/**
 * @license Copyright (c) 2003-2022, CKSource Holding sp. z o.o. All rights reserved.
 * For licensing, see LICENSE.md or https://ckeditor.com/legal/ckeditor-oss-license
 */
/**
 * @module engine/dev-utils/view
 */
/* globals document */
/**
 * Collection of methods for manipulating the {@link module:engine/view/view view} for testing purposes.
 */
import View from '../view/view';
import ViewDocument from '../view/document';
import ViewDocumentFragment from '../view/documentfragment';
import XmlDataProcessor from '../dataprocessor/xmldataprocessor';
import ViewElement from '../view/element';
import DocumentSelection from '../view/documentselection';
import Range from '../view/range';
import Position from '../view/position';
import AttributeElement from '../view/attributeelement';
import ContainerElement from '../view/containerelement';
import EmptyElement from '../view/emptyelement';
import UIElement from '../view/uielement';
import RawElement from '../view/rawelement';
import { StylesProcessor } from '../view/stylesmap';
const ELEMENT_RANGE_START_TOKEN = '[';
const ELEMENT_RANGE_END_TOKEN = ']';
const TEXT_RANGE_START_TOKEN = '{';
const TEXT_RANGE_END_TOKEN = '}';
const allowedTypes = {
    'container': ContainerElement,
    'attribute': AttributeElement,
    'empty': EmptyElement,
    'ui': UIElement,
    'raw': RawElement
};
// Returns simplified implementation of {@link module:engine/view/domconverter~DomConverter#setContentOf DomConverter.setContentOf} method.
// Used to render UIElement and RawElement.
const domConverterStub = {
    setContentOf: (node, html) => {
        node.innerHTML = html;
    }
};
/**
 * Writes the content of the {@link module:engine/view/document~Document document} to an HTML-like string.
 *
 * @param {module:engine/view/view~View} view
 * @param {Object} [options]
 * @param {Boolean} [options.withoutSelection=false] Whether to write the selection. When set to `true`, the selection will
 * not be included in the returned string.
 * @param {Boolean} [options.rootName='main'] The name of the root from which the data should be stringified. If not provided,
 * the default `main` name will be used.
 * @param {Boolean} [options.showType=false] When set to `true`, the type of elements will be printed (`<container:p>`
 * instead of `<p>`, `<attribute:b>` instead of `<b>` and `<empty:img>` instead of `<img>`).
 * @param {Boolean} [options.showPriority=false] When set to `true`, the attribute element's priority will be printed
 * (`<span view-priority="12">`, `<b view-priority="10">`).
 * @param {Boolean} [options.showAttributeElementId=false] When set to `true`, the attribute element's ID will be printed
 * (`<span id="marker:foo">`).
 * @param {Boolean} [options.renderUIElements=false] When set to `true`, the inner content of each
 * {@link module:engine/view/uielement~UIElement} will be printed.
 * @param {Boolean} [options.renderRawElements=false] When set to `true`, the inner content of each
 * {@link module:engine/view/rawelement~RawElement} will be printed.
 * @param {Object} [options.domConverter=null] When set to an actual {@link module:engine/view/domconverter~DomConverter DomConverter}
 * instance, it lets the conversion go through exactly the same flow the editing view is going through,
 * i.e. with view data filtering. Otherwise the simple stub is used.
 * @returns {String} The stringified data.
 */
export function getData(view, options = {}) {
    if (!(view instanceof View)) {
        throw new TypeError('View needs to be an instance of module:engine/view/view~View.');
    }
    const document = view.document;
    const withoutSelection = !!options.withoutSelection;
    const rootName = options.rootName || 'main';
    const root = document.getRoot(rootName);
    const stringifyOptions = {
        showType: options.showType,
        showPriority: options.showPriority,
        renderUIElements: options.renderUIElements,
        renderRawElements: options.renderRawElements,
        ignoreRoot: true,
        domConverter: options.domConverter
    };
    return withoutSelection ?
        getData._stringify(root, null, stringifyOptions) :
        getData._stringify(root, document.selection, stringifyOptions);
}
// Set stringify as getData private method - needed for testing/spying.
getData._stringify = stringify;
/**
 * Sets the content of a view {@link module:engine/view/document~Document document} provided as an HTML-like string.
 *
 * @param {module:engine/view/view~View} view
 * @param {String} data An HTML-like string to write into the document.
 * @param {Object} options
 * @param {String} [options.rootName='main'] The root name where parsed data will be stored. If not provided,
 * the default `main` name will be used.
 */
export function setData(view, data, options = {}) {
    if (!(view instanceof View)) {
        throw new TypeError('View needs to be an instance of module:engine/view/view~View.');
    }
    const document = view.document;
    const rootName = options.rootName || 'main';
    const root = document.getRoot(rootName);
    view.change(writer => {
        const result = setData._parse(data, { rootElement: root });
        if (result.view && result.selection) {
            writer.setSelection(result.selection);
        }
    });
}
// Set parse as setData private method - needed for testing/spying.
setData._parse = parse;
/**
 * Converts view elements to HTML-like string representation.
