comunicmobile/lib/ui/tiles/post_tile.dart

import 'dart:io';

import 'package:comunic/enums/likes_type.dart';
import 'package:comunic/enums/post_kind.dart';
import 'package:comunic/enums/post_visibility_level.dart';
import 'package:comunic/helpers/comments_helper.dart';
import 'package:comunic/helpers/likes_helper.dart';
import 'package:comunic/helpers/posts_helper.dart';
import 'package:comunic/lists/groups_list.dart';
import 'package:comunic/lists/users_list.dart';
import 'package:comunic/models/comment.dart';
import 'package:comunic/models/like_element.dart';
import 'package:comunic/models/new_comment.dart';
import 'package:comunic/models/post.dart';
import 'package:comunic/models/user.dart';
import 'package:comunic/ui/tiles/comment_tile.dart';
import 'package:comunic/ui/widgets/account_image_widget.dart';
import 'package:comunic/ui/widgets/network_image_widget.dart';
import 'package:comunic/utils/date_utils.dart';
import 'package:comunic/utils/files_utils.dart';
import 'package:comunic/utils/intl_utils.dart';
import 'package:comunic/utils/post_utils.dart';
import 'package:comunic/utils/ui_utils.dart';
import 'package:flutter/material.dart';

/// Single posts tile
///
/// @author Pierre HUBERT

/// User style
const TextStyle _userNameStyle = TextStyle(
    color: Color.fromRGBO(0x72, 0xaf, 0xd2, 1.0), //#72afd2
    fontWeight: FontWeight.w600,
    fontSize: 16.0);

/// Post actions
enum _PostActions { DELETE, UPDATE_CONTENT }

class PostTile extends StatefulWidget {
  final Post post;
  final UsersList usersInfo;
  final GroupsList groupsInfo;
  final void Function(Post) onDeletedPost;
  final bool showPostTarget;

  const PostTile({
    Key key,
    @required this.post,
    @required this.usersInfo,
    @required this.onDeletedPost,
    @required this.showPostTarget,
    @required this.groupsInfo,
  })  : assert(post != null),
        assert(usersInfo != null),
        assert(onDeletedPost != null),
        assert(showPostTarget != null),
        assert(groupsInfo != null),
        super(key: key);

  @override
  State<StatefulWidget> createState() => _PostTileState();
}

class _PostTileState extends State<PostTile> {
  // Helpers
  final _postsHelper = PostsHelper();
  final _likesHelper = LikesHelper();
  final _commentsHelper = CommentsHelper();

  // Class members
  TextEditingController _commentController = TextEditingController();
  File _commentImage;
  bool _submitting = false;

  User get _user => widget.usersInfo.getUser(widget.post.userID);

  bool get _commentValid => _commentController.text.toString().length > 3;

  bool get _hasImage => _commentImage != null;

  bool get _canSubmitComment => !_submitting && (_commentValid || _hasImage);

  set _sendingComment(bool sending) => setState(() => _submitting = sending);

  String _getPostTarget() {
    if (!widget.showPostTarget ||
        (!widget.post.isGroupPost &&
            widget.post.userID == widget.post.userPageID)) return "";

    return " > " +
        (widget.post.isGroupPost
            ? widget.groupsInfo[widget.post.groupID].displayName
            : widget.usersInfo.getUser(widget.post.userPageID).displayName);
  }

  Widget _buildHeaderRow() {
    // Header row
    return Row(
      children: <Widget>[
        // User account image
        Padding(
          padding: const EdgeInsets.only(right: 8.0, left: 8.0),
          child: AccountImageWidget(user: _user),
        ),

        // Column with user name + post target
        Expanded(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: <Widget>[
              Text(
                _user.displayName + _getPostTarget(),
                style: _userNameStyle,
              ),
              Text(diffTimeFromNowToStr(widget.post.timeSent)),
            ],
          ),
        ),

        InkWell(
          child: Icon(
            PostVisibilityLevelsMapIcons[widget.post.visibilityLevel],
            color: Colors.grey,
          ),
          onTap: widget.post.canUpdate ? updatePostVisibilityLevel : null,
        ),

        PopupMenuButton<_PostActions>(
          itemBuilder: (c) => [
                // Update post content
                PopupMenuItem(
                  child: Text(tr("Update content")),
                  value: _PostActions.UPDATE_CONTENT,
                  enabled: widget.post.canUpdate,
                ),

                // Delete post
                PopupMenuItem(
                  child: Text(tr("Delete")),
                  value: _PostActions.DELETE,
                  enabled: widget.post.canDelete,
                ),
              ],
          onSelected: _selectedPostMenuAction,
        )
      ],
    );
  }

