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

module.exports = {
  /*
   * Parse an array
   * ```ebnf
   * array ::= T_ARRAY '(' array_pair_list ')' |
   *   '[' array_pair_list ']'
   * ```
   */
  read_array: function () {
    let expect = null;
    let shortForm = false;
    const result = this.node("array");

    if (this.token === this.tok.T_ARRAY) {
      this.next().expect("(");
      expect = ")";
    } else {
      shortForm = true;
      expect = "]";
    }
    let items = [];
    if (this.next().token !== expect) {
      items = this.read_array_pair_list(shortForm);
    }
    this.expect(expect);
    this.next();
    return result(shortForm, items);
  },
  /*
   * Reads an array of items
   * ```ebnf
   * array_pair_list ::= array_pair (',' array_pair?)*
   * ```
   */
  read_array_pair_list: function (shortForm) {
    const self = this;
    return this.read_list(
      function () {
        return self.read_array_pair(shortForm);
      },
      ",",
      true
    );
  },
  /*
   * Reads an entry
   * array_pair:
   *  expr T_DOUBLE_ARROW expr
   *  | expr
   *  | expr T_DOUBLE_ARROW '&' variable
   *  | '&' variable
   *  | expr T_DOUBLE_ARROW T_LIST '(' array_pair_list ')'
   *  | T_LIST '(' array_pair_list ')'
   */
  read_array_pair: function (shortForm) {
    if (
      (!shortForm && this.token === ")") ||
      (shortForm && this.token === "]")
    ) {
      return;
    }

    if (this.token === ",") {
      return this.node("noop")();
    }

    const entry = this.node("entry");

    let key = null;
    let value = null;
    let byRef = false;
    let unpack = false;

    if (this.token === "&") {
      this.next();
      byRef = true;
      value = this.read_variable(true, false);
    } else if (this.token === this.tok.T_ELLIPSIS && this.version >= 704) {
      this.next();
      if (this.token === "&") {
        this.error();
      }
      unpack = true;
      value = this.read_expr();
    } else {
      const expr = this.read_expr();

      if (this.token === this.tok.T_DOUBLE_ARROW) {
        this.next();
        key = expr;

        if (this.token === "&") {
          this.next();
          byRef = true;
          value = this.read_variable(true, false);
        } else {
          value = this.read_expr();
        }
      } else {
        value = expr;
      }
    }

    return entry(key, value, byRef, unpack);
  },
};