 *
 * A root element can be provided as {@link module:engine/view/text~Text text}:
 *
 *		const text = downcastWriter.createText( 'foobar' );
 *		stringify( text ); // 'foobar'
 *
 * or as an {@link module:engine/view/element~Element element}:
 *
 *		const element = downcastWriter.createElement( 'p', null, downcastWriter.createText( 'foobar' ) );
 *		stringify( element ); // '<p>foobar</p>'
 *
 * or as a {@link module:engine/view/documentfragment~DocumentFragment document fragment}:
 *
 *		const text = downcastWriter.createText( 'foobar' );
 *		const b = downcastWriter.createElement( 'b', { name: 'test' }, text );
 *		const p = downcastWriter.createElement( 'p', { style: 'color:red;' } );
 *		const fragment = downcastWriter.createDocumentFragment( [ p, b ] );
 *
 *		stringify( fragment ); // '<p style="color:red;"></p><b name="test">foobar</b>'
 *
 * Additionally, a {@link module:engine/view/documentselection~DocumentSelection selection} instance can be provided.
 * Ranges from the selection will then be included in the output data.
 * If a range position is placed inside the element node, it will be represented with `[` and `]`:
 *
 *		const text = downcastWriter.createText( 'foobar' );
 *		const b = downcastWriter.createElement( 'b', null, text );
 *		const p = downcastWriter.createElement( 'p', null, b );
 *		const selection = downcastWriter.createSelection(
 *			downcastWriter.createRangeIn( p )
 *		);
 *
 *		stringify( p, selection ); // '<p>[<b>foobar</b>]</p>'
 *
 * If a range is placed inside the text node, it will be represented with `{` and `}`:
 *
 *		const text = downcastWriter.createText( 'foobar' );
 *		const b = downcastWriter.createElement( 'b', null, text );
 *		const p = downcastWriter.createElement( 'p', null, b );
 *		const selection = downcastWriter.createSelection(
 *			downcastWriter.createRange( downcastWriter.createPositionAt( text, 1 ), downcastWriter.createPositionAt( text, 5 ) )
 *		);
 *
 *		stringify( p, selection ); // '<p><b>f{ooba}r</b></p>'
 *
 * ** Note: **
 * It is possible to unify selection markers to `[` and `]` for both (inside and outside text)
 * by setting the `sameSelectionCharacters=true` option. It is mainly used when the view stringify option is used by
 * model utilities.
 *
 * Multiple ranges are supported:
 *
 *		const text = downcastWriter.createText( 'foobar' );
 *		const selection = downcastWriter.createSelection( [
 *			downcastWriter.createRange( downcastWriter.createPositionAt( text, 0 ), downcastWriter.createPositionAt( text, 1 ) ),
 *			downcastWriter.createRange( downcastWriter.createPositionAt( text, 3 ), downcastWriter.createPositionAt( text, 5 ) )
 *		] );
 *
 *		stringify( text, selection ); // '{f}oo{ba}r'
 *
 * A {@link module:engine/view/range~Range range} or {@link module:engine/view/position~Position position} instance can be provided
 * instead of the {@link module:engine/view/documentselection~DocumentSelection selection} instance. If a range instance
 * is provided, it will be converted to a selection containing this range. If a position instance is provided, it will
 * be converted to a selection containing one range collapsed at this position.
 *
 *		const text = downcastWriter.createText( 'foobar' );
 *		const range = downcastWriter.createRange( downcastWriter.createPositionAt( text, 0 ), downcastWriter.createPositionAt( text, 1 ) );
 *		const position = downcastWriter.createPositionAt( text, 3 );
 *
 *		stringify( text, range ); // '{f}oobar'
 *		stringify( text, position ); // 'foo{}bar'
 *
 * An additional `options` object can be provided.
 * If `options.showType` is set to `true`, element's types will be
 * presented for {@link module:engine/view/attributeelement~AttributeElement attribute elements},
 * {@link module:engine/view/containerelement~ContainerElement container elements}
 * {@link module:engine/view/emptyelement~EmptyElement empty elements}
 * and {@link module:engine/view/uielement~UIElement UI elements}:
 *
 *		const attribute = downcastWriter.createAttributeElement( 'b' );
 *		const container = downcastWriter.createContainerElement( 'p' );
 *		const empty = downcastWriter.createEmptyElement( 'img' );
 *		const ui = downcastWriter.createUIElement( 'span' );
 *		getData( attribute, null, { showType: true } ); // '<attribute:b></attribute:b>'
 *		getData( container, null, { showType: true } ); // '<container:p></container:p>'
 *		getData( empty, null, { showType: true } ); // '<empty:img></empty:img>'
 *		getData( ui, null, { showType: true } ); // '<ui:span></ui:span>'
 *
 * If `options.showPriority` is set to `true`, a priority will be displayed for all
 * {@link module:engine/view/attributeelement~AttributeElement attribute elements}.
 *
 *		const attribute = downcastWriter.createAttributeElement( 'b' );
 *		attribute._priority = 20;
 *		getData( attribute, null, { showPriority: true } ); // <b view-priority="20"></b>
 *
 * If `options.showAttributeElementId` is set to `true`, the attribute element's id will be displayed for all
 * {@link module:engine/view/attributeelement~AttributeElement attribute elements} that have it set.
 *
 *		const attribute = downcastWriter.createAttributeElement( 'span' );
 *		attribute._id = 'marker:foo';
 *		getData( attribute, null, { showAttributeElementId: true } ); // <span view-id="marker:foo"></span>
 *
 * @param {module:engine/view/text~Text|module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment}
 * node The node to stringify.