  Widget _buildContentRow() {
    Widget postContent;
    switch (widget.post.kind) {
      case PostKind.IMAGE:
        postContent = _buildPostImage();
        break;

      default:
    }

    return Column(
      children: <Widget>[
        // Post "rich" content
        Container(child: postContent),

        // Post text
        Container(
            child: widget.post.hasContent ? Text(widget.post.content) : null),
      ],
    );
  }

  Widget _buildButtonsArea() {
    return Padding(
      padding:
          const EdgeInsets.only(top: 16.0, left: 8.0, right: 8.0, bottom: 16.0),
      child: Column(
        children: <Widget>[
          // Like button
          Center(
            child: InkWell(
              onTap: () => _updatePostLike(),
              child: Row(
                crossAxisAlignment: CrossAxisAlignment.center,
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  Padding(
                    padding: const EdgeInsets.only(left: 8.0, right: 8.0),
                    child: Icon(
                      Icons.thumb_up,
                      color: widget.post.userLike ? Colors.blue : null,
                    ),
                  ),
                  Text(widget.post.likes < 2
                      ? tr("%num% like",
                          args: {"num": widget.post.likes.toString()})
                      : tr("%num% likes",
                          args: {"num": widget.post.likes.toString()}))
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: 1.0,
      child: Column(
        children: <Widget>[
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Column(
              children: <Widget>[
                _buildHeaderRow(),
                _buildContentRow(),
                _buildButtonsArea(),
              ],
            ),
          ),
          Container(
            child: widget.post.hasComments ? _buildComments() : null,
          ),
        ],
      ),
    );
  }

  Widget _buildPostImage() {
    return NetworkImageWidget(
      url: widget.post.fileURL,
      allowFullScreen: true,
      roundedEdges: false,
      loadingHeight: 150,
    );
  }

  /// Build the list of comments
  Widget _buildComments() {
    assert(widget.post.hasComments);

    final comments = List<Widget>.generate(
      widget.post.comments.length,
      (num) => CommentTile(
            comment: widget.post.comments[num],
            user: widget.usersInfo.getUser(widget.post.comments[num].userID),
            onUpdateLike: _updateCommentLike,
            onUpdateComment: _updateCommentContent,
            onDeleteComment: _deleteComment,
          ),
    );

    // Add comments form
    comments.add(_buildCommentsForm());

    return Container(
      color: Colors.grey[300],
      child: Padding(
        padding: const EdgeInsets.only(top: 8.0, bottom: 8.0),
        child: Column(
          children: comments,
        ),
      ),
    );
  }

  /// Build comments form
  Widget _buildCommentsForm() {
    return Padding(
      padding: EdgeInsets.only(
          left: 8.0,
          right: 8.0,
          top: (widget.post.comments.length > 0 ? 8.0 : 0)),
      child: Row(
        children: <Widget>[
          // Comment input
          Expanded(
            child: TextField(
              // Comment max size
              maxLength: 255,
              maxLines: null,
              buildCounter: smartInputCounterWidgetBuilder,

              controller: _commentController,
              onChanged: (s) => setState(() {}),
              onSubmitted: _canSubmitComment ? (s) => _submitComment() : null,
              decoration: InputDecoration(
                hintText: tr("New comment..."),
                hintStyle: TextStyle(color: Colors.grey, fontSize: 12),
                fillColor: Colors.white,
                filled: true,
                border: OutlineInputBorder(
                    borderSide: BorderSide(width: 0.5, color: Colors.grey),
                    borderRadius: BorderRadius.only(
                      topLeft: Radius.circular(3),
                      bottomLeft: Radius.circular(3),
                    ),
                    gapPadding: 1),
                contentPadding: EdgeInsets.only(
                  left: 10,
                  right: 10,
                  bottom: 5,
                  top: 5,
                ),
              ),
            ),
          ),

          // Image button
          Container(
            width: 30,
            child: FlatButton(
              padding: EdgeInsets.only(),
              onPressed: _pickImageForComment,
              child: Icon(
                Icons.image,
                color: _hasImage ? Colors.blue : Colors.grey,
              ),
            ),
          ),

          // Submit button
          Container(
            width: 40,
            child: FlatButton(
              padding: EdgeInsets.only(),
              onPressed: _canSubmitComment ? () => _submitComment() : null,
              child: Icon(
                Icons.send,
                color: _canSubmitComment ? Colors.blue : Colors.grey,
              ),
            ),
          ),
        ],
      ),
    );
  }

  /// Clear comments submitting form
  void clearCommentForm() {
    setState(() {
      _commentController.text = "";
      _commentImage = null;
    });
  }

