package internalhttp

import (
	"bytes"
	"context"
	"encoding/json"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	"galaxy/lobby/internal/adapters/gameinmem"
	"galaxy/lobby/internal/domain/common"
	"galaxy/lobby/internal/domain/game"
	"galaxy/lobby/internal/ports"
	"galaxy/lobby/internal/service/cancelgame"
	"galaxy/lobby/internal/service/creategame"
	"galaxy/lobby/internal/service/openenrollment"
	"galaxy/lobby/internal/service/updategame"

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

type stubIDGenerator struct {
	next common.GameID
}

func (g *stubIDGenerator) NewGameID() (common.GameID, error) {
	return g.next, nil
}

func (g *stubIDGenerator) NewApplicationID() (common.ApplicationID, error) {
	return "application-stub", nil
}

func (g *stubIDGenerator) NewInviteID() (common.InviteID, error) {
	return "invite-stub", nil
}

func (g *stubIDGenerator) NewMembershipID() (common.MembershipID, error) {
	return "membership-stub", nil
}

func silentLogger() *slog.Logger {
	return slog.New(slog.NewTextHandler(io.Discard, nil))
}

func fixedClock(at time.Time) func() time.Time {
	return func() time.Time { return at }
}

func buildHandler(t *testing.T, store *gameinmem.Store, ids ports.IDGenerator, clock func() time.Time) http.Handler {
	t.Helper()

	logger := silentLogger()

	createSvc, err := creategame.NewService(creategame.Dependencies{
		Games:  store,
		IDs:    ids,
		Clock:  clock,
		Logger: logger,
	})
	require.NoError(t, err)
	updateSvc, err := updategame.NewService(updategame.Dependencies{
		Games:  store,
		Clock:  clock,
		Logger: logger,
	})
	require.NoError(t, err)
	openSvc, err := openenrollment.NewService(openenrollment.Dependencies{
		Games:  store,
		Clock:  clock,
		Logger: logger,
	})
	require.NoError(t, err)
	cancelSvc, err := cancelgame.NewService(cancelgame.Dependencies{
		Games:  store,
		Clock:  clock,
		Logger: logger,
	})
	require.NoError(t, err)

	return newHandler(Dependencies{
		Logger:         logger,
		CreateGame:     createSvc,
		UpdateGame:     updateSvc,
		OpenEnrollment: openSvc,
		CancelGame:     cancelSvc,
	}, logger)
}

func doRequest(t *testing.T, handler http.Handler, method, path string, body any) *httptest.ResponseRecorder {
	t.Helper()

	var reader io.Reader
	if body != nil {
		data, err := json.Marshal(body)
		require.NoError(t, err)
		reader = bytes.NewReader(data)
	}

	req := httptest.NewRequestWithContext(context.Background(), method, path, reader)
	if reader != nil {
		req.Header.Set("Content-Type", "application/json")
	}

	rec := httptest.NewRecorder()
	handler.ServeHTTP(rec, req)
	return rec
}

func decodeGameRecord(t *testing.T, rec *httptest.ResponseRecorder) gameRecordResponse {
	t.Helper()

	var payload gameRecordResponse
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &payload))
	return payload
}

func decodeError(t *testing.T, rec *httptest.ResponseRecorder) errorResponse {
	t.Helper()

	var payload errorResponse
	require.NoError(t, json.Unmarshal(rec.Body.Bytes(), &payload))
	return payload
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gameinmem.NewStore()
	handler := buildHandler(t, store, &stubIDGenerator{next: "game-public"}, fixedClock(now))

	body := createGameRequest{
		GameName:            "Winter Open",
		GameType:            "public",
		MinPlayers:          4,
		MaxPlayers:          8,
		StartGapHours:       6,
		StartGapPlayers:     2,
		EnrollmentEndsAt:    now.Add(48 * time.Hour).Unix(),
		TurnSchedule:        "0 */4 * * *",
		TargetEngineVersion: "2.0.0",
	}
	rec := doRequest(t, handler, http.MethodPost, "/api/v1/lobby/games", body)
	require.Equal(t, http.StatusCreated, rec.Code)

	decoded := decodeGameRecord(t, rec)
	require.Equal(t, "public", decoded.GameType)
	require.Equal(t, "", decoded.OwnerUserID)
	require.Equal(t, "draft", decoded.Status)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	handler := buildHandler(t, gameinmem.NewStore(), &stubIDGenerator{next: "game-priv"}, fixedClock(now))

	body := createGameRequest{
		GameName:            "Private Lobby",
		GameType:            "private",
		MinPlayers:          2,
		MaxPlayers:          4,
		StartGapHours:       4,
		StartGapPlayers:     1,
		EnrollmentEndsAt:    now.Add(time.Hour).Unix(),
		TurnSchedule:        "0 0 * * *",
		TargetEngineVersion: "1.0.0",
	}
	rec := doRequest(t, handler, http.MethodPost, "/api/v1/lobby/games", body)
	require.Equal(t, http.StatusForbidden, rec.Code)
	decoded := decodeError(t, rec)
	require.Equal(t, "forbidden", decoded.Error.Code)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	handler := buildHandler(t, gameinmem.NewStore(), &stubIDGenerator{next: "game-bad"}, fixedClock(now))

