// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'package:flutter/material.dart';

import '../utils/elevations.dart';

/// Defines a widget that builds the tile chrome for a story.
class TileChrome extends StatelessWidget {
  static const _kBorderSize = 16.0;

  final bool focused;
  final bool showTitle;
  final bool fullscreen;
  final bool draggable;
  final String name;
  final Widget child;
  final double width;
  final double height;
  final ValueChanged<Offset> onDragComplete;
  final VoidCallback onDelete;
  final VoidCallback onFullscreen;
  final VoidCallback onMinimize;

  const TileChrome({
    @required this.name,
    this.child,
    this.showTitle = true,
    this.fullscreen = false,
    this.focused = false,
    this.draggable = false,
    this.width,
    this.height,
    this.onDragComplete,
    this.onDelete,
    this.onFullscreen,
    this.onMinimize,
  });

  @override
  Widget build(BuildContext context) {
    Widget chrome = Stack(
      children: [
        // Border.
        Positioned.fill(
          child: Container(
            decoration: showTitle && !fullscreen
                ? BoxDecoration(
                    border: Border.all(
                      color: focused ? Colors.white : Colors.grey,
                      width: _kBorderSize,
                    ),
                  )
                : null,
            child: child ?? Container(color: Colors.transparent),
          ),
        ),

        // Title.
        Positioned(
          left: 0,
          top: 0,
          right: 0,
          height: _kBorderSize,
          child: showTitle
              ? fullscreen // Display title bar on top of story.
                  ? Material(
                      elevation: elevations.systemOverlayElevation,
                      color: focused ? Colors.white : Colors.grey,
                      child: _buildTitlebar(context),
                    )
                  : _buildTitlebar(context)
              : Offstage(),
        )
      ],
    );
    return draggable
        ? Draggable(
            child: chrome,
            feedback: SizedBox(
              width: width,
              height: height,
              child: chrome,
            ),
            childWhenDragging: Container(),
            onDragCompleted: () => print('onDragCompleted'),
            onDraggableCanceled: (velocity, offset) =>
                onDragComplete?.call(offset),
          )
        : chrome;
  }

  Widget _buildTitlebar(BuildContext context) => Row(
        crossAxisAlignment: CrossAxisAlignment.center,
        children: <Widget>[
          Padding(
            padding: EdgeInsets.only(left: 8),
          ),
          Expanded(
            child: Text(
              name ?? '<>',
              textAlign: TextAlign.center,
              style: Theme.of(context).textTheme.caption.copyWith(
                    color: focused ? Colors.black : Colors.white,
                  ),
            ),
          ),
          Padding(
            padding: EdgeInsets.only(left: 8),
          ),
          GestureDetector(
            child: Icon(
              Icons.remove,
              size: _kBorderSize,
              color: focused ? Colors.black : Colors.white,
            ),
            onTap: onMinimize?.call,
          ),
          Padding(
            padding: EdgeInsets.only(left: 8),
          ),
          GestureDetector(
            child: Icon(
              Icons.add,
              size: _kBorderSize,
              color: focused ? Colors.black : Colors.white,
            ),
            onTap: onFullscreen?.call,
          ),
          Padding(
            padding: EdgeInsets.only(left: 8),
          ),
          GestureDetector(
            child: Icon(
              Icons.clear,
              size: _kBorderSize,
              color: focused ? Colors.black : Colors.white,
            ),
            onTap: onDelete?.call,
          ),
          Padding(
            padding: EdgeInsets.only(left: 8),
          ),
        ],
      );
}