package wkapi

import (
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"sync/atomic"
	"testing"
)

func TestSendMessageRetriesRetryRequiredWithSameClientMessageNumber(t *testing.T) {
	var attempts atomic.Int32
	var clientMsgNo string
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/message/send" {
			t.Fatalf("path = %s, want /message/send", r.URL.Path)
		}
		var got SendMessageRequest
		if err := json.NewDecoder(r.Body).Decode(&got); err != nil {
			t.Fatalf("decode request: %v", err)
		}
		if clientMsgNo == "" {
			clientMsgNo = got.ClientMsgNo
		} else if got.ClientMsgNo != clientMsgNo {
			t.Fatalf("client_msg_no = %q, want stable %q", got.ClientMsgNo, clientMsgNo)
		}
		if attempts.Add(1) <= 2 {
			w.WriteHeader(http.StatusServiceUnavailable)
			_, _ = w.Write([]byte(`{"error":"retry required"}`))
			return
		}
		w.Header().Set("Content-Type", "application/json")
		_, _ = w.Write([]byte(`{"message_id":101,"message_seq":7,"reason":1}`))
	}))
	defer server.Close()

	client := New(server.URL)
	response, err := client.SendMessage(SendMessageRequest{
		FromUID: "user_1", ChannelID: "agent_channel", ChannelType: 2,
		ClientMsgNo: "lineup-idempotent-message", Payload: "aGVsbG8=",
	})
	if err != nil {
		t.Fatalf("SendMessage() error = %v", err)
	}
	if response.MessageID != 101 || response.MessageSeq != 7 {
		t.Fatalf("SendMessage() response = %#v", response)
	}
	if got := attempts.Load(); got != 3 {
		t.Fatalf("attempts = %d, want 3", got)
	}
}

func TestSendMessageDoesNotRetryPermanentAPIError(t *testing.T) {
	var attempts atomic.Int32
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		attempts.Add(1)
		w.WriteHeader(http.StatusBadRequest)
		_, _ = w.Write([]byte(`{"error":"invalid request"}`))
	}))
	defer server.Close()

	_, err := New(server.URL).SendMessage(SendMessageRequest{ClientMsgNo: "invalid"})
	if err == nil {
		t.Fatal("SendMessage() error = nil, want permanent error")
	}
	if got := attempts.Load(); got != 1 {
		t.Fatalf("attempts = %d, want 1", got)
	}
}