package lobbyservice_test

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

	"galaxy/gateway/internal/downstream"
	"galaxy/gateway/internal/downstream/lobbyservice"
	lobbymodel "galaxy/model/lobby"
	"galaxy/transcoder"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestExecuteMyGamesListSuccess(t *testing.T) {
	t.Parallel()

	expectedResponse := lobbymodel.MyGamesListResponse{
		Items: []lobbymodel.GameSummary{
			{
				GameID:           "game-1",
				GameName:         "Nebula Clash",
				GameType:         "private",
				Status:           "draft",
				OwnerUserID:      "user-1",
				MinPlayers:       2,
				MaxPlayers:       8,
				EnrollmentEndsAt: time.Date(2026, 5, 1, 12, 0, 0, 0, time.UTC),
				CreatedAt:        time.Date(2026, 4, 28, 9, 0, 0, 0, time.UTC),
				UpdatedAt:        time.Date(2026, 4, 28, 9, 5, 0, 0, time.UTC),
			},
		},
	}

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodGet, r.Method)
		assert.Equal(t, "/api/v1/lobby/my/games", r.URL.Path)
		assert.Equal(t, "user-1", r.Header.Get("X-User-Id"))
		w.Header().Set("Content-Type", "application/json")
		require.NoError(t, json.NewEncoder(w).Encode(expectedResponse))
	}))
	t.Cleanup(server.Close)

	client, err := lobbyservice.NewHTTPClient(server.URL)
	require.NoError(t, err)
	t.Cleanup(func() { require.NoError(t, client.Close()) })

	requestBytes, err := transcoder.MyGamesListRequestToPayload(&lobbymodel.MyGamesListRequest{})
	require.NoError(t, err)

	result, err := client.ExecuteCommand(context.Background(), downstream.AuthenticatedCommand{
		MessageType:  lobbymodel.MessageTypeMyGamesList,
		UserID:       "user-1",
		PayloadBytes: requestBytes,
	})
	require.NoError(t, err)
	assert.Equal(t, "ok", result.ResultCode)

	decoded, err := transcoder.PayloadToMyGamesListResponse(result.PayloadBytes)
	require.NoError(t, err)
	require.Len(t, decoded.Items, 1)
	assert.Equal(t, expectedResponse.Items[0].GameID, decoded.Items[0].GameID)
	assert.Equal(t, expectedResponse.Items[0].OwnerUserID, decoded.Items[0].OwnerUserID)
	assert.Equal(t, expectedResponse.Items[0].MinPlayers, decoded.Items[0].MinPlayers)
}

func TestExecuteOpenEnrollmentSuccess(t *testing.T) {
	t.Parallel()

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		assert.Equal(t, http.MethodPost, r.Method)
		assert.Equal(t, "/api/v1/lobby/games/game-77/open-enrollment", r.URL.Path)
		assert.Equal(t, "owner-1", r.Header.Get("X-User-Id"))
		w.Header().Set("Content-Type", "application/json")
		require.NoError(t, json.NewEncoder(w).Encode(map[string]any{
			"game_id": "game-77",
			"status":  "enrollment_open",
		}))
	}))
	t.Cleanup(server.Close)

	client, err := lobbyservice.NewHTTPClient(server.URL)
	require.NoError(t, err)
	t.Cleanup(func() { require.NoError(t, client.Close()) })

	requestBytes, err := transcoder.OpenEnrollmentRequestToPayload(&lobbymodel.OpenEnrollmentRequest{GameID: "game-77"})
	require.NoError(t, err)

	result, err := client.ExecuteCommand(context.Background(), downstream.AuthenticatedCommand{
		MessageType:  lobbymodel.MessageTypeOpenEnrollment,
		UserID:       "owner-1",
		PayloadBytes: requestBytes,
	})
	require.NoError(t, err)
	assert.Equal(t, "ok", result.ResultCode)

	decoded, err := transcoder.PayloadToOpenEnrollmentResponse(result.PayloadBytes)
	require.NoError(t, err)
	assert.Equal(t, "game-77", decoded.GameID)
	assert.Equal(t, "enrollment_open", decoded.Status)
}

func TestExecuteOpenEnrollmentForbiddenProjectsErrorEnvelope(t *testing.T) {
	t.Parallel()

