withLicenseDetector bool, ctx context.Context, mod *testModule, fetchVersion string) (*FetchResult, *licenses.Detector) {
	t.Helper()

	modulePath := mod.mod.ModulePath
	version := mod.mod.Version
	if version == "" {
		version = sample.VersionString
	}
	if fetchVersion == "" {
		fetchVersion = version
	}

	sourceClient := source.NewClient(sourceTimeout)
	proxyClient, teardownProxy := proxy.SetupTestClient(t, []*proxy.Module{{
		ModulePath: modulePath,
		Version:    version,
		Files:      mod.mod.Files,
	}})
	defer teardownProxy()
	got := FetchModule(ctx, modulePath, fetchVersion, proxyClient, sourceClient)
	if !withLicenseDetector {
		return got, nil
	}

	d := licenseDetector(ctx, t, modulePath, got.ResolvedVersion, proxyClient)
	return got, d
}

// localFetcher is a helper function that creates a test directory to hold a module,
// fetches the module from the directory using FetchLocalModule, and returns a fetch
// result, and a license detector.
func localFetcher(t *testing.T, withLicenseDetector bool, ctx context.Context, mod *testModule, fetchVersion string) (*FetchResult, *licenses.Detector) {
	t.Helper()

	directory, err := testhelper.CreateTestDirectory(mod.mod.Files)
	if err != nil {
		t.Fatalf("couldn't create test files")
	}
	defer os.RemoveAll(directory)

	modulePath := mod.mod.ModulePath
	sourceClient := source.NewClient(sourceTimeout)
	got := FetchLocalModule(ctx, modulePath, directory, sourceClient)
	if !withLicenseDetector {
		return got, nil
	}

	zipReader, err := createZipReader(directory, modulePath, LocalVersion)
	if err != nil {
		t.Fatal("couldn't create zip reader")
	}
	d := licenses.NewDetector(modulePath, LocalVersion, zipReader, func(format string, args ...interface{}) {
		log.Infof(ctx, format, args...)
	})
	return got, d
}

func licenseDetector(ctx context.Context, t *testing.T, modulePath, version string, proxyClient *proxy.Client) *licenses.Detector {
	t.Helper()
	var (
		zipReader *zip.Reader
		err       error
	)
	if modulePath == stdlib.ModulePath {
		zipReader, _, err = stdlib.Zip(version)
		if err != nil {
			t.Fatal(err)
		}
	} else {
		zipReader, err = proxyClient.GetZip(ctx, modulePath, version)
		if err != nil {
			t.Fatal(err)
		}
	}
	logf := func(format string, args ...interface{}) {
		log.Infof(ctx, format, args...)
	}
	return licenses.NewDetector(modulePath, version, zipReader, logf)
}

func sortFetchResult(fr *FetchResult) {
	sort.Slice(fr.Module.LegacyPackages, func(i, j int) bool {
		return fr.Module.LegacyPackages[i].Path < fr.Module.LegacyPackages[j].Path
	})
	sort.Slice(fr.Module.Units, func(i, j int) bool {
		return fr.Module.Units[i].Path < fr.Module.Units[j].Path
	})
	sort.Slice(fr.Module.Licenses, func(i, j int) bool {
		return fr.Module.Licenses[i].FilePath < fr.Module.Licenses[j].FilePath
	})
	sort.Slice(fr.PackageVersionStates, func(i, j int) bool {
		return fr.PackageVersionStates[i].PackagePath < fr.PackageVersionStates[j].PackagePath
	})
	for _, dir := range fr.Module.Units {
		sort.Slice(dir.Licenses, func(i, j int) bool {
			return dir.Licenses[i].FilePath < dir.Licenses[j].FilePath
		})
	}
	for _, pkg := range fr.Module.LegacyPackages {
		sort.Slice(pkg.Licenses, func(i, j int) bool {
			return pkg.Licenses[i].FilePath < pkg.Licenses[j].FilePath
		})
	}
}

// validateDocumentationHTML checks that the doc HTML contains a set of
// substrings. The desired strings consist of the "want" module's documentation
// fields, with multiple substrings separated by '~'.
func validateDocumentationHTML(t *testing.T, got, want *internal.Module) {
	t.Helper()
	defer func() {
		if r := recover(); r != nil {
			t.Fatalf("Recovered in checkDocumentationHTML: %v \n; diff = %s", r, cmp.Diff(want, got))
		}
	}()

	checkHTML := func(msg string, i int, hGot, hWant safehtml.HTML) {
		t.Helper()
		got := hGot.String()
		// Treat the wanted DocumentationHTML as a set of substrings to look for, separated by ~.
		for _, want := range strings.Split(hWant.String(), "~") {
			want = strings.TrimSpace(want)
			if !strings.Contains(got, want) {
				t.Errorf("doc for %s[%d]:\nmissing %q; got\n%q", msg, i, want, got)
			}
		}
	}

	for i := 0; i < len(want.LegacyPackages); i++ {
		checkHTML("LegacyPackages", i, got.LegacyPackages[i].DocumentationHTML, want.LegacyPackages[i].DocumentationHTML)
	}
	for i := 0; i < len(want.Units); i++ {
		if !want.Units[i].IsPackage() {
			continue
		}
		checkHTML("Directories", i, got.Units[i].Documentation.HTML, want.Units[i].Documentation.HTML)
	}
}