package telegram

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

	"github.com/kamelion/ratatoskr-go/internal/chat"
)

// fakeTG — тестовый сервер, имитирующий Telegram Bot API.
type fakeTG struct {
	srv    *httptest.Server
	mu     sync.Mutex
	sent   []sendReq
	updCh  chan []update // следующая пачка обновлений
	closed bool
}

type sendReq struct {
	ChatID string `json:"chat_id"`
	Text   string `json:"text"`
}

func newFakeTG(t *testing.T) *fakeTG {
	t.Helper()
	f := &fakeTG{updCh: make(chan []update, 10)}
	mux := http.NewServeMux()
	mux.HandleFunc("/botTOKEN/sendMessage", func(w http.ResponseWriter, r *http.Request) {
		var req sendReq
		json.NewDecoder(r.Body).Decode(&req)
		f.mu.Lock()
		f.sent = append(f.sent, req)
		f.mu.Unlock()
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]bool{"ok": true})
	})
	mux.HandleFunc("/botTOKEN/getUpdates", func(w http.ResponseWriter, r *http.Request) {
		f.mu.Lock()
		upds := []update{}
		if len(f.updCh) > 0 {
			upds = <-f.updCh
		}
		f.mu.Unlock()
		w.Header().Set("Content-Type", "application/json")
		json.NewEncoder(w).Encode(map[string]any{"ok": true, "result": upds})
	})

	f.srv = httptest.NewServer(mux)
	t.Cleanup(f.srv.Close)
	return f
}

func (f *fakeTG) push(text string) {
	msg := message{MessageID: int64(len(f.sent) + 1), Text: text}
	msg.Chat.ID = 123
	f.updCh <- []update{{
		UpdateID: int64(len(f.sent) + 1),
		Message:  &msg,
	}}
}

func TestSend(t *testing.T) {
	f := newFakeTG(t)
	ch := New("TOKEN", time.Second)
	ch.client = f.srv.Client()
	// подменяем baseURL на тестовый
	ch.apiURL = f.srv.URL + "/bot%s/"

	err := ch.Send(context.Background(), "tg://123", chat.Message{Text: "hello"})
	if err != nil {
		t.Fatalf("Send: %v", err)
	}
	if len(f.sent) != 1 {
		t.Fatal("не отправлено")
	}
	if f.sent[0].Text != "hello" {
		t.Errorf("text = %q", f.sent[0].Text)
	}
}

func TestSendWithOptions(t *testing.T) {
	f := newFakeTG(t)
	ch := New("TOKEN", time.Second)
	ch.client = f.srv.Client()
	ch.apiURL = f.srv.URL + "/bot%s/"

	err := ch.Send(context.Background(), "tg://123", chat.Message{
		Text: "Выбери:",
		Options: []chat.Option{
			{ID: "a", Label: "Чай"},
			{ID: "b", Label: "Кофе"},
		},
	})
	if err != nil {
		t.Fatalf("Send: %v", err)
	}
	if !strings.Contains(f.sent[0].Text, "<b>1.</b> Чай") {
		t.Errorf("формат options: %s", f.sent[0].Text)
	}
	if !strings.Contains(f.sent[0].Text, "<b>2.</b> Кофе") {
		t.Errorf("формат options: %s", f.sent[0].Text)
	}
}

func TestIncoming(t *testing.T) {
	f := newFakeTG(t)
	ch := New("TOKEN", time.Second)
	ch.client = f.srv.Client()
	ch.apiURL = f.srv.URL + "/bot%s/"

	incoming := make(chan chat.Incoming, 1)
	ch.OnMessage(func(inc chat.Incoming) {
		incoming <- inc
	})

	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
	defer cancel()

	go ch.Run(ctx)

	f.push("тест")

	select {
	case inc := <-incoming:
		if inc.UserID != "123" {
			t.Errorf("UserID = %q, want 123", inc.UserID)
		}
		if inc.Address != "tg://123" {
			t.Errorf("Address = %q", inc.Address)
		}
		if inc.Msg.Text != "тест" {
			t.Errorf("text = %q", inc.Msg.Text)
		}
	case <-ctx.Done():
		t.Fatal("timeout ожидания входящего")
	}
}