/**
 * Removes the task from the task list and shot list, and show the 'task-add-link'
 * when this was the last task in its category.
 */
function _remove_task_from_list(task_id) {
    var $task_link = $('#task-' + task_id)
    var $task_link_parent = $task_link.parent();
    $task_link.hideAndRemove(300, function() {
        if ($task_link_parent.children('.task-link').length == 0) {
            $task_link_parent.find('.task-add-link').removeClass('hidden');
        }
    });
}

/**
 * Open an item such as tasks/shots in the #item-details div
 */
function item_open(item_id, item_type, pushState)
{
    if (item_id === undefined || item_type === undefined) {
        throw new ReferenceError("item_open(" + item_id + ", " + item_type + ") called.");
    }

    var project_url = ProjectUtils.projectUrl();
    if (typeof project_url === 'undefined') {
        throw new ReferenceError("ProjectUtils.projectUrl() undefined");
    }

    $('#col_right .col_header span.header_text').text(item_type + ' details');

    // Style elements starting with item_type and dash, e.g. "#shot-uuid"
    $('[id^="' + item_type + '-"]').removeClass('active');
    $('#' + item_type + '-' + item_id).addClass('active');

    var item_url = '/attract/' + project_url + '/' + item_type + 's/' + item_id;
    var push_url = item_url;
    if (ProjectUtils.context() == 'shot' && item_type == 'task'){
        push_url = '/attract/' + project_url + '/shots/with-task/' + item_id;
    }

    $.get(item_url, function(item_data) {
        $('#item-details').html(item_data);
    }).fail(function(xhr) {
        if (console) {
            console.log('Error fetching task', item_id, 'from', item_url);
            console.log('XHR:', xhr);
        }
        $('#status-bar').text('Opening ' + item_type + ' failed.');
        if (xhr.status) {
            $('#item-details').html(xhr.responseText);
        } else {
            $('#item-details').html('<p class="text-danger">Opening ' + item_type + ' failed. There possibly was ' +
            'an error connecting to the server. Please check your network connection and ' +
            'try again.</p>');
        }
    });

    // Determine whether we should push the new state or not.
    pushState = (typeof pushState !== 'undefined') ? pushState : true;
    if (!pushState) return;

    // Push the correct URL onto the history.
    var push_state = {itemId: item_id, itemType: item_type};

    window.history.pushState(
            push_state,
            item_type + ': ' + item_id,
            push_url
    );
}

function task_open(task_id)
{
    item_open(task_id, 'task');
}

function shot_open(shot_id)
{
    item_open(shot_id, 'shot');
}

window.onpopstate = function(event)
{
    var state = event.state;

    item_open(state.itemId, state.itemType, false);
}

/**
 * Create a task and show it in the #item-details div.
 * NOTE: Not used at the moment, we're creating shots via Blender's VSE
 */
function shot_create(project_url)
{
    if (project_url === undefined) {
        throw new ReferenceError("shot_create(" + project_url+ ") called.");
    }
    var url = '/attract/' + project_url + '/shots/create';

    data = {
        project_url: project_url
    };

    $.post(url, data, function(shot_data) {
        shot_open(shot_data.shot_id);
    })
    .fail(function(xhr) {
        if (console) {
            console.log('Error creating task');
            console.log('XHR:', xhr);
        }
        $('#item-details').html(xhr.responseText);
    });
}

/**
 * Adds the task item to the shots/tasks list
 */
function task_add(shot_id, task_id, project_url, task_type){

    var url = '/attract/' + project_url + '/tasks/' + task_id;

    if (ProjectUtils.context() == 'task'){
        $('#task-list').append('\
            <a class="col-list-item task-list-item status-todo task-link"\
                href="' + url + '"\
                data-task-id="' + task_id + '"\
                id="task-' + task_id + '">\
                <span class="status-indicator"></span>\
                <span class="name">New Task</span>\
                <span class="type">none</span>\
            </a>\
            ');
    } else if (ProjectUtils.context() == 'shot'){
        var $shot_cell = $('#shot-' + shot_id + ' .table-cell.task-type.' + task_type);
        var url = '/attract/' + project_url + '/shots/with-task/' + task_id;

        $shot_cell.append('\
            <a class="status-todo task-link"\
                title="New task"\
                href="' + url + '"\
                data-task-id="' + task_id + '"\
                id="task-' + task_id + '">\
            </a>\
        ');

        $shot_cell.find('.task-add.task-add-link').addClass('hidden');
    }
}

/**
 * Create a task and show it in the #item-details div.
 */
function task_create(shot_id, project_url, task_type)
{
    if (project_url === undefined || task_type === undefined) {
        throw new ReferenceError("task_create(" + project_url+ ", " + task_type + ") called.");
    }

    var url = '/attract/' + project_url + '/tasks/create';

    data = {
        task_type: task_type,
        parent: shot_id,
    };

    $.post(url, data, function(task_data) {
        task_open(task_data.task_id, project_url);
        task_add(shot_id, task_data.task_id, project_url, task_type);
    })
    .fail(function(xhr) {
        if (console) {
            console.log('Error creating task');
            console.log('XHR:', xhr);
        }
        $('#item-details').html(xhr.responseText);
    })
    .done(function(){
        $('#item-details input[name="name"]').focus();
    });
}

function attract_form_save(form_id, item_id, item_save_url, options)
{
    // Mandatory option.
    if (typeof options === 'undefined' || typeof options.type === 'undefined') {
        throw new ReferenceError('attract_form_save(): options.type is mandatory.');
    }

    var $form = $('#' + form_id);
    var $button = $form.find("button[type='submit']");

    var payload = $form.serialize();
    var $item = $('#' + item_id);