  /// Pick an image
  Future<void> _pickImageForComment() async {
    // Ask the user to confirm image removal if there is already one selected
    if (_hasImage) {
      if (await showConfirmDialog(
        context: context,
        title: tr("Remove selected image"),
        message: tr("Do you want to unselected currently selected image ?"),
      )) {
        setState(() {
          _commentImage = null;
        });
      }

      return;
    }

    // Pick a new image
    final newImage = await pickImage(context);
    setState(() {
      _commentImage = newImage;
    });
  }

  /// Submit comment entered by the user
  Future<void> _submitComment() async {
    _sendingComment = true;

    final commentID = await _commentsHelper.createComment(NewComment(
      postID: widget.post.id,
      content: _commentController.text,
      image: _commentImage,
    ));

    _sendingComment = false;

    if (commentID < 1)
      return showSimpleSnack(context, tr("Could not create comment!"));

    clearCommentForm();

    // Get and show new comment
    final newComment = await _commentsHelper.getSingle(commentID);

    if (newComment == null)
      return showSimpleSnack(
          context, tr("Could not retrieve created comment!"));

    setState(() {
      widget.post.comments.add(newComment);
    });
  }

  /// Update like status
  Future<void> _updatePostLike() async {
    _updateElementLike(LikesType.POST, widget.post);
  }

  /// Invert comment like status
  Future<void> _updateCommentLike(Comment comment) async {
    _updateElementLike(LikesType.COMMENT, comment);
  }

  /// Invert element like status
  Future<void> _updateElementLike(LikesType type, LikeElement element) async {
    // Update liking status
    _likesHelper.setLiking(
      type: type,
      like: !element.userLike,
      id: element.id,
    );

    // Save new like status
    setState(() {
      element.userLike = !element.userLike;
      element.userLike ? element.likes++ : element.likes--;
    });
  }

  /// Update comment content
  Future<void> _updateCommentContent(Comment comment) async {
    final newContent = await askUserString(
      context: context,
      title: tr("Update comment content"),
      message: tr("New content:"),
      defaultValue: comment.content,
      hint: tr("New content..."),
    );

    if (!(await _commentsHelper.updateContent(comment.id, newContent)))
      return showSimpleSnack(context, tr("Could not update comment content!"));

    setState(() {
      comment.content = newContent;
    });
  }

  /// Process the deletion of a user
  Future<void> _deleteComment(Comment comment) async {
    if (!await showConfirmDialog(
        context: context,
        message: tr("Do you really want to delete this comment ?"),
        title: tr("Delete comment"))) return;

    if (!await _commentsHelper.delete(comment.id)) {
      showSimpleSnack(context, tr("Could not delete the comment!"));
      return;
    }

    // Remove the comment from the list
    setState(() {
      widget.post.comments.remove(comment);
    });
  }

  /// Method called each time the user has selected an option
  void _selectedPostMenuAction(_PostActions value) {
    switch (value) {
      // Update post content
      case _PostActions.UPDATE_CONTENT:
        updateContent();
        break;

      // Delete post
      case _PostActions.DELETE:
        confirmDelete();
        break;
    }
  }

  /// Update post visibility level
  Future<void> updatePostVisibilityLevel() async {
    final newLevel = await showPostVisibilityPicker(
      context: context,
      initialLevel: widget.post.visibilityLevel,
      isGroup: widget.post.isGroupPost,
    );

    if (newLevel == null || newLevel == widget.post.visibilityLevel) return;

    // Update post visibility
    if (!await _postsHelper.setVisibility(widget.post.id, newLevel)) {
      showSimpleSnack(context, tr("Could not update post visibility!"));
      return;
    }

    setState(() => widget.post.visibilityLevel = newLevel);
  }

  /// Update post content
  Future<void> updateContent() async {
    final newContent = await askUserString(
      context: context,
      title: tr("Update post content"),
      message: tr("Please enter message content: "),
      defaultValue: widget.post.content,
      hint: tr("Post content"),
    );

    if (newContent == null) return;

    if (!await _postsHelper.updateContent(widget.post.id, newContent)) {
      showSimpleSnack(context, tr("Could not update post content!"));
      return;
    }

    setState(() => widget.post.content = newContent);
  }

  /// Perform the deletion of the post
  Future<void> confirmDelete() async {
    // Ask user confirmation
    if (!await showConfirmDialog(
      context: context,
      message: tr(
          "Do you really want to delete this post ? The operation can not be reverted !"),
    )) return;

    if (!await _postsHelper.delete(widget.post.id)) {
      showSimpleSnack(context, tr("Could not delete the post!"));
      return;
    }

    widget.onDeletedPost(widget.post);
  }
}