package http

import (
	"encoding/json"
	"net/http"

	roomv1 "hyapp/api/proto/room/v1"
	"hyapp/pkg/idgen"
	"hyapp/services/gateway-service/internal/auth"
	"hyapp/services/gateway-service/internal/client"
)

// Handler 负责把 HTTP JSON 请求转换为 room-service gRPC 调用。
type Handler struct {
	roomClient client.RoomClient
}

// NewHandler 初始化 gateway HTTP 入口。
func NewHandler(roomClient client.RoomClient) *Handler {
	return &Handler{roomClient: roomClient}
}

// Routes 注册首版房间命令 HTTP 接口。
func (h *Handler) Routes(jwtVerifier *auth.Verifier) http.Handler {
	mux := http.NewServeMux()

	mux.Handle("/rooms/create", jwtVerifier.Middleware(http.HandlerFunc(h.createRoom)))
	mux.Handle("/rooms/join", jwtVerifier.Middleware(http.HandlerFunc(h.joinRoom)))
	mux.Handle("/rooms/leave", jwtVerifier.Middleware(http.HandlerFunc(h.leaveRoom)))
	mux.Handle("/rooms/mic/up", jwtVerifier.Middleware(http.HandlerFunc(h.micUp)))
	mux.Handle("/rooms/mic/down", jwtVerifier.Middleware(http.HandlerFunc(h.micDown)))
	mux.Handle("/rooms/mic/change", jwtVerifier.Middleware(http.HandlerFunc(h.changeMicSeat)))
	mux.Handle("/rooms/user/mute", jwtVerifier.Middleware(http.HandlerFunc(h.muteUser)))
	mux.Handle("/rooms/user/kick", jwtVerifier.Middleware(http.HandlerFunc(h.kickUser)))
	mux.Handle("/rooms/gift/send", jwtVerifier.Middleware(http.HandlerFunc(h.sendGift)))

	return mux
}

func (h *Handler) createRoom(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID      string `json:"room_id"`
		OwnerUserID int64  `json:"owner_user_id"`
		HostUserID  int64  `json:"host_user_id"`
		SeatCount   int32  `json:"seat_count"`
		Mode        string `json:"mode"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.CreateRoom(request.Context(), &roomv1.CreateRoomRequest{
		Meta:        meta(request, body.RoomID),
		OwnerUserId: body.OwnerUserID,
		HostUserId:  body.HostUserID,
		SeatCount:   body.SeatCount,
		Mode:        body.Mode,
	})
	write(writer, resp, err)
}

func (h *Handler) joinRoom(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID string `json:"room_id"`
		Role   string `json:"role"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.JoinRoom(request.Context(), &roomv1.JoinRoomRequest{
		Meta: meta(request, body.RoomID),
		Role: body.Role,
	})
	write(writer, resp, err)
}

func (h *Handler) leaveRoom(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID string `json:"room_id"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.LeaveRoom(request.Context(), &roomv1.LeaveRoomRequest{
		Meta: meta(request, body.RoomID),
	})
	write(writer, resp, err)
}

func (h *Handler) micUp(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID string `json:"room_id"`
		SeatNo int32  `json:"seat_no"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.MicUp(request.Context(), &roomv1.MicUpRequest{
		Meta:   meta(request, body.RoomID),
		SeatNo: body.SeatNo,
	})
	write(writer, resp, err)
}

func (h *Handler) micDown(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID       string `json:"room_id"`
		TargetUserID int64  `json:"target_user_id"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.MicDown(request.Context(), &roomv1.MicDownRequest{
		Meta:         meta(request, body.RoomID),
		TargetUserId: body.TargetUserID,
	})
	write(writer, resp, err)
}

func (h *Handler) changeMicSeat(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID       string `json:"room_id"`
		TargetUserID int64  `json:"target_user_id"`
		SeatNo       int32  `json:"seat_no"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.ChangeMicSeat(request.Context(), &roomv1.ChangeMicSeatRequest{
		Meta:         meta(request, body.RoomID),
		TargetUserId: body.TargetUserID,
		SeatNo:       body.SeatNo,
	})
	write(writer, resp, err)
}

func (h *Handler) muteUser(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID       string `json:"room_id"`
		TargetUserID int64  `json:"target_user_id"`
		Muted        bool   `json:"muted"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.MuteUser(request.Context(), &roomv1.MuteUserRequest{
		Meta:         meta(request, body.RoomID),
		TargetUserId: body.TargetUserID,
		Muted:        body.Muted,
	})
	write(writer, resp, err)
}

func (h *Handler) kickUser(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID       string `json:"room_id"`
		TargetUserID int64  `json:"target_user_id"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.KickUser(request.Context(), &roomv1.KickUserRequest{
		Meta:         meta(request, body.RoomID),
		TargetUserId: body.TargetUserID,
	})
	write(writer, resp, err)
}

func (h *Handler) sendGift(writer http.ResponseWriter, request *http.Request) {
	var body struct {
		RoomID        string `json:"room_id"`
		TargetUserID  int64  `json:"target_user_id"`
		GiftID        string `json:"gift_id"`
		GiftCount     int32  `json:"gift_count"`
		GiftUnitValue int64  `json:"gift_unit_value"`
	}

	if !decode(writer, request, &body) {
		return
	}

	resp, err := h.roomClient.SendGift(request.Context(), &roomv1.SendGiftRequest{
		Meta:          meta(request, body.RoomID),
		TargetUserId:  body.TargetUserID,
		GiftId:        body.GiftID,
		GiftCount:     body.GiftCount,
		GiftUnitValue: body.GiftUnitValue,
	})
	write(writer, resp, err)
}

func meta(request *http.Request, roomID string) *roomv1.RequestMeta {
	return &roomv1.RequestMeta{
		RequestId:     idgen.New("req"),
		CommandId:     idgen.New("cmd"),
		ActorUserId:   auth.UserIDFromContext(request.Context()),
		RoomId:        roomID,
		GatewayNodeId: "gateway-local",
		SessionId:     idgen.New("sess"),
		SentAtMs:      0,
	}
}

func decode(writer http.ResponseWriter, request *http.Request, out any) bool {
	if err := json.NewDecoder(request.Body).Decode(out); err != nil {
		http.Error(writer, err.Error(), http.StatusBadRequest)
		return false
	}

	return true
}

func write(writer http.ResponseWriter, body any, err error) {
	if err != nil {
		http.Error(writer, err.Error(), http.StatusBadGateway)
		return
	}

	writer.Header().Set("Content-Type", "application/json")
	_ = json.NewEncoder(writer).Encode(body)
}