/*!
 * deep-diff.
 * Licensed under the MIT License.
 */
;(function(root, factory) {
  'use strict';
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define([], function() {
      return factory();
    });
  } else if (typeof exports === 'object') {
    // Node. Does not work with strict CommonJS, but
    // only CommonJS-like environments that support module.exports,
    // like Node.
    module.exports = factory();
  } else {
    // Browser globals (root is window)
    root.DeepDiff = factory();
  }
}(this, function(undefined) {
  'use strict';

  var $scope, conflict, conflictResolution = [];
  if (typeof global === 'object' && global) {
    $scope = global;
  } else if (typeof window !== 'undefined') {
    $scope = window;
  } else {
    $scope = {};
  }
  conflict = $scope.DeepDiff;
  if (conflict) {
    conflictResolution.push(
      function() {
        if ('undefined' !== typeof conflict && $scope.DeepDiff === accumulateDiff) {
          $scope.DeepDiff = conflict;
          conflict = undefined;
        }
      });
  }

  // nodejs compatible on server side and in the browser.
  function inherits(ctor, superCtor) {
    ctor.super_ = superCtor;
    ctor.prototype = Object.create(superCtor.prototype, {
      constructor: {
        value: ctor,
        enumerable: false,
        writable: true,
        configurable: true
      }
    });
  }

  function Diff(kind, path) {
    Object.defineProperty(this, 'kind', {
      value: kind,
      enumerable: true
    });
    if (path && path.length) {
      Object.defineProperty(this, 'path', {
        value: path,
        enumerable: true
      });
    }
  }

  function DiffEdit(path, origin, value) {
    DiffEdit.super_.call(this, 'E', path);
    Object.defineProperty(this, 'lhs', {
      value: origin,
      enumerable: true
    });
    Object.defineProperty(this, 'rhs', {
      value: value,
      enumerable: true
    });
  }
  inherits(DiffEdit, Diff);

  function DiffNew(path, value) {
    DiffNew.super_.call(this, 'N', path);
    Object.defineProperty(this, 'rhs', {
      value: value,
      enumerable: true
    });
  }
  inherits(DiffNew, Diff);

  function DiffDeleted(path, value) {
    DiffDeleted.super_.call(this, 'D', path);
    Object.defineProperty(this, 'lhs', {
      value: value,
      enumerable: true
    });
  }
  inherits(DiffDeleted, Diff);

  function DiffArray(path, index, item) {
    DiffArray.super_.call(this, 'A', path);
    Object.defineProperty(this, 'index', {
      value: index,
      enumerable: true
    });
    Object.defineProperty(this, 'item', {
      value: item,
      enumerable: true
    });
  }
  inherits(DiffArray, Diff);

  function arrayRemove(arr, from, to) {
    var rest = arr.slice((to || from) + 1 || arr.length);
    arr.length = from < 0 ? arr.length + from : from;
    arr.push.apply(arr, rest);
    return arr;
  }

  function realTypeOf(subject) {
    var type = typeof subject;
    if (type !== 'object') {
      return type;
    }

    if (subject === Math) {
      return 'math';
    } else if (subject === null) {
      return 'null';
    } else if (Array.isArray(subject)) {
      return 'array';
    } else if (Object.prototype.toString.call(subject) === '[object Date]') {
      return 'date';
    } else if (typeof subject.toString !== 'undefined' && /^\/.*\//.test(subject.toString())) {
      return 'regexp';
    }
    return 'object';
  }

  function deepDiff(lhs, rhs, changes, prefilter, path, key, stack) {
    path = path || [];
    var currentPath = path.slice(0);
    if (typeof key !== 'undefined') {
      if (prefilter) {
        if (typeof(prefilter) === 'function' && prefilter(currentPath, key)) { return; }
        else if (typeof(prefilter) === 'object') {
          if (prefilter.prefilter && prefilter.prefilter(currentPath, key)) { return; }
          if (prefilter.normalize) {
            var alt = prefilter.normalize(currentPath, key, lhs, rhs);
            if (alt) {
              lhs = alt[0];
              rhs = alt[1];
            }
          }
        }
      }
      currentPath.push(key);
    }

    // Use string comparison for regexes
    if (realTypeOf(lhs) === 'regexp' && realTypeOf(rhs) === 'regexp') {
      lhs = lhs.toString();
      rhs = rhs.toString();
    }

    var ltype = typeof lhs;
    var rtype = typeof rhs;
    if (ltype === 'undefined') {
      if (rtype !== 'undefined') {
        changes(new DiffNew(currentPath, rhs));
      }
    } else if (rtype === 'undefined') {
      changes(new DiffDeleted(currentPath, lhs));
    } else if (realTypeOf(lhs) !== realTypeOf(rhs)) {
      changes(new DiffEdit(currentPath, lhs, rhs));
    } else if (Object.prototype.toString.call(lhs) === '[object Date]' && Object.prototype.toString.call(rhs) === '[object Date]' && ((lhs - rhs) !== 0)) {
      changes(new DiffEdit(currentPath, lhs, rhs));
    } else if (ltype === 'object' && lhs !== null && rhs !== null) {
      stack = stack || [];
      if (stack.indexOf(lhs) < 0) {
        stack.push(lhs);
        if (Array.isArray(lhs)) {
          var i, len = lhs.length;
          for (i = 0; i < lhs.length; i++) {
            if (i >= rhs.length) {
              changes(new DiffArray(currentPath, i, new DiffDeleted(undefined, lhs[i])));
            } else {
              deepDiff(lhs[i], rhs[i], changes, prefilter, currentPath, i, stack);
            }
          }
          while (i < rhs.length) {
            changes(new DiffArray(currentPath, i, new DiffNew(undefined, rhs[i++])));
          }
        } else {
          var akeys = Object.keys(lhs);
          var pkeys = Object.keys(rhs);
          akeys.forEach(function(k, i) {
            var other = pkeys.indexOf(k);
            if (other >= 0) {
              deepDiff(lhs[k], rhs[k], changes, prefilter, currentPath, k, stack);
              pkeys = arrayRemove(pkeys, other);
            } else {
              deepDiff(lhs[k], undefined, changes, prefilter, currentPath, k, stack);
            }
          });
          pkeys.forEach(function(k) {
            deepDiff(undefined, rhs[k], changes, prefilter, currentPath, k, stack);
          });
        }
        stack.length = stack.length - 1;
      }
    } else if (lhs !== rhs) {
      if (!(ltype === 'number' && isNaN(lhs) && isNaN(rhs))) {
        changes(new DiffEdit(currentPath, lhs, rhs));
      }
    }
  }