    $button.attr('disabled', true);
    $item.addClass('processing');
    $('#status-bar').text('Saving ' + options.type + '...');

    if (console) console.log('Sending:', payload);

    $.post(item_save_url, payload)
        .done(function(saved_item) {
            if (console) console.log('Done saving', saved_item);
            $('#status-bar')
                .text('Saved ' + options.type + '. ' + saved_item._updated);
            $form.find("input[name='_etag']").val(saved_item._etag);

            if (options.done) options.done($item, saved_item);
        })
        .fail(function(xhr_or_response_data) {
            // jQuery sends the response data (if JSON), or an XHR object (if not JSON).
            if (console) console.log('Failed saving', options.type, xhr_or_response_data);

            $button.removeClass('btn-default').addClass('btn-danger');
            $('#status-bar').text('Failed saving. ' + xhr_or_response_data.status);

            if (options.fail) options.fail($item, xhr_or_response_data);
        })
        .always(function() {
            $button.attr('disabled', false);
            $item.removeClass('processing');

            if (options.always) options.always($item);
        })
    ;

    return false; // prevent synchronous POST to current page.
}

function task_save(task_id, task_url) {
    return attract_form_save('task_form', 'task-' + task_id, task_url, {
        done: function($task, saved_task) {
            // Update the task list.
            // NOTE: this is tightly linked to the HTML of the task list in for_project.jade.
            $('.task-name-' + saved_task._id).text(saved_task.name).flashOnce();
            $task.find('span.name').text(saved_task.name);
            $task.find('span.type').text(saved_task.properties.task_type);
            $task.find('span.status').text(saved_task.properties.status.replace('_', ' '));

            $task
                .removeClassPrefix('status-')
                .addClass('status-' + saved_task.properties.status)
                .flashOnce()
            ;
        },
        fail: function($item, xhr_or_response_data) {
            if (xhr_or_response_data.status == 412) {
                // TODO: implement something nice here. Just make sure we don't throw
                // away the user's edits. It's up to the user to handle this.
            } else {
                $('#item-details').html(xhr_or_response_data.responseText);
            }
        },
        type: 'task'
    });
}

function shot_save(shot_id, shot_url) {
    return attract_form_save('shot_form', 'shot-' + shot_id, shot_url, {
        done: function($shot, saved_shot) {
            // Update the shot list.
            $('.shot-name-' + saved_shot._id).text(saved_shot.name);
            $shot
                .removeClassPrefix('status-')
                .addClass('status-' + saved_shot.properties.status)
                .flashOnce()
            ;
        },
        fail: function($item, xhr_or_response_data) {
            if (xhr_or_response_data.status == 412) {
                // TODO: implement something nice here. Just make sure we don't throw
                // away the user's edits. It's up to the user to handle this.
            } else {
                $('#item-details').html(xhr_or_response_data.responseText);
            }
        },
        type: 'shot'
    });
}

function task_delete(task_id, task_etag, task_delete_url) {
    if (task_id === undefined || task_etag === undefined || task_delete_url === undefined) {
        throw new ReferenceError("task_delete(" + task_id + ", " + task_etag + ", " + task_delete_url + ") called.");
    }

    $('#task-' + task_id).addClass('processing');

    $.ajax({
        type: 'DELETE',
        url: task_delete_url,
        data: {'etag': task_etag}
    })
    .done(function(e) {
        if (console) console.log('Task', task_id, 'was deleted.');
        $('#item-details').fadeOutAndClear();
        _remove_task_from_list(task_id);
    })
    .fail(function(xhr) {
        $('#status-bar').text('Unable to delete task, code ' + xhr.status);
        if (xhr.status == 412) {
            alert('Someone else edited this task before you deleted it; refresh to try again.');
            // TODO: implement something nice here. Just make sure we don't throw
            // away the user's edits. It's up to the user to handle this.
            // TODO: refresh activity feed and point user to it.
        } else {
            // TODO: find a better place to put this error message, without overwriting the
            // task the user is looking at in-place.
            $('#task-view-feed').html(xhr.responseText);
        }
    });
}

$(function() {
    $("a.shot-link[data-shot-id]").click(function(e) {
        e.preventDefault();
        // delegateTarget is the thing the event hander was attached to,
        // rather than the thing we clicked on.
        var shot_id = e.delegateTarget.dataset.shotId;
        shot_open(shot_id);

        if ($(window).scrollTop() > 100) {
            $("html, body").animate({scrollTop: 50 }, '500', 'swing');
        }
    });

    $("a.task-link[data-task-id]").click(function(e) {
        e.preventDefault();
        var task_id = e.delegateTarget.dataset.taskId;
        task_open(task_id);

        if (ProjectUtils.context() == 'shot'){
            $('[id^="shot-"]').removeClass('active');
            $(this).parent().parent().addClass('active');
        }

        if ($(window).scrollTop() > 100) {
            $("html, body").animate({scrollTop: 50 }, '500', 'swing');
        }
    });
});