 * @param {module:engine/view/documentselection~DocumentSelection|module:engine/view/position~Position|module:engine/view/range~Range}
 * [selectionOrPositionOrRange = null ]
 * A selection instance whose ranges will be included in the returned string data. If a range instance is provided, it will be
 * converted to a selection containing this range. If a position instance is provided, it will be converted to a selection
 * containing one range collapsed at this position.
 * @param {Object} [options] An object with additional options.
 * @param {Boolean} [options.showType=false] When set to `true`, the type of elements will be printed (`<container:p>`
 * instead of `<p>`, `<attribute:b>` instead of `<b>` and `<empty:img>` instead of `<img>`).
 * @param {Boolean} [options.showPriority=false] When set to `true`,  the attribute element's priority will be printed
 * (`<span view-priority="12">`, `<b view-priority="10">`).
 * @param {Boolean} [options.showAttributeElementId=false] When set to `true`, attribute element's id will be printed
 * (`<span id="marker:foo">`).
 * @param {Boolean} [options.ignoreRoot=false] When set to `true`, the root's element opening and closing will not be printed.
 * Mainly used by the `getData` function to ignore the {@link module:engine/view/document~Document document's} root element.
 * @param {Boolean} [options.sameSelectionCharacters=false] When set to `true`, the selection inside the text will be marked as
 *  `{` and `}` and the selection outside the text as `[` and `]`. When set to `false`, both will be marked as `[` and `]` only.
 * @param {Boolean} [options.renderUIElements=false] When set to `true`, the inner content of each
 * {@link module:engine/view/uielement~UIElement} will be printed.
 * @param {Boolean} [options.renderRawElements=false] When set to `true`, the inner content of each
 * {@link module:engine/view/rawelement~RawElement} will be printed.
 * @param {Object} [options.domConverter={}] When set to an actual {@link module:engine/view/domconverter~DomConverter DomConverter}
 * instance, it lets the conversion go through exactly the same flow the editing view is going through,
 * i.e. with view data filtering. Otherwise the simple stub is used.
 * @returns {String} An HTML-like string representing the view.
 */
export function stringify(node, selectionOrPositionOrRange = null, options = {}) {
    let selection;
    if (selectionOrPositionOrRange instanceof Position ||
        selectionOrPositionOrRange instanceof Range) {
        selection = new DocumentSelection(selectionOrPositionOrRange);
    }
    else {
        selection = selectionOrPositionOrRange;
    }
    const viewStringify = new ViewStringify(node, selection, options);
    return viewStringify.stringify();
}
/**
 * Parses an HTML-like string and returns a view tree.
 * A simple string will be converted to a {@link module:engine/view/text~Text text} node:
 *
 *		parse( 'foobar' ); // Returns an instance of text.
 *
 * {@link module:engine/view/element~Element Elements} will be parsed with attributes as children:
 *
 *		parse( '<b name="baz">foobar</b>' ); // Returns an instance of element with the `baz` attribute and a text child node.
 *
 * Multiple nodes provided on root level will be converted to a
 * {@link module:engine/view/documentfragment~DocumentFragment document fragment}:
 *
 *		parse( '<b>foo</b><i>bar</i>' ); // Returns a document fragment with two child elements.
 *
 * The method can parse multiple {@link module:engine/view/range~Range ranges} provided in string data and return a
 * {@link module:engine/view/documentselection~DocumentSelection selection} instance containing these ranges. Ranges placed inside
 * {@link module:engine/view/text~Text text} nodes should be marked using `{` and `}` brackets:
 *
 *		const { text, selection } = parse( 'f{ooba}r' );
 *
 * Ranges placed outside text nodes should be marked using `[` and `]` brackets:
 *
 *		const { root, selection } = parse( '<p>[<b>foobar</b>]</p>' );
 *
 * ** Note: **
 * It is possible to unify selection markers to `[` and `]` for both (inside and outside text)
 * by setting `sameSelectionCharacters=true` option. It is mainly used when the view parse option is used by model utilities.
 *
 * Sometimes there is a need for defining the order of ranges inside the created selection. This can be achieved by providing
 * the range order array as an additional parameter:
 *
 *		const { root, selection } = parse( '{fo}ob{ar}{ba}z', { order: [ 2, 3, 1 ] } );
 *
 * In the example above, the first range (`{fo}`) will be added to the selection as the second one, the second range (`{ar}`) will be
 * added as the third and the third range (`{ba}`) will be added as the first one.
 *
 * If the selection's last range should be added as a backward one
 * (so the {@link module:engine/view/documentselection~DocumentSelection#anchor selection anchor} is represented
 * by the `end` position and {@link module:engine/view/documentselection~DocumentSelection#focus selection focus} is
 * represented by the `start` position), use the `lastRangeBackward` flag:
 *
 *		const { root, selection } = parse( `{foo}bar{baz}`, { lastRangeBackward: true } );
 *
 * Some more examples and edge cases:
 *
 *		// Returns an empty document fragment.
 *		parse( '' );
 *
 *		// Returns an empty document fragment and a collapsed selection.
 *		const { root, selection } = parse( '[]' );
 *
 *		// Returns an element and a selection that is placed inside the document fragment containing that element.
 *		const { root, selection } = parse( '[<a></a>]' );
 *
 * @param {String} data An HTML-like string to be parsed.
