/**
 * @fileoverview Prevent string definitions for references and prevent referencing this.refs
 * @author Tom Hastjarjanto
 */
'use strict';

var Components = require('../util/Components');

// ------------------------------------------------------------------------------
// Rule Definition
// ------------------------------------------------------------------------------

module.exports = Components.detect(function(context, components, utils) {
  /**
   * Checks if we are using refs
   * @param {ASTNode} node The AST node being checked.
   * @returns {Boolean} True if we are using refs, false if not.
   */
  function isRefsUsage(node) {
    return Boolean(
      (
        utils.getParentES6Component() ||
        utils.getParentES5Component()
      ) &&
      node.object.type === 'ThisExpression' &&
      node.property.name === 'refs'
    );
  }

  /**
   * Checks if we are using a ref attribute
   * @param {ASTNode} node The AST node being checked.
   * @returns {Boolean} True if we are using a ref attribute, false if not.
   */
  function isRefAttribute(node) {
    return Boolean(
      node.type === 'JSXAttribute' &&
      node.name &&
      node.name.name === 'ref'
    );
  }

  /**
   * Checks if a node contains a string value
   * @param {ASTNode} node The AST node being checked.
   * @returns {Boolean} True if the node contains a string value, false if not.
   */
  function containsStringLiteral(node) {
    return Boolean(
      node.value &&
      node.value.type === 'Literal' &&
      typeof node.value.value === 'string'
    );
  }

  /**
   * Checks if a node contains a string value within a jsx expression
   * @param {ASTNode} node The AST node being checked.
   * @returns {Boolean} True if the node contains a string value within a jsx expression, false if not.
   */
  function containsStringExpressionContainer(node) {
    return Boolean(
      node.value &&
      node.value.type === 'JSXExpressionContainer' &&
      node.value.expression &&
      node.value.expression.type === 'Literal' &&
      typeof node.value.expression.value === 'string'
    );
  }

  return {
    MemberExpression: function(node) {
      if (isRefsUsage(node)) {
        context.report(node, 'Using this.refs is deprecated.');
      }
    },
    JSXAttribute: function(node) {
      if (
        isRefAttribute(node) &&
        (containsStringLiteral(node) || containsStringExpressionContainer(node))
      ) {
        context.report(node, 'Using string literals in ref attributes is deprecated.');
      }
    }
  };
});

module.exports.schema = [];