define([
    "jquery",
    "underscore",
    "utils",
    "storage",
    "crel",
    "rangy",
    "classes/Extension",
    "text!html/commentsPopoverContent.html",
    "bootstrap"
], function($, _, utils, storage, crel, rangy, Extension, commentsPopoverContentHTML) {

    var comments = new Extension("comments", 'Comments', false, true);

    var commentTmpl = [
        '<div class="comment-block<%= reply ? \' reply\' : \'\' %>">',
        '    <div class="comment-author"><i class="icon-comment"></i> <%= author %></div>',
        '    <div class="comment-content"><%= content %></div>',
        '</div>',
    ].join('');
    var popoverTitleTmpl = [
        '<span class="clearfix">',
        '    <a href="#" class="action-remove-discussion pull-right">',
        '        <i class="icon-trash"></i>',
        '    </a>',
        '    “<%- title %>”',
        '</span>',
    ].join('');

    var eventMgr;
    comments.onEventMgrCreated = function(eventMgrParam) {
        eventMgr = eventMgrParam;
    };

    var editor;
    var selectionMgr;
    comments.onEditorCreated = function(editorParam) {
        editor = editorParam;
        selectionMgr = editor.selectionMgr;
    };

    var offsetMap = {};
    function setCommentEltCoordinates(commentElt, y) {
        var lineIndex = Math.round(y / 5);
        // Try to find the nearest existing lineIndex
        if(offsetMap.hasOwnProperty(lineIndex)) {
            // Keep current lineIndex
        }
        else if(offsetMap.hasOwnProperty(lineIndex - 1)) {
            lineIndex--;
        }
        else if(offsetMap.hasOwnProperty(lineIndex + 1)) {
            lineIndex++;
        }
        var yOffset = -8;
        if(commentElt.className.indexOf(' icon-split') !== -1) {
            yOffset = -12;
        }
        var top = y + yOffset;
        var right = (offsetMap[lineIndex] || 0) * 25 + 10;
        commentElt.orderedIndex = lineIndex * 10000 + right;
        commentElt.style.top = top + 'px';
        commentElt.style.right = right + 'px';
        return lineIndex;
    }

    var inputElt;
    var marginElt;
    var newCommentElt = crel('a', {
        class: 'discussion icon-comment new'
    });
    var cursorY;
    comments.onCursorCoordinates = function(x, y) {
        cursorY = y;
        setCommentEltCoordinates(newCommentElt, cursorY);
    };

    function Context(commentElt, fileDesc) {
        this.commentElt = commentElt;
        this.$commentElt = $(commentElt).addClass('active');
        this.fileDesc = fileDesc;
        this.discussionIndex = commentElt.discussionIndex;
    }
    Context.prototype.getDiscussion = function() {
        if(!this.discussionIndex) {
            return this.fileDesc.newDiscussion;
        }
        return this.fileDesc.discussionList[this.discussionIndex];
    };
    Context.prototype.getPopoverElt = function() {
        return document.querySelector('.comments-popover .popover:last-child');
    };
    var currentContext;
    function movePopover(commentElt) {
        // Move popover in the margin
        var popoverElt = currentContext.getPopoverElt();
        var left = 0;
        if(popoverElt.offsetWidth < marginElt.offsetWidth - 10) {
            left = marginElt.offsetWidth - 10 - popoverElt.offsetWidth;
        }
        popoverElt.style.left = left + 'px';
        popoverElt.querySelector('.arrow').style.left = (marginElt.offsetWidth - parseInt(commentElt.style.right) - commentElt.offsetWidth / 2 - left) + 'px';
        var popoverTopOffset = window.innerHeight - currentContext.hr.getBoundingClientRect().top;
        if(popoverTopOffset < 0) {
            popoverElt.style.top = (parseInt(popoverElt.style.top) + popoverTopOffset) + 'px';
        }
    }

