// Copyright 2011 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 build

import (
	"io"
	"os"
	"path/filepath"
	"reflect"
	"runtime"
	"strings"
	"testing"
)

func TestMatch(t *testing.T) {
	ctxt := Default
	what := "default"
	match := func(tag string, want map[string]bool) {
		m := make(map[string]bool)
		if !ctxt.match(tag, m) {
			t.Errorf("%s context should match %s, does not", what, tag)
		}
		if !reflect.DeepEqual(m, want) {
			t.Errorf("%s tags = %v, want %v", tag, m, want)
		}
	}
	nomatch := func(tag string, want map[string]bool) {
		m := make(map[string]bool)
		if ctxt.match(tag, m) {
			t.Errorf("%s context should NOT match %s, does", what, tag)
		}
		if !reflect.DeepEqual(m, want) {
			t.Errorf("%s tags = %v, want %v", tag, m, want)
		}
	}

	match(runtime.GOOS+","+runtime.GOARCH, map[string]bool{runtime.GOOS: true, runtime.GOARCH: true})
	match(runtime.GOOS+","+runtime.GOARCH+",!foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
	nomatch(runtime.GOOS+","+runtime.GOARCH+",foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})

	what = "modified"
	ctxt.BuildTags = []string{"foo"}
	match(runtime.GOOS+","+runtime.GOARCH, map[string]bool{runtime.GOOS: true, runtime.GOARCH: true})
	match(runtime.GOOS+","+runtime.GOARCH+",foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
	nomatch(runtime.GOOS+","+runtime.GOARCH+",!foo", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "foo": true})
	match(runtime.GOOS+","+runtime.GOARCH+",!bar", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "bar": true})
	nomatch(runtime.GOOS+","+runtime.GOARCH+",bar", map[string]bool{runtime.GOOS: true, runtime.GOARCH: true, "bar": true})
	nomatch("!", map[string]bool{})
}

func TestDotSlashImport(t *testing.T) {
	p, err := ImportDir("testdata/other", 0)
	if err != nil {
		t.Fatal(err)
	}
	if len(p.Imports) != 1 || p.Imports[0] != "./file" {
		t.Fatalf("testdata/other: Imports=%v, want [./file]", p.Imports)
	}

	p1, err := Import("./file", "testdata/other", 0)
	if err != nil {
		t.Fatal(err)
	}
	if p1.Name != "file" {
		t.Fatalf("./file: Name=%q, want %q", p1.Name, "file")
	}
	dir := filepath.Clean("testdata/other/file") // Clean to use \ on Windows
	if p1.Dir != dir {
		t.Fatalf("./file: Dir=%q, want %q", p1.Name, dir)
	}
}

func TestEmptyImport(t *testing.T) {
	p, err := Import("", Default.GOROOT, FindOnly)
	if err == nil {
		t.Fatal(`Import("") returned nil error.`)
	}
	if p == nil {
		t.Fatal(`Import("") returned nil package.`)
	}
	if p.ImportPath != "" {
		t.Fatalf("ImportPath=%q, want %q.", p.ImportPath, "")
	}
}

func TestEmptyFolderImport(t *testing.T) {
	_, err := Import(".", "testdata/empty", 0)
	if _, ok := err.(*NoGoError); !ok {
		t.Fatal(`Import("testdata/empty") did not return NoGoError.`)
	}
}

func TestMultiplePackageImport(t *testing.T) {
	_, err := Import(".", "testdata/multi", 0)
	mpe, ok := err.(*MultiplePackageError)
	if !ok {
		t.Fatal(`Import("testdata/multi") did not return MultiplePackageError.`)
	}
	want := &MultiplePackageError{
		Dir:      filepath.FromSlash("testdata/multi"),
		Packages: []string{"main", "test_package"},
		Files:    []string{"file.go", "file_appengine.go"},
	}
	if !reflect.DeepEqual(mpe, want) {
		t.Errorf("got %#v; want %#v", mpe, want)
	}
}

func TestLocalDirectory(t *testing.T) {
	if runtime.GOOS == "darwin" {
		switch runtime.GOARCH {
		case "arm", "arm64":
			t.Skipf("skipping on %s/%s, no valid GOROOT", runtime.GOOS, runtime.GOARCH)
		}
	}

