var AWS = require('../core');
var util = require('../util');
var Rest = require('./rest');

function populateBody(req) {
  var input = req.service.api.operations[req.operation].input;
  var builder = new AWS.XML.Builder();
  var params = req.params;

  var payload = input.payload;
  if (payload) {
    var payloadMember = input.members[payload];
    params = params[payload];
    if (params === undefined) return;

    if (payloadMember.type === 'structure') {
      var rootElement = payloadMember.name;
      req.httpRequest.body = builder.toXML(params, payloadMember, rootElement, true);
    } else { // non-xml payload
      req.httpRequest.body = params;
    }
  } else {
    req.httpRequest.body = builder.toXML(params, input, input.name ||
      input.shape || util.string.upperFirst(req.operation) + 'Request');
  }
}

function buildRequest(req) {
  Rest.buildRequest(req);

  // never send body payload on GET/HEAD
  if (['GET', 'HEAD'].indexOf(req.httpRequest.method) < 0) {
    populateBody(req);
  }
}

function extractError(resp) {
  Rest.extractError(resp);

  var data = new AWS.XML.Parser().parse(resp.httpResponse.body.toString());
  if (data.Errors) data = data.Errors;
  if (data.Error) data = data.Error;
  if (data.Code) {
    resp.error = util.error(new Error(), {
      code: data.Code,
      message: data.Message
    });
  } else {
    resp.error = util.error(new Error(), {
      code: resp.httpResponse.statusCode,
      message: null
    });
  }
}

function extractData(resp) {
  Rest.extractData(resp);

  var parser;
  var req = resp.request;
  var body = resp.httpResponse.body;
  var operation = req.service.api.operations[req.operation];
  var output = operation.output;

  var payload = output.payload;
  if (payload) {
    var payloadMember = output.members[payload];
    if (payloadMember.isStreaming) {
      resp.data[payload] = body;
    } else if (payloadMember.type === 'structure') {
      parser = new AWS.XML.Parser();
      resp.data[payload] = parser.parse(body.toString(), payloadMember);
    } else {
      resp.data[payload] = body.toString();
    }
  } else if (body.length > 0) {
    parser = new AWS.XML.Parser();
    var data = parser.parse(body.toString(), output);
    util.update(resp.data, data);
  }
}

module.exports = {
  buildRequest: buildRequest,
  extractError: extractError,
  extractData: extractData
};