    var cssApplier;
    var currentFileDesc;
    var refreshTimeoutId;
    var commentEltMap = {};
    var sortedCommentEltList = [];
    var someReplies = false;
    var $openDiscussionElt;
    var $openDiscussionIconElt;
    var refreshDiscussions = _.debounce(function() {
        if(currentFileDesc === undefined) {
            return;
        }
        someReplies = false;
        sortedCommentEltList = [];
        var author = storage['author.name'];
        offsetMap = {};
        var discussionList = _.values(currentFileDesc.discussionList);
        function refreshOne() {
            if(discussionList.length === 0) {
                // Remove outdated commentElt
                _.filter(commentEltMap, function(commentElt, discussionIndex) {
                    return !_.has(currentFileDesc.discussionList, discussionIndex);
                }).forEach(function(commentElt) {
                    marginElt.removeChild(commentElt);
                    delete commentEltMap[commentElt.discussionIndex];
                });
                // Move newCommentElt
                setCommentEltCoordinates(newCommentElt, cursorY);
                if(currentContext && !currentContext.discussionIndex) {
                    inputElt.scrollTop += parseInt(newCommentElt.style.top) - inputElt.scrollTop - inputElt.offsetHeight * 3 / 4;
                    movePopover(newCommentElt);
                }
                sortedCommentEltList = _.sortBy(commentEltMap, function(commentElt) {
                    return commentElt.orderedIndex;
                });
                $openDiscussionElt.toggleClass('some', sortedCommentEltList.length !== 0);
                $openDiscussionElt.toggleClass('replied', someReplies);
                $openDiscussionIconElt.toggleClass('icon-chat', sortedCommentEltList.length !== 0);
                return;
            }
            var discussion = discussionList.pop();
            var commentElt = commentEltMap[discussion.discussionIndex];
            if(!commentElt) {
                commentElt = crel('a');
            }
            var className = 'discussion';
            var isReplied = !discussion.commentList || _.last(discussion.commentList).author != author;
            isReplied && (someReplies = true);
            if(discussion.type == 'conflict') {
                className += ' icon-split';
            }
            else {
                className += ' icon-comment';
            }
            className += isReplied ? ' replied' : ' added';
            commentElt.className = className;
            commentElt.discussionIndex = discussion.discussionIndex;
            var coordinates = selectionMgr.getCoordinates(discussion.selectionEnd);
            var lineIndex = setCommentEltCoordinates(commentElt, coordinates.y);
            offsetMap[lineIndex] = (offsetMap[lineIndex] || 0) + 1;

            marginElt.appendChild(commentElt);
            commentEltMap[discussion.discussionIndex] = commentElt;

            if(currentContext && currentContext.getDiscussion() === discussion) {
                inputElt.scrollTop += parseInt(commentElt.style.top) - inputElt.scrollTop - inputElt.offsetHeight * 3 / 4;
                movePopover(commentElt);
            }
            refreshTimeoutId = setTimeout(refreshOne, 5);
        }
        clearTimeout(refreshTimeoutId);
        refreshTimeoutId = setTimeout(refreshOne, 5);
    }, 50);
    comments.onLayoutResize = refreshDiscussions;

    comments.onFileOpen = function(fileDesc) {
        currentFileDesc = fileDesc;
        refreshDiscussions();
    };

    comments.onContentChanged = function(fileDesc) {
        currentFileDesc === fileDesc && refreshDiscussions();
    };

    comments.onCommentsChanged = function(fileDesc) {
        if(currentFileDesc !== fileDesc) {
            return;
        }
        if(currentContext !== undefined) {
            // Refresh conversation if popover is open
            var context = currentContext;
            if(context.discussionIndex) {
                context.getPopoverElt().querySelector('.discussion-comment-list').innerHTML = getDiscussionComments();
            }
            try {
                cssApplier.undoToRange(context.rangyRange);
            }
            catch(e) {}
            var discussion = context.getDiscussion();
            context.selectionRange = selectionMgr.createRange(discussion.selectionStart, discussion.selectionEnd);