 * @param {Object} options
 * @param {Array.<Number>} [options.order] An array with the order of parsed ranges added to the returned
 * {@link module:engine/view/documentselection~DocumentSelection Selection} instance. Each element should represent the
 * desired position of each range in the selection instance. For example: `[2, 3, 1]` means that the first range will be
 * placed as the second, the second as the third and the third as the first.
 * @param {Boolean} [options.lastRangeBackward=false] If set to `true`, the last range will be added as backward to the returned
 * {@link module:engine/view/documentselection~DocumentSelection selection} instance.
 * @param {module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment}
 * [options.rootElement=null] The default root to use when parsing elements.
 * When set to `null`, the root element will be created automatically. If set to
 * {@link module:engine/view/element~Element Element} or {@link module:engine/view/documentfragment~DocumentFragment DocumentFragment},
 * this node will be used as the root for all parsed nodes.
 * @param {Boolean} [options.sameSelectionCharacters=false] When set to `false`, the selection inside the text should be marked using
 * `{` and `}` and the selection outside the ext using `[` and `]`. When set to `true`, both should be marked with `[` and `]` only.
 * @param {module:engine/view/stylesmap~StylesProcessor} [options.stylesProcessor] Styles processor.
 * @returns {module:engine/view/text~Text|module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment|Object}
 * Returns the parsed view node or an object with two fields: `view` and `selection` when selection ranges were included in the data
 * to parse.
 */
export function parse(data, options = {}) {
    const viewDocument = new ViewDocument(new StylesProcessor());
    options.order = options.order || [];
    const rangeParser = new RangeParser({
        sameSelectionCharacters: options.sameSelectionCharacters
    });
    const processor = new XmlDataProcessor(viewDocument, {
        namespaces: Object.keys(allowedTypes)
    });
    // Convert data to view.
    let view = processor.toView(data);
    // At this point we have a view tree with Elements that could have names like `attribute:b:1`. In the next step
    // we need to parse Element's names and convert them to AttributeElements and ContainerElements.
    view = _convertViewElements(view);
    // If custom root is provided - move all nodes there.
    if (options.rootElement) {
        const root = options.rootElement;
        const nodes = view._removeChildren(0, view.childCount);
        root._removeChildren(0, root.childCount);
        root._appendChild(nodes);
        view = root;
    }
    // Parse ranges included in view text nodes.
    const ranges = rangeParser.parse(view, options.order);
    // If only one element is returned inside DocumentFragment - return that element.
    if (view.is('documentFragment') && view.childCount === 1) {
        view = view.getChild(0);
    }
    // When ranges are present - return object containing view, and selection.
    if (ranges.length) {
        const selection = new DocumentSelection(ranges, { backward: !!options.lastRangeBackward });
        return {
            view,
            selection
        };
    }
    // If single element is returned without selection - remove it from parent and return detached element.
    if (view.parent) {
        view._remove();
    }
    return view;
}
/**
 * Private helper class used for converting ranges represented as text inside view {@link module:engine/view/text~Text text nodes}.
 *
 * @private
 */
class RangeParser {
    /**
     * Creates a range parser instance.
     *
     * @param {Object} options The range parser configuration.
     * @param {Boolean} [options.sameSelectionCharacters=false] When set to `true`, the selection inside the text is marked as
     * `{` and `}` and the selection outside the text as `[` and `]`. When set to `false`, both are marked as `[` and `]`.
     */
    constructor(options) {
        this.sameSelectionCharacters = !!options.sameSelectionCharacters;
    }
    /**
     * Parses the view and returns ranges represented inside {@link module:engine/view/text~Text text nodes}.
     * The method will remove all occurrences of `{`, `}`, `[` and `]` from found text nodes. If a text node is empty after
     * the process, it will be removed, too.
     *
     * @param {module:engine/view/node~Node} node The starting node.
     * @param {Array.<Number>} order The order of ranges. Each element should represent the desired position of the range after
     * sorting. For example: `[2, 3, 1]` means that the first range will be placed as the second, the second as the third and the third
     * as the first.
     * @returns {Array.<module:engine/view/range~Range>} An array with ranges found.
     */
    parse(node, order) {
        this._positions = [];
        // Remove all range brackets from view nodes and save their positions.
        this._getPositions(node);
        // Create ranges using gathered positions.
        let ranges = this._createRanges();
        // Sort ranges if needed.
        if (order.length) {
            if (order.length != ranges.length) {
                throw new Error(`Parse error - there are ${ranges.length} ranges found, but ranges order array contains ${order.length} elements.`);
            }
            ranges = this._sortRanges(ranges, order);
        }
        return ranges;
    }
    /**
     * Gathers positions of brackets inside the view tree starting from the provided node. The method will remove all occurrences of
     * `{`, `}`, `[` and `]` from found text nodes. If a text node is empty after the process, it will be removed, too.
     *
     * @private
     * @param {module:engine/view/node~Node} node Staring node.
