package gonexapp_test

import (
	"context"
	"encoding/base64"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/chromedp/cdproto/network"
	"github.com/chromedp/chromedp"

	"gitea.neitzel.de/konrad/go-nc-exapp"
)

const browserLanguage = "de-DE,de;q=0.9"

func TestUILanguageChrome(t *testing.T) {
	german := chromeSeen{
		lang: "de", open: "Navigation öffnen", close: "Navigation schließen",
		fold: "Domains einklappen", cancel: "Abbrechen", ok: "OK",
	}
	english := chromeSeen{
		lang: "en", open: "Open navigation", close: "Close navigation",
		fold: "Fold Domains", cancel: "Cancel", ok: "OK",
	}
	tests := []struct {
		name   string
		user   bool
		status int
		ncLang string
		want   chromeSeen
	}{
		{name: "german", user: true, status: http.StatusOK, ncLang: "de", want: german},
		{name: "english", user: true, status: http.StatusOK, ncLang: "en", want: english},
		{name: "formal german", user: true, status: http.StatusOK, ncLang: "de_DE", want: german},
		{name: "british english", user: true, status: http.StatusOK, ncLang: "en_GB", want: english},
		{name: "french", user: true, status: http.StatusOK, ncLang: "fr", want: english},
		{name: "failed read", user: true, status: http.StatusInternalServerError, ncLang: "de", want: english},
		{name: "missing user", user: false, status: http.StatusOK, ncLang: "de", want: english},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			nc := fakeLanguage(tt.status, tt.ncLang)
			t.Cleanup(nc.Close)
			page := languagePage(nc.URL)
			t.Cleanup(page.Close)

			headers := network.Headers{"Accept-Language": browserLanguage}
			if tt.user {
				headers["AUTHORIZATION-APP-API"] = base64.StdEncoding.EncodeToString([]byte("alice:secret"))
			}
			got := readChrome(t, page.URL+"/?item=domains", headers)
			if !strings.Contains(got.page, "domains-page") {
				t.Fatalf("page did not render: %+v", got)
			}
			if got.lang != tt.want.lang || got.open != tt.want.open || got.close != tt.want.close ||
				got.fold != tt.want.fold || got.cancel != tt.want.cancel || got.ok != tt.want.ok || got.agree != "Remove" {
				t.Fatalf("got %+v, want %+v with agree %q", got, tt.want, "Remove")
			}
		})
	}
}

type chromeSeen struct {
	lang   string
	open   string
	close  string
	fold   string
	cancel string
	ok     string
	agree  string
	page   string
}

func fakeLanguage(status int, language string) *httptest.Server {
	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodGet || !strings.Contains(r.URL.Path, "/cloud/users/") {
			http.NotFound(w, r)
			return
		}
		if status != http.StatusOK {
			http.Error(w, "language unavailable", status)
			return
		}
		// A read that drops the browser language must not look like a hit.
		lang := language
		if r.Header.Get("Accept-Language") != browserLanguage {
			lang = "en"
		}
		// locale differs from language so a read of the wrong field fails the page.
		locale := "fr"
		if language == "fr" || language == "en_GB" {
			locale = "de"
		}
		w.Header().Set("Content-Type", "application/json")
		fmt.Fprintf(w, `{"ocs":{"meta":{"status":"ok","statuscode":200,"message":"OK"},"data":{"language":%q,"locale":%q}}}`, lang, locale)
	}))
}

func languagePage(ncBase string) *httptest.Server {
	nav := sampleNavigation()
	nav.Cred = gonexapp.Credentials{
		BaseURL:    ncBase,
		AppID:      "exapp",
		AppVersion: "1.0.0",
		AAVersion:  "1.0.0",
		AppSecret:  "secret",
	}
	nav.Page = func(_ *http.Request, id string) (string, bool) {
		switch id {
		case "domains":
			return `<p>domains-page</p><button type="button" id="ask">Ask</button>
<script>
document.getElementById("ask").addEventListener("click", function () {
  exappDialog.confirm({ text: "Sure?", agree: "Remove" });
});
</script>`, true
		case "keys":
			return "<p>keys-page</p>", true
		case "example.com":
			return "<p>zone-page</p>", true
		default:
			return "", false
		}
	}
	return httptest.NewServer(nav.Handler())
}

func readChrome(t *testing.T, pageURL string, headers network.Headers) chromeSeen {
	t.Helper()
	ctx, cancel := chromedp.NewContext(allocCtx)
	t.Cleanup(cancel)
	ctx, cancel = context.WithTimeout(ctx, 25*time.Second)
	t.Cleanup(cancel)

	var raw, closeLabel, agree string
	err := chromedp.Run(ctx,
		network.Enable(),
		network.SetExtraHTTPHeaders(headers),
		chromedp.Navigate(pageURL),
		chromedp.Evaluate(chromeProbeJS, &raw),
		chromedp.Evaluate(`document.getElementById("nav-toggle").click()`, nil),
		chromedp.Evaluate(`document.getElementById("nav-toggle").getAttribute("aria-label")`, &closeLabel),
		chromedp.Evaluate(`document.getElementById("ask").click()`, nil),
		chromedp.Evaluate(`document.getElementById("exapp-dialog-agree").textContent`, &agree),
	)
	if err != nil {
		t.Fatal(err)
	}
	var probe struct {
		Lang   string `json:"lang"`
		Open   string `json:"open"`
		Fold   string `json:"fold"`
		Cancel string `json:"cancel"`
		OK     string `json:"ok"`
		Page   string `json:"page"`
	}
	if err := json.Unmarshal([]byte(raw), &probe); err != nil {
		t.Fatal(err)
	}
	return chromeSeen{
		lang: probe.Lang, open: probe.Open, close: closeLabel, fold: probe.Fold,
		cancel: probe.Cancel, ok: probe.OK, agree: agree, page: probe.Page,
	}
}

const chromeProbeJS = `(() => {
  const fold = document.querySelector("button.fold");
  return JSON.stringify({
    lang: document.documentElement.lang,
    open: document.getElementById("nav-toggle").getAttribute("aria-label"),
    fold: fold ? fold.getAttribute("aria-label") : "",
    cancel: document.getElementById("exapp-dialog-cancel").textContent,
    ok: document.getElementById("exapp-dialog-agree").textContent,
    page: document.querySelector("main").textContent
  });
})()`