http_api.go

package clset

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

	"github.com/gorilla/mux"
)

type HTTPServer struct {
	crdt *CRDT
	mux  *mux.Router
}

func NewHTTPServer(crdt *CRDT) *HTTPServer {
	server := &HTTPServer{
		crdt: crdt,
		mux:  mux.NewRouter(),
	}

	server.routes()
	return server
}

func (s *HTTPServer) routes() {
	s.mux.HandleFunc("/key/{key}", s.handleGetKey).Methods("GET")
	s.mux.HandleFunc("/key/{key}", s.handlePutKey).Methods("PUT")
	s.mux.HandleFunc("/key/{key}", s.handleDeleteKey).Methods("DELETE")
	s.mux.HandleFunc("/count", s.handleCountKeys).Methods("GET")
}

func (s *HTTPServer) Serve(addr string) {
	log.Printf("HTTP API listening at %s", addr)
	log.Fatal(http.ListenAndServe(addr, s.mux))
}

func (s *HTTPServer) handleGetKey(w http.ResponseWriter, r *http.Request) {
	key := mux.Vars(r)["key"]
	val, exists, err := s.crdt.Get(key)
	if err != nil {
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	if !exists {
		http.Error(w, "Key not found", http.StatusNotFound)
		return
	}

	json.NewEncoder(w).Encode(map[string]string{
		"key":   key,
		"value": string(val),
	})
}

func (s *HTTPServer) handlePutKey(w http.ResponseWriter, r *http.Request) {
	key := mux.Vars(r)["key"]
	var data struct {
		Value string `json:"value"`
	}
	if err := json.NewDecoder(r.Body).Decode(&data); err != nil {
		http.Error(w, "Invalid JSON", http.StatusBadRequest)
		return
	}

	if err := s.crdt.Set(key, []byte(data.Value)); err != nil {
		http.Error(w, "Failed to set key", http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusNoContent)
}

func (s *HTTPServer) handleDeleteKey(w http.ResponseWriter, r *http.Request) {
	key := mux.Vars(r)["key"]
	if err := s.crdt.Delete(key); err != nil {
		http.Error(w, "Failed to delete key", http.StatusInternalServerError)
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (s *HTTPServer) handleCountKeys(w http.ResponseWriter, r *http.Request) {
	count, err := s.crdt.KeyCount()
	if err != nil {
		http.Error(w, "Failed to count keys", http.StatusInternalServerError)
		return
	}
	json.NewEncoder(w).Encode(map[string]uint64{"count": count})
}