define(['../internal/assignOwnDefaults', '../internal/assignWith', '../utility/attempt', '../internal/baseAssign', '../internal/baseToString', '../internal/baseValues', '../internal/escapeStringChar', '../lang/isError', '../internal/isIterateeCall', '../object/keys', '../internal/reInterpolate', './templateSettings'], function(assignOwnDefaults, assignWith, attempt, baseAssign, baseToString, baseValues, escapeStringChar, isError, isIterateeCall, keys, reInterpolate, templateSettings) {

  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
  var undefined;

  /** Used to match empty string literals in compiled template source. */
  var reEmptyStringLeading = /\b__p \+= '';/g,
      reEmptyStringMiddle = /\b(__p \+=) '' \+/g,
      reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g;

  /** Used to match [ES template delimiters](http://ecma-international.org/ecma-262/6.0/#sec-template-literal-lexical-components). */
  var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g;

  /** Used to ensure capturing order of template delimiters. */
  var reNoMatch = /($^)/;

  /** Used to match unescaped characters in compiled string literals. */
  var reUnescapedString = /['\n\r\u2028\u2029\\]/g;

  /**
   * Creates a compiled template function that can interpolate data properties
   * in "interpolate" delimiters, HTML-escape interpolated data properties in
   * "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data
   * properties may be accessed as free variables in the template. If a setting
   * object is provided it takes precedence over `_.templateSettings` values.
   *
   * **Note:** In the development build `_.template` utilizes
   * [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl)
   * for easier debugging.
   *
   * For more information on precompiling templates see
   * [lodash's custom builds documentation](https://lodash.com/custom-builds).
   *
   * For more information on Chrome extension sandboxes see
   * [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval).
   *
   * @static
   * @memberOf _
   * @category String
   * @param {string} [string=''] The template string.
   * @param {Object} [options] The options object.
   * @param {RegExp} [options.escape] The HTML "escape" delimiter.
   * @param {RegExp} [options.evaluate] The "evaluate" delimiter.
   * @param {Object} [options.imports] An object to import into the template as free variables.
   * @param {RegExp} [options.interpolate] The "interpolate" delimiter.
   * @param {string} [options.sourceURL] The sourceURL of the template's compiled source.
   * @param {string} [options.variable] The data object variable name.
   * @param- {Object} [otherOptions] Enables the legacy `options` param signature.
   * @returns {Function} Returns the compiled template function.
   * @example
   *
   * // using the "interpolate" delimiter to create a compiled template
   * var compiled = _.template('hello <%= user %>!');
   * compiled({ 'user': 'fred' });
   * // => 'hello fred!'
   *
   * // using the HTML "escape" delimiter to escape data property values
   * var compiled = _.template('<b><%- value %></b>');
   * compiled({ 'value': '<script>' });
   * // => '<b>&lt;script&gt;</b>'
   *
   * // using the "evaluate" delimiter to execute JavaScript and generate HTML
   * var compiled = _.template('<% _.forEach(users, function(user) { %><li><%- user %></li><% }); %>');
   * compiled({ 'users': ['fred', 'barney'] });
   * // => '<li>fred</li><li>barney</li>'
   *
   * // using the internal `print` function in "evaluate" delimiters
   * var compiled = _.template('<% print("hello " + user); %>!');
   * compiled({ 'user': 'barney' });
   * // => 'hello barney!'
   *
   * // using the ES delimiter as an alternative to the default "interpolate" delimiter
   * var compiled = _.template('hello ${ user }!');
   * compiled({ 'user': 'pebbles' });
   * // => 'hello pebbles!'
   *
   * // using custom template delimiters
   * _.templateSettings.interpolate = /{{([\s\S]+?)}}/g;
   * var compiled = _.template('hello {{ user }}!');
   * compiled({ 'user': 'mustache' });
   * // => 'hello mustache!'
   *
   * // using backslashes to treat delimiters as plain text
   * var compiled = _.template('<%= "\\<%- value %\\>" %>');
   * compiled({ 'value': 'ignored' });
   * // => '<%- value %>'
   *
   * // using the `imports` option to import `jQuery` as `jq`
   * var text = '<% jq.each(users, function(user) { %><li><%- user %></li><% }); %>';
   * var compiled = _.template(text, { 'imports': { 'jq': jQuery } });
   * compiled({ 'users': ['fred', 'barney'] });
   * // => '<li>fred</li><li>barney</li>'
   *
   * // using the `sourceURL` option to specify a custom sourceURL for the template
   * var compiled = _.template('hello <%= user %>!', { 'sourceURL': '/basic/greeting.jst' });
   * compiled(data);
   * // => find the source of "greeting.jst" under the Sources tab or Resources panel of the web inspector
   *
   * // using the `variable` option to ensure a with-statement isn't used in the compiled template
   * var compiled = _.template('hi <%= data.user %>!', { 'variable': 'data' });
   * compiled.source;
   * // => function(data) {
   * //   var __t, __p = '';
   * //   __p += 'hi ' + ((__t = ( data.user )) == null ? '' : __t) + '!';
   * //   return __p;
   * // }
   *
   * // using the `source` property to inline compiled templates for meaningful
   * // line numbers in error messages and a stack trace
   * fs.writeFileSync(path.join(cwd, 'jst.js'), '\
   *   var JST = {\
   *     "main": ' + _.template(mainText).source + '\
   *   };\
   * ');
   */
  function template(string, options, otherOptions) {
    // Based on John Resig's `tmpl` implementation (http://ejohn.org/blog/javascript-micro-templating/)
    // and Laura Doktorova's doT.js (https://github.com/olado/doT).
    var settings = templateSettings.imports._.templateSettings || templateSettings;

