package health

import (
	"fmt"
	"log"
	"net/http"
	"sync"
)

// Handler 健康检查处理器
type Handler struct {
	serviceName string
	port        int
	server      *http.Server
	wg          sync.WaitGroup
}

// NewHandler 创建健康检查处理器
func NewHandler(serviceName string, port int) *Handler {
	return &Handler{
		serviceName: serviceName,
		port:        port,
	}
}

// Start 启动健康检查 HTTP 服务器
func (h *Handler) Start() {
	mux := http.NewServeMux()
	mux.HandleFunc("/health", h.handleHealth)

	h.server = &http.Server{
		Addr:    fmt.Sprintf(":%d", h.port),
		Handler: mux,
	}

	h.wg.Add(1)
	go func() {
		defer h.wg.Done()
		log.Printf("[%s] Health check server started on port %d", h.serviceName, h.port)
		if err := h.server.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Printf("[%s] Health check server error: %v", h.serviceName, err)
		}
	}()
}

// Stop 停止健康检查 HTTP 服务器
func (h *Handler) Stop() {
	if h.server != nil {
		if err := h.server.Close(); err != nil {
			log.Printf("[%s] Health check server close error: %v", h.serviceName, err)
		}
	}
	h.wg.Wait()
	log.Printf("[%s] Health check server stopped", h.serviceName)
}

func (h *Handler) handleHealth(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Header().Set("Content-Type", "application/json")
	fmt.Fprintf(w, `{"status":"ok","service":"%s"}`, h.serviceName)
}