	body := createGameRequest{
		GameName:            "",
		GameType:            "public",
		MinPlayers:          2,
		MaxPlayers:          4,
		StartGapHours:       4,
		StartGapPlayers:     1,
		EnrollmentEndsAt:    now.Add(time.Hour).Unix(),
		TurnSchedule:        "0 0 * * *",
		TargetEngineVersion: "1.0.0",
	}
	rec := doRequest(t, handler, http.MethodPost, "/api/v1/lobby/games", body)
	require.Equal(t, http.StatusBadRequest, rec.Code)
	decoded := decodeError(t, rec)
	require.Equal(t, "invalid_request", decoded.Error.Code)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gameinmem.NewStore()
	seedDraftForTest(t, store, "game-u", game.GameTypePublic, "", now)

	handler := buildHandler(t, store, &stubIDGenerator{next: "unused"}, fixedClock(now.Add(time.Hour)))

	desc := "Updated by admin"
	body := updateGameRequest{Description: &desc}
	rec := doRequest(t, handler, http.MethodPatch, "/api/v1/lobby/games/game-u", body)
	require.Equal(t, http.StatusOK, rec.Code)
	decoded := decodeGameRecord(t, rec)
	require.Equal(t, "Updated by admin", decoded.Description)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gameinmem.NewStore()
	seedDraftForTest(t, store, "game-oe", game.GameTypePublic, "", now)

	handler := buildHandler(t, store, &stubIDGenerator{next: "unused"}, fixedClock(now.Add(time.Hour)))

	rec := doRequest(t, handler, http.MethodPost, "/api/v1/lobby/games/game-oe/open-enrollment", nil)
	require.Equal(t, http.StatusOK, rec.Code)
	decoded := decodeGameRecord(t, rec)
	require.Equal(t, "enrollment_open", decoded.Status)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	store := gameinmem.NewStore()
	record := seedDraftForTest(t, store, "game-run", game.GameTypePublic, "", now)
	// Force status to running to exercise the 409 conflict path.
	record.Status = game.StatusRunning
	startedAt := now.Add(time.Minute)
	record.StartedAt = &startedAt
	record.UpdatedAt = startedAt
	require.NoError(t, store.Save(context.Background(), record))

	handler := buildHandler(t, store, &stubIDGenerator{next: "unused"}, fixedClock(now.Add(time.Hour)))

	rec := doRequest(t, handler, http.MethodPost, "/api/v1/lobby/games/game-run/cancel", nil)
	require.Equal(t, http.StatusConflict, rec.Code)
	decoded := decodeError(t, rec)
	require.Equal(t, "conflict", decoded.Error.Code)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	handler := buildHandler(t, gameinmem.NewStore(), &stubIDGenerator{next: "unused"}, fixedClock(now))

	desc := "x"
	body := updateGameRequest{Description: &desc}
	rec := doRequest(t, handler, http.MethodPatch, "/api/v1/lobby/games/game-missing", body)
	require.Equal(t, http.StatusNotFound, rec.Code)
}

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

	now := time.Date(2026, 4, 24, 10, 0, 0, 0, time.UTC)
	handler := buildHandler(t, gameinmem.NewStore(), &stubIDGenerator{next: "unused"}, fixedClock(now))

	reqBody := map[string]any{
		"game_name":             "x",
		"game_type":             "public",
		"min_players":           2,
		"max_players":           4,
		"start_gap_hours":       4,
		"start_gap_players":     1,
		"enrollment_ends_at":    now.Add(time.Hour).Unix(),
		"turn_schedule":         "0 0 * * *",
		"target_engine_version": "1.0.0",
		"unexpected":            "nope",
	}
	rec := doRequest(t, handler, http.MethodPost, "/api/v1/lobby/games", reqBody)
	require.Equal(t, http.StatusBadRequest, rec.Code)
}

func seedDraftForTest(
	t *testing.T,
	store *gameinmem.Store,
	id common.GameID,
	gameType game.GameType,
	ownerUserID string,
	now time.Time,
) game.Game {
	t.Helper()

	record, err := game.New(game.NewGameInput{
		GameID:              id,
		GameName:            "Seed",
		GameType:            gameType,
		OwnerUserID:         ownerUserID,
		MinPlayers:          2,
		MaxPlayers:          4,
		StartGapHours:       4,
		StartGapPlayers:     1,
		EnrollmentEndsAt:    now.Add(24 * time.Hour),
		TurnSchedule:        "0 */6 * * *",
		TargetEngineVersion: "1.0.0",
		Now:                 now,
	})
	require.NoError(t, err)
	require.NoError(t, store.Save(context.Background(), record))
	return record
}