// Copyright 2021 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 integration

import (
	"context"
	"fmt"
	"os"
	"strings"
	"testing"

	"golang.org/x/net/html"
	"golang.org/x/pkgsite/internal"
	"golang.org/x/pkgsite/internal/experiment"
	"golang.org/x/pkgsite/internal/postgres"
	"golang.org/x/pkgsite/internal/testing/htmlcheck"
)

var (
	in      = htmlcheck.In
	hasText = htmlcheck.HasText
)

func TestFrontendMainPage(t *testing.T) {
	defer postgres.ResetTestDB(testDB, t)
	defer postgres.ResetTestDB(testDB, t)
	for _, exp := range []struct {
		name string
		exps []string
	}{
		{
			"no experiment",
			[]string{
				internal.ExperimentSymbolHistoryMainPage,
			},
		},
		{
			"experiment insert and read symbol_history",
			[]string{
				internal.ExperimentReadSymbolHistory,
				internal.ExperimentSymbolHistoryMainPage,
			},
		},
	} {
		t.Run(exp.name, func(t *testing.T) {
			exps := exp.exps
			processVersions(
				experiment.NewContext(context.Background(), exps...),
				t, testModules)

			const modulePath = "example.com/symbols"
			for _, test := range []struct {
				name, pkgPath string
				want          htmlcheck.Checker
			}{
				{
					"main page symbols - one version all symbols",
					modulePath,
					in("",
						in("#F",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#I1",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#I2",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#Int",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#Num",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#S1",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#S2",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#String",
							in(".Documentation-sinceVersion > .Documentation-sinceVersionVersion", hasText("v1.1.0"))),
						in("#T",
							in(".Documentation-sinceVersion", hasText(""))),
						in("#TF",
							in(".Documentation-sinceVersion", hasText(""))),
					),
				},
				{
					"main page hello - multi GOOS default page",
					modulePath + "/hello",
					// Hello is the only symbol when GOOS is not set, so return the
					// empty string instead of v1.2.0.
					// TODO(https://golang.org/issue/37102): decide whether it makes
					// sense to show the version in this case.
					in("", in("#Hello",
						in(".Documentation-sinceVersion", hasText("")))),
				},
				/*
					TODO: fix flaky test and uncomment
					{
						"main page hello - multi GOOS JS page",
						modulePath + "/hello?GOOS=js",
						in("",
							// HelloJS was introduced in v1.1.0, the earliest version of
							// this package. Omit the version, even though it is not the
							// earliest version of the module.
							in("#HelloJS",
								in(".Documentation-sinceVersion", hasText(""))),
							// Hello is not the only symbol when GOOS=js, so show that
							// it was added in v1.2.0.
							in("#Hello",
								in(".Documentation-sinceVersion", hasText("v1.2.0")))),
					},
				*/
			} {
				t.Run(test.name, func(t *testing.T) {
					urlPath := fmt.Sprintf("/%s", test.pkgPath)
					body := getFrontendPage(t, urlPath, exps...)
					doc, err := html.Parse(strings.NewReader(body))
					if err != nil {
						t.Fatal(err)
					}
					if err := test.want(doc); err != nil {
						if testing.Verbose() {
							html.Render(os.Stdout, doc)
						}
						t.Error(err)
					}
				})
			}
		})
	}
}