            // Highlight selected text
            context.rangyRange = rangy.createRange();
            context.rangyRange.setStart(context.selectionRange.startContainer, context.selectionRange.startOffset);
            context.rangyRange.setEnd(context.selectionRange.endContainer, context.selectionRange.endOffset);
            setTimeout(function() { // Need to delay this because it's not refreshed properly
                if(currentContext === context) {
                    cssApplier.applyToRange(context.rangyRange);
                }
            }, 50);
        }
        refreshDiscussions();
    };

    function closeCurrentPopover() {
        currentContext && currentContext.$commentElt.popover('toggle').popover('destroy');
    }

    comments.onDiscussionCreated = function(fileDesc) {
        currentFileDesc === fileDesc && refreshDiscussions();
    };

    comments.onDiscussionRemoved = function(fileDesc, discussion) {
        if(currentFileDesc === fileDesc) {
            // Close popover if the discussion has been removed
            if(currentContext !== undefined && currentContext.discussionIndex == discussion.discussionIndex) {
                closeCurrentPopover();
            }
            refreshDiscussions();
        }
    };

    function getDiscussionComments() {
        var discussion = currentContext.getDiscussion();
        var author = storage['author.name'];
        var result = [];
        if(discussion.commentList) {
            result = discussion.commentList.map(function(comment) {
                var commentAuthor = comment.author || 'Anonymous';
                return _.template(commentTmpl, {
                    author: commentAuthor,
                    content: comment.content,
                    reply: comment.author != author
                });
            });
        }
        if(discussion.type == 'conflict') {
            result.unshift(_.template(commentTmpl, {
                author: 'StackEdit',
                content: 'Multiple users have made conflicting modifications.',
                reply: true
            }));
        }
        return result.join('');
    }

    comments.onReady = function() {
        cssApplier = rangy.createCssClassApplier("comment-highlight", {
            normalize: false
        });
        var previousContent = '';

        inputElt = document.getElementById('wmd-input');
        marginElt = document.querySelector('#wmd-input > .editor-margin');
        marginElt.appendChild(newCommentElt);
        $(document.body).append(crel('div', {
            class: 'comments-popover'
        })).on('click', function(evt) {
            // Close on click outside the popover
            if(currentContext && currentContext.$commentElt[0] !== evt.target) {
                closeCurrentPopover();
            }
        }).popover({
            placement: 'auto top',
            container: '.comments-popover',
            html: true,
            title: function() {
                if(!currentContext) {
                    return true;
                }
                var discussion = currentContext.getDiscussion();
                var titleLength = discussion.selectionEnd - discussion.selectionStart;
                var title = editor.getValue().substr(discussion.selectionStart, titleLength > 20 ? 20 : titleLength);
                if(titleLength > 20) {
                    title += '...';
                }
                return _.template(popoverTitleTmpl, {
                    title: title,
                });
            },
            content: function() {
                var content = _.template(commentsPopoverContentHTML, {
                    commentList: getDiscussionComments(),
                });
                return content;
            },
            selector: '#wmd-input > .editor-margin > .discussion'
        }).on('show.bs.popover', '#wmd-input > .editor-margin', function(evt) {
            closeCurrentPopover();
            var context = new Context(evt.target, currentFileDesc);
            currentContext = context;

            // If it's not an existing discussion
            var discussion = context.getDiscussion();
            if(!discussion) {
                // Get selected text
                var selectionStart = Math.min(selectionMgr.selectionStart, selectionMgr.selectionEnd);
                var selectionEnd = Math.max(selectionMgr.selectionStart, selectionMgr.selectionEnd);
                if(selectionStart === selectionEnd) {
                    var offset = selectionMgr.getClosestWordOffset(selectionStart);
                    selectionStart = offset.start;
                    selectionEnd = offset.end;
                }
                discussion = {
                    selectionStart: selectionStart,
                    selectionEnd: selectionEnd,
                    commentList: []
                };
                currentFileDesc.newDiscussion = discussion;
            }
            context.selectionRange = selectionMgr.setSelectionStartEnd(discussion.selectionStart, discussion.selectionEnd, undefined, true);
            inputElt.scrollTop += parseInt(evt.target.style.top) - inputElt.scrollTop - inputElt.offsetHeight * 3 / 4;

        }).on('shown.bs.popover', '#wmd-input > .editor-margin', function(evt) {
            var context = currentContext;
            var popoverElt = context.getPopoverElt();
            context.$authorInputElt = $(popoverElt.querySelector('.input-comment-author')).val(storage['author.name']);
            context.$contentInputElt = $(popoverElt.querySelector('.input-comment-content'));
            context.hr = popoverElt.querySelector('hr');
            movePopover(context.commentElt);

