// Package health provides the /health HTTP handler for spa-server.
// The wire format is identical to web/health.Response so responses are
// consistent across all Einherjar modules — without importing the web module.
package health

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

	"code.nochebuena.dev/einherjar/contracts/logging"
)

// response mirrors web/health.Response: {"status":"UP","components":{}}.
type response struct {
	Status     string            `json:"status"`
	Components map[string]string `json:"components"`
}

type handler struct {
	logger logging.Logger
}

// NewHandler returns an http.Handler that always responds 200 UP.
// spa-server has no external dependencies to probe; being reachable is the health check.
func NewHandler(logger logging.Logger) http.Handler {
	return &handler{logger: logger}
}

func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(http.StatusOK)
	if err := json.NewEncoder(w).Encode(response{Status: "UP", Components: map[string]string{}}); err != nil {
		h.logger.Error("health: encode response", err)
	}
}