using System;
using System.Collections.Generic;
using ChatComponents;
using uiwidgets;
using Unity.UIWidgets.async;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.material;
using Unity.UIWidgets.painting;
using Unity.UIWidgets.ui;
using Unity.UIWidgets.widgets;
using UnityEngine;
using Color = Unity.UIWidgets.ui.Color;

namespace UIWidgetsSample
{
    public delegate string CustomDateHeaderText(DateTime dateTime);

    public delegate void OnAttachmentPressed();

    public delegate Future OnEndReached();

    public delegate void OnMessageLongPress(ChatComponents.Message message);

    public delegate void OnMessageTap(ChatComponents.Message message);

    public delegate void OnPreviewDataFetched( PreviewData previewData,ChatComponents.TextMessage textMessage = null);

    public delegate void OnSendPressed(PartialText partialText);

    public delegate void OnTextChanged(string _str);

    public delegate Widget BuildCustomMessage(ChatComponents.Message message);

    public class Chat : StatefulWidget
    {
        /// See [Message.buildCustomMessage]
        /// If [dateFormat], [dateLocale] and/or [timeFormat] is not enough to
        /// customize date headers in your case, use this to return an arbitrary
        /// string based on a [DateTime] of a particular message. Can be helpful to
        /// return "Today" if [DateTime] is today. IMPORTANT: this will replace
        /// all default date headers, so you must handle all cases yourself, like
        /// for example today, yesterday and before. Or you can just return the same
        /// date header for any message.
        public readonly BuildCustomMessage buildCustomMessage;

        public readonly CustomDateHeaderText customDateHeaderText;

        /// Allows you to customize the date format. IMPORTANT: only for the date,
        /// do not return time here. See [timeFormat] to customize the time format.
        /// [dateLocale] will be ignored if you use this, so if you want a localized date
        /// make sure you initialize your [DateFormat] with a locale. See [customDateHeaderText]
        /// for more customization.
        public readonly DateTime? dateFormat;

        /// Locale will be passed to the `Intl` package. Make sure you initialized
        /// date formatting in your app before passing any locale here, otherwise
        /// an error will be thrown. Also see [customDateHeaderText], [dateFormat], [timeFormat].
        public readonly string dateLocale;

        /// Disable automatic image preview on tap.
        public readonly bool? disableImageGallery;

        /// See [Input.isAttachmentUploading]
        public readonly bool? isAttachmentUploading;

        /// See [ChatList.isLastPage]
        public readonly bool? isLastPage;

        /// Localized copy. Extend [ChatL10n] class to create your own copy or use
        /// existing one, like the default [ChatL10nEn]. You can customize only
        /// certain variables, see more here [ChatL10nEn].
        public readonly ChatL10n l10n;

        /// List of [types.Message] to render in the chat widget
        public readonly List<ChatComponents.Message> messages;

        /// See [Input.onAttachmentPressed]
        public readonly OnAttachmentPressed onAttachmentPressed;

        /// See [ChatList.onEndReached]
        public readonly OnEndReached onEndReached;

        /// See [ChatList.onEndReachedThreshold]
        public readonly float? onEndReachedThreshold;

        /// See [Message.onMessageLongPress]
        public readonly OnMessageLongPress onMessageLongPress;

        /// See [Message.onMessageTap]
        public readonly OnMessageTap onMessageTap;

        /// See [Message.onPreviewDataFetched]
        public readonly OnPreviewDataFetched onPreviewDataFetched;

        /// See [Input.onSendPressed]
        public readonly OnSendPressed onSendPressed;

        /// See [Input.onTextChanged]
        public readonly OnTextChanged onTextChanged;

        /// See [Message.showUserAvatars]
        public readonly bool showUserAvatars;

        /// Show user names for received messages. Useful for a group chat. Will be
        /// shown only on text messages.
        public readonly bool showUserNames;

        /// Chat theme. Extend [ChatTheme] class to create your own theme or use
        /// existing one, like the [DefaultChatTheme]. You can customize only certain
        /// variables, see more here [DefaultChatTheme].
        public readonly ChatTheme theme;

        /// Allows you to customize the time format. IMPORTANT: only for the time,
        /// do not return date here. See [dateFormat] to customize the date format.
        /// [dateLocale] will be ignored if you use this, so if you want a localized time
        /// make sure you initialize your [DateFormat] with a locale. See [customDateHeaderText]
        /// for more customization.
        public readonly DateTime? timeFormat;

        /// See [Message.usePreviewData]
        public readonly bool usePreviewData;

        /// See [InheritedUser.user]
        public readonly User user;

