package gameapi

import (
	"io"
	"log/slog"
	"net/http"
	"strconv"
	"strings"
	"time"

	gamev1 "hyapp.local/api/proto/game/v1"
	userv1 "hyapp.local/api/proto/user/v1"
	"hyapp/pkg/appcode"
	"hyapp/pkg/logx"
	"hyapp/pkg/xerr"
	"hyapp/services/gateway-service/internal/auth"
	"hyapp/services/gateway-service/internal/transport/http/httpkit"
)

const (
	diceAccessTokenRenewBefore = 10 * time.Minute
	hyappAccessTokenHeader     = "X-Hyapp-Access-Token"
	hyappTokenTypeHeader       = "X-Hyapp-Token-Type"
	hyappExpiresInHeader       = "X-Hyapp-Expires-In"
)

func (h *Handler) listGames(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil || h.userProfileClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	userID := auth.UserIDFromContext(request.Context())
	userResp, err := h.userProfileClient.GetUser(request.Context(), &userv1.GetUserRequest{
		Meta:   httpkit.UserMeta(request, ""),
		UserId: userID,
	})
	if err != nil {
		httpkit.WriteRPCError(writer, request, err)
		return
	}
	resp, err := h.gameClient.ListGames(request.Context(), &gamev1.ListGamesRequest{
		Meta:           gameMeta(request),
		UserId:         userID,
		Scene:          strings.TrimSpace(request.URL.Query().Get("scene")),
		RoomId:         strings.TrimSpace(request.URL.Query().Get("room_id")),
		RegionId:       userResp.GetUser().GetRegionId(),
		Language:       requestLanguage(request),
		ClientPlatform: httpkit.FirstHeader(request, "X-App-Platform", "X-Platform"),
	})
	httpkit.Write(writer, request, gameListDataFromProto(resp), err)
}

func (h *Handler) listRecentGames(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil || h.userProfileClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	pageSize, ok := recentGamePageSize(request)
	if !ok {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	userID := auth.UserIDFromContext(request.Context())
	userResp, err := h.userProfileClient.GetUser(request.Context(), &userv1.GetUserRequest{
		Meta:   httpkit.UserMeta(request, ""),
		UserId: userID,
	})
	if err != nil {
		httpkit.WriteRPCError(writer, request, err)
		return
	}
	// 最近常玩仍传 scene、room、region、language 和 platform，让 game-service 在真实启动记录之外，
	// 继续按当前房间场景和用户区域过滤，避免 App 展示用户已不能进入的游戏。
	resp, err := h.gameClient.ListRecentGames(request.Context(), &gamev1.ListRecentGamesRequest{
		Meta:           gameMeta(request),
		UserId:         userID,
		Scene:          strings.TrimSpace(request.URL.Query().Get("scene")),
		RoomId:         strings.TrimSpace(request.URL.Query().Get("room_id")),
		RegionId:       userResp.GetUser().GetRegionId(),
		Language:       requestLanguage(request),
		ClientPlatform: httpkit.FirstHeader(request, "X-App-Platform", "X-Platform"),
		PageSize:       pageSize,
	})
	httpkit.Write(writer, request, gameListDataFromProto(resp), err)
}

func (h *Handler) getBridgeScript(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	// 桥接脚本配置是 App 级启动预热信息，不依赖房间和用户区域；保持接口轻量，避免拖慢进 App 主流程。
	resp, err := h.gameClient.GetBridgeScript(request.Context(), &gamev1.GetBridgeScriptRequest{
		Meta: gameMeta(request),
	})
	httpkit.Write(writer, request, gameBridgeScriptDataFromProto(resp), err)
}

