HORIZON PROJECT

var assignInWith = require('./assignInWith'),

    attempt = require('./attempt'),

    baseValues = require('./_baseValues'),

    customDefaultsAssignIn = require('./_customDefaultsAssignIn'),

    escapeStringChar = require('./_escapeStringChar'),

    isError = require('./isError'),

    isIterateeCall = require('./_isIterateeCall'),

    keys = require('./keys'),

    reInterpolate = require('./_reInterpolate'),

    templateSettings = require('./templateSettings'),

    toString = require('./toString');

/** 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-262/7.0/#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 given, 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

 * @since 0.1.0

 * @memberOf _

 * @category String

 * @param {string} [string=''] The template string.

 * @param {Object} [options={}] The options object.

 * @param {RegExp} [options.escape=_.templateSettings.escape]

 *  The HTML "escape" delimiter.

 * @param {RegExp} [options.evaluate=_.templateSettings.evaluate]

 *  The "evaluate" delimiter.

 * @param {Object} [options.imports=_.templateSettings.imports]

 *  An object to import into the template as free variables.

 * @param {RegExp} [options.interpolate=_.templateSettings.interpolate]

 *  The "interpolate" delimiter.

 * @param {string} [options.sourceURL='templateSources[n]']

 *  The sourceURL of the compiled template.

 * @param {string} [options.variable='obj']

 *  The data object variable name.

 * @param- {Object} [guard] Enables use as an iteratee for methods like `_.map`.

 * @returns {Function} Returns the compiled template function.

 * @example

 *

 * // Use the "interpolate" delimiter to create a compiled template.

 * var compiled = _.template('hello <%= user %>!');

 * compiled({ 'user': 'fred' });

 * // => 'hello fred!'

 *

 * // Use the HTML "escape" delimiter to escape data property values.

 * var compiled = _.template('<b><%- value %></b>');

 * compiled({ 'value': '<script>' });

 * // => '<b>&lt;script&gt;</b>'

 *

 * // Use 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>'

 *

 * // Use the internal `print` function in "evaluate" delimiters.

 * var compiled = _.template('<% print("hello " + user); %>!');

 * compiled({ 'user': 'barney' });

 * // => 'hello barney!'

 *

 * // Use the ES template literal delimiter as an "interpolate" delimiter.

 * // Disable support by replacing the "interpolate" delimiter.

 * var compiled = _.template('hello ${ user }!');

 * compiled({ 'user': 'pebbles' });

 * // => 'hello pebbles!'

 *

 * // Use backslashes to treat delimiters as plain text.

 * var compiled = _.template('<%= "\\<%- value %\\>" %>');

 * compiled({ 'value': 'ignored' });

 * // => '<%- value %>'

 *

 * // Use 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>'

 *

 * // Use 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.

 *

 * // Use 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;

 * // }

 *

 * // Use custom template delimiters.

 * _.templateSettings.interpolate = /{{([\s\S]+?)}}/g;

 * var compiled = _.template('hello {{ user }}!');

 * compiled({ 'user': 'mustache' });

 * // => 'hello mustache!'

 *

 * // Use the `source` property to inline compiled templates for meaningful

 * // line numbers in error messages and stack traces.

 * fs.writeFileSync(path.join(process.cwd(), 'jst.js'), '\

 *   var JST = {\

 *     "main": ' + _.template(mainText).source + '\

 *   };\

 * ');

 */

function template(string, options, guard) {

  // 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 (guard && isIterateeCall(string, options, guard)) {

    options = undefined;

  }

  string = toString(string);

  options = assignInWith({}, options, settings, customDefaultsAssignIn);

  var imports = assignInWith({}, options.imports, settings.imports, customDefaultsAssignIn),

      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 needs `match` returned 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;

}

module.exports = template;