function AnalyseAlbumViewModel() {
    var self = this;

    self.imagesFailed = ko.observableArray();
    self.imagesToAnalyse = ko.observableArray();
    self.numberSuccessful = ko.observable(0);
    self.numberFailed = ko.observable(0);

    self.numberTotal = ko.computed(function () {
        return self.imagesToAnalyse().length;
    });

    self.failedPercentage = ko.computed(function () {
        return ((self.numberFailed() / self.numberTotal()) * 100).toFixed(2) + '%';
    });
    self.successfulPercentage = ko.computed(function () {
        return ((self.numberSuccessful() / self.numberTotal()) * 100).toFixed(2) + '%';
    });

    self.isCompleted = ko.computed(function () {
        return self.numberTotal() > 0 && (self.numberSuccessful() + self.numberFailed() >= self.numberTotal());
    });

    // When an image is added to the array, automatically issue it for analysis
    self.imagesToAnalyse.subscribe(function (changes) {
        // changes[0].value is an instance of AnalyseImageViewModel
        var item = changes[0].value;
        $.ajax(
            item.url(),
            {
                dataType: 'json',
                error: function (xhr, textStatus, errorThrown) {
                    self.numberFailed(self.numberFailed() + 1);
                    self.imagesFailed.push({
                        'name': item.name(),
                        'reason': textStatus
                    });
                    item.isSuccessful(false);
                    item.isPending(false);
                },
                method: 'POST',
                success: function (data) {
                    if (data.is_successful) {
                        self.numberSuccessful(self.numberSuccessful() + 1);
                        item.isSuccessful(true);
                        item.isPending(false);
                    }
                    else {
                        self.numberFailed(self.numberFailed() + 1);
                        self.imagesFailed.push({
                            'name': item.name(),
                            'reason': data.message
                        });
                        item.isSuccessful(false);
                        item.isPending(false);
                    }
                }
            }
        );
    }, null, 'arrayChange');
}

function AnalyseImageViewModel(image_info) {
    var self = this;

    self.isPending = ko.observable(true);
    self.isSuccessful = ko.observable(false);
    self.name = ko.observable(image_info.name);
    self.photoID = ko.observable(image_info.photo_id);
    self.url = ko.observable(image_info.url);

    self.iconClass = ko.computed(function () {
        var string = 'fa fa-fw ';

        if (!self.isPending()) {
            string += (self.isSuccessful() ? 'check text-success' : 'times text-danger')
        }

        return string;
    });
}

/**
 * This model is used by admin/show_album.blade.php to handle photo changes.
 * @param album_id ID of the album the photos are in
 * @param language Array containing language strings
 * @param urls Array containing URLs
 * @constructor
 */
function EditPhotosViewModel(album_id, language, urls) {
    var self = this;

    self.albums = ko.observableArray();
    self.bulkModifyMethod = ko.observable();
    self.photoIDs = ko.observableArray();

    /* Called when the Apply button on the "bulk apply selected actions" form is clicked */
    self.bulkModifySelected = function()
    {
        var bulk_form = $('form#bulk-modify-form');

        if (self.bulkModifyMethod() == 'change_album')
        {
            // Prompt for the new album to move to
            self.promptForNewAlbum(function(dialog) {
                var album_id = $('select', dialog).val();
                $('input[name="new-album-id"]', form).val(album_id);
                bulk_form.submit();
            });

            return false;
        }
        else if (self.bulkModifyMethod() == 'delete')
        {
            // Prompt for a confirmation - are you sure?!
            bootbox.dialog({
                message: language.delete_bulk_confirm_message.replace(':number', self.photoIDs().length),
                title: language.delete_bulk_confirm_title.replace(':number', self.photoIDs().length),
                buttons: {
                    cancel: {
                        label: language.action_cancel,
                        className: "btn-default"
                    },
                    confirm: {
                        label: language.action_delete,
                        className: "btn-danger",
                        callback: function() {
                            bulk_form.submit();
                        }
                    }
                }
            });
            
            return false;
        }

        // All other methods submit the form as normal
        return true;
    };

    self.changeAlbum = function()
    {
        self.selectPhotoSingle(this);

        self.promptForNewAlbum(function(dialog) {
            var album_id = $('select', dialog).val();
            $.post(urls.move_photo.replace(/\/0$/, '/' + self.photoIDs()[0]), { 'new_album_id': album_id }, function()
            {
                window.location.reload();
            });
        });

        return false;
    };

    self.delete = function() {
        self.selectPhotoSingle(this);

        bootbox.dialog({
            message: language.delete_confirm_message,
            title: language.delete_confirm_title,
            buttons: {
                cancel: {
                    label: language.action_cancel,
                    className: "btn-default"
                },
                confirm: {
                    label: language.action_delete,
                    className: "btn-danger",
                    callback: function() {
                        var url = urls.delete_photo;
                        url = url.replace(/\/0$/, '/' + self.photoIDs()[0]);

