package rest

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

// ErrorResponse represents an API error response
type ErrorResponse struct {
	Error ErrorDetail `json:"error"`
}

// ErrorDetail contains error details
type ErrorDetail struct {
	Code    string `json:"code"`
	Message string `json:"message"`
	Details string `json:"details,omitempty"`
}

// writeError writes an error response
func writeError(w http.ResponseWriter, statusCode int, code, message string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(statusCode)
	json.NewEncoder(w).Encode(ErrorResponse{
		Error: ErrorDetail{
			Code:    code,
			Message: message,
		},
	})
}

// writeNotFound writes a 404 error response
func writeNotFound(w http.ResponseWriter, resource string) {
	writeError(w, http.StatusNotFound, "NOT_FOUND", resource+" not found")
}

// writeInternalError writes a 500 error response
func writeInternalError(w http.ResponseWriter, message string) {
	writeError(w, http.StatusInternalServerError, "INTERNAL_ERROR", message)
}

// writeUnauthorized writes a 401 error response
func writeUnauthorized(w http.ResponseWriter) {
	writeError(w, http.StatusUnauthorized, "UNAUTHORIZED", "Authentication required")
}

// writeForbidden writes a 403 error response
func writeForbidden(w http.ResponseWriter) {
	writeError(w, http.StatusForbidden, "FORBIDDEN", "Access denied")
}

// writeMethodNotAllowed writes a 405 error response (JSON)
func writeMethodNotAllowed(w http.ResponseWriter) {
	writeError(w, http.StatusMethodNotAllowed, "METHOD_NOT_ALLOWED", "Method not allowed")
}