	cwd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}

	p, err := ImportDir(cwd, 0)
	if err != nil {
		t.Fatal(err)
	}
	if p.ImportPath != "github.com/magefile/mage/build" {
		t.Fatalf("ImportPath=%q, want %q", p.ImportPath, "github.com/magefile/mage/build")
	}
}

func TestShouldBuild(t *testing.T) {
	const file1 = "// +build tag1\n\n" +
		"package main\n"
	want1 := map[string]bool{"tag1": true}

	const file2 = "// +build cgo\n\n" +
		"// This package implements parsing of tags like\n" +
		"// +build tag1\n" +
		"package build"
	want2 := map[string]bool{"cgo": true}

	const file3 = "// Copyright The Go Authors.\n\n" +
		"package build\n\n" +
		"// shouldBuild checks tags given by lines of the form\n" +
		"// +build tag\n" +
		"func shouldBuild(content []byte)\n"
	want3 := map[string]bool{}

	ctx := &Context{BuildTags: []string{"tag1"}}
	m := map[string]bool{}
	if !ctx.shouldBuild([]byte(file1), m, nil) {
		t.Errorf("shouldBuild(file1) = false, want true")
	}
	if !reflect.DeepEqual(m, want1) {
		t.Errorf("shouldBuild(file1) tags = %v, want %v", m, want1)
	}

	m = map[string]bool{}
	if ctx.shouldBuild([]byte(file2), m, nil) {
		t.Errorf("shouldBuild(file2) = true, want false")
	}
	if !reflect.DeepEqual(m, want2) {
		t.Errorf("shouldBuild(file2) tags = %v, want %v", m, want2)
	}

	m = map[string]bool{}
	ctx = &Context{BuildTags: nil}
	if !ctx.shouldBuild([]byte(file3), m, nil) {
		t.Errorf("shouldBuild(file3) = false, want true")
	}
	if !reflect.DeepEqual(m, want3) {
		t.Errorf("shouldBuild(file3) tags = %v, want %v", m, want3)
	}
}

func TestRequiredTags(t *testing.T) {
	tests := []struct {
		name   string
		file   string
		should bool
	}{
		{
			"no req tag",
			"package main",
			false,
		},
		{
			"has req tag",
			`// +build req
			
			package main`,
			true,
		},
		{
			"OR with req",
			`// +build no req
			
			package main`,
			true,
		},
	}

	ctx := &Context{
		BuildTags:    []string{"req"},
		RequiredTags: []string{"req"},
	}
	for _, tst := range tests {
		t.Run(tst.name, func(t *testing.T) {
			if tst.should != ctx.shouldBuild([]byte(tst.file), nil, nil) {
				t.Errorf("shouldBuild = %v, want %v", !tst.should, tst.should)
			}
		})
	}
}

type readNopCloser struct {
	io.Reader
}

func (r readNopCloser) Close() error {
	return nil
}

var (
	ctxtP9      = Context{GOARCH: "arm", GOOS: "plan9"}
	ctxtAndroid = Context{GOARCH: "arm", GOOS: "android"}
)

var matchFileTests = []struct {
	ctxt  Context
	name  string
	data  string
	match bool
}{
	{ctxtP9, "foo_arm.go", "", true},
	{ctxtP9, "foo1_arm.go", "// +build linux\n\npackage main\n", false},
	{ctxtP9, "foo_darwin.go", "", false},
	{ctxtP9, "foo.go", "", true},
	{ctxtP9, "foo1.go", "// +build linux\n\npackage main\n", false},
	{ctxtP9, "foo.badsuffix", "", false},
	{ctxtAndroid, "foo_linux.go", "", true},
	{ctxtAndroid, "foo_android.go", "", true},
	{ctxtAndroid, "foo_plan9.go", "", false},
	{ctxtAndroid, "android.go", "", true},
	{ctxtAndroid, "plan9.go", "", true},
	{ctxtAndroid, "plan9_test.go", "", true},
	{ctxtAndroid, "arm.s", "", true},
	{ctxtAndroid, "amd64.s", "", true},
}

