// Copyright 2018 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 gitrepo

import (
	"archive/zip"
	"bytes"
	"fmt"
	"internal/testenv"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
	"time"

	"cmd/go/internal/modfetch/codehost"
)

func TestMain(m *testing.M) {
	os.Exit(testMain(m))
}

const gitrepo1 = "https://vcs-test.golang.org/git/gitrepo1"

// localGitRepo is like gitrepo1 but allows archive access.
var localGitRepo string

func testMain(m *testing.M) int {
	if _, err := exec.LookPath("git"); err != nil {
		fmt.Fprintln(os.Stderr, "skipping because git binary not found")
		fmt.Println("PASS")
		return 0
	}

	dir, err := ioutil.TempDir("", "gitrepo-test-")
	if err != nil {
		log.Fatal(err)
	}
	defer os.RemoveAll(dir)
	codehost.WorkRoot = dir

	if testenv.HasExternalNetwork() && testenv.HasExec() {
		// Clone gitrepo1 into a local directory.
		// If we use a file:// URL to access the local directory,
		// then git starts up all the usual protocol machinery,
		// which will let us test remote git archive invocations.
		localGitRepo = filepath.Join(dir, "gitrepo2")
		if _, err := codehost.Run("", "git", "clone", "--mirror", gitrepo1, localGitRepo); err != nil {
			log.Fatal(err)
		}
		if _, err := codehost.Run(localGitRepo, "git", "config", "daemon.uploadarch", "true"); err != nil {
			log.Fatal(err)
		}
	}

	return m.Run()
}

func testRepo(remote string) (codehost.Repo, error) {
	if remote == "localGitRepo" {
		remote = "file://" + filepath.ToSlash(localGitRepo)
	}
	// Re ?root: nothing should care about the second argument,
	// so use a string that will be distinctive if it does show up.
	return LocalRepo(remote, "?root")
}

var tagsTests = []struct {
	repo   string
	prefix string
	tags   []string
}{
	{gitrepo1, "xxx", []string{}},
	{gitrepo1, "", []string{"v1.2.3", "v1.2.4-annotated", "v2.0.1", "v2.0.2", "v2.3"}},
	{gitrepo1, "v", []string{"v1.2.3", "v1.2.4-annotated", "v2.0.1", "v2.0.2", "v2.3"}},
	{gitrepo1, "v1", []string{"v1.2.3", "v1.2.4-annotated"}},
	{gitrepo1, "2", []string{}},
}

func TestTags(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	testenv.MustHaveExec(t)

	for _, tt := range tagsTests {
		f := func(t *testing.T) {
			r, err := testRepo(tt.repo)
			if err != nil {
				t.Fatal(err)
			}
			tags, err := r.Tags(tt.prefix)
			if err != nil {
				t.Fatal(err)
			}
			if !reflect.DeepEqual(tags, tt.tags) {
				t.Errorf("Tags: incorrect tags\nhave %v\nwant %v", tags, tt.tags)
			}
		}
		t.Run(tt.repo+"/"+tt.prefix, f)
		if tt.repo == gitrepo1 {
			tt.repo = "localGitRepo"
			t.Run(tt.repo+"/"+tt.prefix, f)
		}
	}
}

var latestTests = []struct {
	repo string
	info *codehost.RevInfo
}{
	{
		gitrepo1,
		&codehost.RevInfo{
			Name:    "ede458df7cd0fdca520df19a33158086a8a68e81",
			Short:   "ede458df7cd0",
			Version: "ede458df7cd0fdca520df19a33158086a8a68e81",
			Time:    time.Date(2018, 4, 17, 19, 43, 22, 0, time.UTC),
		},
	},
}

func TestLatest(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	testenv.MustHaveExec(t)

	for _, tt := range latestTests {
		f := func(t *testing.T) {
			r, err := testRepo(tt.repo)
			if err != nil {
				t.Fatal(err)
			}
			info, err := r.Latest()
			if err != nil {
				t.Fatal(err)
			}
			if *info != *tt.info {
				t.Errorf("Latest: incorrect info\nhave %+v\nwant %+v", *info, *tt.info)
			}
		}
		t.Run(tt.repo, f)
		if tt.repo == gitrepo1 {
			tt.repo = "localGitRepo"
			t.Run(tt.repo, f)
		}
	}
}

var readFileTests = []struct {
	repo string
	rev  string
	file string
	err  string
	data string
}{
	{
		repo: gitrepo1,
		rev:  "HEAD",
		file: "README",
		data: "",
	},
	{
		repo: gitrepo1,
		rev:  "v2",
		file: "another.txt",
		data: "another\n",
	},
	{
		repo: gitrepo1,
		rev:  "v2.3.4",
		file: "another.txt",
		err:  os.ErrNotExist.Error(),
	},
}

func TestReadFile(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	testenv.MustHaveExec(t)

