// Globals
// -----------------------------------------------------------------------------
var privileges = [ { id: 0, label: 'Δημόσιο' } ];
var files = [];
var table;



// Supplamentary functions
// -----------------------------------------------------------------------------

// array.indexOf polyfill
// --- -- -- - - -
if (!Array.prototype.indexOf)
{
  Array.prototype.indexOf = function(elt /*, from*/)
  {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++)
    {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}


// function for sorting an array by 'label' attribute
// --- -- -- - - -
function compare_label (a,b) {
    if ( a.label < b.label ) { return -1; }
    if ( a.label > b.label ) { return 1; }
    return 0;
}


// return file record by file-id
// --- -- -- - - -
function privilege_record(id) {
    var record = 0;
    files.forEach(el => { if (el.id == id) record = el; });  
    return record;
}


/** privilege(id) 
 * label of privilege with
 * @param id (int)
 */
function privilege_(id) {
    let reply = false;
    privileges.forEach( pri => { if (pri.id == id) reply = pri.label; });
    return reply;
}


// create actions html (edit and delete buttons)
// --- -- -- - - -
function create_actions_html(id) {

    var del, edit;

    del = "";

    edit = [
        '<button type="button" class="btn btn-sm btn-warning"',
            'data-bs-toggle="modal" data-bs-target="#manageFiles"',
            'data-id="'+ id +'">',
            '<i class="fas fa-pencil-alt"></i>',
        '</button>'
    ].join('\n');

    return edit +' '+ del;
}



$(document).ready(function() {

    // When document is ready
    // -------------------------------------------------------------------------

    
    /** init selec2 element (used to specify parent-category)
     * --- -- -- - - -
     */
    $("#privilege_id").select2({
        placeholder: 'Επίπεδο πρόσβασης',
        dropdownParent: $('#manageFiles'),
        width: '100%',
    });

    
    /** init_table
     * --- -- -- - - -
     * get categories
     * constuct categories array
     * render dataTable 
     */
    function init_table() {

        // get all categories from server (ajax)
        $.getJSON( "/admin/api/files")
        .done(function( json ) {
            // then ...

            // reset categories
            files.length = 0;

            // construct (new) categories data
            Object.keys(json).forEach( key => {
                el = json[key];
                files.push({
                    id: el.id,
                    label: el.label,
                    path: el.path,
                    type: el.type,
                    privilege_id: ((el.privilege_id == null) ? 0 : el.privilege_id),
                    privilege: privilege_( ((el.privilege_id == null) ? 0 : el.privilege_id) ),
                    actions: create_actions_html(el.id)
                });
            });

            // sort by breadcrumb
            // categories.sort( compare_breadcrumb );

            // destroy previous datatable table instances
            $('#dt-files').dataTable().fnClearTable();
            $('#dt-files').dataTable().fnDestroy();

            // (re-)create categories datatable
            table = $('#dt-files').DataTable({
                language: { url: '/libs/DataTables/localization/Greek.json' },           
                data: files,
                ordering: false,
                columns: [
                    { data: 'id' },
                    { data: 'label' },
                    { data: 'path' },
                    { data: 'type' },
                    { data: 'privilege' },
                    { data: 'actions' }
                ]
            });

        })
        .fail(function( jqxhr, textStatus, error ) {
            console.log( "Request Failed (" + error +")" );
        });

    }



    $.getJSON( "/admin/api/privileges" )
    .done( function( response ) {

        // construct provileges data
        // ---
        response.forEach( el => {
            privileges.push({
                id: el.id,
                label: el.label
            });
        });
        privileges.sort( compare_label );  // sort categories by breadcrumb

        init_table();   // init table on first run
    });



    /** When modal show-up
     * -------------------------------------------------------------------------
     * ... prepare the manage-category form 
     * ... update select2 with possible parents
     */
    $('#managePrivileges').on('show.bs.modal', event => {
        var button = $(event.relatedTarget);        // Button that triggered the modal
        var id = parseInt( button.data('id') );     // category_id from data-id
        // var modal = $(this);    // modal object     
        
        // update modal literature
        // ---
        $('#managePrivileges .modal-title').html(             // modal title
            (id) ? 'Ενημέρωση Επιπέδου Πρόσβασης' : 'Δημιουργία Επιπέδου Πρόσβασης'
        );
        $('#managePrivileges form input[name=id]').val( id );     // category id (hidden)
        $('#managePrivileges form input[name=label]').val(    // category label
            (id) ? privilege_record(id).label : ""
        );
        prepare_included_element(id);        // prepare <select> for parents
    })

    /** prepare_included_element()
     * ---
     * @param id (int) : id of selected privilege
     * -> Get all posible included privileges
     * -> call set_included_options() to render the options
     */
    function prepare_included_element(id) {
        var may_included = [];

        if (id) {   // get all possible parents

            // TODO: 
            // specify forbiden privilege IDs for being included

            // filter privileges adn prepare possible included privileges
            privileges.forEach( el => {
                if (id != el.id)  {
                    may_included.push({
                        id: el.id,
                        label: el.label
                    });
                }
            });
            console.log(may_included);
            set_included_options(may_included, privilege_record(id).included_id);


        } else {    // new record; all categories are possible parrents
            privileges.forEach( el => {
                may_included.push({
                    id: el.id,
                    label: el.label,
                });
            })
            set_included_options(may_included, -1);
        }
    }

    /** set_included_options()
     * -> create options for parents <select>
     * -> choose selected parent
     * @param may_included (array): array of possible included privileges
     * @param selected (int): selected included privilege
     */
    function set_included_options(may_included, selected) {
        // sort parents by breadcrumb
        // parents.sort( compare_breadcrumb );

        // remove any olded options from select2
        $('#included_id option').each(function() { $(this).remove(); });

        // first option is the root category
        $('#included_id').append('<option value="0">— κανένα —</option>')

        // add all other parent options
        may_included.forEach( i => {
            $('#included_id').append(`<option value="${i.id}">${i.label}</option>`);
        });

        if (selected == -1) {   // new category; remove any parent pre-selection
            $('#included_id').val(0).trigger('change');

        } else {    // category exists; choose selected parent
            $('#included_id').val(selected).trigger('change');
        }
    }




    // When form is submited
    // -------------------------------------------------------------------------

    $('#manageCategory form').submit( event => {
        event.preventDefault();

        // prepare data to POST
        var data = {
            id: parseInt($('#manageCategory form input[name=id]').val()),
            label: $('#manageCategory form input[name=label]').val(),
            parent_id: parseInt($('#parent_id').select2('data')[0].id)
        };

        // select action url (add or update)
        var request = '/admin/api/category/' + ((data.id == 0)  ? 'add' : 'update');

        // send POST request
        $.post(request, data)
        .done(function( data ) {

            $('#manageCategory').modal('hide');     // when done, close modal

            init_table();       // reload table of categories
        });       

    });

});