func TestMatchFile(t *testing.T) {
	for _, tt := range matchFileTests {
		ctxt := tt.ctxt
		ctxt.OpenFile = func(path string) (r io.ReadCloser, err error) {
			if path != "x+"+tt.name {
				t.Fatalf("OpenFile asked for %q, expected %q", path, "x+"+tt.name)
			}
			return &readNopCloser{strings.NewReader(tt.data)}, nil
		}
		ctxt.JoinPath = func(elem ...string) string {
			return strings.Join(elem, "+")
		}
		match, err := ctxt.MatchFile("x", tt.name)
		if match != tt.match || err != nil {
			t.Fatalf("MatchFile(%q) = %v, %v, want %v, nil", tt.name, match, err, tt.match)
		}
	}
}

func TestImportCmd(t *testing.T) {
	if runtime.GOOS == "darwin" {
		switch runtime.GOARCH {
		case "arm", "arm64":
			t.Skipf("skipping on %s/%s, no valid GOROOT", runtime.GOOS, runtime.GOARCH)
		}
	}

	p, err := Import("cmd/internal/objfile", "", 0)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.HasSuffix(filepath.ToSlash(p.Dir), "src/cmd/internal/objfile") {
		t.Fatalf("Import cmd/internal/objfile returned Dir=%q, want %q", filepath.ToSlash(p.Dir), ".../src/cmd/internal/objfile")
	}
}

var (
	expandSrcDirPath = filepath.Join(string(filepath.Separator)+"projects", "src", "add")
)

var expandSrcDirTests = []struct {
	input, expected string
}{
	{"-L ${SRCDIR}/libs -ladd", "-L /projects/src/add/libs -ladd"},
	{"${SRCDIR}/add_linux_386.a -pthread -lstdc++", "/projects/src/add/add_linux_386.a -pthread -lstdc++"},
	{"Nothing to expand here!", "Nothing to expand here!"},
	{"$", "$"},
	{"$$", "$$"},
	{"${", "${"},
	{"$}", "$}"},
	{"$FOO ${BAR}", "$FOO ${BAR}"},
	{"Find me the $SRCDIRECTORY.", "Find me the $SRCDIRECTORY."},
	{"$SRCDIR is missing braces", "$SRCDIR is missing braces"},
}

func TestExpandSrcDir(t *testing.T) {
	for _, test := range expandSrcDirTests {
		output, _ := expandSrcDir(test.input, expandSrcDirPath)
		if output != test.expected {
			t.Errorf("%q expands to %q with SRCDIR=%q when %q is expected", test.input, output, expandSrcDirPath, test.expected)
		} else {
			t.Logf("%q expands to %q with SRCDIR=%q", test.input, output, expandSrcDirPath)
		}
	}
}

func TestShellSafety(t *testing.T) {
	tests := []struct {
		input, srcdir, expected string
		result                  bool
	}{
		{"-I${SRCDIR}/../include", "/projects/src/issue 11868", "-I/projects/src/issue 11868/../include", true},
		{"-I${SRCDIR}", "wtf$@%", "-Iwtf$@%", true},
		{"-X${SRCDIR}/1,${SRCDIR}/2", "/projects/src/issue 11868", "-X/projects/src/issue 11868/1,/projects/src/issue 11868/2", true},
		{"-I/tmp -I/tmp", "/tmp2", "-I/tmp -I/tmp", true},
		{"-I/tmp", "/tmp/[0]", "-I/tmp", true},
		{"-I${SRCDIR}/dir", "/tmp/[0]", "-I/tmp/[0]/dir", false},
		{"-I${SRCDIR}/dir", "/tmp/go go", "-I/tmp/go go/dir", true},
		{"-I${SRCDIR}/dir dir", "/tmp/go", "-I/tmp/go/dir dir", true},
	}
	for _, test := range tests {
		output, ok := expandSrcDir(test.input, test.srcdir)
		if ok != test.result {
			t.Errorf("Expected %t while %q expands to %q with SRCDIR=%q; got %t", test.result, test.input, output, test.srcdir, ok)
		}
		if output != test.expected {
			t.Errorf("Expected %q while %q expands with SRCDIR=%q; got %q", test.expected, test.input, test.srcdir, output)
		}
	}
}

