/**
 * Copyright (C) 2018 Glayzzle (BSD3 License)
 * @authors https://github.com/glayzzle/php-parser/graphs/contributors
 * @url http://glayzzle.com
 */
"use strict";

module.exports = {
  /*
   * Reads a short form of tokens
   * @param {Number} token - The ending token
   * @return {Block}
   */
  read_short_form(token) {
    const body = this.node("block");
    const items = [];
    /* istanbul ignore next */
    if (this.expect(":")) this.next();
    while (this.token != this.EOF && this.token !== token) {
      items.push(this.read_inner_statement());
    }
    if (
      items.length === 0 &&
      this.extractDoc &&
      this._docs.length > this._docIndex
    ) {
      items.push(this.node("noop")());
    }
    /* istanbul ignore next */
    if (this.expect(token)) this.next();
    this.expectEndOfStatement();
    return body(null, items);
  },

  /*
   * https://wiki.php.net/rfc/trailing-comma-function-calls
   * @param {*} item
   * @param {*} separator
   */
  read_function_list(item, separator) {
    const result = [];
    do {
      if (this.token == separator && this.version >= 703 && result.length > 0) {
        result.push(this.node("noop")());
        break;
      }
      result.push(item.apply(this, []));
      if (this.token != separator) {
        break;
      }
      if (this.next().token == ")" && this.version >= 703) {
        break;
      }
    } while (this.token != this.EOF);
    return result;
  },

  /*
   * Helper : reads a list of tokens / sample : T_STRING ',' T_STRING ...
   * ```ebnf
   * list ::= separator? ( item separator )* item
   * ```
   */
  read_list(item, separator, preserveFirstSeparator) {
    const result = [];

    if (this.token == separator) {
      if (preserveFirstSeparator) {
        result.push(typeof item === "function" ? this.node("noop")() : null);
      }
      this.next();
    }

    if (typeof item === "function") {
      do {
        const itemResult = item.apply(this, []);
        if (itemResult) {
          result.push(itemResult);
        }
        if (this.token != separator) {
          break;
        }
      } while (this.next().token != this.EOF);
    } else {
      if (this.expect(item)) {
        result.push(this.text());
      } else {
        return [];
      }
      while (this.next().token != this.EOF) {
        if (this.token != separator) break;
        // trim current separator & check item
        if (this.next().token != item) break;
        result.push(this.text());
      }
    }
    return result;
  },

  /*
   * Reads a list of names separated by a comma
   *
   * ```ebnf
   * name_list ::= namespace (',' namespace)*
   * ```
   *
   * Sample code :
   * ```php
   * <?php class foo extends bar, baz { }
   * ```
   *
   * @see https://github.com/php/php-src/blob/master/Zend/zend_language_parser.y#L726
   * @return {Reference[]}
   */
  read_name_list() {
    return this.read_list(this.read_namespace_name, ",", false);
  },

  /*
   * Reads the byref token and assign it to the specified node
   * @param {*} cb
   */
  read_byref(cb) {
    let byref = this.node("byref");
    this.next();
    byref = byref(null);
    const result = cb();
    if (result) {
      this.ast.swapLocations(result, byref, result, this);
      result.byref = true;
    }
    return result;
  },

  /*
   * Reads a list of variables declarations
   *
   * ```ebnf
   * variable_declaration ::= T_VARIABLE ('=' expr)?*
   * variable_declarations ::= variable_declaration (',' variable_declaration)*
   * ```
   *
   * Sample code :
   * ```php
   * <?php static $a = 'hello', $b = 'world';
   * ```
   * @return {StaticVariable[]} Returns an array composed by a list of variables, or
   * assign values
   */
  read_variable_declarations() {
    return this.read_list(function () {
      const node = this.node("staticvariable");
      let variable = this.node("variable");
      // plain variable name
      /* istanbul ignore else */
      if (this.expect(this.tok.T_VARIABLE)) {
        const name = this.text().substring(1);
        this.next();
        variable = variable(name, false);
      } else {
        variable = variable("#ERR", false);
      }
      if (this.token === "=") {
        return node(variable, this.next().read_expr());
      } else {
        return variable;
      }
    }, ",");
  },

  /*
   * Reads class extends
   */
  read_extends_from() {
    if (this.token === this.tok.T_EXTENDS) {
      return this.next().read_namespace_name();
    }

    return null;
  },

  /*
   * Reads interface extends list
   */
  read_interface_extends_list() {
    if (this.token === this.tok.T_EXTENDS) {
      return this.next().read_name_list();
    }

    return null;
  },

  /*
   * Reads implements list
   */
  read_implements_list() {
    if (this.token === this.tok.T_IMPLEMENTS) {
      return this.next().read_name_list();
    }

    return null;
  },
};
