import EventEmitter from './events.js';
import { parse, parseFragment, serialize } from 'parse5';

class HTML extends EventEmitter {
    constructor(ctx) {
        super();
        this.ctx = ctx;
        this.rewriteUrl = ctx.rewriteUrl;
        this.sourceUrl = ctx.sourceUrl;
    };
    rewrite(str, options = {}) {
        if (!str) return str;
        return this.recast(str, node => {
            if (node.tagName) this.emit('element', node, 'rewrite');
            if (node.attr) this.emit('attr', node, 'rewrite');
            if (node.nodeName === '#text') this.emit('text', node, 'rewrite');
        }, options)
    };
    source(str, options = {}) {
        if (!str) return str;
        return this.recast(str, node => {
            if (node.tagName) this.emit('element', node, 'source');
            if (node.attr) this.emit('attr', node, 'source');
            if (node.nodeName === '#text') this.emit('text', node, 'source');
        }, options)
    };
    recast(str, fn, options = {}) {
        try {
            const ast = (options.document ? parse : parseFragment)(new String(str).toString());
            this.iterate(ast, fn, options);
            return serialize(ast);
        } catch(e) {
            return str;
        };
    };
    iterate(ast, fn, fnOptions) {
        if (!ast) return ast;
    
        if (ast.tagName) {
            const element = new P5Element(ast, false, fnOptions);
            fn(element);
            if (ast.attrs) {
                for (const attr of ast.attrs) {
                    if (!attr.skip) fn(new AttributeEvent(element, attr, fnOptions));
                };
            };
        };

        if (ast.childNodes) {
            for (const child of ast.childNodes) {
                if (!child.skip) this.iterate(child, fn, fnOptions);
            };
        };

        if (ast.nodeName === '#text') {
            fn(new TextEvent(ast, new P5Element(ast.parentNode), false, fnOptions));
        };

        return ast;
    };
    wrapSrcset(str, meta = this.ctx.meta) {
        return str.split(',').map(src => {
            const parts = src.trimStart().split(' ');
            if (parts[0]) parts[0] = this.ctx.rewriteUrl(parts[0], meta);
            return parts.join(' ');
        }).join(', ');
    };
    unwrapSrcset(str, meta = this.ctx.meta) {
        return str.split(',').map(src => {
            const parts = src.trimStart().split(' ');
            if (parts[0]) parts[0] = this.ctx.sourceUrl(parts[0], meta);
            return parts.join(' ');
        }).join(', ');
    };
    static parse = parse;
    static parseFragment = parseFragment;
    static serialize = serialize;  
};

class P5Element extends EventEmitter {
    constructor(node, stream = false, options = {}) {
        super();
        this.stream = stream;
        this.node = node;
        this.options = options;
    };
    setAttribute(name, value) {
        for (const attr of this.attrs) {
            if (attr.name === name) {
                attr.value = value;
                return true;
            };
        };

        this.attrs.push(
            {
                name,
                value,
            }
        );
    };
    getAttribute(name) {
        const attr = this.attrs.find(attr => attr.name === name) || {};
        return attr.value;
    };
    hasAttribute(name) {
        return !!this.attrs.find(attr => attr.name === name);
    };
    removeAttribute(name) {
        const i = this.attrs.findIndex(attr => attr.name === name);
        if (typeof i !== 'undefined') this.attrs.splice(i, 1);
    };
    get tagName() {
        return this.node.tagName;
    };
    set tagName(val) {
        this.node.tagName = val;
    };
    get childNodes() {
        return !this.stream ? this.node.childNodes : null;
    };
    get innerHTML() {
        return !this.stream ? serialize(
            {
                nodeName: '#document-fragment',
                childNodes: this.childNodes,
            }
        ) : null;
    };
    set innerHTML(val) {
        if (!this.stream) this.node.childNodes = parseFragment(val).childNodes;
    };
    get outerHTML() {
        return !this.stream ? serialize(
            {
                nodeName: '#document-fragment',
                childNodes: [ this ],
            }
        ) : null;
    };
    set outerHTML(val) {
        if (!this.stream) this.parentNode.childNodes.splice(this.parentNode.childNodes.findIndex(node => node === this.node), 1, ...parseFragment(val).childNodes);
    };
    get textContent() {
        if (this.stream) return null;

        let str = '';
        iterate(this.node, node => {
            if (node.nodeName === '#text') str += node.value;
        });
        
        return str;
    };
    set textContent(val) {
        if (!this.stream) this.node.childNodes = [ 
            { 
                nodeName: '#text', 
                value: val,
                parentNode: this.node 
            }
        ];
    };
    get nodeName() {
        return this.node.nodeName;
    } 
    get parentNode() {
        return this.node.parentNode ? new P5Element(this.node.parentNode) : null;
    };
    get attrs() {
        return this.node.attrs;
    }
    get namespaceURI() {
        return this.node.namespaceURI;
    }
};

class AttributeEvent {
    constructor(node, attr, options = {}) {
        this.attr = attr;
        this.attrs = node.attrs;
        this.node = node;
        this.options = options;
    };
    delete() {
        const i = this.attrs.findIndex(attr => attr === this.attr);

        this.attrs.splice(i, 1);

        Object.defineProperty(this, 'deleted', {
            get: () => true,
        });

        return true;
    };
    get name() {
        return this.attr.name;
    };

    set name(val) {
        this.attr.name = val;
    };
    get value() {
        return this.attr.value;
    };

    set value(val) {
        this.attr.value = val;
    };
    get deleted() {
        return false;
    };
};

class TextEvent {
    constructor(node, element, stream = false, options = {}) {
        this.stream = stream;
        this.node = node;
        this.element = element;
        this.options = options;
    };
    get nodeName() {
        return this.node.nodeName;
    } 
    get parentNode() {
        return this.element;
    };
    get value() {
        return this.stream ? this.node.text : this.node.value;
    };
    set value(val) {

        if (this.stream) this.node.text = val;
        else this.node.value = val;
    };
};

export default HTML;