// Want to get a "cannot find package" error when directory for package does not exist.
// There should be valid partial information in the returned non-nil *Package.
func TestImportDirNotExist(t *testing.T) {
	MustHaveGoBuild(t) // really must just have source
	ctxt := Default
	ctxt.GOPATH = ""

	tests := []struct {
		label        string
		path, srcDir string
		mode         ImportMode
	}{
		{"Import(full, 0)", "go/build/doesnotexist", "", 0},
		{"Import(local, 0)", "./doesnotexist", filepath.Join(ctxt.GOROOT, "src/go/build"), 0},
		{"Import(full, FindOnly)", "go/build/doesnotexist", "", FindOnly},
		{"Import(local, FindOnly)", "./doesnotexist", filepath.Join(ctxt.GOROOT, "src/go/build"), FindOnly},
	}
	for _, test := range tests {
		p, err := ctxt.Import(test.path, test.srcDir, test.mode)
		if err == nil || !strings.HasPrefix(err.Error(), "cannot find package") {
			t.Errorf(`%s got error: %q, want "cannot find package" error`, test.label, err)
		}
		// If an error occurs, build.Import is documented to return
		// a non-nil *Package containing partial information.
		if p == nil {
			t.Fatalf(`%s got nil p, want non-nil *Package`, test.label)
		}
		// Verify partial information in p.
		if p.ImportPath != "go/build/doesnotexist" {
			t.Errorf(`%s got p.ImportPath: %q, want "go/build/doesnotexist"`, test.label, p.ImportPath)
		}
	}
}

func TestImportVendor(t *testing.T) {
	MustHaveGoBuild(t) // really must just have source
	ctxt := Default
	ctxt.GOPATH = ""
	p, err := ctxt.Import("golang_org/x/net/http2/hpack", filepath.Join(ctxt.GOROOT, "src/net/http"), 0)
	if err != nil {
		t.Fatalf("cannot find vendored golang_org/x/net/http2/hpack from net/http directory: %v", err)
	}
	want := "vendor/golang_org/x/net/http2/hpack"
	if p.ImportPath != want {
		t.Fatalf("Import succeeded but found %q, want %q", p.ImportPath, want)
	}
}

func TestImportVendorFailure(t *testing.T) {
	MustHaveGoBuild(t) // really must just have source
	ctxt := Default
	ctxt.GOPATH = ""
	p, err := ctxt.Import("x.com/y/z", filepath.Join(ctxt.GOROOT, "src/net/http"), 0)
	if err == nil {
		t.Fatalf("found made-up package x.com/y/z in %s", p.Dir)
	}

	e := err.Error()
	if !strings.Contains(e, " (vendor tree)") {
		t.Fatalf("error on failed import does not mention GOROOT/src/vendor directory:\n%s", e)
	}
}

func TestImportVendorParentFailure(t *testing.T) {
	MustHaveGoBuild(t) // really must just have source
	ctxt := Default
	ctxt.GOPATH = ""
	// This import should fail because the vendor/golang.org/x/net/http2 directory has no source code.
	p, err := ctxt.Import("golang_org/x/net/http2", filepath.Join(ctxt.GOROOT, "src/net/http"), 0)
	if err == nil {
		t.Fatalf("found empty parent in %s", p.Dir)
	}
	if p != nil && p.Dir != "" {
		t.Fatalf("decided to use %s", p.Dir)
	}
	e := err.Error()
	if !strings.Contains(e, " (vendor tree)") {
		t.Fatalf("error on failed import does not mention GOROOT/src/vendor directory:\n%s", e)
	}
}

// HasGoBuild reports whether the current system can build programs with ``go build''
// and then run them with os.StartProcess or exec.Command.
func HasGoBuild() bool {
	switch runtime.GOOS {
	case "android", "nacl":
		return false
	case "darwin":
		if strings.HasPrefix(runtime.GOARCH, "arm") {
			return false
		}
	}
	return true
}

// MustHaveGoBuild checks that the current system can build programs with ``go build''
// and then run them with os.StartProcess or exec.Command.
// If not, MustHaveGoBuild calls t.Skip with an explanation.
func MustHaveGoBuild(t *testing.T) {
	if !HasGoBuild() {
		t.Skipf("skipping test: 'go build' not available on %s/%s", runtime.GOOS, runtime.GOARCH)
	}
}