'use strict';

/*!
 * VisualEditor ContentEditable MWReferencesListNode class.
 *
 * @copyright 2011-2018 VisualEditor Team's Cite sub-team and others; see AUTHORS.txt
 * @license MIT
 */

const MWDataTransitionHelper = require( './ve.dm.MWDataTransitionHelper.js' );
const MWDocumentReferences = require( './ve.dm.MWDocumentReferences.js' );
const MWReferenceModel = require( './ve.dm.MWReferenceModel.js' );

/**
 * ContentEditable MediaWiki references list node.
 *
 * @constructor
 * @extends ve.ce.LeafNode
 * @mixes ve.ce.FocusableNode
 * @param {ve.dm.MWReferencesListNode} model Model to observe
 * @param {Object} [config] Configuration options
 */
ve.ce.MWReferencesListNode = function VeCeMWReferencesListNode() {
	// Parent constructor
	ve.ce.MWReferencesListNode.super.apply( this, arguments );

	// Mixin constructors
	ve.ce.FocusableNode.call( this );

	// Properties
	this.modified = false;
	this.interactive = false;

	// DOM changes
	this.$element.addClass( 've-ce-mwReferencesListNode' );
	this.$reflist = $( '<ol>' ).addClass( 'mw-references references' );
	this.$originalRefList = null;
	this.$refmsg = $( '<p>' )
		.addClass( 've-ce-mwReferencesListNode-muted' );

	// Events
	this.getModel().connect( this, { attributeChange: 'onAttributeChange' } );

	this.updateDebounced = ve.debounce( this.update.bind( this ) );

	// Initialization
	// Rendering the reference list can be slow, so do it in an idle callback
	// (i.e. after the editor has finished loading). Previously we used the
	// Parsoid DOM rendering for the first paint, and updated only when references
	// were modified, but this means the reference list is out of sync with the
	// model for features such as T54750.
	mw.requestIdleCallback( this.update.bind( this ) );
};

/* Inheritance */

OO.inheritClass( ve.ce.MWReferencesListNode, ve.ce.LeafNode );

OO.mixinClass( ve.ce.MWReferencesListNode, ve.ce.FocusableNode );

/* Static Properties */

ve.ce.MWReferencesListNode.static.name = 'mwReferencesList';

ve.ce.MWReferencesListNode.static.tagName = 'div';

ve.ce.MWReferencesListNode.static.primaryCommandName = 'referencesList';

/* Static Methods */

/**
 * @override
 * @see ve.ce.LeafNode
 */
ve.ce.MWReferencesListNode.static.getDescription = function ( model ) {
	return model.getAttribute( 'refGroup' );
};

/**
 * @override
 * @see ve.ce.FocusableNode
 */
ve.ce.MWReferencesListNode.prototype.getExtraHighlightClasses = function () {
	const classes = ve.ce.FocusableNode.prototype.getExtraHighlightClasses.apply( this, arguments );
	return this.interactive ?
		classes.concat( [ 've-ce-mwReferencesListNode-highlight' ] ) :
		classes;
};

/* Methods */

/**
 * Handle setup events.
 */
ve.ce.MWReferencesListNode.prototype.onSetup = function () {
	const internalList = this.getModel().getDocument().getInternalList();
	const listNode = internalList.getListNode();

	internalList.connect( this, { update: 'onInternalListUpdate' } );
	listNode.connect( this, { update: 'onListNodeUpdate' } );

	// Parent method
	ve.ce.MWReferencesListNode.super.prototype.onSetup.call( this );
};

/**
 * Handle teardown events.
 */
ve.ce.MWReferencesListNode.prototype.onTeardown = function () {
	// Parent method
	ve.ce.MWReferencesListNode.super.prototype.onTeardown.call( this );

	// The model is potentially gone after .destroy() was called
	if ( !this.getModel() || !this.getModel().getDocument() ) {
		return;
	}
	const internalList = this.getModel().getDocument().getInternalList();
	const listNode = internalList.getListNode();

	internalList.disconnect( this, { update: 'onInternalListUpdate' } );
	listNode.disconnect( this, { update: 'onListNodeUpdate' } );
};

