/**
   * @fileoverview Rule to forbid mixing LF and LFCR line breaks.
   * @author Erik Mueller
   * @copyright 2015 Varun Verma. All rights reserverd.
   * @copyright 2015 James Whitney. All rights reserved.
   * @copyright 2015 Erik Mueller. All rights reserved.
   */
  
  "use strict";
  
  //------------------------------------------------------------------------------
  // Rule Definition
  //------------------------------------------------------------------------------
  
  module.exports = function(context) {
  
      var EXPECTED_LF_MSG = "Expected linebreaks to be 'LF' but found 'CRLF'.",
          EXPECTED_CRLF_MSG = "Expected linebreaks to be 'CRLF' but found 'LF'.";
  
      //--------------------------------------------------------------------------
      // Helpers
      //--------------------------------------------------------------------------
  
      /**
       * Builds a fix function that replaces text at the specified range in the source text.
       * @param {int[]} range The range to replace
       * @param {string} text The text to insert.
       * @returns {function} Fixer function
       * @private
       */
      function createFix(range, text) {
          return function(fixer) {
              return fixer.replaceTextRange(range, text);
          };
      }
  
      //--------------------------------------------------------------------------
      // Public
      //--------------------------------------------------------------------------
  
      return {
          "Program": function checkForlinebreakStyle(node) {
              var linebreakStyle = context.options[0] || "unix",
                  expectedLF = linebreakStyle === "unix",
                  expectedLFChars = expectedLF ? "
  " : "\r
  ",
                  source = context.getSource(),
                  pattern = /\r
  |\r|
  |\u2028|\u2029/g,
                  match,
                  index,
                  range;
  
              var i = 0;
              while ((match = pattern.exec(source)) !== null) {
                  i++;
                  if (match[0] === expectedLFChars) {
                      continue;
                  }
  
                  index = match.index;
                  range = [index, index + match[0].length];
                  context.report({
                      node: node,
                      loc: {
                          line: i,
                          column: context.getSourceLines()[i - 1].length
                      },
                      message: expectedLF ? EXPECTED_LF_MSG : EXPECTED_CRLF_MSG,
                      fix: createFix(range, expectedLFChars)
                  });
              }
          }
      };
  };
  
  module.exports.schema = [
      {
          "enum": ["unix", "windows"]
      }
  ];