/**
   * @fileoverview Prevent usage of setState in componentDidMount
   * @author David Petersen
   */
  'use strict';
  
  var Components = require('../util/Components');
  
  // ------------------------------------------------------------------------------
  // Rule Definition
  // ------------------------------------------------------------------------------
  
  module.exports = Components.detect(function(context, components, utils) {
  
    /**
     * Checks if the component is valid
     * @param {Object} component The component to process
     * @returns {Boolean} True if the component is valid, false if not.
     */
    function isValid(component) {
      return Boolean(component && !component.mutateSetState);
    }
  
    /**
     * Reports undeclared proptypes for a given component
     * @param {Object} component The component to process
     */
    function reportMutations(component) {
      var mutation;
      for (var i = 0, j = component.mutations.length; i < j; i++) {
        mutation = component.mutations[i];
        context.report(mutation, 'Do not mutate state directly. Use setState().');
      }
    }
  
    // --------------------------------------------------------------------------
    // Public
    // --------------------------------------------------------------------------
  
    return {
      AssignmentExpression: function(node) {
        var item;
        if (!node.left || !node.left.object || !node.left.object.object) {
          return;
        }
        item = node.left.object;
        while (item.object.property) {
          item = item.object;
        }
        if (
          item.object.type === 'ThisExpression' &&
          item.property.name === 'state'
        ) {
          var component = components.get(utils.getParentComponent());
          var mutations = component && component.mutations || [];
          mutations.push(node.left.object);
          components.set(node, {
            mutateSetState: true,
            mutations: mutations
          });
        }
      },
  
      'Program:exit': function() {
        var list = components.list();
        for (var component in list) {
          if (!list.hasOwnProperty(component) || isValid(list[component])) {
            continue;
          }
          reportMutations(list[component]);
        }
      }
    };
  
  });