// Main perser class

'use strict';


var utils        = require('./common/utils');
var helpers      = require('./helpers');
var Renderer     = require('./renderer');
var ParserCore   = require('./parser_core');
var ParserBlock  = require('./parser_block');
var ParserInline = require('./parser_inline');

var config = {
  'default': require('./presets/default'),
  zero: require('./presets/zero'),
  full: require('./presets/full'),
  commonmark: require('./presets/commonmark')
};


function StateCore(self, src, env) {
  this.src = src;
  this.env = env;
  this.options = self.options;
  this.tokens = [];
  this.inlineMode = false;

  this.inline = self.inline;
  this.block = self.block;
  this.renderer = self.renderer;
  this.typographer = self.typographer;
}

/**
 * class MarkdownIt
 *
 * Main parser/renderer class.
 *
 * ##### Usage
 *
 * ```javascript
 * // node.js, "classic" way:
 * var MarkdownIt = require('markdown-it'),
 *     md = new MarkdownIt();
 * var result = md.render('# markdown-it rulezz!');
 *
 * // node.js, the same, but with sugar:
 * var md = require('markdown-it')();
 * var result = md.render('# markdown-it rulezz!');
 *
 * // browser without AMD, added to "window" on script load
 * // Note, there are no dash.
 * var md = window.markdownit();
 * var result = md.render('# markdown-it rulezz!');
 * ```
 *
 * Single line rendering, without paragraph wrap:
 *
 * ```javascript
 * var md = require('markdown-it')();
 * var result = md.renderInline('__markdown-it__ rulezz!');
 * ```
 **/

/**
 * new MarkdownIt([presetName, options])
 * - presetName (String): optional, `commonmark` / `full` / `zero`
 * - options (Object)
 *
 * Creates parser instanse with given config. Can be called without `new`.
 *
 * ##### presetName
 *
 * MarkdownIt provides named presets as a convenience to quickly
 * enable/disable active syntax rules and options for common use cases.
 *
 * - ["commonmark"](https://github.com/markdown-it/markdown-it/blob/master/lib/presets/commonmark.js) -
 *   configures parser to strict [CommonMark](http://commonmark.org/) mode.
 * - ["full"](https://github.com/markdown-it/markdown-it/blob/master/lib/presets/full.js) -
 *   enables all available rules, but still without html, typographer & autolinker.
 * - [default](https://github.com/markdown-it/markdown-it/blob/master/lib/presets/default.js) -
 *   similar to GFM, used when no preset name given.
 * - ["zero"](https://github.com/markdown-it/markdown-it/blob/master/lib/presets/zero.js) -
 *   all rules disabled. Useful to quickly setup your config via `.enable()`.
 *   For example, when you need only `bold` and `italic` markup and nothing else.
 *
 * ##### options:
 *
 * - __html__ - `false`. Set `true` to enable HTML tags in source. Be careful!
 *   That's not safe! You may need external sanitizer to protect output from XSS.
 *   It's better to extend features via plugins, instead of enabling HTML.
 * - __xhtmlOut__ - `false`. Set `true` to add '/' when closing single tags
 *   (`<br />`). This is needed only for full CommonMark compatibility. In real
 *   world you will need HTML output.
 * - __breaks__ - `false`. Set `true` to convert `\n` in paragraphs into `<br>`.
 * - __langPrefix__ - `language-`. CSS language class prefix for fenced blocks.
 *   Can be useful for external highlighters.
 * - __linkify__ - `false`. Set `true` to autoconvert URL-like text to links.
 * - __typographer__  - `false`. Set `true` to enable [some language-neutral
 *   replacement](https://github.com/markdown-it/markdown-it/blob/master/lib/rules_core/replacements.js) +
 *   quotes beautification (smartquotes).
 * - __quotes__ - `“”‘’`, string. Double + single quotes replacement pairs, when
 *   typographer enabled and smartquotes on. Set doubles to '«»' for Russian,
 *   '„“' for German.
 * - __highlight__ - `null`. Highlighter function for fenced code blocks.
 *   Highlighter `function (str, lang)` should return escaped HTML. It can also
 *   return empty string if the source was not changed and should be escaped externaly.
 *
 * ##### Example
 *
 * ```javascript
 * // commonmark mode
 * var md = require('markdown-it')('commonmark');
 *
 * // default mode
 * var md = require('markdown-it')();
 *
 * // enable everything
 * var md = require('markdown-it')('full', {
 *   html: true,
 *   linkify: true,
 *   typographer: true
 * });
 * ```
 *
 * ##### Syntax highlighting
 *
 * ```js
 * var hljs = require('highlight.js') // https://highlightjs.org/
 *
 * var md = require('markdown-it')({
 *   highlight: function (str, lang) {
 *     if (lang && hljs.getLanguage(lang)) {
 *       try {
 *         return hljs.highlight(lang, str).value;
 *       } catch (__) {}
 *     }
 *
 *     try {
 *       return hljs.highlightAuto(str).value;
 *     } catch (__) {}
 *
 *     return ''; // use external default escaping
 *   }
 * });
 * ```
 **/
function MarkdownIt(presetName, options) {
  if (!(this instanceof MarkdownIt)) {
    return new MarkdownIt(presetName, options);
  }