     */
    _getPositions(node) {
        if (node.is('documentFragment') || node.is('element')) {
            // Copy elements into the array, when nodes will be removed from parent node this array will still have all the
            // items needed for iteration.
            const children = [...node.getChildren()];
            for (const child of children) {
                this._getPositions(child);
            }
        }
        if (node.is('$text')) {
            const regexp = new RegExp(`[${TEXT_RANGE_START_TOKEN}${TEXT_RANGE_END_TOKEN}\\${ELEMENT_RANGE_END_TOKEN}\\${ELEMENT_RANGE_START_TOKEN}]`, 'g');
            let text = node.data;
            let match;
            let offset = 0;
            const brackets = [];
            // Remove brackets from text and store info about offset inside text node.
            while ((match = regexp.exec(text))) {
                const index = match.index;
                const bracket = match[0];
                brackets.push({
                    bracket,
                    textOffset: index - offset
                });
                offset++;
            }
            text = text.replace(regexp, '');
            node._data = text;
            const index = node.index;
            const parent = node.parent;
            // Remove empty text nodes.
            if (!text) {
                node._remove();
            }
            for (const item of brackets) {
                // Non-empty text node.
                if (text) {
                    if (this.sameSelectionCharacters ||
                        (!this.sameSelectionCharacters &&
                            (item.bracket == TEXT_RANGE_START_TOKEN || item.bracket == TEXT_RANGE_END_TOKEN))) {
                        // Store information about text range delimiter.
                        this._positions.push({
                            bracket: item.bracket,
                            position: new Position(node, item.textOffset)
                        });
                    }
                    else {
                        // Check if element range delimiter is not placed inside text node.
                        if (!this.sameSelectionCharacters && item.textOffset !== 0 && item.textOffset !== text.length) {
                            throw new Error(`Parse error - range delimiter '${item.bracket}' is placed inside text node.`);
                        }
                        // If bracket is placed at the end of the text node - it should be positioned after it.
                        const offset = (item.textOffset === 0 ? index : index + 1);
                        // Store information about element range delimiter.
                        this._positions.push({
                            bracket: item.bracket,
                            position: new Position(parent, offset)
                        });
                    }
                }
                else {
                    if (!this.sameSelectionCharacters &&
                        item.bracket == TEXT_RANGE_START_TOKEN ||
                        item.bracket == TEXT_RANGE_END_TOKEN) {
                        throw new Error(`Parse error - text range delimiter '${item.bracket}' is placed inside empty text node. `);
                    }
                    // Store information about element range delimiter.
                    this._positions.push({
                        bracket: item.bracket,
                        position: new Position(parent, index)
                    });
                }
            }
        }
    }
    /**
     * Sorts ranges in a given order. Range order should be an array and each element should represent the desired position
     * of the range after sorting.
     * For example: `[2, 3, 1]` means that the first range will be placed as the second, the second as the third and the third
     * as the first.
     *
     * @private
     * @param {Array.<module:engine/view/range~Range>} ranges Ranges to sort.
     * @param {Array.<Number>} rangesOrder An array with new range order.
     * @returns {Array} Sorted ranges array.
     */
    _sortRanges(ranges, rangesOrder) {
        const sortedRanges = [];
        let index = 0;
        for (const newPosition of rangesOrder) {
            if (ranges[newPosition - 1] === undefined) {
                throw new Error('Parse error - provided ranges order is invalid.');
            }
            sortedRanges[newPosition - 1] = ranges[index];
            index++;
        }
        return sortedRanges;
    }
    /**
     * Uses all found bracket positions to create ranges from them.
     *
     * @private
     * @returns {Array.<module:engine/view/range~Range>}
     */
    _createRanges() {
        const ranges = [];
        let range = null;
        for (const item of this._positions) {
            // When end of range is found without opening.
            if (!range && (item.bracket == ELEMENT_RANGE_END_TOKEN || item.bracket == TEXT_RANGE_END_TOKEN)) {
                throw new Error(`Parse error - end of range was found '${item.bracket}' but range was not started before.`);
            }
            // When second start of range is found when one is already opened - selection does not allow intersecting
            // ranges.
            if (range && (item.bracket == ELEMENT_RANGE_START_TOKEN || item.bracket == TEXT_RANGE_START_TOKEN)) {
                throw new Error(`Parse error - start of range was found '${item.bracket}' but one range is already started.`);
            }
            if (item.bracket == ELEMENT_RANGE_START_TOKEN || item.bracket == TEXT_RANGE_START_TOKEN) {
                range = new Range(item.position, item.position);
            }
            else {
                range.end = item.position;
                ranges.push(range);
                range = null;
            }
        }
        // Check if all ranges have proper ending.
        if (range !== null) {
            throw new Error('Parse error - range was started but no end delimiter was found.');
        }
        return ranges;
    }
}
/**
 * Private helper class used for converting the view tree to a string.
 *
 * @private
 */
class ViewStringify {
    /**
     * Creates a view stringify instance.
     *
     * @param root
     * @param {module:engine/view/documentselection~DocumentSelection} selection A selection whose ranges
     * should also be converted to a string.
     * @param {Object} options An options object.
     * @param {Boolean} [options.showType=false] When set to `true`, the type of elements will be printed (`<container:p>`
     * instead of `<p>`, `<attribute:b>` instead of `<b>` and `<empty:img>` instead of `<img>`).
     * @param {Boolean} [options.showPriority=false] When set to `true`, the attribute element's priority will be printed.
     * @param {Boolean} [options.ignoreRoot=false] When set to `true`, the root's element opening and closing tag will not
     * be outputted.
     * @param {Boolean} [options.sameSelectionCharacters=false] When set to `true`, the selection inside the text is marked as
     * `{` and `}` and the selection outside the text as `[` and `]`. When set to `false`, both are marked as `[` and `]`.