	for _, tt := range readFileTests {
		f := func(t *testing.T) {
			r, err := testRepo(tt.repo)
			if err != nil {
				t.Fatal(err)
			}
			data, err := r.ReadFile(tt.rev, tt.file, 100)
			if err != nil {
				if tt.err == "" {
					t.Fatalf("ReadFile: unexpected error %v", err)
				}
				if !strings.Contains(err.Error(), tt.err) {
					t.Fatalf("ReadFile: wrong error %q, want %q", err, tt.err)
				}
				if len(data) != 0 {
					t.Errorf("ReadFile: non-empty data %q with error %v", data, err)
				}
				return
			}
			if tt.err != "" {
				t.Fatalf("ReadFile: no error, wanted %v", tt.err)
			}
			if string(data) != tt.data {
				t.Errorf("ReadFile: incorrect data\nhave %q\nwant %q", data, tt.data)
			}
		}
		t.Run(tt.repo+"/"+tt.rev+"/"+tt.file, f)
		if tt.repo == gitrepo1 {
			tt.repo = "localGitRepo"
			t.Run(tt.repo+"/"+tt.rev+"/"+tt.file, f)
		}
	}
}

var readZipTests = []struct {
	repo         string
	rev          string
	subdir       string
	actualSubdir string
	err          string
	files        map[string]uint64
}{
	{
		repo:   gitrepo1,
		rev:    "v2.3.4",
		subdir: "",
		files: map[string]uint64{
			"prefix/":       0,
			"prefix/README": 0,
			"prefix/v2":     3,
		},
	},
	{
		repo:   gitrepo1,
		rev:    "v2",
		subdir: "",
		files: map[string]uint64{
			"prefix/":            0,
			"prefix/README":      0,
			"prefix/v2":          3,
			"prefix/another.txt": 8,
			"prefix/foo.txt":     13,
		},
	},
	{
		repo:   gitrepo1,
		rev:    "v3",
		subdir: "",
		files: map[string]uint64{
			"prefix/":                    0,
			"prefix/v3/":                 0,
			"prefix/v3/sub/":             0,
			"prefix/v3/sub/dir/":         0,
			"prefix/v3/sub/dir/file.txt": 16,
			"prefix/README":              0,
		},
	},
	{
		repo:   gitrepo1,
		rev:    "v3",
		subdir: "v3/sub/dir",
		files: map[string]uint64{
			"prefix/":                    0,
			"prefix/v3/":                 0,
			"prefix/v3/sub/":             0,
			"prefix/v3/sub/dir/":         0,
			"prefix/v3/sub/dir/file.txt": 16,
		},
	},
	{
		repo:   gitrepo1,
		rev:    "v3",
		subdir: "v3/sub",
		files: map[string]uint64{
			"prefix/":                    0,
			"prefix/v3/":                 0,
			"prefix/v3/sub/":             0,
			"prefix/v3/sub/dir/":         0,
			"prefix/v3/sub/dir/file.txt": 16,
		},
	},
	{
		repo:   gitrepo1,
		rev:    "aaaaaaaaab",
		subdir: "",
		err:    "cannot find hash",
	},
	{
		repo:   "https://github.com/rsc/vgotest1",
		rev:    "submod/v1.0.4",
		subdir: "submod",
		files: map[string]uint64{
			"prefix/":                0,
			"prefix/submod/":         0,
			"prefix/submod/go.mod":   53,
			"prefix/submod/pkg/":     0,
			"prefix/submod/pkg/p.go": 31,
		},
	},
}

type zipFile struct {
	name string
	size int64
}

func TestReadZip(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	testenv.MustHaveExec(t)

	for _, tt := range readZipTests {
		f := func(t *testing.T) {
			r, err := testRepo(tt.repo)
			if err != nil {
				t.Fatal(err)
			}
			rc, actualSubdir, err := r.ReadZip(tt.rev, tt.subdir, 100000)
			if err != nil {
				if tt.err == "" {
					t.Fatalf("ReadZip: unexpected error %v", err)
				}
				if !strings.Contains(err.Error(), tt.err) {
					t.Fatalf("ReadZip: wrong error %q, want %q", err, tt.err)
				}
				if rc != nil {
					t.Errorf("ReadZip: non-nil io.ReadCloser with error %v", err)
				}
				return
			}
			defer rc.Close()
			if tt.err != "" {
				t.Fatalf("ReadZip: no error, wanted %v", tt.err)
			}
			if actualSubdir != tt.actualSubdir {
				t.Fatalf("ReadZip: actualSubdir = %q, want %q", actualSubdir, tt.actualSubdir)
			}
			zipdata, err := ioutil.ReadAll(rc)
			if err != nil {
				t.Fatal(err)
			}
			z, err := zip.NewReader(bytes.NewReader(zipdata), int64(len(zipdata)))
			if err != nil {
				t.Fatalf("ReadZip: cannot read zip file: %v", err)
			}
			have := make(map[string]bool)
			for _, f := range z.File {
				size, ok := tt.files[f.Name]
				if !ok {
					t.Errorf("ReadZip: unexpected file %s", f.Name)
					continue
				}
				have[f.Name] = true
				if f.UncompressedSize64 != size {
					t.Errorf("ReadZip: file %s has unexpected size %d != %d", f.Name, f.UncompressedSize64, size)
				}
			}
			for name := range tt.files {
				if !have[name] {
					t.Errorf("ReadZip: missing file %s", name)
				}
			}
		}
		t.Run(tt.repo+"/"+tt.rev+"/"+tt.subdir, f)
		if tt.repo == gitrepo1 {
			tt.repo = "localGitRepo"
			t.Run(tt.repo+"/"+tt.rev+"/"+tt.subdir, f)
		}
	}
}

