package api

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

// errorBody is the JSON envelope for failures on /api/*. Kept separate from
// the Subsonic envelope so native clients don't have to parse two shapes.
type errorBody struct {
	Error errorPayload `json:"error"`
}

type errorPayload struct {
	Code    string `json:"code"`
	Message string `json:"message"`
}

// writeErr is the canonical way to emit a failure. Code is a stable
// short-string clients can switch on; message is human-readable.
func writeErr(w http.ResponseWriter, status int, code, message string) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(errorBody{Error: errorPayload{Code: code, Message: message}})
}

// writeJSON emits a 2xx response with the given body JSON-encoded. Mirrors
// writeErr's shape so handlers have one shape for success and one for
// failure.
func writeJSON(w http.ResponseWriter, status int, body any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(body)
}