func (h *Handler) launchGame(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil || h.userProfileClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	gameID := strings.TrimSpace(request.PathValue("game_id"))
	if gameID == "" {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	var body struct {
		Scene  string `json:"scene"`
		RoomID string `json:"room_id"`
	}
	if !httpkit.Decode(writer, request, &body) {
		return
	}
	userID := auth.UserIDFromContext(request.Context())
	userResp, err := h.userProfileClient.GetUser(request.Context(), &userv1.GetUserRequest{
		Meta:   httpkit.UserMeta(request, ""),
		UserId: userID,
	})
	if err != nil {
		httpkit.WriteRPCError(writer, request, err)
		return
	}
	resp, err := h.gameClient.LaunchGame(request.Context(), &gamev1.LaunchGameRequest{
		Meta:          gameMeta(request),
		UserId:        userID,
		DisplayUserId: userResp.GetUser().GetDisplayUserId(),
		GameId:        gameID,
		Scene:         body.Scene,
		RoomId:        body.RoomID,
		AccessToken:   bearerAccessToken(request),
	})
	httpkit.Write(writer, request, gameLaunchDataFromProto(resp), err)
}

func (h *Handler) getDiceConfig(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	gameID := strings.TrimSpace(request.URL.Query().Get("game_id"))
	if gameID == "" {
		gameID = "dice"
	}
	// 配置接口只返回当前 App 的可下注档位和费率，不接受客户端传 app_code。
	resp, err := h.gameClient.GetDiceConfig(request.Context(), &gamev1.GetDiceConfigRequest{
		Meta:   gameMeta(request),
		GameId: gameID,
	})
	if err == nil {
		h.renewDiceAccessTokenIfNeeded(writer, request)
	}
	httpkit.Write(writer, request, diceConfigDataFromProto(resp), err)
}

func (h *Handler) matchDice(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil || h.userProfileClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	var body struct {
		GameID    string `json:"game_id"`
		RoomID    string `json:"room_id"`
		StakeCoin int64  `json:"stake_coin"`
	}
	if !httpkit.Decode(writer, request, &body) {
		return
	}
	if strings.TrimSpace(body.GameID) == "" {
		body.GameID = "dice"
	}
	if body.StakeCoin <= 0 {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	userID := auth.UserIDFromContext(request.Context())
	userResp, err := h.userProfileClient.GetUser(request.Context(), &userv1.GetUserRequest{
		Meta:   httpkit.UserMeta(request, ""),
		UserId: userID,
	})
	if err != nil {
		httpkit.WriteRPCError(writer, request, err)
		return
	}
	resp, err := h.gameClient.MatchDice(request.Context(), &gamev1.MatchDiceRequest{
		Meta:      gameMeta(request),
		UserId:    userID,
		GameId:    strings.TrimSpace(body.GameID),
		RoomId:    strings.TrimSpace(body.RoomID),
		RegionId:  userResp.GetUser().GetRegionId(),
		StakeCoin: body.StakeCoin,
	})
	h.writeDiceMatch(writer, request, resp, err)
}

func (h *Handler) createDiceMatch(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil || h.userProfileClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	// gateway 只接受 H5 的展示输入；user_id、region_id、app_code 和 request_id 都由网关上下文补齐。
	var body struct {
		GameID     string `json:"game_id"`
		RoomID     string `json:"room_id"`
		StakeCoin  int64  `json:"stake_coin"`
		MinPlayers int32  `json:"min_players"`
		MaxPlayers int32  `json:"max_players"`
	}
	if !httpkit.Decode(writer, request, &body) {
		return
	}
	if strings.TrimSpace(body.GameID) == "" || body.StakeCoin <= 0 {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	userID := auth.UserIDFromContext(request.Context())
	userResp, err := h.userProfileClient.GetUser(request.Context(), &userv1.GetUserRequest{
		Meta:   httpkit.UserMeta(request, ""),
		UserId: userID,
	})
	if err != nil {
		httpkit.WriteRPCError(writer, request, err)
		return
	}
	// region_id 来自 user-service 当前用户资料，不信任客户端 body，避免跨区域创建可结算局。
	resp, err := h.gameClient.CreateDiceMatch(request.Context(), &gamev1.CreateDiceMatchRequest{
		Meta:       gameMeta(request),
		UserId:     userID,
		GameId:     strings.TrimSpace(body.GameID),
		RoomId:     strings.TrimSpace(body.RoomID),
		RegionId:   userResp.GetUser().GetRegionId(),
		StakeCoin:  body.StakeCoin,
		MinPlayers: body.MinPlayers,
		MaxPlayers: body.MaxPlayers,
	})
	h.writeDiceMatch(writer, request, resp, err)
}