  if (!options) {
    if (!utils.isString(presetName)) {
      options = presetName || {};
      presetName = 'default';
    }
  }

  /**
   * MarkdownIt#inline -> ParserInline
   *
   * Instance of inline parser. You may need it to add new rules when
   * writing plugins. For simple rules control use [[MarkdownIt.disable]] and
   * [[MarkdownIt.enable]].
   **/
  this.inline = new ParserInline();

  /**
   * MarkdownIt#block -> ParserBlock
   *
   * Instance of block parser. You may need it to add new rules when
   * writing plugins. For simple rules control use [[MarkdownIt.disable]] and
   * [[MarkdownIt.enable]].
   **/
  this.block = new ParserBlock();

  /**
   * MarkdownIt#core -> ParserCore
   *
   * Instance of core chain executor. You may need it to add new rules when
   * writing plugins. For simple rules control use [[MarkdownIt.disable]] and
   * [[MarkdownIt.enable]].
   **/
  this.core = new ParserCore();

  /**
   * MarkdownIt#renderer -> Renderer
   *
   * Instance of Renderer. Use it to modify output look. Or to add rendering
   * rules for new token types, generated by plugins.
   *
   * ##### Example
   *
   * ```javascript
   * var md = require('markdown-it')();
   *
   * function myToken(tokens, idx, options, env, self) {
   *   //...
   *   return result;
   * };
   *
   * md.renderer.rules['my_token'] = myToken
   * ```
   *
   * See [[Renderer]] docs and [source code](https://github.com/markdown-it/markdown-it/blob/master/lib/renderer.js).
   **/
  this.renderer = new Renderer();

  // Expose utils & helpers for easy acces from plugins

  /**
   * MarkdownIt#utils -> utils
   *
   * Assorted utility functions, useful to write plugins. See details
   * [here](https://github.com/markdown-it/markdown-it/blob/master/lib/common/utils.js).
   **/
  this.utils    = utils;

  /**
   * MarkdownIt#helpers -> helpers
   *
   * Link components parser functions, useful to write plugins. See details
   * [here](https://github.com/markdown-it/markdown-it/blob/master/lib/helpers).
   **/
  this.helpers  = helpers;


  this.options  = {};
  this.configure(config[presetName]);

  if (options) { this.set(options); }
}


/** chainable
 * MarkdownIt.set(options)
 *
 * Set parser options (in the same format as in constructor). Probably, you
 * will never need it, but you can change options after constructor call.
 *
 * ##### Example
 *
 * ```javascript
 * var md = require('markdown-it')()
 *             .set({ html: true, breaks: true })
 *             .set({ typographer, true });
 * ```
 *
 * __Note:__ To achieve the best possible performance, don't modify a
 * `markdown-it` instance options on the fly. If you need multiple configurations
 * it's best to create multiple instances and initialize each with separate
 * config.
 **/
MarkdownIt.prototype.set = function (options) {
  utils.assign(this.options, options);
  return this;
};


