namespace Xilium.CefGlue
{
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Runtime.InteropServices;
    using Xilium.CefGlue.Interop;

    /// <summary>
    /// Implement this interface to handle context menu events. The methods of this
    /// class will be called on the UI thread.
    /// </summary>
    public abstract unsafe partial class CefContextMenuHandler
    {
        private void on_before_context_menu(cef_context_menu_handler_t* self, cef_browser_t* browser, cef_frame_t* frame, cef_context_menu_params_t* @params, cef_menu_model_t* model)
        {
            CheckSelf(self);

            var mBrowser = CefBrowser.FromNative(browser);
            var mFrame = CefFrame.FromNative(frame);
            using (var mState = CefContextMenuParams.FromNative(@params))
            using (var mModel = CefMenuModel.FromNative(model))
            {
                OnBeforeContextMenu(mBrowser, mFrame, mState, mModel);
            }
        }

        /// <summary>
        /// Called before a context menu is displayed. |params| provides information
        /// about the context menu state. |model| initially contains the default
        /// context menu. The |model| can be cleared to show no context menu or
        /// modified to show a custom menu. Do not keep references to |params| or
        /// |model| outside of this callback.
        /// </summary>
        protected virtual void OnBeforeContextMenu(CefBrowser browser, CefFrame frame, CefContextMenuParams state, CefMenuModel model)
        {
        }


        private int run_context_menu(cef_context_menu_handler_t* self, cef_browser_t* browser, cef_frame_t* frame, cef_context_menu_params_t* @params, cef_menu_model_t* model, cef_run_context_menu_callback_t* callback)
        {
            CheckSelf(self);

            var mBrowser = CefBrowser.FromNative(browser);
            var mFrame = CefFrame.FromNative(frame);
            using (var mParameters = CefContextMenuParams.FromNative(@params))
            using (var mModel = CefMenuModel.FromNative(model))
            {
                var mCallback = CefRunContextMenuCallback.FromNative(callback);
                var result = RunContextMenu(mBrowser, mFrame, mParameters, mModel, mCallback);

                return result ? 1 : 0;
            }
        }

        /// <summary>
        /// Called to allow custom display of the context menu. |params| provides
        /// information about the context menu state. |model| contains the context menu
        /// model resulting from OnBeforeContextMenu. For custom display return true
        /// and execute |callback| either synchronously or asynchronously with the
        /// selected command ID. For default display return false. Do not keep
        /// references to |params| or |model| outside of this callback.
        /// </summary>
        protected virtual bool RunContextMenu(CefBrowser browser, CefFrame frame, CefContextMenuParams parameters, CefMenuModel model, CefRunContextMenuCallback callback)
        {
            return false;
        }


        private int on_context_menu_command(cef_context_menu_handler_t* self, cef_browser_t* browser, cef_frame_t* frame, cef_context_menu_params_t* @params, int command_id, CefEventFlags event_flags)
        {
            CheckSelf(self);

            var mBrowser = CefBrowser.FromNative(browser);
            var mFrame = CefFrame.FromNative(frame);
            using (var mState = CefContextMenuParams.FromNative(@params))
            {
                var result = OnContextMenuCommand(mBrowser, mFrame, mState, command_id, event_flags);
                return result ? 1 : 0;
            }
        }

        /// <summary>
        /// Called to execute a command selected from the context menu. Return true if
        /// the command was handled or false for the default implementation. See
        /// cef_menu_id_t for the command ids that have default implementations. All
        /// user-defined command ids should be between MENU_ID_USER_FIRST and
        /// MENU_ID_USER_LAST. |params| will have the same values as what was passed to
        /// OnBeforeContextMenu(). Do not keep a reference to |params| outside of this
        /// callback.
        /// </summary>
        protected virtual bool OnContextMenuCommand(CefBrowser browser, CefFrame frame, CefContextMenuParams state, int commandId, CefEventFlags eventFlags)
        {
            return false;
        }


        private void on_context_menu_dismissed(cef_context_menu_handler_t* self, cef_browser_t* browser, cef_frame_t* frame)
        {
            CheckSelf(self);

            var mBrowser = CefBrowser.FromNative(browser);
            var mFrame = CefFrame.FromNative(frame);

            OnContextMenuDismissed(mBrowser, mFrame);
        }

        /// <summary>
        /// Called when the context menu is dismissed irregardless of whether the menu
        /// was empty or a command was selected.
        /// </summary>
        protected virtual void OnContextMenuDismissed(CefBrowser browser, CefFrame frame)
        {
        }
    }
}