  function accumulateDiff(lhs, rhs, prefilter, accum) {
    accum = accum || [];
    deepDiff(lhs, rhs,
      function(diff) {
        if (diff) {
          accum.push(diff);
        }
      },
      prefilter);
    return (accum.length) ? accum : undefined;
  }

  function applyArrayChange(arr, index, change) {
    if (change.path && change.path.length) {
      var it = arr[index],
          i, u = change.path.length - 1;
      for (i = 0; i < u; i++) {
        it = it[change.path[i]];
      }
      switch (change.kind) {
        case 'A':
          applyArrayChange(it[change.path[i]], change.index, change.item);
          break;
        case 'D':
          delete it[change.path[i]];
          break;
        case 'E':
        case 'N':
          it[change.path[i]] = change.rhs;
          break;
      }
    } else {
      switch (change.kind) {
        case 'A':
          applyArrayChange(arr[index], change.index, change.item);
          break;
        case 'D':
          arr = arrayRemove(arr, index);
          break;
        case 'E':
        case 'N':
          arr[index] = change.rhs;
          break;
      }
    }
    return arr;
  }

  function applyChange(target, source, change) {
    if (target && source && change && change.kind) {
      var it = target,
          i = -1,
          last = change.path ? change.path.length - 1 : 0;
      while (++i < last) {
        if (typeof it[change.path[i]] === 'undefined') {
          it[change.path[i]] = (typeof change.path[i] === 'number') ? [] : {};
        }
        it = it[change.path[i]];
      }
      switch (change.kind) {
        case 'A':
          applyArrayChange(change.path ? it[change.path[i]] : it, change.index, change.item);
          break;
        case 'D':
          delete it[change.path[i]];
          break;
        case 'E':
        case 'N':
          it[change.path[i]] = change.rhs;
          break;
      }
    }
  }

  function revertArrayChange(arr, index, change) {
    if (change.path && change.path.length) {
      // the structure of the object at the index has changed...
      var it = arr[index],
          i, u = change.path.length - 1;
      for (i = 0; i < u; i++) {
        it = it[change.path[i]];
      }
      switch (change.kind) {
        case 'A':
          revertArrayChange(it[change.path[i]], change.index, change.item);
          break;
        case 'D':
          it[change.path[i]] = change.lhs;
          break;
        case 'E':
          it[change.path[i]] = change.lhs;
          break;
        case 'N':
          delete it[change.path[i]];
          break;
      }
    } else {
      // the array item is different...
      switch (change.kind) {
        case 'A':
          revertArrayChange(arr[index], change.index, change.item);
          break;
        case 'D':
          arr[index] = change.lhs;
          break;
        case 'E':
          arr[index] = change.lhs;
          break;
        case 'N':
          arr = arrayRemove(arr, index);
          break;
      }
    }
    return arr;
  }

  function revertChange(target, source, change) {
    if (target && source && change && change.kind) {
      var it = target,
          i, u;
      u = change.path.length - 1;
      for (i = 0; i < u; i++) {
        if (typeof it[change.path[i]] === 'undefined') {
          it[change.path[i]] = {};
        }
        it = it[change.path[i]];
      }
      switch (change.kind) {
        case 'A':
          // Array was modified...
          // it will be an array...
          revertArrayChange(it[change.path[i]], change.index, change.item);
          break;
        case 'D':
          // Item was deleted...
          it[change.path[i]] = change.lhs;
          break;
        case 'E':
          // Item was edited...
          it[change.path[i]] = change.lhs;
          break;
        case 'N':
          // Item is new...
          delete it[change.path[i]];
          break;
      }
    }
  }

  function applyDiff(target, source, filter) {
    if (target && source) {
      var onChange = function(change) {
        if (!filter || filter(target, source, change)) {
          applyChange(target, source, change);
        }
      };
      deepDiff(target, source, onChange);
    }
  }

  Object.defineProperties(accumulateDiff, {

    diff: {
      value: accumulateDiff,
      enumerable: true
    },
    observableDiff: {
      value: deepDiff,
      enumerable: true
    },
    applyDiff: {
      value: applyDiff,
      enumerable: true
    },
    applyChange: {
      value: applyChange,
      enumerable: true
    },
    revertChange: {
      value: revertChange,
      enumerable: true
    },
    isConflict: {
      value: function() {
        return 'undefined' !== typeof conflict;
      },
      enumerable: true
    },
    noConflict: {
      value: function() {
        if (conflictResolution) {
          conflictResolution.forEach(function(it) {
            it();
          });
          conflictResolution = null;
        }
        return accumulateDiff;
      },
      enumerable: true
    }
  });

  return accumulateDiff;
}));