'use strict';

const createBufferReader = require("../../buffer-reader");
const parseDirectoryRecord = require("../directory-record");

module.exports = function parsePrimaryVolumeDescriptor(data, encoding = "ascii") {
    let bufferReader = createBufferReader(data, {
        encoding: encoding
    });

    /* NOTE: Technically, the spec states that we should use strA and strD in a primary volume descriptor, and not strA1 and strD1. However, using the encoding-specific versions makes it easier to base the supplementary volume descriptor parser on this one, and since this parser defaults to an 'ascii' encoding anyway, it doesn't matter from a functional perspective. */

    return {
        systemIdentifier: bufferReader.strA1(1, 32),
        volumeIdentifier: bufferReader.strD1(33, 32),
        sectorCount: bufferReader.int32_LSB_MSB(73),
        setSize: bufferReader.int16_LSB_MSB(113),
        sequenceNumber: bufferReader.int16_LSB_MSB(117),
        sectorSize: bufferReader.int16_LSB_MSB(121),
        pathTableSize: bufferReader.int32_LSB_MSB(125),
        pathTableLocationL: bufferReader.int32_LSB(133), // FIXME: Pointer? (location is expressed in 'sectors')
        optionalPathTableLocationL: bufferReader.int32_LSB(137), // FIXME: Pointer? (location is expressed in 'sectors')
        pathTableLocationM: bufferReader.int32_MSB(141), // FIXME: Pointer? (location is expressed in 'sectors')
        optionalPathTableLocationM: bufferReader.int32_MSB(145), // FIXME: Pointer? (location is expressed in 'sectors')
        rootDirectory: parseDirectoryRecord(bufferReader.slice(149, 34), {encoding: encoding}),
        volumeSetIdentifier: bufferReader.strD1(183, 128),
        publisherIdentifier: bufferReader.strA1(311, 128), // FIXME: null for unspecified & extended publisher information
        dataPreparerIdentifier: bufferReader.strA1(439, 128), // FIXME: null for unspecified & extended publisher information
        applicationIdentifier: bufferReader.strA1(567, 128), // FIXME: null for unspecified & extended publisher information
        copyrightFile: bufferReader.strD1(695, 36), // FIXME: seek for file, optionally?
        abstractFile: bufferReader.strD1(732, 36), // FIXME: seek for file, optionally?
        bibliographicFile: bufferReader.strD1(769, 36), // FIXME: seek for file, optionally?
        creationDate: bufferReader.decDatetime(806),
        modificationDate: bufferReader.decDatetime(823),
        expirationDate: bufferReader.decDatetime(840),
        effectiveDate: bufferReader.decDatetime(857),
        fileStructureVersion: bufferReader.int8(874),
        applicationData: data.slice(876, 876 + 512)
    }
};