/** chainable, internal
 * MarkdownIt.configure(presets)
 *
 * Batch load of all options and compenent settings. This is internal method,
 * and you probably will not need it. But if you with - see available presets
 * and data structure [here](https://github.com/markdown-it/markdown-it/tree/master/lib/presets)
 **/
MarkdownIt.prototype.configure = function (presets) {
  var self = this;

  if (!presets) { throw new Error('Wrong `markdown-it` preset, check name/content'); }

  if (presets.options) { self.set(presets.options); }

  if (presets.components) {
    Object.keys(presets.components).forEach(function (name) {
      if (presets.components[name].rules) {
        self[name].ruler.enableOnly(presets.components[name].rules);
      }
    });
  }
  return this;
};


/** chainable
 * MarkdownIt.enable(list)
 * - list (String|Array): rule name or list of rule names to enable
 *
 * Enable list or rules. It will automatically find appropriate components,
 * containing rules with given names.
 *
 * ##### Example
 *
 * ```javascript
 * var md = require('markdown-it')()
 *             .enable(['sub', 'sup'])
 *             .disable('smartquotes');
 * ```
 **/
MarkdownIt.prototype.enable = function (list) {
  [ 'core', 'block', 'inline' ].forEach(function (chain) {
    this[chain].ruler.enable(list, true);
  }, this);
  return this;
};


/** chainable
 * MarkdownIt.disable(list)
 * - list (String|Array): rule name or list of rule names to disable.
 *
 * The same as [[MarkdownIt.enable]], but turn specified rules off.
 **/
MarkdownIt.prototype.disable = function (list) {
  [ 'core', 'block', 'inline' ].forEach(function (chain) {
    this[chain].ruler.disable(list, true);
  }, this);
  return this;
};


/** chainable
 * MarkdownIt.use(plugin, options)
 *
 * Load specified plugin with given options into current parser instance.
 *
 * ##### Example
 *
 * ```javascript
 * var md = require('markdown-it')()
 *             .use(require('makkdown-it-emoji'));
 * ```
 **/
MarkdownIt.prototype.use = function (plugin, options) {
  plugin(this, options);
  return this;
};


/** internal
 * MarkdownIt.parse(src, env) -> Array
 * - src (String): source string
 * - env (Object): enviroment variables
 *
 * Parse input string and returns list of block tokens (special token type
 * "inline" will contain list of inline tokens). You should not call this
 * method directly, until you write custom renderer (for example, to produce
 * AST).
 *
 * `env` is modified with additional info. For example, with references data.
 * Also `env` can be used to pass external info to plugins.
 **/
MarkdownIt.prototype.parse = function (src, env) {
  var state = new StateCore(this, src, env);

  this.core.process(state);

  return state.tokens;
};


/**
 * MarkdownIt.render(src [, env]) -> String
 * - src (String): source string
 * - env (Object): optional, enviroment variables
 *
 * Render markdown string into html. It does all magic for you :).
 *
 * `env` is `{}` by default. It's not used now directly, but you can pass
 *  with it any additional data to plugins.
 **/
MarkdownIt.prototype.render = function (src, env) {
  env = env || {};

  return this.renderer.render(this.parse(src, env), this.options, env);
};


/** internal
 * MarkdownIt.parseInline(src, env) -> Array
 * - src (String): source string
 * - env (Object): enviroment variables
 *
 * The same as [[MarkdownIt.parse]] but skip all block rules. It returns the
 * block tokens list with th single `inline` element, containing parsed inline
 * tokens in `children` property.
 **/
MarkdownIt.prototype.parseInline = function (src, env) {
  var state = new StateCore(this, src, env);

  state.inlineMode = true;
  this.core.process(state);

  return state.tokens;
};


/**
 * MarkdownIt.renderInline(src [, env]) -> String
 * - src (String): source string
 * - env (Object): optional, enviroment variables
 *
 * Similar to [[MarkdownIt.render]] but for single paragraph content. Result
 * will NOT be wrapped into `<p>` tags.
 **/
MarkdownIt.prototype.renderInline = function (src, env) {
  env = env || {};

  return this.renderer.render(this.parseInline(src, env), this.options, env);
};


module.exports = MarkdownIt;