     * @param {Boolean} [options.renderUIElements=false] When set to `true`, the inner content of each
     * {@link module:engine/view/uielement~UIElement} will be printed.
     * @param {Boolean} [options.renderRawElements=false] When set to `true`, the inner content of each
     * @param {Object} [options.domConverter={}] When set to an actual {@link module:engine/view/domconverter~DomConverter DomConverter}
     * instance, it lets the conversion go through exactly the same flow the editing view is going through,
     * i.e. with view data filtering. Otherwise the simple stub is used.
     * {@link module:engine/view/rawelement~RawElement} will be printed.
     */
    constructor(root, selection, options) {
        this.root = root;
        this.selection = selection;
        this.ranges = [];
        if (selection) {
            this.ranges = [...selection.getRanges()];
        }
        this.showType = !!options.showType;
        this.showPriority = !!options.showPriority;
        this.showAttributeElementId = !!options.showAttributeElementId;
        this.ignoreRoot = !!options.ignoreRoot;
        this.sameSelectionCharacters = !!options.sameSelectionCharacters;
        this.renderUIElements = !!options.renderUIElements;
        this.renderRawElements = !!options.renderRawElements;
        this.domConverter = options.domConverter || domConverterStub;
    }
    /**
     * Converts the view to a string.
     *
     * @returns {String} String representation of the view elements.
     */
    stringify() {
        let result = '';
        this._walkView(this.root, chunk => {
            result += chunk;
        });
        return result;
    }
    /**
     * Executes a simple walker that iterates over all elements in the view tree starting from the root element.
     * Calls the `callback` with parsed chunks of string data.
     *
     * @private
     * @param {module:engine/view/documentfragment~DocumentFragment|module:engine/view/element~Element|module:engine/view/text~Text} root
     * @param {Function} callback
     */
    _walkView(root, callback) {
        const ignore = this.ignoreRoot && this.root === root;
        if (root.is('element') || root.is('documentFragment')) {
            if (root.is('element') && !ignore) {
                callback(this._stringifyElementOpen(root));
            }
            if ((this.renderUIElements && root.is('uiElement'))) {
                callback(root.render(document, this.domConverter).innerHTML);
            }
            else if (this.renderRawElements && root.is('rawElement')) {
                // There's no DOM element for "root" to pass to render(). Creating
                // a surrogate container to render the children instead.
                const rawContentContainer = document.createElement('div');
                root.render(rawContentContainer, this.domConverter);
                callback(rawContentContainer.innerHTML);
            }
            else {
                let offset = 0;
                callback(this._stringifyElementRanges(root, offset));
                for (const child of root.getChildren()) {
                    this._walkView(child, callback);
                    offset++;
                    callback(this._stringifyElementRanges(root, offset));
                }
            }
            if (root.is('element') && !ignore) {
                callback(this._stringifyElementClose(root));
            }
        }
        if (root.is('$text')) {
            callback(this._stringifyTextRanges(root));
        }
    }
    /**
     * Checks if a given {@link module:engine/view/element~Element element} has a {@link module:engine/view/range~Range#start range start}
     * or a {@link module:engine/view/range~Range#start range end} placed at a given offset and returns its string representation.
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @param {Number} offset
     */
    _stringifyElementRanges(element, offset) {
        let start = '';
        let end = '';
        let collapsed = '';
        for (const range of this.ranges) {
            if (range.start.parent == element && range.start.offset === offset) {
                if (range.isCollapsed) {
                    collapsed += ELEMENT_RANGE_START_TOKEN + ELEMENT_RANGE_END_TOKEN;
                }
                else {
                    start += ELEMENT_RANGE_START_TOKEN;
                }
            }
            if (range.end.parent === element && range.end.offset === offset && !range.isCollapsed) {
                end += ELEMENT_RANGE_END_TOKEN;
            }
        }
        return end + collapsed + start;
    }
    /**
     * Checks if a given {@link module:engine/view/element~Element Text node} has a
     * {@link module:engine/view/range~Range#start range start} or a
     * {@link module:engine/view/range~Range#start range end} placed somewhere inside. Returns a string representation of text
     * with range delimiters placed inside.
     *
     * @private
     * @param {module:engine/view/text~Text} node
     */
    _stringifyTextRanges(node) {
        const length = node.data.length;
        const data = node.data.split('');
        let rangeStartToken, rangeEndToken;
        if (this.sameSelectionCharacters) {
            rangeStartToken = ELEMENT_RANGE_START_TOKEN;
            rangeEndToken = ELEMENT_RANGE_END_TOKEN;
        }
        else {
            rangeStartToken = TEXT_RANGE_START_TOKEN;
            rangeEndToken = TEXT_RANGE_END_TOKEN;
        }
        // Add one more element for ranges ending after last character in text.
        data[length] = '';
        // Represent each letter as object with information about opening/closing ranges at each offset.
        const result = data.map(letter => {
            return {
                letter,
                start: '',
                end: '',
                collapsed: ''
            };
        });
        for (const range of this.ranges) {
            const start = range.start;
            const end = range.end;
            if (start.parent == node && start.offset >= 0 && start.offset <= length) {
                if (range.isCollapsed) {
                    result[end.offset].collapsed += rangeStartToken + rangeEndToken;
                }
                else {
                    result[start.offset].start += rangeStartToken;
                }
            }
            if (end.parent == node && end.offset >= 0 && end.offset <= length && !range.isCollapsed) {
                result[end.offset].end += rangeEndToken;
            }
        }
        return result.map(item => item.end + item.collapsed + item.start + item.letter).join('');
    }
    /**
     * Converts the passed {@link module:engine/view/element~Element element} to an opening tag.