func (h *Handler) joinDiceMatch(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	matchID := strings.TrimSpace(request.PathValue("match_id"))
	if matchID == "" {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	// join 不接受 body 里的 user_id 或 stake_coin；参与者身份来自 JWT，押注金额来自 match 当前事实。
	resp, err := h.gameClient.JoinDiceMatch(request.Context(), &gamev1.JoinDiceMatchRequest{
		Meta:    gameMeta(request),
		UserId:  auth.UserIDFromContext(request.Context()),
		MatchId: matchID,
	})
	h.writeDiceMatch(writer, request, resp, err)
}

func (h *Handler) getDiceMatch(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	matchID := strings.TrimSpace(request.PathValue("match_id"))
	if matchID == "" {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	// 查询接口只是透传当前局事实，前端轮询或 IM 事件后的刷新都可以复用这条路径。
	resp, err := h.gameClient.GetDiceMatch(request.Context(), &gamev1.GetDiceMatchRequest{
		Meta:    gameMeta(request),
		UserId:  auth.UserIDFromContext(request.Context()),
		MatchId: matchID,
	})
	h.writeDiceMatch(writer, request, resp, err)
}

func (h *Handler) rollDiceMatch(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	matchID := strings.TrimSpace(request.PathValue("match_id"))
	if matchID == "" {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	// roll 不接收骰子点数、结果或派奖金额；这些全部由 game-service 服务端随机和结算。
	resp, err := h.gameClient.RollDiceMatch(request.Context(), &gamev1.RollDiceMatchRequest{
		Meta:    gameMeta(request),
		UserId:  auth.UserIDFromContext(request.Context()),
		MatchId: matchID,
	})
	h.writeDiceMatch(writer, request, resp, err)
}

func (h *Handler) cancelDiceMatch(writer http.ResponseWriter, request *http.Request) {
	if h.gameClient == nil {
		httpkit.WriteError(writer, request, http.StatusBadGateway, httpkit.CodeUpstreamError, "upstream service error")
		return
	}
	matchID := strings.TrimSpace(request.PathValue("match_id"))
	if matchID == "" {
		httpkit.WriteError(writer, request, http.StatusBadRequest, httpkit.CodeInvalidArgument, "invalid argument")
		return
	}
	resp, err := h.gameClient.CancelDiceMatch(request.Context(), &gamev1.CancelDiceMatchRequest{
		Meta:    gameMeta(request),
		UserId:  auth.UserIDFromContext(request.Context()),
		MatchId: matchID,
	})
	h.writeDiceMatch(writer, request, resp, err)
}

func (h *Handler) writeDiceMatch(writer http.ResponseWriter, request *http.Request, resp *gamev1.DiceMatchResponse, err error) {
	if err != nil {
		httpkit.Write(writer, request, diceMatchData{}, err)
		return
	}
	data := diceMatchDataFromProto(resp)
	h.enrichDiceMatchParticipants(request, &data.Match)
	h.renewDiceAccessTokenIfNeeded(writer, request)
	httpkit.Write(writer, request, data, nil)
}

func (h *Handler) renewDiceAccessTokenIfNeeded(writer http.ResponseWriter, request *http.Request) {
	if h.userAuthClient == nil {
		return
	}
	expiresAtMS := auth.AccessTokenExpiresAtMSFromContext(request.Context())
	if expiresAtMS <= 0 || time.Until(time.UnixMilli(expiresAtMS)) > diceAccessTokenRenewBefore {
		// 旧测试 token 或距离过期还很久的 token 不做续签，避免每秒轮询把 user-service 和登录审计打满。
		return
	}
	sessionID := auth.SessionIDFromContext(request.Context())
	if strings.TrimSpace(sessionID) == "" {
		return
	}
	resp, err := h.userAuthClient.AppHeartbeat(request.Context(), &userv1.AppHeartbeatRequest{
		Meta:      httpkit.UserMeta(request, httpkit.FirstHeader(request, "X-Device-ID", "X-HY-Device-ID")),
		UserId:    auth.UserIDFromContext(request.Context()),
		SessionId: sessionID,
	})
	if err != nil {
		// 游戏事实响应已经成功，续签失败只记录日志；客户端下一次仍可走 refresh token 兜底。
		logx.Warn(request.Context(), "dice_access_token_renew_failed", slog.String("component", "gateway_game"), slog.String("session_id", sessionID), slog.String("error", err.Error()))
		return
	}
	token := resp.GetToken()
	accessToken := strings.TrimSpace(token.GetAccessToken())
	if accessToken == "" {
		return
	}
	writer.Header().Set(hyappAccessTokenHeader, accessToken)
	writer.Header().Set(hyappTokenTypeHeader, strings.TrimSpace(token.GetTokenType()))
	writer.Header().Set(hyappExpiresInHeader, strconv.FormatInt(token.GetExpiresInSec(), 10))
}

