// Copyright 2023 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 frontend

import (
	"context"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"
	"time"

	"github.com/google/safehtml/template"
	"github.com/jba/templatecheck"
	"golang.org/x/pkgsite/internal"
	"golang.org/x/pkgsite/internal/frontend/page"
	"golang.org/x/pkgsite/internal/frontend/versions"
	"golang.org/x/pkgsite/internal/testing/fakedatasource"
	"golang.org/x/pkgsite/static"
	thirdparty "golang.org/x/pkgsite/third_party"
)

type testModule struct {
	path            string
	redistributable bool
	versions        []string
	packages        []testPackage
}

type testPackage struct {
	name           string
	suffix         string
	readmeContents string
	readmeFilePath string
	docs           []*internal.Documentation
}

func newTestServer(t *testing.T, cacher Cacher) (*Server, http.Handler) {
	t.Helper()

	s, err := NewServer(ServerConfig{
		DataSourceGetter: func(context.Context) internal.DataSource { return fakedatasource.New() },
		TemplateFS:       template.TrustedFSFromEmbed(static.FS),
		// Use the embedded FSs here to make sure they're tested.
		// Integration tests will use the actual directories.
		StaticFS:     static.FS,
		ThirdPartyFS: thirdparty.FS,
		StaticPath:   "../../static",
	})
	if err != nil {
		t.Fatal(err)
	}
	mux := http.NewServeMux()
	s.Install(mux.Handle, cacher, nil)

	return s, mux
}

func TestHTMLInjection(t *testing.T) {
	_, handler := newTestServer(t, nil)
	w := httptest.NewRecorder()
	handler.ServeHTTP(w, httptest.NewRequest("GET", "/<em>UHOH</em>", nil))
	if strings.Contains(w.Body.String(), "<em>") {
		t.Error("User input was rendered unescaped.")
	}
}

func mustRequest(urlPath string, t *testing.T) *http.Request {
	t.Helper()
	r, err := http.NewRequest(http.MethodGet, "http://localhost"+urlPath, nil)
	if err != nil {
		t.Fatal(err)
	}
	return r
}

func TestDetailsTTL(t *testing.T) {
	tests := []struct {
		r    *http.Request
		want time.Duration
	}{
		{mustRequest("/host.com/module@v1.2.3/suffix", t), longTTL},
		{mustRequest("/host.com/module/suffix", t), shortTTL},
		{mustRequest("/host.com/module@v1.2.3/suffix?tab=overview", t), longTTL},
		{mustRequest("/host.com/module@v1.2.3/suffix?tab=versions", t), defaultTTL},
		{mustRequest("/host.com/module@v1.2.3/suffix?tab=importedby", t), defaultTTL},
		{
			func() *http.Request {
				r := mustRequest("/host.com/module@v1.2.3/suffix?tab=overview", t)
				r.Header.Set("user-agent",
					"Mozilla/5.0 (compatible; AhrefsBot/7.0; +http://ahrefs.com/robot/)")
				return r
			}(),
			tinyTTL,
		},
	}
	for _, test := range tests {
		if got := detailsTTL(test.r); got != test.want {
			t.Errorf("detailsTTL(%v) = %v, want %v", test.r, got, test.want)
		}
	}
}

func TestTagRoute(t *testing.T) {
	mustRequest := func(url string) *http.Request {
		req, err := http.NewRequest("GET", url, nil)
		if err != nil {
			t.Fatal(err)
		}
		return req
	}
	tests := []struct {
		route string
		req   *http.Request
		want  string
	}{
		{"/pkg", mustRequest("http://localhost/pkg/foo?tab=versions"), "pkg-versions"},
		{"/", mustRequest("http://localhost/foo?tab=imports"), "imports"},
		{"/search", mustRequest("http://localhost/search?q=net&m=vuln"), "search-vuln"},
		{"/search", mustRequest("http://localhost/search?q=net&m=package"), "search-package"},
		{"/search", mustRequest("http://localhost/search?q=net&m=symbol"), "search-symbol"},
		{"/search", mustRequest("http://localhost/search?q=net"), "search-package"},
	}
	for _, test := range tests {
		t.Run(test.want, func(t *testing.T) {
			if got := TagRoute(test.route, test.req); got != test.want {
				t.Errorf("TagRoute(%q, %v) = %q, want %q", test.route, test.req, got, test.want)
			}
		})
	}
}