        /// Creates a chat widget
        public Chat(
            List<ChatComponents.Message> messages,
            OnSendPressed onSendPressed,
            User user,
            Key key = null,
            BuildCustomMessage buildCustomMessage = null,
            CustomDateHeaderText customDateHeaderText = null,
            DateTime? dateFormat = null,
            string dateLocale = null,
            bool? disableImageGallery = null,
            bool? isAttachmentUploading = null,
            bool? isLastPage = null,
            ChatL10nEn l10n = null,
            OnAttachmentPressed onAttachmentPressed = null,
            OnEndReached onEndReached = null,
            float? onEndReachedThreshold = null,
            OnMessageLongPress onMessageLongPress = null,
            OnMessageTap onMessageTap = null,
            OnPreviewDataFetched onPreviewDataFetched = null,
            OnTextChanged onTextChanged = null,
            bool showUserAvatars = false,
            bool showUserNames = false,
            ChatTheme theme = null,
            DateTime? timeFormat = null,
            bool usePreviewData = true
        ) : base(key)
        {
            this.buildCustomMessage = buildCustomMessage;
            this.customDateHeaderText = customDateHeaderText;
            this.dateFormat = dateFormat;
            this.dateLocale = dateLocale;
            this.disableImageGallery = disableImageGallery;
            this.isAttachmentUploading = isAttachmentUploading;
            this.isLastPage = isLastPage;
            this.l10n = l10n == null ? new ChatL10nEn() : l10n;
            this.messages = messages;
            this.onAttachmentPressed = onAttachmentPressed;
            this.onEndReached = onEndReached;
            this.onEndReachedThreshold = onEndReachedThreshold;
            this.onMessageLongPress = onMessageLongPress;
            this.onMessageTap = onMessageTap;
            this.onPreviewDataFetched = onPreviewDataFetched;
            this.onSendPressed = onSendPressed;
            this.onTextChanged = onTextChanged;
            this.showUserAvatars = showUserAvatars;
            this.showUserNames = showUserNames;
            this.theme = theme == null ? new DefaultChatTheme() : theme;
            this.timeFormat = timeFormat;
            this.usePreviewData = usePreviewData;
            this.user = user;
        }

        public override State createState()
        {
            return new _ChatState();
        }
    }

    /// [Chat] widget state
    public class _ChatState : State<Chat>
    {
        private List<object> _chatMessages = new List<object>();
        private List<PreviewImage> _gallery = new List<PreviewImage>();
        private int _imageViewIndex;
        private bool _isImageViewVisible;

        public override void initState()
        {
            base.initState();

            didUpdateWidget(widget);
        }

        public override void didUpdateWidget(StatefulWidget oldWidget)
        {
            oldWidget = (Chat) oldWidget;
            base.didUpdateWidget((Chat)oldWidget);

            if (widget.messages.isNotEmpty())
            {
                var result = ChatUtils.calculateChatMessages(
                    widget.messages,
                    widget.user,
                    customDateHeaderText: widget.customDateHeaderText,
                    dateFormat: widget.dateFormat,
                    dateLocale: widget.dateLocale,
                    showUserNames: widget.showUserNames,
                    timeFormat: widget.timeFormat
                );

                _chatMessages = result[0] as List<object>;
                _gallery = result[1] as List<PreviewImage>;
            }
        }

        /*private Widget _buildImageGallery()
        {
            return new Dismissible(
                GlobalKey.key("photo_view_gallery"),
                direction:
                DismissDirection.down,
                onDismissed:
                direction => _onCloseGalleryPressed(),
                child:
                new Stack(
                    children: new List<Widget>
                    {
                        PhotoViewGallery.builder(
                            builder: (BuildContext context, int index) =>
                                PhotoViewGalleryPageOptions(
                                    imageProvider: new BrowserConditional().getProvider(_gallery[index].uri)
                                ),
                            itemCount: _gallery.Count,
                            loadingBuilder: (_context, _event) =>
                                _imageGalleryLoadingBuilder(_context, _event),
                            onPageChanged:
                            _onPageChanged,
                            pageController:
                            new PageController(_imageViewIndex),
                            scrollPhysics:
                            new ClampingScrollPhysics()
                        ),
                        new Positioned(
                            right: 16,
                            top: 56,
                            child: new CloseButton(
                                color: Colors.white,
                                onPressed: _onCloseGalleryPressed
                            )
                        )
                    }
                )
            );
        }*/

        private Widget _buildMessage(object _object)
        {
            if (_object is DateHeader)
            {
                return new Container(
                    alignment: Alignment.center,
                    margin: EdgeInsets.only(
                        bottom: 32,
                        top: 16
                    ),
                    child:
                    new Text(
                        ((DateHeader) _object).text,
                        style: widget.theme.dateDividerTextStyle
                    )
                );

            }

            else if (_object is MessageSpacer)
            {
                var height = ((MessageSpacer) _object).height;
                return new SizedBox(
                    height: height
                );
            
