angular.module('ui.bootstrap.pagination', [])

.controller('PaginationController', ['$scope', '$attrs', '$parse', function ($scope, $attrs, $parse) {
  var self = this,
      ngModelCtrl = { $setViewValue: angular.noop }, // nullModelCtrl
      setNumPages = $attrs.numPages ? $parse($attrs.numPages).assign : angular.noop;

  this.init = function(ngModelCtrl_, config) {
    ngModelCtrl = ngModelCtrl_;
    this.config = config;

    ngModelCtrl.$render = function() {
      self.render();
    };

    if ($attrs.itemsPerPage) {
      $scope.$parent.$watch($parse($attrs.itemsPerPage), function(value) {
        self.itemsPerPage = parseInt(value, 10);
        $scope.totalPages = self.calculateTotalPages();
      });
    } else {
      this.itemsPerPage = config.itemsPerPage;
    }
  };

  this.calculateTotalPages = function() {
    var totalPages = this.itemsPerPage < 1 ? 1 : Math.ceil($scope.totalItems / this.itemsPerPage);
    return Math.max(totalPages || 0, 1);
  };

  this.render = function() {
    $scope.page = parseInt(ngModelCtrl.$viewValue, 10) || 1;
  };

  $scope.selectPage = function(page) {
    if ( $scope.page !== page && page > 0 && page <= $scope.totalPages) {
      ngModelCtrl.$setViewValue(page);
      ngModelCtrl.$render();
    }
  };

  $scope.getText = function( key ) {
    return $scope[key + 'Text'] || self.config[key + 'Text'];
  };
  $scope.noPrevious = function() {
    return $scope.page === 1;
  };
  $scope.noNext = function() {
    return $scope.page === $scope.totalPages;
  };

  $scope.$watch('totalItems', function() {
    $scope.totalPages = self.calculateTotalPages();
  });

  $scope.$watch('totalPages', function(value) {
    setNumPages($scope.$parent, value); // Readonly variable

    if ( $scope.page > value ) {
      $scope.selectPage(value);
    } else {
      ngModelCtrl.$render();
    }
  });
}])

.constant('paginationConfig', {
  itemsPerPage: 10,
  boundaryLinks: false,
  directionLinks: true,
  firstText: 'First',
  previousText: 'Previous',
  nextText: 'Next',
  lastText: 'Last',
  rotate: true
})

.directive('pagination', ['$parse', 'paginationConfig', function($parse, paginationConfig) {
  return {
    restrict: 'EA',
    scope: {
      totalItems: '=',
      firstText: '@',
      previousText: '@',
      nextText: '@',
      lastText: '@'
    },
    require: ['pagination', '?ngModel'],
    controller: 'PaginationController',
    templateUrl: 'template/pagination/pagination.html',
    replace: true,
    link: function(scope, element, attrs, ctrls) {
      var paginationCtrl = ctrls[0], ngModelCtrl = ctrls[1];

      if (!ngModelCtrl) {
         return; // do nothing if no ng-model
      }

      // Setup configuration parameters
      var maxSize = angular.isDefined(attrs.maxSize) ? scope.$parent.$eval(attrs.maxSize) : paginationConfig.maxSize,
          rotate = angular.isDefined(attrs.rotate) ? scope.$parent.$eval(attrs.rotate) : paginationConfig.rotate;
      scope.boundaryLinks = angular.isDefined(attrs.boundaryLinks) ? scope.$parent.$eval(attrs.boundaryLinks) : paginationConfig.boundaryLinks;
      scope.directionLinks = angular.isDefined(attrs.directionLinks) ? scope.$parent.$eval(attrs.directionLinks) : paginationConfig.directionLinks;

      paginationCtrl.init(ngModelCtrl, paginationConfig);

      if (attrs.maxSize) {
        scope.$parent.$watch($parse(attrs.maxSize), function(value) {
          maxSize = parseInt(value, 10);
          paginationCtrl.render();
        });
      }

      // Create page object used in template
      function makePage(number, text, isActive) {
        return {
          number: number,
          text: text,
          active: isActive
        };
      }

      function getPages(currentPage, totalPages) {
        var pages = [];

        // Default page limits
        var startPage = 1, endPage = totalPages;
        var isMaxSized = ( angular.isDefined(maxSize) && maxSize < totalPages );

        // recompute if maxSize
        if ( isMaxSized ) {
          if ( rotate ) {
            // Current page is displayed in the middle of the visible ones
            startPage = Math.max(currentPage - Math.floor(maxSize/2), 1);
            endPage   = startPage + maxSize - 1;

            // Adjust if limit is exceeded
            if (endPage > totalPages) {
              endPage   = totalPages;
              startPage = endPage - maxSize + 1;
            }
          } else {
            // Visible pages are paginated with maxSize
            startPage = ((Math.ceil(currentPage / maxSize) - 1) * maxSize) + 1;

            // Adjust last page if limit is exceeded
            endPage = Math.min(startPage + maxSize - 1, totalPages);
          }
        }

        // Add page number links
        for (var number = startPage; number <= endPage; number++) {
          var page = makePage(number, number, number === currentPage);
          pages.push(page);
        }

        // Add links to move between page sets
        if ( isMaxSized && ! rotate ) {
          if ( startPage > 1 ) {
            var previousPageSet = makePage(startPage - 1, '...', false);
            pages.unshift(previousPageSet);
          }

          if ( endPage < totalPages ) {
            var nextPageSet = makePage(endPage + 1, '...', false);
            pages.push(nextPageSet);
          }
        }

        return pages;
      }

      var originalRender = paginationCtrl.render;
      paginationCtrl.render = function() {
        originalRender();
        if (scope.page > 0 && scope.page <= scope.totalPages) {
          scope.pages = getPages(scope.page, scope.totalPages);
        }
      };
    }
  };
}])

.constant('pagerConfig', {
  itemsPerPage: 10,
  previousText: '« Previous',
  nextText: 'Next »',
  align: true
})

.directive('pager', ['pagerConfig', function(pagerConfig) {
  return {
    restrict: 'EA',
    scope: {
      totalItems: '=',
      previousText: '@',
      nextText: '@'
    },
    require: ['pager', '?ngModel'],
    controller: 'PaginationController',
    templateUrl: 'template/pagination/pager.html',
    replace: true,
    link: function(scope, element, attrs, ctrls) {
      var paginationCtrl = ctrls[0], ngModelCtrl = ctrls[1];

      if (!ngModelCtrl) {
         return; // do nothing if no ng-model
      }

      scope.align = angular.isDefined(attrs.align) ? scope.$parent.$eval(attrs.align) : pagerConfig.align;
      paginationCtrl.init(ngModelCtrl, pagerConfig);
    }
  };
}]);
