import { each, isArray, isFunction, isUndefined } from 'underscore';
import { ObjectAny } from '../../common';
import { CssRuleJSON } from '../../css_composer/model/CssRule';
import { ComponentDefinitionDefined } from '../../dom_components/model/types';
import EditorModel from '../../editor/model/Editor';
import { HTMLParserOptions, ParserConfig } from '../config/config';
import BrowserParserHtml from './BrowserParserHtml';

type StringObject = Record<string, string>;

type HTMLParseResult = {
  html: ComponentDefinitionDefined | ComponentDefinitionDefined[]; // TODO replace with components
  css?: CssRuleJSON[];
};

const modelAttrStart = 'data-gjs-';
const event = 'parse:html';

const ParserHtml = (em?: EditorModel, config: ParserConfig & { returnArray?: boolean } = {}) => {
  return {
    compTypes: '',

    modelAttrStart,

    getPropAttribute(attrName: string, attrValue?: string) {
      const name = attrName.replace(this.modelAttrStart, '');
      const valueLen = attrValue?.length || 0;
      const firstChar = attrValue?.substring(0, 1);
      const lastChar = attrValue?.substring(valueLen - 1);
      let value: any = attrValue === 'true' ? true : attrValue === 'false' ? false : attrValue;

      // Try to parse JSON where it's possible
      // I can get false positive here (eg. a selector '[data-attr]')
      // so put it under try/catch and let fail silently
      try {
        value =
          (firstChar == '{' && lastChar == '}') || (firstChar == '[' && lastChar == ']') ? JSON.parse(value) : value;
      } catch (e) {}

      return {
        name,
        value,
      };
    },

    /**
     * Extract component props from an attribute object
     * @param {Object} attr
     * @returns {Object} An object containing props and attributes without them
     */
    splitPropsFromAttr(attr: ObjectAny = {}) {
      const props: ObjectAny = {};
      const attrs: StringObject = {};

      each(attr, (value, key) => {
        if (key.indexOf(this.modelAttrStart) === 0) {
          const propsResult = this.getPropAttribute(key, value);
          props[propsResult.name] = propsResult.value;
        } else {
          attrs[key] = value;
        }
      });

      return {
        props,
        attrs,
      };
    },

    /**
     * Parse style string to object
     * @param {string} str
     * @return {Object}
     * @example
     * var stl = ParserHtml.parseStyle('color:black; width:100px; test:value;');
     * console.log(stl);
     * // {color: 'black', width: '100px', test: 'value'}
     */
    parseStyle(str: string) {
      const result: Record<string, string | string[]> = {};

      while (str.indexOf('/*') >= 0) {
        const start = str.indexOf('/*');
        const end = str.indexOf('*/') + 2;
        str = str.replace(str.slice(start, end), '');
      }

      const decls = str.split(';');

      for (let i = 0, len = decls.length; i < len; i++) {
        const decl = decls[i].trim();
        if (!decl) continue;
        const prop = decl.split(':');
        const key = prop[0].trim();
        const value = prop.slice(1).join(':').trim();

        // Support multiple values for the same key
        if (result[key]) {
          if (!isArray(result[key])) {
            result[key] = [result[key] as string];
          }

          (result[key] as string[]).push(value);
        } else {
          result[key] = value;
        }
      }

      return result;
    },

    /**
     * Parse class string to array
     * @param {string} str
     * @return {Array<string>}
     * @example
     * var res = ParserHtml.parseClass('test1 test2 test3');
     * console.log(res);
     * // ['test1', 'test2', 'test3']
     */
    parseClass(str: string) {
      const result = [];
      const cls = str.split(' ');

      for (let i = 0, len = cls.length; i < len; i++) {
        const cl = cls[i].trim();
        if (!cl) continue;
        result.push(cl);
      }

      return result;
    },

    /**
     * Get data from the node element
     * @param  {HTMLElement} el DOM element to traverse
     * @return {Array<Object>}
     */
    parseNode(el: HTMLElement, opts: ObjectAny = {}) {
      const result: ComponentDefinitionDefined[] = [];
      const nodes = el.childNodes;

      for (var i = 0, len = nodes.length; i < len; i++) {
        const node = nodes[i] as HTMLElement;
        const attrs = node.attributes || [];
        const attrsLen = attrs.length;
        const nodePrev = result[result.length - 1];
        const nodeChild = node.childNodes.length;
        const ct = this.compTypes;
        let model: ComponentDefinitionDefined = {}; // TODO use component properties

        // Start with understanding what kind of component it is
        if (ct) {
          let obj: any = '';
          let type = node.getAttribute && node.getAttribute(`${this.modelAttrStart}type`);

          // If the type is already defined, use it
          if (type) {
            model = { type };
          } else {
            // Iterate over all available Component Types and
            // the first with a valid result will be that component
            for (let it = 0; it < ct.length; it++) {
              const compType = ct[it];
              // @ts-ignore
              obj = compType.model.isComponent(node, opts);

              if (obj) {
                if (typeof obj !== 'object') {
                  // @ts-ignore
                  obj = { type: compType.id };
                }
                break;
              }
            }

            model = obj;
          }
        }

        // Set tag name if not yet done
        if (!model.tagName) {
          const tag = node.tagName || '';
          const ns = node.namespaceURI || '';
          model.tagName = tag && ns === 'http://www.w3.org/1999/xhtml' ? tag.toLowerCase() : tag;
        }

        if (attrsLen) {
          model.attributes = {};
        }

        // Parse attributes
        for (let j = 0; j < attrsLen; j++) {
          const nodeName = attrs[j].nodeName;
          let nodeValue: string | boolean = attrs[j].nodeValue!;

