package api

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

	"AI-Status-Light/internal/database"
)

type Server struct {
	db     *database.DB
	server *http.Server
}

type Response struct {
	Code    int         `json:"code"`
	Message string      `json:"message"`
	Data    interface{} `json:"data,omitempty"`
}

func New(db *database.DB, addr string) *Server {
	s := &Server{db: db}

	mux := http.NewServeMux()
	mux.HandleFunc("/api/mqtt", s.handleMQTT)
	mux.HandleFunc("/api/mqtt/", s.handleMQTTByID)
	mux.HandleFunc("/api/health", s.handleHealth)

	s.server = &http.Server{
		Addr:    addr,
		Handler: corsMiddleware(mux),
	}
	return s
}

func (s *Server) Start() error {
	return s.server.ListenAndServe()
}

func corsMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type")

		if r.Method == "OPTIONS" {
			w.WriteHeader(http.StatusOK)
			return
		}

		next.ServeHTTP(w, r)
	})
}

func (s *Server) handleHealth(w http.ResponseWriter, r *http.Request) {
	writeJSON(w, http.StatusOK, Response{Code: 0, Message: "ok"})
}

func (s *Server) handleMQTT(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case http.MethodGet:
		s.listMQTTConfigs(w, r)
	case http.MethodPost:
		s.createMQTTConfig(w, r)
	default:
		writeJSON(w, http.StatusMethodNotAllowed, Response{Code: -1, Message: "方法不允许"})
	}
}

func (s *Server) handleMQTTByID(w http.ResponseWriter, r *http.Request) {
	idStr := strings.TrimPrefix(r.URL.Path, "/api/mqtt/")
	id, err := strconv.Atoi(idStr)
	if err != nil {
		writeJSON(w, http.StatusBadRequest, Response{Code: -1, Message: "无效的 ID"})
		return
	}

	switch r.Method {
	case http.MethodGet:
		s.getMQTTConfig(w, id)
	case http.MethodPut:
		s.updateMQTTConfig(w, r, id)
	case http.MethodDelete:
		s.deleteMQTTConfig(w, id)
	default:
		writeJSON(w, http.StatusMethodNotAllowed, Response{Code: -1, Message: "方法不允许"})
	}
}

func (s *Server) listMQTTConfigs(w http.ResponseWriter, r *http.Request) {
	configs, err := s.db.ListMQTTConfigs()
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, Response{Code: -1, Message: err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, Response{Code: 0, Message: "ok", Data: configs})
}

func (s *Server) createMQTTConfig(w http.ResponseWriter, r *http.Request) {
	var cfg database.MQTTConfig
	if err := json.NewDecoder(r.Body).Decode(&cfg); err != nil {
		writeJSON(w, http.StatusBadRequest, Response{Code: -1, Message: "无效的请求体"})
		return
	}

	if cfg.Broker == "" {
		writeJSON(w, http.StatusBadRequest, Response{Code: -1, Message: "broker 不能为空"})
		return
	}

	if cfg.ClientID == "" {
		cfg.ClientID = "opencode-monitor"
	}
	if cfg.Topic == "" {
		cfg.Topic = "opencode/status"
	}

	if err := s.db.SaveMQTTConfig(&cfg); err != nil {
		writeJSON(w, http.StatusInternalServerError, Response{Code: -1, Message: err.Error()})
		return
	}

	writeJSON(w, http.StatusCreated, Response{Code: 0, Message: "创建成功", Data: cfg})
}

func (s *Server) getMQTTConfig(w http.ResponseWriter, id int) {
	configs, err := s.db.ListMQTTConfigs()
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, Response{Code: -1, Message: err.Error()})
		return
	}

	for _, cfg := range configs {
		if cfg.ID == id {
			writeJSON(w, http.StatusOK, Response{Code: 0, Message: "ok", Data: cfg})
			return
		}
	}

	writeJSON(w, http.StatusNotFound, Response{Code: -1, Message: "配置不存在"})
}

func (s *Server) updateMQTTConfig(w http.ResponseWriter, r *http.Request, id int) {
	var cfg database.MQTTConfig
	if err := json.NewDecoder(r.Body).Decode(&cfg); err != nil {
		writeJSON(w, http.StatusBadRequest, Response{Code: -1, Message: "无效的请求体"})
		return
	}

	cfg.ID = id
	if cfg.Broker == "" {
		writeJSON(w, http.StatusBadRequest, Response{Code: -1, Message: "broker 不能为空"})
		return
	}

	if cfg.ClientID == "" {
		cfg.ClientID = "opencode-monitor"
	}
	if cfg.Topic == "" {
		cfg.Topic = "opencode/status"
	}

	if err := s.db.SaveMQTTConfig(&cfg); err != nil {
		writeJSON(w, http.StatusInternalServerError, Response{Code: -1, Message: err.Error()})
		return
	}

	writeJSON(w, http.StatusOK, Response{Code: 0, Message: "更新成功", Data: cfg})
}

func (s *Server) deleteMQTTConfig(w http.ResponseWriter, id int) {
	if err := s.db.DeleteMQTTConfig(id); err != nil {
		writeJSON(w, http.StatusInternalServerError, Response{Code: -1, Message: err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, Response{Code: 0, Message: "删除成功"})
}

func writeJSON(w http.ResponseWriter, statusCode int, data interface{}) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(statusCode)
	json.NewEncoder(w).Encode(data)
}

func (s *Server) GetAddr() string {
	return s.server.Addr
}