    if (otherOptions && isIterateeCall(string, options, otherOptions)) {
      options = otherOptions = undefined;
    }
    string = baseToString(string);
    options = assignWith(baseAssign({}, otherOptions || options), settings, assignOwnDefaults);

    var imports = assignWith(baseAssign({}, options.imports), settings.imports, assignOwnDefaults),
        importsKeys = keys(imports),
        importsValues = baseValues(imports, importsKeys);

    var isEscaping,
        isEvaluating,
        index = 0,
        interpolate = options.interpolate || reNoMatch,
        source = "__p += '";

    // Compile the regexp to match each delimiter.
    var reDelimiters = RegExp(
      (options.escape || reNoMatch).source + '|' +
      interpolate.source + '|' +
      (interpolate === reInterpolate ? reEsTemplate : reNoMatch).source + '|' +
      (options.evaluate || reNoMatch).source + '|$'
    , 'g');

    // Use a sourceURL for easier debugging.
    var sourceURL = 'sourceURL' in options ? '//# sourceURL=' + options.sourceURL + '\n' : '';

    string.replace(reDelimiters, function(match, escapeValue, interpolateValue, esTemplateValue, evaluateValue, offset) {
      interpolateValue || (interpolateValue = esTemplateValue);

      // Escape characters that can't be included in string literals.
      source += string.slice(index, offset).replace(reUnescapedString, escapeStringChar);

      // Replace delimiters with snippets.
      if (escapeValue) {
        isEscaping = true;
        source += "' +\n__e(" + escapeValue + ") +\n'";
      }
      if (evaluateValue) {
        isEvaluating = true;
        source += "';\n" + evaluateValue + ";\n__p += '";
      }
      if (interpolateValue) {
        source += "' +\n((__t = (" + interpolateValue + ")) == null ? '' : __t) +\n'";
      }
      index = offset + match.length;

      // The JS engine embedded in Adobe products requires returning the `match`
      // string in order to produce the correct `offset` value.
      return match;
    });

    source += "';\n";

    // If `variable` is not specified wrap a with-statement around the generated
    // code to add the data object to the top of the scope chain.
    var variable = options.variable;
    if (!variable) {
      source = 'with (obj) {\n' + source + '\n}\n';
    }
    // Cleanup code by stripping empty strings.
    source = (isEvaluating ? source.replace(reEmptyStringLeading, '') : source)
      .replace(reEmptyStringMiddle, '$1')
      .replace(reEmptyStringTrailing, '$1;');

    // Frame code as the function body.
    source = 'function(' + (variable || 'obj') + ') {\n' +
      (variable
        ? ''
        : 'obj || (obj = {});\n'
      ) +
      "var __t, __p = ''" +
      (isEscaping
         ? ', __e = _.escape'
         : ''
      ) +
      (isEvaluating
        ? ', __j = Array.prototype.join;\n' +
          "function print() { __p += __j.call(arguments, '') }\n"
        : ';\n'
      ) +
      source +
      'return __p\n}';

    var result = attempt(function() {
      return Function(importsKeys, sourceURL + 'return ' + source).apply(undefined, importsValues);
    });

    // Provide the compiled function's source by its `toString` method or
    // the `source` property as a convenience for inlining compiled templates.
    result.source = source;
    if (isError(result)) {
      throw result;
    }
    return result;
  }

  return template;
});