          // Isolate attributes
          if (nodeName == 'style') {
            model.style = this.parseStyle(nodeValue);
          } else if (nodeName == 'class') {
            model.classes = this.parseClass(nodeValue);
          } else if (nodeName == 'contenteditable') {
            continue;
          } else if (nodeName.indexOf(this.modelAttrStart) === 0) {
            const propsResult = this.getPropAttribute(nodeName, nodeValue);
            model[propsResult.name] = propsResult.value;
          } else {
            // @ts-ignore Check for attributes from props (eg. required, disabled)
            if (nodeValue === '' && node[nodeName] === true) {
              nodeValue = true;
            }

            model.attributes[nodeName] = nodeValue;
          }
        }

        // Check for nested elements but avoid it if already provided
        if (nodeChild && !model.components) {
          // Avoid infinite nested text nodes
          const firstChild = node.childNodes[0];

          // If there is only one child and it's a TEXTNODE
          // just make it content of the current node
          if (nodeChild === 1 && firstChild.nodeType === 3) {
            !model.type && (model.type = 'text');
            model.components = {
              type: 'textnode',
              content: firstChild.nodeValue,
            };
          } else {
            model.components = this.parseNode(node, {
              ...opts,
              inSvg: opts.inSvg || model.type === 'svg',
            });
          }
        }

        // Check if it's a text node and if could be moved to the prevous model
        if (model.type == 'textnode') {
          if (nodePrev && nodePrev.type == 'textnode') {
            nodePrev.content += model.content;
            continue;
          }

          // Throw away empty nodes (keep spaces)
          if (!opts.keepEmptyTextNodes) {
            const content = node.nodeValue;
            if (content != ' ' && !content!.trim()) {
              continue;
            }
          }
        }

        // Check for custom void elements (valid in XML)
        if (!nodeChild && `${node.outerHTML}`.slice(-2) === '/>') {
          model.void = true;
        }

        // If all children are texts and there is some textnode the parent should
        // be text too otherwise I'm unable to edit texnodes
        const comps = model.components;
        if (!model.type && comps) {
          let allTxt = 1;
          let foundTextNode = 0;

          for (let ci = 0; ci < comps.length; ci++) {
            const comp = comps[ci];
            const cType = comp.type;

            if (['text', 'textnode'].indexOf(cType) < 0 && config.textTags!.indexOf(comp.tagName) < 0) {
              allTxt = 0;
              break;
            }

            if (cType == 'textnode') {
              foundTextNode = 1;
            }
          }

          if (allTxt && foundTextNode) {
            model.type = 'text';
          }
        }

        // If tagName is still empty and is not a textnode, do not push it
        if (!model.tagName && model.type != 'textnode') {
          continue;
        }

        result.push(model);
      }

      return result;
    },

    /**
     * Parse HTML string to a desired model object
     * @param  {string} str HTML string
     * @param  {ParserCss} parserCss In case there is style tags inside HTML
     * @return {Object}
     */
    parse(str: string, parserCss?: any, opts: HTMLParserOptions = {}) {
      const conf = em?.get('Config') || {};
      const res: HTMLParseResult = { html: [] };
      const cf: ObjectAny = { ...config, ...opts };
      const options = {
        ...config.optionsHtml,
        // @ts-ignore Support previous `configParser.htmlType` option
        htmlType: config.optionsHtml?.htmlType || config.htmlType,
        ...opts,
      };
      const el = isFunction(cf.parserHtml) ? cf.parserHtml(str, options) : BrowserParserHtml(str, options);
      const scripts = el.querySelectorAll('script');
      let i = scripts.length;

      // Support previous `configMain.allowScripts` option
      const allowScripts = !isUndefined(conf.allowScripts) ? conf.allowScripts : options.allowScripts;

      // Remove script tags
      if (!allowScripts) {
        while (i--) scripts[i].parentNode.removeChild(scripts[i]);
      }

      // Remove unsafe attributes
      if (!options.allowUnsafeAttr) {
        this.__clearUnsafeAttr(el);
      }

      // Detach style tags and parse them
      if (parserCss) {
        const styles = el.querySelectorAll('style');
        let j = styles.length;
        let styleStr = '';

        while (j--) {
          styleStr = styles[j].innerHTML + styleStr;
          styles[j].parentNode.removeChild(styles[j]);
        }

        if (styleStr) res.css = parserCss.parse(styleStr);
      }

      em && em.trigger(`${event}:root`, { input: str, root: el });
      const result = this.parseNode(el, cf);
      // I have to keep it otherwise it breaks the DomComponents.addComponent (returns always array)
      const resHtml = result.length === 1 && !cf.returnArray ? result[0] : result;
      res.html = resHtml;
      em && em.trigger(event, { input: str, output: res });

      return res;
    },

    __clearUnsafeAttr(node: HTMLElement) {
      const attrs = node.attributes || [];
      const nodes = node.childNodes || [];
      const toRemove: string[] = [];
      each(attrs, attr => {
        const name = attr.nodeName || '';
        name.indexOf('on') === 0 && toRemove.push(name);
      });
      toRemove.map(name => node.removeAttribute(name));
      each(nodes, node => this.__clearUnsafeAttr(node as HTMLElement));
    },
  };
};

export default ParserHtml;