func (h *Handler) handleGameCallback(writer http.ResponseWriter, request *http.Request) {
	raw, err := io.ReadAll(request.Body)
	if err != nil {
		http.Error(writer, "invalid request body", http.StatusBadRequest)
		return
	}
	h.handleGameCallbackRaw(writer, request, raw, strings.TrimSpace(request.PathValue("platform_code")), strings.TrimSpace(request.PathValue("operation")))
}

func (h *Handler) handleGameCallbackRaw(writer http.ResponseWriter, request *http.Request, raw []byte, platformCode string, operation string) {
	if h.gameClient == nil {
		http.Error(writer, "upstream service error", http.StatusBadGateway)
		return
	}
	resp, err := h.gameClient.HandleCallback(request.Context(), &gamev1.CallbackRequest{
		Meta:         gameMeta(request),
		PlatformCode: strings.TrimSpace(platformCode),
		Operation:    strings.TrimSpace(operation),
		RawBody:      raw,
		Headers:      flattenedHeaders(request),
		Query:        flattenedQuery(request),
		RemoteAddr:   request.RemoteAddr,
	})
	if err != nil {
		status := xerr.SpecOf(xerr.ReasonFromGRPC(err)).HTTPStatus
		http.Error(writer, xerr.SpecOf(xerr.ReasonFromGRPC(err)).PublicMessage, status)
		return
	}
	contentType := strings.TrimSpace(resp.GetContentType())
	if contentType == "" {
		contentType = "application/json"
	}
	writer.Header().Set("Content-Type", contentType)
	writer.WriteHeader(http.StatusOK)
	_, _ = writer.Write(resp.GetRawBody())
}

func gameMeta(request *http.Request) *gamev1.RequestMeta {
	return &gamev1.RequestMeta{
		RequestId:     httpkit.RequestIDFromContext(request.Context()),
		Caller:        "gateway-service",
		GatewayNodeId: "",
		ActorUserId:   auth.UserIDFromContext(request.Context()),
		SentAtMs:      time.Now().UnixMilli(),
		AppCode:       appcode.FromContext(request.Context()),
	}
}

func requestLanguage(request *http.Request) string {
	value := httpkit.FirstHeader(request, "X-App-Language", "X-Language")
	if value == "" {
		value = request.Header.Get("Accept-Language")
	}
	if index := strings.Index(value, ","); index >= 0 {
		value = value[:index]
	}
	return strings.TrimSpace(value)
}

func recentGamePageSize(request *http.Request) (int32, bool) {
	if strings.TrimSpace(request.URL.Query().Get("limit")) != "" {
		return httpkit.PositiveInt32Query(request, "limit", 4)
	}
	return httpkit.PositiveInt32Query(request, "page_size", 4)
}

func bearerAccessToken(request *http.Request) string {
	header := strings.TrimSpace(request.Header.Get("Authorization"))
	if !strings.HasPrefix(header, "Bearer ") {
		return ""
	}
	return strings.TrimSpace(strings.TrimPrefix(header, "Bearer "))
}

func flattenedHeaders(request *http.Request) map[string]string {
	headers := make(map[string]string, len(request.Header))
	for key, values := range request.Header {
		if len(values) > 0 {
			headers[key] = values[0]
		}
	}
	return headers
}

func flattenedQuery(request *http.Request) map[string]string {
	query := request.URL.Query()
	result := make(map[string]string, len(query))
	for key, values := range query {
		if len(values) > 0 {
			result[key] = values[0]
		}
	}
	return result
}