                        $('.loading', parent).show();

                        $.post(url, {'_method': 'DELETE'}, function(data)
                        {
                            window.location.reload();
                        });
                    }
                }
            }
        });

        return false;
    };

    self.promptForNewAlbum = function(callback_on_selected)
    {
        var albums = self.albums();
        var select = $('<select/>')
            .attr('name', 'album_id')
            .addClass('form-control');

        for (var i = 0; i < albums.length; i++)
        {
            var option = $('<option/>')
                .attr('value', albums[i].id)
                .html(albums[i].name)
                .appendTo(select);

            // Pre-select the current album
            if (album_id == albums[i].id)
            {
                option.attr('selected', 'selected');
            }
        }

        bootbox.dialog({
            message: $('<p/>').html(language.change_album_message).prop('outerHTML') + select.prop('outerHTML'),
            title: language.change_album_title,
            buttons:
            {
                cancel:
                {
                    label: language.action_cancel,
                    className: 'btn-default'
                },
                confirm:
                {
                    label: language.action_continue,
                    className: 'btn-success',
                    callback: function()
                    {
                        callback_on_selected(this);
                    }
                }
            }
        });
    };

    self.selectPhotoSingle = function (link_item) {
        // Get the photo ID from the clicked link
        var parent = $(link_item).parents('.photo');
        var photo_id = $(parent).data('photo-id');

        // Save the photo ID
        self.photoIDs.removeAll();
        self.photoIDs.push(photo_id);

        // Hide the dropdown
        $(link_item).dropdown('toggle');
    };
}

function StorageLocationsViewModel() {
    var self = this;

    self.selectedLocation = ko.observable(true);
}

/**
 * This model is used by admin/show_album.blade.php to handle photo uploads.
 * @param album_id ID of the album the photos are being uploaded to
 * @param language Array containing language strings
 * @param urls Array containing URLs
 * @constructor
 */
function UploadPhotosViewModel(album_id, language, urls) {
    var self = this;

    self.currentStatus = ko.observable('');
    self.imagesFailed = ko.observable(0);
    self.imagesUploaded = ko.observable(0);
    self.imagesTotal = ko.observable(0);
    self.isBulkUploadInProgress = ko.observable(false);
    self.isUploadInProgress = ko.observable(false);
    self.statusMessages = ko.observableArray();

    self.failedPercentage = ko.computed(function () {
        return ((self.imagesFailed() / self.imagesTotal()) * 100).toFixed(2) + '%';
    });

    // This method is called when an image is uploaded - regardless if it fails or not
    self.onUploadCompleted = function () {
        self.currentStatus(language.upload_status
        .replace(':current', (self.imagesUploaded() + self.imagesFailed()))
        .replace(':total', self.imagesTotal()));

        if ((self.imagesFailed() + self.imagesUploaded()) >= self.imagesTotal()) {
            self.isUploadInProgress(false);

            if (self.imagesFailed() == 0 && self.imagesUploaded() > 0) {
                window.location = urls.analyse;
            }
        }
    };

    // This method is called when an uploaded image fails
    self.onUploadFailed = function (data, file_name) {
        self.imagesFailed(self.imagesFailed() + 1);
        self.statusMessages.push({
            'message_class': 'text-danger',
            'message_text': language.image_failed.replace(':file_name', file_name)
        });
        self.onUploadCompleted();
    };

    // This method is called when an uploaded image succeeds
    self.onUploadSuccessful = function (data, file_name) {
        if (data.is_successful) {
            self.imagesUploaded(self.imagesUploaded() + 1);
            // Don't add to statusMessages() array so user only sees errors
            /*self.statusMessages.push({
             'message_class': 'text-success',
             'message_text': language.image_uploaded.replace(':file_name', file_name)
             });*/
            self.onUploadCompleted();
        }
        else {
            self.onUploadFailed(data, file_name);
        }
    };

    self.startUpload = function (number_images) {
        self.currentStatus('');
        self.statusMessages.removeAll();
        self.imagesUploaded(0);
        self.imagesFailed(0);
        self.imagesTotal(number_images);
        self.isUploadInProgress(true);
    };

    self.successfulPercentage = ko.computed(function () {
        return ((self.imagesUploaded() / self.imagesTotal()) * 100).toFixed(2) + '%';
    });

    self.uploadFile = function uploadImageFile(formObject, imageFile) {
        var formData = new FormData();
        formData.append('album_id', album_id);
        formData.append('photo[]', imageFile, imageFile.name);

        $.ajax(
            {
                contentType: false,
                data: formData,
                error: function (data) {
                    self.onUploadFailed(data, imageFile.name);
                },
                method: $(formObject).attr('method'),
                processData: false,
                success: function (data) {
                    self.onUploadSuccessful(data, imageFile.name);
                },
                url: $(formObject).attr('action')
            }
        );
        viewModel.isUploadInProgress(true);
    };
}