     *
     * Depending on the current configuration, the opening tag can be simple (`<a>`), contain a type prefix (`<container:p>`,
     * `<attribute:a>` or `<empty:img>`), contain priority information ( `<attribute:a view-priority="20">` ),
     * or contain element id ( `<attribute:span view-id="foo">` ). Element attributes will also be included
     * (`<a href="https://ckeditor.com" name="foobar">`).
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @returns {String}
     */
    _stringifyElementOpen(element) {
        const priority = this._stringifyElementPriority(element);
        const id = this._stringifyElementId(element);
        const type = this._stringifyElementType(element);
        const name = [type, element.name].filter(i => i !== '').join(':');
        const attributes = this._stringifyElementAttributes(element);
        const parts = [name, priority, id, attributes];
        return `<${parts.filter(i => i !== '').join(' ')}>`;
    }
    /**
     * Converts the passed {@link module:engine/view/element~Element element} to a closing tag.
     * Depending on the current configuration, the closing tag can be simple (`</a>`) or contain a type prefix (`</container:p>`,
     * `</attribute:a>` or `</empty:img>`).
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @returns {String}
     */
    _stringifyElementClose(element) {
        const type = this._stringifyElementType(element);
        const name = [type, element.name].filter(i => i !== '').join(':');
        return `</${name}>`;
    }
    /**
     * Converts the passed {@link module:engine/view/element~Element element's} type to its string representation
     *
     * Returns:
     * * 'attribute' for {@link module:engine/view/attributeelement~AttributeElement attribute elements},
     * * 'container' for {@link module:engine/view/containerelement~ContainerElement container elements},
     * * 'empty' for {@link module:engine/view/emptyelement~EmptyElement empty elements},
     * * 'ui' for {@link module:engine/view/uielement~UIElement UI elements},
     * * 'raw' for {@link module:engine/view/rawelement~RawElement raw elements},
     * * an empty string when the current configuration is preventing showing elements' types.
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @returns {String}
     */
    _stringifyElementType(element) {
        if (this.showType) {
            for (const type in allowedTypes) {
                if (element instanceof allowedTypes[type]) {
                    return type;
                }
            }
        }
        return '';
    }
    /**
     * Converts the passed {@link module:engine/view/element~Element element} to its priority representation.
     *
     * The priority string representation will be returned when the passed element is an instance of
     * {@link module:engine/view/attributeelement~AttributeElement attribute element} and the current configuration allows to show the
     * priority. Otherwise returns an empty string.
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @returns {String}
     */
    _stringifyElementPriority(element) {
        if (this.showPriority && element.is('attributeElement')) {
            return `view-priority="${element.priority}"`;
        }
        return '';
    }
    /**
     * Converts the passed {@link module:engine/view/element~Element element} to its id representation.
     *
     * The id string representation will be returned when the passed element is an instance of
     * {@link module:engine/view/attributeelement~AttributeElement attribute element}, the element has an id
     * and the current configuration allows to show the id. Otherwise returns an empty string.
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @returns {String}
     */
    _stringifyElementId(element) {
        if (this.showAttributeElementId && element.is('attributeElement') && element.id) {
            return `view-id="${element.id}"`;
        }
        return '';
    }
    /**
     * Converts the passed {@link module:engine/view/element~Element element} attributes to their string representation.
     * If an element has no attributes, an empty string is returned.
     *
     * @private
     * @param {module:engine/view/element~Element} element
     * @returns {String}
     */
    _stringifyElementAttributes(element) {
        const attributes = [];
        const keys = [...element.getAttributeKeys()].sort();
        for (const attribute of keys) {
            let attributeValue;
            if (attribute === 'class') {
                attributeValue = [...element.getClassNames()]
                    .sort()
                    .join(' ');
            }
            else if (attribute === 'style') {
                attributeValue = [...element.getStyleNames()]
                    .sort()
                    .map(style => `${style}:${element.getStyle(style)}`)
                    .join(';');
            }
            else {
                attributeValue = element.getAttribute(attribute);
            }
            attributes.push(`${attribute}="${attributeValue}"`);
        }
        return attributes.join(' ');
    }
}
// Converts {@link module:engine/view/element~Element elements} to
// {@link module:engine/view/attributeelement~AttributeElement attribute elements},
// {@link module:engine/view/containerelement~ContainerElement container elements},
// {@link module:engine/view/emptyelement~EmptyElement empty elements} or
// {@link module:engine/view/uielement~UIElement UI elements}.
// It converts the whole tree starting from the `rootNode`. The conversion is based on element names.
// See the `_convertElement` method for more details.
//
// @param {module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment|module:engine/view/text~Text}
//  rootNode The root node to convert.
