package ref

import (
	"io"
	"net/http"
	"net/http/cookiejar"
	"net/http/httptest"
	"net/url"
	"regexp"
	"strings"
	"testing"
)

func newTestServer(t *testing.T) *httptest.Server {
	t.Helper()
	srv := httptest.NewUnstartedServer(nil)
	srv.Start()
	srv.Config.Handler = NewApp(srv.URL, "../../../shared")
	t.Cleanup(srv.Close)
	return srv
}

func client(t *testing.T) *http.Client {
	t.Helper()
	jar, _ := cookiejar.New(nil)
	return &http.Client{
		Jar:           jar,
		CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse },
	}
}

func post(t *testing.T, c *http.Client, srv *httptest.Server, path string, form url.Values, origin string) *http.Response {
	t.Helper()
	req, _ := http.NewRequest("POST", srv.URL+path, strings.NewReader(form.Encode()))
	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
	if origin != "" {
		req.Header.Set("Origin", origin)
	}
	res, err := c.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	res.Body.Close()
	return res
}

func get(t *testing.T, c *http.Client, srv *httptest.Server, path string) (int, string) {
	t.Helper()
	res, err := c.Get(srv.URL + path)
	if err != nil {
		t.Fatal(err)
	}
	defer res.Body.Close()
	b, _ := io.ReadAll(res.Body)
	return res.StatusCode, string(b)
}

var liRe = regexp.MustCompile(`<li[^>]*data-id="([^"]+)"`)

func ids(body string) []string {
	var out []string
	for _, m := range liRe.FindAllStringSubmatch(body, -1) {
		out = append(out, m[1])
	}
	return out
}

func TestAddRedirectsToFilter(t *testing.T) {
	srv := newTestServer(t)
	c := client(t)
	get(t, c, srv, "/")
	res := post(t, c, srv, "/todos", url.Values{"title": {" a "}, "filter": {"active"}}, srv.URL)
	if res.StatusCode != 303 || res.Header.Get("Location") != "/active" {
		t.Fatalf("got %d %q, want 303 /active", res.StatusCode, res.Header.Get("Location"))
	}
	_, body := get(t, c, srv, "/")
	if n := len(ids(body)); n != 1 {
		t.Fatalf("want 1 item, got %d", n)
	}
	if !strings.Contains(body, "<label>a</label>") {
		t.Fatalf("want trimmed label 'a'")
	}
}

func TestForeignOriginForbidden(t *testing.T) {
	srv := newTestServer(t)
	c := client(t)
	get(t, c, srv, "/")
	res := post(t, c, srv, "/todos", url.Values{"title": {"x"}}, "https://evil.example")
	if res.StatusCode != 403 {
		t.Fatalf("got %d, want 403", res.StatusCode)
	}
}

func TestOtherListIDNotFound(t *testing.T) {
	srv := newTestServer(t)
	a, b := client(t), client(t)
	get(t, a, srv, "/")
	get(t, b, srv, "/")
	post(t, a, srv, "/todos", url.Values{"title": {"mine"}}, srv.URL)
	_, body := get(t, a, srv, "/")
	id := ids(body)[0]
	res := post(t, b, srv, "/todos/"+id+"/toggle", nil, srv.URL)
	if res.StatusCode != 404 {
		t.Fatalf("got %d, want 404", res.StatusCode)
	}
	_, body = get(t, a, srv, "/completed")
	if len(ids(body)) != 0 {
		t.Fatalf("A's item was toggled by B")
	}
}

func TestGarbledCookieGetsEmptyList(t *testing.T) {
	srv := newTestServer(t)
	req, _ := http.NewRequest("GET", srv.URL+"/", nil)
	req.Header.Set("Cookie", "todo=%%%")
	res, err := http.DefaultClient.Do(req)
	if err != nil {
		t.Fatal(err)
	}
	b, _ := io.ReadAll(res.Body)
	res.Body.Close()
	if res.StatusCode != 200 || len(ids(string(b))) != 0 {
		t.Fatalf("got %d with %d items", res.StatusCode, len(ids(string(b))))
	}
}