func TestCheckTemplates(t *testing.T) {
	// Perform additional checks on parsed templates.
	staticFS := template.TrustedFSFromEmbed(static.FS)
	templates, err := parsePageTemplates(staticFS)
	if err != nil {
		t.Fatal(err)
	}
	for _, c := range []struct {
		name    string
		subs    []string
		typeval any
	}{
		{"badge", nil, badgePage{}},
		// error.tmpl omitted because relies on an associated "message" template
		// that's parsed on demand; see renderErrorPage above.
		{"fetch", nil, page.ErrorPage{}},
		{"homepage", nil, homepage{}},
		{"license-policy", nil, licensePolicyPage{}},
		{"search", nil, SearchPage{}},
		{"search-help", nil, page.BasePage{}},
		{"unit/main", nil, UnitPage{}},
		{
			"unit/main",
			[]string{"unit-outline", "unit-readme", "unit-doc", "unit-files", "unit-directories"},
			MainDetails{},
		},
		{"unit/importedby", nil, UnitPage{}},
		{"unit/importedby", []string{"importedby"}, ImportedByDetails{}},
		{"unit/imports", nil, UnitPage{}},
		{"unit/imports", []string{"imports"}, ImportsDetails{}},
		{"unit/licenses", nil, UnitPage{}},
		{"unit/licenses", []string{"licenses"}, LicensesDetails{}},
		{"unit/versions", nil, UnitPage{}},
		{"unit/versions", []string{"versions"}, versions.VersionsDetails{}},
		{"vuln", nil, page.BasePage{}},
		{"vuln/list", nil, VulnListPage{}},
		{"vuln/entry", nil, VulnEntryPage{}},
	} {
		t.Run(c.name, func(t *testing.T) {
			tm := templates[c.name]
			if tm == nil {
				t.Fatalf("no template %q", c.name)
			}
			if c.subs == nil {
				if err := templatecheck.CheckSafe(tm, c.typeval); err != nil {
					t.Fatal(err)
				}
			} else {
				for _, n := range c.subs {
					s := tm.Lookup(n)
					if s == nil {
						t.Fatalf("no sub-template %q of %q", n, c.name)
					}
					if err := templatecheck.CheckSafe(s, c.typeval); err != nil {
						t.Fatalf("%s: %v", n, err)
					}
				}
			}
		})
	}
}

func TestStripScheme(t *testing.T) {
	for _, test := range []struct {
		url, want string
	}{
		{"http://github.com", "github.com"},
		{"https://github.com/path/to/something", "github.com/path/to/something"},
		{"example.com", "example.com"},
		{"chrome-extension://abcd", "abcd"},
		{"nonwellformed.com/path?://query=1", "query=1"},
	} {
		if got := stripScheme(test.url); got != test.want {
			t.Errorf("%q: got %q, want %q", test.url, got, test.want)
		}
	}
}

func TestInstallFS(t *testing.T) {
	s, handler := newTestServer(t, nil)
	s.InstallFS("/dir", os.DirFS("."))
	// Request this file.
	w := httptest.NewRecorder()
	handler.ServeHTTP(w, httptest.NewRequest("GET", "/files/dir/frontend_test.go", nil))
	if w.Code != http.StatusOK {
		t.Errorf("got status code = %d, want %d", w.Code, http.StatusOK)
	}
	if want := "TestInstallFS"; !strings.Contains(w.Body.String(), want) {
		t.Errorf("body does not contain %q", want)
	}
}