package server

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

	"github.com/charmbracelet/log"
)

type WebServer struct {
	server     *Server
	logger     *log.Logger
	httpServer *http.Server
}

func NewWebServer(server *Server) *WebServer {
	ws := &WebServer{
		server: server,
		logger: server.Logger,
		httpServer: &http.Server{
			Addr: fmt.Sprintf(":%d", server.Config.Web.Port),
		},
	}

	mux := http.NewServeMux()
	mux.HandleFunc("/health", ws.healthHandler)
	mux.HandleFunc("/next_birthdays", ws.nextBirthdayHandler)

	ws.httpServer.Handler = mux

	return ws
}

func (ws *WebServer) Start() error {
	ws.logger.Debug("starting web server")

	go func() {
		if err := ws.httpServer.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			ws.logger.Fatal("cannot start web server", "error", err)
		}
	}()

	return nil
}

func (ws *WebServer) Stop() error {
	ws.logger.Debug("stopping web server")

	if err := ws.httpServer.Close(); err != nil {
		return fmt.Errorf("cannot stop web server: %w", err)
	}

	return nil
}

func (ws *WebServer) healthHandler(w http.ResponseWriter, r *http.Request) {
	fmt.Fprint(w, "OK")
}

func (ws *WebServer) nextBirthdayHandler(w http.ResponseWriter, r *http.Request) {
	ws.JSON(w, http.StatusOK, ws.server.NextBirthdays())
}

func (ws *WebServer) JSON(w http.ResponseWriter, statusCode int, data any) {
	b, err := json.Marshal(data)
	if err != nil {
		ws.logger.Error("cannot marshal data", "error", err)
		http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(statusCode)
	w.Write(b)
}