var util = require("../../util");
var t    = require("../../types");

exports.ForOfStatement = function (node, parent, file, scope) {
  var left = node.left;
  var declar;

  var stepKey   = file.generateUidIdentifier("step", scope);
  var stepValue = t.memberExpression(stepKey, t.identifier("value"));

  if (t.isIdentifier(left)) {
    declar = t.expressionStatement(t.assignmentExpression("=", left, stepValue));
  } else if (t.isVariableDeclaration(left)) {
    declar = t.variableDeclaration(left.kind, [
      t.variableDeclarator(left.declarations[0].id, stepValue)
    ]);
  } else {
    throw file.errorWithNode(left, "Unknown node type " + left.type + " in ForOfStatement");
  }

  var node2 = util.template("for-of", {
    ITERATOR_KEY: file.generateUidIdentifier("iterator", scope),
    STEP_KEY:     stepKey,
    OBJECT:       node.right
  });

  t.ensureBlock(node);

  var block = node2.body;
  block.body.push(declar);
  block.body = block.body.concat(node.body.body);

  return node2;
};