package response

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

// ErrorBody is the standard JSON error response shape.
type ErrorBody struct {
	Error   string `json:"error"`
	Message string `json:"message,omitempty"`
}

// JSON writes a JSON body with status code and Content-Type.
func JSON(w http.ResponseWriter, status int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	if v != nil {
		_ = json.NewEncoder(w).Encode(v)
	}
}

// OK writes 200 with optional JSON body.
func OK(w http.ResponseWriter, v any) {
	if v == nil {
		w.WriteHeader(http.StatusOK)
		w.Write([]byte("ok"))
		return
	}
	JSON(w, http.StatusOK, v)
}

// Error writes a JSON error response.
func Error(w http.ResponseWriter, status int, err string, message string) {
	JSON(w, status, ErrorBody{Error: err, Message: message})
}

// BadRequest writes 400 with error message.
func BadRequest(w http.ResponseWriter, message string) {
	Error(w, http.StatusBadRequest, "bad_request", message)
}

// InternalError writes 500 and logs the err.
func InternalError(w http.ResponseWriter, message string, logErr error) {
	if logErr != nil {
		slog.Error(message, "err", logErr)
	}
	Error(w, http.StatusInternalServerError, "internal_error", message)
}

// NotFound writes 404.
func NotFound(w http.ResponseWriter, message string) {
	Error(w, http.StatusNotFound, "not_found", message)
}