/**
 * Handle the updating of the InternalList object.
 *
 * This will occur after a document transaction.
 *
 * @param {string[]} groupsChanged A list of groups which have changed in this transaction
 */
ve.ce.MWReferencesListNode.prototype.onInternalListUpdate = function ( groupsChanged ) {
	// The model is potentially gone after .destroy() was called
	if ( !this.getModel() ) {
		return;
	}
	// Only update if this group has been changed
	if ( groupsChanged.includes( this.getModel().getAttribute( 'listGroup' ) ) ) {
		this.modified = true;
		this.updateDebounced();
	}
};

/**
 * Rerender when the 'listGroup' attribute changes in the model.
 *
 * @param {string} key Attribute key
 * @param {string} from Old value
 * @param {string} to New value
 */
ve.ce.MWReferencesListNode.prototype.onAttributeChange = function ( key ) {
	switch ( key ) {
		case 'listGroup':
			this.updateDebounced();
			this.modified = true;
			break;
		case 'isResponsive':
			this.updateClasses();
			break;
	}
};

/**
 * Handle the updating of the InternalListNode.
 *
 * This will occur after changes to any InternalItemNode.
 */
ve.ce.MWReferencesListNode.prototype.onListNodeUpdate = function () {
	// When the list node updates we're not sure which list group the item
	// belonged to so we always update
	// TODO: Only re-render the reference which has been edited
	this.updateDebounced();
};

/**
 * Update the references list.
 */
ve.ce.MWReferencesListNode.prototype.update = function () {
	const model = this.getModel();

	this.interactive = false;

	// Check the node hasn't been destroyed, as this method is debounced.
	if ( !model ) {
		return;
	}

	const refGroup = model.getAttribute( 'refGroup' );
	const listGroup = model.getAttribute( 'listGroup' );

	const docRefs = MWDocumentReferences.static.refsForDoc( model.getDocument() );
	const groupRefs = docRefs.getGroupRefs( listGroup );
	const hasModelReferences = !groupRefs.isEmpty();

	const emptyText = ve.msg(
		refGroup ? 'cite-ve-referenceslist-isempty' : 'cite-ve-referenceslist-isempty-default',
		refGroup
	);

	let originalDomElements;
	if ( model.getElement().originalDomElementsHash ) {
		originalDomElements = model.getStore().value(
			model.getElement().originalDomElementsHash
		);
	}
	// Use the Parsoid-provided DOM if:
	//
	// * There are no references in the model
	// * There have been no changes to the references in the model (!this.modified)
	//
	// In practice this is for he.wiki where references are template-generated (T187495)
	if (
		!hasModelReferences &&
		!this.modified &&
		originalDomElements
	) {
		// Create a copy when importing to the main document, as extensions may
		this.$originalRefList = $( ve.copyDomElements( originalDomElements, document ) );
		// modify DOM nodes in the main doc.
		if ( this.$originalRefList.find( 'li' ).length ) {
			this.$element.append( this.$originalRefList );
		} else {
			this.$refmsg.text( emptyText );
			this.$element.append( this.$refmsg );
		}
		return;
	}

	if ( this.$originalRefList ) {
		this.$originalRefList.remove();
		this.$originalRefList = null;
	}
	// Copy CSS to dynamic ref list
	if ( originalDomElements ) {
		// Get first container, e.g. skipping TemplateStyles
		const div = originalDomElements.find( ( element ) => element.tagName === 'DIV' );
		if ( div ) {
			// eslint-disable-next-line mediawiki/class-doc
			this.$element.addClass( div.getAttribute( 'class' ) );
			this.$element.attr( 'style', div.getAttribute( 'style' ) );
		}
	}

	this.$reflist.detach().empty().attr( 'data-mw-group', refGroup || null );
	this.$refmsg.detach();

	if ( !hasModelReferences ) {
		this.$refmsg.text( emptyText );
		this.$element.append( this.$refmsg );
	} else {
		// Render all at once.

		const nodeGroup = model.getDocument().getInternalList().getNodeGroup( listGroup );
		this.$reflist.append(
			new MWDataTransitionHelper().buildReflistStructure( nodeGroup )
				.map( ( refInfo ) => this.renderListItem( groupRefs, refGroup, refInfo ) )
		);

		this.interactive = true;

		this.updateClasses();
		this.$element.append( this.$reflist );
	}
};