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusForbidden)
		require.NoError(t, json.NewEncoder(w).Encode(map[string]any{
			"error": map[string]string{
				"code":    "forbidden",
				"message": "only the game owner may open enrollment",
			},
		}))
	}))
	t.Cleanup(server.Close)

	client, err := lobbyservice.NewHTTPClient(server.URL)
	require.NoError(t, err)
	t.Cleanup(func() { require.NoError(t, client.Close()) })

	requestBytes, err := transcoder.OpenEnrollmentRequestToPayload(&lobbymodel.OpenEnrollmentRequest{GameID: "game-77"})
	require.NoError(t, err)

	result, err := client.ExecuteCommand(context.Background(), downstream.AuthenticatedCommand{
		MessageType:  lobbymodel.MessageTypeOpenEnrollment,
		UserID:       "non-owner",
		PayloadBytes: requestBytes,
	})
	require.NoError(t, err)
	assert.Equal(t, "forbidden", result.ResultCode)

	decoded, err := transcoder.PayloadToLobbyErrorResponse(result.PayloadBytes)
	require.NoError(t, err)
	assert.Equal(t, "forbidden", decoded.Error.Code)
	assert.NotEmpty(t, decoded.Error.Message)
}

func TestExecuteCommandUnavailableProjectsErrUnavailable(t *testing.T) {
	t.Parallel()

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		w.WriteHeader(http.StatusServiceUnavailable)
	}))
	t.Cleanup(server.Close)

	client, err := lobbyservice.NewHTTPClient(server.URL)
	require.NoError(t, err)
	t.Cleanup(func() { require.NoError(t, client.Close()) })

	requestBytes, err := transcoder.MyGamesListRequestToPayload(&lobbymodel.MyGamesListRequest{})
	require.NoError(t, err)

	_, err = client.ExecuteCommand(context.Background(), downstream.AuthenticatedCommand{
		MessageType:  lobbymodel.MessageTypeMyGamesList,
		UserID:       "user-1",
		PayloadBytes: requestBytes,
	})
	require.Error(t, err)
	assert.True(t, errors.Is(err, downstream.ErrDownstreamUnavailable))
}

func TestExecuteCommandRejectsEmptyUserID(t *testing.T) {
	t.Parallel()

	client, err := lobbyservice.NewHTTPClient("http://127.0.0.1:1")
	require.NoError(t, err)
	t.Cleanup(func() { require.NoError(t, client.Close()) })

	requestBytes, err := transcoder.MyGamesListRequestToPayload(&lobbymodel.MyGamesListRequest{})
	require.NoError(t, err)

	_, err = client.ExecuteCommand(context.Background(), downstream.AuthenticatedCommand{
		MessageType:  lobbymodel.MessageTypeMyGamesList,
		UserID:       "",
		PayloadBytes: requestBytes,
	})
	require.Error(t, err)
	assert.True(t, strings.Contains(err.Error(), "user_id"), "error must mention user_id; got %q", err.Error())
}

func TestNewRoutesReservesUnavailableClientWhenBaseURLEmpty(t *testing.T) {
	t.Parallel()

	routes, closeFn, err := lobbyservice.NewRoutes("")
	require.NoError(t, err)
	t.Cleanup(func() { require.NoError(t, closeFn()) })

	require.Contains(t, routes, lobbymodel.MessageTypeMyGamesList)
	require.Contains(t, routes, lobbymodel.MessageTypeOpenEnrollment)

	requestBytes, err := transcoder.MyGamesListRequestToPayload(&lobbymodel.MyGamesListRequest{})
	require.NoError(t, err)

	_, err = routes[lobbymodel.MessageTypeMyGamesList].ExecuteCommand(
		context.Background(),
		downstream.AuthenticatedCommand{
			MessageType:  lobbymodel.MessageTypeMyGamesList,
			UserID:       "user-1",
			PayloadBytes: requestBytes,
		},
	)
	require.Error(t, err)
	assert.True(t, errors.Is(err, downstream.ErrDownstreamUnavailable))
}