            }
            else
            {
                 
                var map = _object as Dictionary<string, object>;
                var message = map["message"] as ChatComponents.Message;
                var _messageWidth =
                    widget.showUserAvatars && message.author.id != widget.user.id
                        ? Mathf.Min(MediaQuery.of(context).size.width * 0.72f, 440).floor()
                        : Mathf.Min(MediaQuery.of(context).size.width * 0.78f, 440).floor();

                return new Message(
                    key: new ValueKey<string>(message.id),
                    buildCustomMessage: widget.buildCustomMessage,
                    message: message,
                    messageWidth: _messageWidth,
                    onMessageLongPress: widget.onMessageLongPress,
                    onMessageTap: tappedMessage =>
                    {
                        if (tappedMessage is ImageMessage && widget.disableImageGallery != true)
                            _onImagePressed((ImageMessage) tappedMessage);

                        widget.onMessageTap?.Invoke(tappedMessage);
                    },
                    onPreviewDataFetched:
                    (previewData,textMessage)=>
                    {
                        _onPreviewDataFetched( textMessage,previewData);
                    },
                    roundBorder: true, //(map["nextMessageInGroup"] is bool ? (bool) map["nextMessageInGroup"] : false),
                    showAvatar:
                    widget.showUserAvatars && false,
                    //(map["nextMessageInGroup"] is bool ? (bool) map["nextMessageInGroup"] : false) == false,
                    showName:
                    false,
                    //(map["showName"] is bool ? (bool) map["showName"] : false),
                    showStatus:
                    false,
                    //(map["showStatus"] is bool ? (bool) map["showStatus"] : false),
                    showUserAvatars:
                    widget.showUserAvatars,
                    usePreviewData:
                    widget.usePreviewData
                );
            }

        }

        private Widget _imageGalleryLoadingBuilder(
            BuildContext context,
            ImageChunkEvent _event = null
        )
        {
            return new Center(
                child: new SizedBox(
                    width: 20.0f,
                    height: 20.0f,
                    child: new CircularProgressIndicator(
                        value: _event == null || _event.expectedTotalBytes == null
                            ? 0
                            : _event.cumulativeBytesLoaded / _event.expectedTotalBytes
                    )
                )
            );
        }

        private void _onCloseGalleryPressed()
        {
            setState(() => { _isImageViewVisible = false; });
        }

        private void _onImagePressed(ImageMessage message)
        {
            setState(() =>
            {
                /*_imageViewIndex = _gallery.Where(
                    element => element.id == message.id && element.uri == message.uri
                );*/
                foreach (var element in _gallery)
                    if (element.id == message.id && element.uri == message.uri)
                    {
                        _imageViewIndex = _gallery.IndexOf(element);
                        break;
                    }

                _isImageViewVisible = true;
            });
        }

        private void _onPageChanged(int index)
        {
            setState(() => { _imageViewIndex = index; });
        }

        private void _onPreviewDataFetched(
            ChatComponents.TextMessage message,
            PreviewData previewData
        )
        {
            widget.onPreviewDataFetched?.Invoke(previewData,message);
        }

        public override Widget build(BuildContext context)
        {
            var results = new List<Widget>();
            results.Add(new Container(
                color: Color.fromARGB(0, 0, 0, 0),
                child: new SafeArea(
                    bottom: false,
                    child: new Column(
                        children: new List<Widget>
                        {
                            new Flexible(
                                child: widget.messages.isEmpty()
                                    ? (Widget) SizedBox.expand(
                                        child: new Container(
                                            //color: Colors.yellow,
                                            alignment: Alignment.center,
                                            margin: EdgeInsets.symmetric(
                                                horizontal: 24
                                            ),
                                            child: new Text(
                                                widget.l10n.emptyChatPlaceholder,
                                                style: widget.theme.emptyChatPlaceholderTextStyle,
                                                textAlign: TextAlign.center
                                            )
                                        )
                                    )
                                    : new GestureDetector(
                                        onTap: () => FocusManager.instance.primaryFocus?.unfocus(),
                                        child: new ChatList(
                                            isLastPage: widget.isLastPage,
                                            itemBuilder: (item, index) => _buildMessage(item),
                                            items: _chatMessages,
                                            onEndReached: widget.onEndReached,
                                            onEndReachedThreshold: widget.onEndReachedThreshold
                                        )
                                    )
                            ),
                            new Input(
                                isAttachmentUploading: widget.isAttachmentUploading,
                                onAttachmentPressed: widget.onAttachmentPressed,
                                onSendPressed: widget.onSendPressed,
                                onTextChanged: widget.onTextChanged
                            )
                        }
                    )
                )
            ));
           // if (_isImageViewVisible)
           //     results.Add(_buildImageGallery());
           var test = widget.l10n;
           
            return new InheritedUser(
                widget.user,
                new InheritedChatTheme(
                    widget.theme,
                    new InheritedL10n(
                        widget.l10n,
                        new Stack(
                            children: results
                        )
                    )
                )
            );
        }
    }
}