/**
 * Render a reference list item
 *
 * @private
 * @param {ve.dm.MWGroupReferences} groupRefs object holding calculated information about all group refs
 * @param {string} refGroup Reference group
 * @param {ve.dm.MWDataTransitionHelper.RefInfo} refInfo
 * @return {jQuery} Rendered list item
 */
ve.ce.MWReferencesListNode.prototype.renderListItem = function ( groupRefs, refGroup, refInfo ) {
	const internalItem = this.model.getDocument().getInternalList().getItemNode( refInfo.internalListIndex );
	const backlinkNodes = groupRefs.getRefUsages( refInfo.internalListIndex );
	const hasSubRefs = refInfo.subrefs && refInfo.subrefs.length;

	const $li = $( '<li>' )
		.css( '--footnote-number', `"${ refInfo.label }."` )
		.append( this.renderBacklinks( backlinkNodes, refGroup ), ' ' );

	if ( internalItem && internalItem.getLength() ) {
		const refPreview = new ve.ui.MWPreviewElement( internalItem, { useView: true } );
		$li.append(
			$( '<span>' )
				.addClass( 'reference-text' )
				.append( refPreview.$element )
		);

		if ( this.getRoot() ) {
			// TODO: attach to the singleton click handler on the surface
			$li.on( 'mousedown', ( e ) => {
				if ( ve.isUnmodifiedLeftClick( e ) ) {
					const editNodeAction = ve.ui.actionFactory.create(
						'editNode',
						this.getRoot().getSurface().getSurface()
					);
					// FIXME: This will currently only work for main refs
					editNodeAction.execute(
						MWReferenceModel.static.newFromMainNodeAttributes(
							this.getModel().getDocument(),
							'mwReference/' + refGroup,
							null,
							refInfo.internalListIndex
						)
					);
				}
				e.preventDefault();
			} );
		}
	} else {
		$li.append(
			$( '<span>' )
				.addClass( 've-ce-mwReferencesListNode-muted' )
				.text( ve.msg( hasSubRefs ? 'cite-ve-referenceslist-missing-parent' :
					'cite-ve-referenceslist-missingref-in-list' ) )
		).addClass( 've-ce-mwReferencesListNode-missingRef' );
	}

	if ( hasSubRefs ) {
		$li.append(
			$( '<ol>' ).addClass( 'mw-subreference-list' ).append(
				refInfo.subrefs.map( ( subRefInfo ) => this.renderListItem(
					groupRefs, refGroup, subRefInfo
				) )
			)
		);
	}

	return $li;
};

/**
 * Update ref list classes.
 *
 * Currently used to set responsive layout
 */
ve.ce.MWReferencesListNode.prototype.updateClasses = function () {
	const isResponsive = this.getModel().getAttribute( 'isResponsive' );

	this.$element
		.toggleClass( 'mw-references-wrap', isResponsive )
		.toggleClass( 'mw-references-columns', isResponsive && this.$reflist.children().length > 10 );
};

/**
 * Build markers for backlinks
 *
 * @param {ve.dm.Node[]} keyedNodes A list of ref nodes linked to a reference list item
 * @param {string} refGroup Reference group name
 * @return {jQuery} Element containing backlinks
 */
ve.ce.MWReferencesListNode.prototype.renderBacklinks = function ( keyedNodes, refGroup ) {
	if ( keyedNodes.length === 1 ) {
		return $( '<a>' )
			.attr( 'rel', 'mw:referencedBy' )
			.attr( 'data-mw-group', refGroup || null )
			.append( $( '<span>' ).addClass( 'mw-linkback-text' ).text( '↑' ) );
	}

	// named reference with multiple usages
	const $refSpan = $( '<span>' ).attr( 'rel', 'mw:referencedBy' );
	for ( let i = 0; i < keyedNodes.length; i++ ) {
		if ( i > 0 ) {
			$refSpan.append( ' ' );
		}
		$( '<a>' )
			.attr( 'data-mw-group', refGroup || null )
			// FIXME: i18n backlink numbering
			.append( $( '<span>' ).addClass( 'mw-linkback-text' ).text( ( i + 1 ) ) )
			.appendTo( $refSpan );
	}
	return $refSpan;
};

module.exports = ve.ce.MWReferencesListNode;
