'use strict';

const createBufferReader = require("../buffer-reader");
const roundEven = require("../../round-even");

function parseFileFlags(value) {
    /* File flags: (ref http://wiki.osdev.org/ISO_9660#Directories)
     *   Bit      Description
     *   0        If set, the existence of this file need not be made known to the user (basically a 'hidden' flag.
     *   1        If set, this record describes a directory (in other words, it is a subdirectory extent).
     *   2        If set, this file is an "Associated File".
     *   3        If set, the extended attribute record contains information about the format of this file.
     *   4        If set, owner and group permissions are set in the extended attribute record.
     *   5 & 6    Reserved
     *   7        If set, this is not the final directory record for this file (for files spanning several extents, for example files over 4GiB long.
     */

    return {
        hidden: !!(value & 1),
        directory: !!(value & 2),
        associated: !!(value & 4),
        inEAR: !!(value & 8),
        permissionsInEAR: !!(value & 16),
        moreRecordsFollowing: !!(value & 128)
    }
}

module.exports = function parseDirectoryRecord(data) {
    let bufferReader = createBufferReader(data);

    let identifierLength = bufferReader.int8(32);
    let identifierEnd = roundEven(32 + identifierLength);

    return {
        recordLength: bufferReader.int8(0),
        extendedAttributeRecordLength: bufferReader.int8(1),
        extentLocation: bufferReader.int32_LSB_MSB(2),
        extentSize: bufferReader.int32_LSB_MSB(10),
        recordingDate: bufferReader.directoryDatetime(18),
        fileFlags: parseFileFlags(bufferReader.int8(25)),
        interleavedUnitSize: bufferReader.int8(26),
        interleavedGapSize: bufferReader.int8(27),
        sequenceNumber: bufferReader.int16_LSB_MSB(28),
        identifierLength: identifierLength,
        identifier: bufferReader.strFilename(33, identifierLength),
        systemUse: data.slice(identifierEnd, 254) // FIXME: Extensions!
    }
};