// @returns {module:engine/view/element~Element|module:engine/view/documentfragment~DocumentFragment|
// module:engine/view/text~Text} The root node of converted elements.
function _convertViewElements(rootNode) {
    if (rootNode.is('element') || rootNode.is('documentFragment')) {
        // Convert element or leave document fragment.
        const convertedElement = rootNode.is('documentFragment') ?
            new ViewDocumentFragment(rootNode.document) :
            _convertElement(rootNode.document, rootNode);
        // Convert all child nodes.
        // Cache the nodes in array. Otherwise, we would skip some nodes because during iteration we move nodes
        // from `rootNode` to `convertedElement`. This would interfere with iteration.
        for (const child of [...rootNode.getChildren()]) {
            if (convertedElement.is('emptyElement')) {
                throw new Error('Parse error - cannot parse inside EmptyElement.');
            }
            else if (convertedElement.is('uiElement')) {
                throw new Error('Parse error - cannot parse inside UIElement.');
            }
            else if (convertedElement.is('rawElement')) {
                throw new Error('Parse error - cannot parse inside RawElement.');
            }
            convertedElement._appendChild(_convertViewElements(child));
        }
        return convertedElement;
    }
    return rootNode;
}
// Converts an {@link module:engine/view/element~Element element} to
// {@link module:engine/view/attributeelement~AttributeElement attribute element},
// {@link module:engine/view/containerelement~ContainerElement container element},
// {@link module:engine/view/emptyelement~EmptyElement empty element} or
// {@link module:engine/view/uielement~UIElement UI element}.
// If the element's name is in the format of `attribute:b`, it will be converted to
// an {@link module:engine/view/attributeelement~AttributeElement attribute element} with a priority of 11.
// Additionally, attribute elements may have specified priority (for example `view-priority="11"`) and/or
// id (for example `view-id="foo"`).
// If the element's name is in the format of `container:p`, it will be converted to
// a {@link module:engine/view/containerelement~ContainerElement container element}.
// If the element's name is in the format of `empty:img`, it will be converted to
// an {@link module:engine/view/emptyelement~EmptyElement empty element}.
// If the element's name is in the format of `ui:span`, it will be converted to
// a {@link module:engine/view/uielement~UIElement UI element}.
// If the element's name does not contain any additional information, a {@link module:engine/view/element~Element view Element} will be
// returned.
//
// @param {module:engine/view/element~Element} viewElement A view element to convert.
// @returns {module:engine/view/element~Element|module:engine/view/attributeelement~AttributeElement|
// module:engine/view/emptyelement~EmptyElement|module:engine/view/uielement~UIElement|
// module:engine/view/containerelement~ContainerElement} A tree view
// element converted according to its name.
function _convertElement(viewDocument, viewElement) {
    const info = _convertElementNameAndInfo(viewElement);
    const ElementConstructor = allowedTypes[info.type];
    const newElement = ElementConstructor ? new ElementConstructor(viewDocument, info.name) : new ViewElement(viewDocument, info.name);
    if (newElement.is('attributeElement')) {
        if (info.priority !== null) {
            newElement._priority = info.priority;
        }
        if (info.id !== null) {
            newElement._id = info.id;
        }
    }
    // Move attributes.
    for (const attributeKey of viewElement.getAttributeKeys()) {
        newElement._setAttribute(attributeKey, viewElement.getAttribute(attributeKey));
    }
    return newElement;
}
// Converts the `view-priority` attribute and the {@link module:engine/view/element~Element#name element's name} information needed for
// creating {@link module:engine/view/attributeelement~AttributeElement attribute element},
// {@link module:engine/view/containerelement~ContainerElement container element},
// {@link module:engine/view/emptyelement~EmptyElement empty element} or
// {@link module:engine/view/uielement~UIElement UI element}.
// The name can be provided in two formats: as a simple element's name (`div`), or as a type and name (`container:div`,
// `attribute:span`, `empty:img`, `ui:span`);
//
// @param {module:engine/view/element~Element} element The element whose name should be converted.
// @returns {Object} info An object with parsed information.
// @returns {String} info.name The parsed name of the element.
// @returns {String|null} info.type The parsed type of the element. It can be `attribute`, `container` or `empty`.
// returns {Number|null} info.priority The parsed priority of the element.
function _convertElementNameAndInfo(viewElement) {
    const parts = viewElement.name.split(':');
    const priority = _convertPriority(viewElement.getAttribute('view-priority'));
    const id = viewElement.hasAttribute('view-id') ? viewElement.getAttribute('view-id') : null;
    viewElement._removeAttribute('view-priority');
    viewElement._removeAttribute('view-id');
    if (parts.length == 1) {
        return {
            name: parts[0],
            type: priority !== null ? 'attribute' : null,
            priority,
            id
        };
    }
    // Check if type and name: container:div.
    const type = _convertType(parts[0]);
    if (type) {
        return {
            name: parts[1],
            type,
            priority,
            id
        };
    }
    throw new Error(`Parse error - cannot parse element's name: ${viewElement.name}.`);
}
// Checks if the element's type is allowed. Returns `attribute`, `container`, `empty` or `null`.
//
// @param {String} type
// @returns {String|null}
function _convertType(type) {
    return type in allowedTypes ? type : null;
}
// Checks if a given priority is allowed. Returns null if the priority cannot be converted.
//
// @param {String} priorityString
// returns {Number|null}
function _convertPriority(priorityString) {
    const priority = parseInt(priorityString, 10);
    if (!isNaN(priority)) {
        return priority;
    }
    return null;
}