            // Scroll to the bottom of the discussion
            popoverElt.querySelector('.scrollport').scrollTop = 9999999;

            var $addButton = $(popoverElt.querySelector('.action-add-comment'));
            $().add(context.$contentInputElt).add(context.$authorInputElt).keydown(function(evt) {
                // Enter key
                switch(evt.which) {
                case 13:
                    evt.preventDefault();
                    $addButton.click();
                    return;
                case 27:
                    evt.preventDefault();
                    closeCurrentPopover();
                    inputElt.focus();
                    return;
                }
            });
            $addButton.click(function(evt) {
                var author = utils.getInputTextValue(context.$authorInputElt);
                var content = utils.getInputTextValue(context.$contentInputElt, evt);
                if(evt.isPropagationStopped()) {
                    return;
                }

                var discussion = context.getDiscussion();
                context.$contentInputElt.val('');
                closeCurrentPopover();

                discussion.commentList = discussion.commentList || [];
                discussion.commentList.push({
                    author: author,
                    content: content
                });
                var discussionList = context.fileDesc.discussionList || {};
                if(!discussion.discussionIndex) {
                    // Create discussion index
                    var discussionIndex;
                    do {
                        discussionIndex = utils.randomString();
                    } while(_.has(discussionList, discussionIndex));
                    discussion.discussionIndex = discussionIndex;
                    discussionList[discussionIndex] = discussion;
                    context.fileDesc.discussionList = discussionList; // Write discussionList in localStorage
                    eventMgr.onDiscussionCreated(context.fileDesc, discussion);
                }
                else {
                    context.fileDesc.discussionList = discussionList; // Write discussionList in localStorage
                    eventMgr.onCommentsChanged(context.fileDesc);
                }
                inputElt.focus();
            });

            var $removeButton = $(popoverElt.querySelector('.action-remove-discussion'));
            if(evt.target.discussionIndex) {
                // If it's an existing discussion
                $removeButton.click(function() {
                    closeCurrentPopover();
                    var discussion = context.getDiscussion();
                    delete context.fileDesc.discussionList[discussion.discussionIndex];
                    context.fileDesc.discussionList = context.fileDesc.discussionList; // Write discussionList in localStorage
                    eventMgr.onDiscussionRemoved(context.fileDesc, discussion);
                    inputElt.focus();
                });
            }
            else {
                // Otherwise hide the remove button
                $removeButton.hide();
            }

            // Prevent from closing on click inside the popover
            $(popoverElt).on('click', function(evt) {
                evt.stopPropagation();
            });

            // Highlight selected text
            context.rangyRange = rangy.createRange();
            context.rangyRange.setStart(context.selectionRange.startContainer, context.selectionRange.startOffset);
            context.rangyRange.setEnd(context.selectionRange.endContainer, context.selectionRange.endOffset);
            setTimeout(function() { // Need to delay this because it's not refreshed properly
                if(currentContext === context) {
                    cssApplier.applyToRange(context.rangyRange);
                }
            }, 50);

            // Focus on textarea
            context.$contentInputElt.focus().val(previousContent);
        }).on('hide.bs.popover', '#wmd-input > .editor-margin', function() {
            if(!currentContext) {
                return;
            }
            currentContext.$commentElt.removeClass('active');

            // Save content and author for later
            previousContent = currentContext.$contentInputElt.val();
            storage['author.name'] = currentContext.$authorInputElt.val();

            // Remove highlight
            cssApplier.undoToRange(currentContext.rangyRange);
            currentContext = undefined;
            delete currentFileDesc.newDiscussion;
        });

        var $newCommentElt = $(newCommentElt);
        $openDiscussionElt = $('.button-open-discussion').click(function(evt) {
            var $commentElt = $newCommentElt;
            if(currentContext) {
                if(!currentContext.discussionIndex) {
                    $commentElt = $(_.first(sortedCommentEltList) || newCommentElt);
                }
                else {
                    var curentIndex = -1;
                    sortedCommentEltList.some(function(elt, index) {
                        if(elt === currentContext.commentElt) {
                            curentIndex = index;
                            return true;
                        }
                    });
                    $commentElt = $(sortedCommentEltList[(curentIndex + 1) % sortedCommentEltList.length]);
                }
            }
            $commentElt.click();
            evt.stopPropagation();
        });
        $openDiscussionIconElt = $openDiscussionElt.find('i');
    };

    return comments;
});