var statTests = []struct {
	repo string
	rev  string
	err  string
	info *codehost.RevInfo
}{
	{
		repo: gitrepo1,
		rev:  "HEAD",
		info: &codehost.RevInfo{
			Name:    "ede458df7cd0fdca520df19a33158086a8a68e81",
			Short:   "ede458df7cd0",
			Version: "ede458df7cd0fdca520df19a33158086a8a68e81",
			Time:    time.Date(2018, 4, 17, 19, 43, 22, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "v2", // branch
		info: &codehost.RevInfo{
			Name:    "9d02800338b8a55be062c838d1f02e0c5780b9eb",
			Short:   "9d02800338b8",
			Version: "9d02800338b8a55be062c838d1f02e0c5780b9eb",
			Time:    time.Date(2018, 4, 17, 20, 00, 32, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "v2.3.4", // badly-named branch (semver should be a tag)
		info: &codehost.RevInfo{
			Name:    "76a00fb249b7f93091bc2c89a789dab1fc1bc26f",
			Short:   "76a00fb249b7",
			Version: "76a00fb249b7f93091bc2c89a789dab1fc1bc26f",
			Time:    time.Date(2018, 4, 17, 19, 45, 48, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "v2.3", // badly-named tag (we only respect full semver v2.3.0)
		info: &codehost.RevInfo{
			Name:    "76a00fb249b7f93091bc2c89a789dab1fc1bc26f",
			Short:   "76a00fb249b7",
			Version: "v2.3",
			Time:    time.Date(2018, 4, 17, 19, 45, 48, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "v1.2.3", // tag
		info: &codehost.RevInfo{
			Name:    "ede458df7cd0fdca520df19a33158086a8a68e81",
			Short:   "ede458df7cd0",
			Version: "v1.2.3",
			Time:    time.Date(2018, 4, 17, 19, 43, 22, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "ede458df", // hash prefix in refs
		info: &codehost.RevInfo{
			Name:    "ede458df7cd0fdca520df19a33158086a8a68e81",
			Short:   "ede458df7cd0",
			Version: "ede458df7cd0fdca520df19a33158086a8a68e81",
			Time:    time.Date(2018, 4, 17, 19, 43, 22, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "97f6aa59", // hash prefix not in refs
		info: &codehost.RevInfo{
			Name:    "97f6aa59c81c623494825b43d39e445566e429a4",
			Short:   "97f6aa59c81c",
			Version: "97f6aa59c81c623494825b43d39e445566e429a4",
			Time:    time.Date(2018, 4, 17, 20, 0, 19, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "v1.2.4-annotated", // annotated tag uses unwrapped commit hash
		info: &codehost.RevInfo{
			Name:    "ede458df7cd0fdca520df19a33158086a8a68e81",
			Short:   "ede458df7cd0",
			Version: "v1.2.4-annotated",
			Time:    time.Date(2018, 4, 17, 19, 43, 22, 0, time.UTC),
		},
	},
	{
		repo: gitrepo1,
		rev:  "aaaaaaaaab",
		err:  "cannot find hash",
	},
}

func TestStat(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)
	testenv.MustHaveExec(t)

	for _, tt := range statTests {
		f := func(t *testing.T) {
			r, err := testRepo(tt.repo)
			if err != nil {
				t.Fatal(err)
			}
			info, err := r.Stat(tt.rev)
			if err != nil {
				if tt.err == "" {
					t.Fatalf("Stat: unexpected error %v", err)
				}
				if !strings.Contains(err.Error(), tt.err) {
					t.Fatalf("Stat: wrong error %q, want %q", err, tt.err)
				}
				if info != nil {
					t.Errorf("Stat: non-nil info with error %q", err)
				}
				return
			}
			if *info != *tt.info {
				t.Errorf("Stat: incorrect info\nhave %+v\nwant %+v", *info, *tt.info)
			}
		}
		t.Run(filepath.Base(tt.repo)+"/"+tt.rev, f)
		if tt.repo == gitrepo1 {
			tt.repo = "localGitRepo"
			t.Run(filepath.Base(tt.repo)+"/"+tt.rev, f)
		}
	}
}