package cms

import (
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"reflect"
	"strings"
	"testing"

	"gitea.futuresens.co.uk/futuresens/cmstypes"
)

func TestReadHotelSuccess(t *testing.T) {
	const hotelCode = "gb-test-hotel"

	expected := cmstypes.ReservationSystemRec{}

	server := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			if r.Method != http.MethodPost {
				t.Errorf(
					"expected method %s, got %s",
					http.MethodPost,
					r.Method,
				)
			}

			if r.URL.Path != cmstypes.APIHotelDetails {
				t.Errorf(
					"expected path %q, got %q",
					cmstypes.APIHotelDetails,
					r.URL.Path,
				)
			}

			if contentType := r.Header.Get("Content-Type"); contentType != "application/json" {
				t.Errorf(
					"expected Content-Type application/json, got %q",
					contentType,
				)
			}

			if accept := r.Header.Get("Accept"); accept != "application/json" {
				t.Errorf(
					"expected Accept application/json, got %q",
					accept,
				)
			}

			var request cmstypes.RequestRec

			if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
				t.Errorf("decode request: %v", err)
				http.Error(w, "invalid request", http.StatusBadRequest)
				return
			}

			if request.Auth.ID != hotelCode {
				t.Errorf(
					"expected auth ID %q, got %q",
					hotelCode,
					request.Auth.ID,
				)
			}

			if request.Auth.Hotel != hotelCode {
				t.Errorf(
					"expected auth hotel %q, got %q",
					hotelCode,
					request.Auth.Hotel,
				)
			}

			if request.Auth.APIKey != cmstypes.APIKey {
				t.Errorf(
					"expected API key %q, got %q",
					cmstypes.APIKey,
					request.Auth.APIKey,
				)
			}

			if request.Data != hotelCode {
				t.Errorf(
					"expected request data %q, got %q",
					hotelCode,
					request.Data,
				)
			}

			response := cmstypes.HotelResponseRec{}
			response.Status.Code = cmstypes.StatusSuccessCode
			response.TheHotel.Updated = 1
			response.TheHotel.ReservationSystem = expected

			w.Header().Set("Content-Type", "application/json")

			if err := json.NewEncoder(w).Encode(response); err != nil {
				t.Errorf("encode response: %v", err)
			}
		},
	))
	defer server.Close()

	got, err := ReadHotel(hotelCode, server.URL)
	if err != nil {
		t.Fatalf("ReadHotel returned an unexpected error: %v", err)
	}

	if !reflect.DeepEqual(got, expected) {
		t.Errorf(
			"unexpected reservation system:\ngot:  %+v\nwant: %+v",
			got,
			expected,
		)
	}
}

func TestReadHotelValidation(t *testing.T) {
	tests := []struct {
		name        string
		hotelCode   string
		cmsBaseURL  string
		wantMessage string
	}{
		{
			name:        "empty hotel code",
			hotelCode:   "",
			cmsBaseURL:  "http://example.com",
			wantMessage: "hotel code is empty",
		},
		{
			name:        "empty CMS base URL",
			hotelCode:   "gb-test-hotel",
			cmsBaseURL:  "",
			wantMessage: "CMS base URL is empty",
		},
	}

	for _, test := range tests {
		t.Run(test.name, func(t *testing.T) {
			_, err := ReadHotel(test.hotelCode, test.cmsBaseURL)
			if err == nil {
				t.Fatal("expected an error, got nil")
			}

			if err.Error() != test.wantMessage {
				t.Errorf(
					"expected error %q, got %q",
					test.wantMessage,
					err.Error(),
				)
			}
		})
	}
}

func TestReadHotelNotUpdated(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			response := cmstypes.HotelResponseRec{}
			response.Status.Code = cmstypes.StatusSuccessCode
			response.TheHotel.Updated = -1

			w.Header().Set("Content-Type", "application/json")

			if err := json.NewEncoder(w).Encode(response); err != nil {
				t.Errorf("encode response: %v", err)
			}
		},
	))
	defer server.Close()

	_, err := ReadHotel("gb-test-hotel", server.URL)
	if err == nil {
		t.Fatal("expected an error, got nil")
	}

	const expected = "hotel record not updated since last read"

	if err.Error() != expected {
		t.Errorf("expected error %q, got %q", expected, err.Error())
	}
}

func TestReadHotelHTTPError(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			w.WriteHeader(http.StatusInternalServerError)

			if _, err := io.WriteString(w, "CMS unavailable"); err != nil {
				t.Errorf("write response: %v", err)
			}
		},
	))
	defer server.Close()

	_, err := ReadHotel("gb-test-hotel", server.URL)
	if err == nil {
		t.Fatal("expected an error, got nil")
	}

	if !strings.Contains(err.Error(), "HTTP 500 Internal Server Error") {
		t.Errorf("unexpected error: %v", err)
	}

	if !strings.Contains(err.Error(), "CMS unavailable") {
		t.Errorf("expected response body in error, got: %v", err)
	}
}

func TestReadHotelInvalidJSON(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			w.Header().Set("Content-Type", "application/json")

			if _, err := io.WriteString(w, `{invalid JSON`); err != nil {
				t.Errorf("write response: %v", err)
			}
		},
	))
	defer server.Close()

	_, err := ReadHotel("gb-test-hotel", server.URL)
	if err == nil {
		t.Fatal("expected an error, got nil")
	}

	if !strings.Contains(err.Error(), "unmarshal CMS hotel response") {
		t.Errorf("unexpected error: %v", err)
	}
}