/**
 * Copyright 2013-2014, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
/*global exports:true*/
"use strict";
var Syntax = require('jstransform').Syntax;
var utils = require('jstransform/src/utils');

var knownTags = {
  a: true,
  abbr: true,
  address: true,
  applet: true,
  area: true,
  article: true,
  aside: true,
  audio: true,
  b: true,
  base: true,
  bdi: true,
  bdo: true,
  big: true,
  blockquote: true,
  body: true,
  br: true,
  button: true,
  canvas: true,
  caption: true,
  circle: true,
  cite: true,
  code: true,
  col: true,
  colgroup: true,
  command: true,
  data: true,
  datalist: true,
  dd: true,
  defs: true,
  del: true,
  details: true,
  dfn: true,
  dialog: true,
  div: true,
  dl: true,
  dt: true,
  ellipse: true,
  em: true,
  embed: true,
  fieldset: true,
  figcaption: true,
  figure: true,
  footer: true,
  form: true,
  g: true,
  h1: true,
  h2: true,
  h3: true,
  h4: true,
  h5: true,
  h6: true,
  head: true,
  header: true,
  hgroup: true,
  hr: true,
  html: true,
  i: true,
  iframe: true,
  img: true,
  input: true,
  ins: true,
  kbd: true,
  keygen: true,
  label: true,
  legend: true,
  li: true,
  line: true,
  linearGradient: true,
  link: true,
  main: true,
  map: true,
  mark: true,
  marquee: true,
  mask: false,
  menu: true,
  menuitem: true,
  meta: true,
  meter: true,
  nav: true,
  noscript: true,
  object: true,
  ol: true,
  optgroup: true,
  option: true,
  output: true,
  p: true,
  param: true,
  path: true,
  pattern: false,
  picture: true,
  polygon: true,
  polyline: true,
  pre: true,
  progress: true,
  q: true,
  radialGradient: true,
  rect: true,
  rp: true,
  rt: true,
  ruby: true,
  s: true,
  samp: true,
  script: true,
  section: true,
  select: true,
  small: true,
  source: true,
  span: true,
  stop: true,
  strong: true,
  style: true,
  sub: true,
  summary: true,
  sup: true,
  svg: true,
  table: true,
  tbody: true,
  td: true,
  text: true,
  textarea: true,
  tfoot: true,
  th: true,
  thead: true,
  time: true,
  title: true,
  tr: true,
  track: true,
  tspan: true,
  u: true,
  ul: true,
  'var': true,
  video: true,
  wbr: true
};

function renderXJSLiteral(object, isLast, state, start, end) {
  var lines = object.value.split(/\r\n|\n|\r/);

  if (start) {
    utils.append(start, state);
  }

  var lastNonEmptyLine = 0;

  lines.forEach(function (line, index) {
    if (line.match(/[^ \t]/)) {
      lastNonEmptyLine = index;
    }
  });

  lines.forEach(function (line, index) {
    var isFirstLine = index === 0;
    var isLastLine = index === lines.length - 1;
    var isLastNonEmptyLine = index === lastNonEmptyLine;

    // replace rendered whitespace tabs with spaces
    var trimmedLine = line.replace(/\t/g, ' ');

    // trim whitespace touching a newline
    if (!isFirstLine) {
      trimmedLine = trimmedLine.replace(/^[ ]+/, '');
    }
    if (!isLastLine) {
      trimmedLine = trimmedLine.replace(/[ ]+$/, '');
    }

    if (!isFirstLine) {
      utils.append(line.match(/^[ \t]*/)[0], state);
    }

    if (trimmedLine || isLastNonEmptyLine) {
      utils.append(
        JSON.stringify(trimmedLine) +
        (!isLastNonEmptyLine ? " + ' ' +" : ''),
        state);

      if (isLastNonEmptyLine) {
        if (end) {
          utils.append(end, state);
        }
        if (!isLast) {
          utils.append(', ', state);
        }
      }

      // only restore tail whitespace if line had literals
      if (trimmedLine && !isLastLine) {
        utils.append(line.match(/[ \t]*$/)[0], state);
      }
    }

    if (!isLastLine) {
      utils.append('\n', state);
    }
  });

  utils.move(object.range[1], state);
}

function renderXJSExpressionContainer(traverse, object, isLast, path, state) {
  // Plus 1 to skip `{`.
  utils.move(object.range[0] + 1, state);
  utils.catchup(object.expression.range[0], state);
  traverse(object.expression, path, state);

  if (!isLast && object.expression.type !== Syntax.XJSEmptyExpression) {
    // If we need to append a comma, make sure to do so after the expression.
    utils.catchup(object.expression.range[1], state, trimLeft);
    utils.append(', ', state);
  }

  // Minus 1 to skip `}`.
  utils.catchup(object.range[1] - 1, state, trimLeft);
  utils.move(object.range[1], state);
  return false;
}

function quoteAttrName(attr) {
  // Quote invalid JS identifiers.
  if (!/^[a-z_$][a-z\d_$]*$/i.test(attr)) {
    return '"' + attr + '"';
  }
  return attr;
}

function trimLeft(value) {
  return value.replace(/^[ ]+/, '');
}

exports.knownTags = knownTags;
exports.renderXJSExpressionContainer = renderXJSExpressionContainer;
exports.renderXJSLiteral = renderXJSLiteral;
exports.quoteAttrName = quoteAttrName;
exports.trimLeft = trimLeft;