// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
import { compareArrayBuffers, concatenateArrayBuffers } from '@loaders.gl/loader-utils';
import { searchFromTheEnd } from "./search-from-the-end.js";
import { setFieldToNumber } from "./zip64-info-generation.js";
const eoCDSignature = new Uint8Array([0x50, 0x4b, 0x05, 0x06]);
const zip64EoCDLocatorSignature = new Uint8Array([0x50, 0x4b, 0x06, 0x07]);
const zip64EoCDSignature = new Uint8Array([0x50, 0x4b, 0x06, 0x06]);
// offsets accroding to https://en.wikipedia.org/wiki/ZIP_(file_format)
const CD_RECORDS_NUMBER_OFFSET = 8n;
const CD_RECORDS_NUMBER_ON_DISC_OFFSET = 10n;
const CD_CD_BYTE_SIZE_OFFSET = 12n;
const CD_START_OFFSET_OFFSET = 16n;
const CD_COMMENT_OFFSET = 22n;
const ZIP64_EOCD_START_OFFSET_OFFSET = 8n;
const ZIP64_CD_RECORDS_NUMBER_OFFSET = 24n;
const ZIP64_CD_RECORDS_NUMBER_ON_DISC_OFFSET = 32n;
const ZIP64_CD_CD_BYTE_SIZE_OFFSET = 40n;
const ZIP64_CD_START_OFFSET_OFFSET = 48n;
const ZIP64_COMMENT_OFFSET = 56n;
/**
 * Parses end of central directory record of zip file
 * @param file - FileProvider instance
 * @returns Info from the header
 */
export const parseEoCDRecord = async (file) => {
    const zipEoCDOffset = await searchFromTheEnd(file, eoCDSignature);
    let cdRecordsNumber = BigInt(await file.getUint16(zipEoCDOffset + CD_RECORDS_NUMBER_OFFSET));
    let cdByteSize = BigInt(await file.getUint32(zipEoCDOffset + CD_CD_BYTE_SIZE_OFFSET));
    let cdStartOffset = BigInt(await file.getUint32(zipEoCDOffset + CD_START_OFFSET_OFFSET));
    let zip64EoCDLocatorOffset = zipEoCDOffset - 20n;
    let zip64EoCDOffset = 0n;
    const magicBytes = await file.slice(zip64EoCDLocatorOffset, zip64EoCDLocatorOffset + 4n);
    if (compareArrayBuffers(magicBytes, zip64EoCDLocatorSignature)) {
        zip64EoCDOffset = await file.getBigUint64(zip64EoCDLocatorOffset + ZIP64_EOCD_START_OFFSET_OFFSET);
        const endOfCDMagicBytes = await file.slice(zip64EoCDOffset, zip64EoCDOffset + 4n);
        if (!compareArrayBuffers(endOfCDMagicBytes, zip64EoCDSignature.buffer)) {
            throw new Error('zip64 EoCD not found');
        }
        cdRecordsNumber = await file.getBigUint64(zip64EoCDOffset + ZIP64_CD_RECORDS_NUMBER_OFFSET);
        cdByteSize = await file.getBigUint64(zip64EoCDOffset + ZIP64_CD_CD_BYTE_SIZE_OFFSET);
        cdStartOffset = await file.getBigUint64(zip64EoCDOffset + ZIP64_CD_START_OFFSET_OFFSET);
    }
    else {
        zip64EoCDLocatorOffset = 0n;
    }
    return {
        cdRecordsNumber,
        cdStartOffset,
        cdByteSize,
        offsets: {
            zip64EoCDOffset,
            zip64EoCDLocatorOffset,
            zipEoCDOffset
        }
    };
};
/**
 * updates EoCD record to add more files to the archieve
 * @param eocdBody buffer containing header
 * @param oldEoCDOffsets info read from EoCD record befor updating
 * @param newCDStartOffset CD start offset to be updated
 * @param eocdStartOffset EoCD start offset to be updated
 * @returns new EoCD header
 */
export function updateEoCD(eocdBody, oldEoCDOffsets, newCDStartOffset, eocdStartOffset, newCDRecordsNumber) {
    const eocd = new DataView(eocdBody);
    const classicEoCDOffset = oldEoCDOffsets.zip64EoCDOffset
        ? oldEoCDOffsets.zipEoCDOffset - oldEoCDOffsets.zip64EoCDOffset
        : 0n;
    // updating classic EoCD record with new CD records number in general and on disc
    if (Number(newCDRecordsNumber) <= 0xffff) {
        setFieldToNumber(eocd, 2, classicEoCDOffset + CD_RECORDS_NUMBER_OFFSET, newCDRecordsNumber);
        setFieldToNumber(eocd, 2, classicEoCDOffset + CD_RECORDS_NUMBER_ON_DISC_OFFSET, newCDRecordsNumber);
    }
    // updating zip64 EoCD record with new size of CD
    if (eocdStartOffset - newCDStartOffset <= 0xffffffff) {
        setFieldToNumber(eocd, 4, classicEoCDOffset + CD_CD_BYTE_SIZE_OFFSET, eocdStartOffset - newCDStartOffset);
    }
    // updating classic EoCD record with new CD start offset
    if (newCDStartOffset < 0xffffffff) {
        setFieldToNumber(eocd, 4, classicEoCDOffset + CD_START_OFFSET_OFFSET, newCDStartOffset);
    }
    // updating zip64 EoCD locator and record with new EoCD record start offset and cd records number
    if (oldEoCDOffsets.zip64EoCDLocatorOffset && oldEoCDOffsets.zip64EoCDOffset) {
        // updating zip64 EoCD locator with new EoCD record start offset
        const locatorOffset = oldEoCDOffsets.zip64EoCDLocatorOffset - oldEoCDOffsets.zip64EoCDOffset;
        setFieldToNumber(eocd, 8, locatorOffset + ZIP64_EOCD_START_OFFSET_OFFSET, eocdStartOffset);
        // updating zip64 EoCD record with new cd start offset
        setFieldToNumber(eocd, 8, ZIP64_CD_START_OFFSET_OFFSET, newCDStartOffset);
        // updating zip64 EoCD record with new cd records number
        setFieldToNumber(eocd, 8, ZIP64_CD_RECORDS_NUMBER_OFFSET, newCDRecordsNumber);
        setFieldToNumber(eocd, 8, ZIP64_CD_RECORDS_NUMBER_ON_DISC_OFFSET, newCDRecordsNumber);
        // updating zip64 EoCD record with new size of CD
        setFieldToNumber(eocd, 8, ZIP64_CD_CD_BYTE_SIZE_OFFSET, eocdStartOffset - newCDStartOffset);
    }
    return new Uint8Array(eocd.buffer);
}
/**
 * generates EoCD record
 * @param options data to generate EoCD record
 * @returns ArrayBuffer with EoCD record
 */
export function generateEoCD(options) {
    const header = new DataView(new ArrayBuffer(Number(CD_COMMENT_OFFSET)));
    for (const field of EOCD_FIELDS) {
        setFieldToNumber(header, field.size, field.offset, options[field.name ?? ''] ?? field.default ?? 0);
    }
    const locator = generateZip64InfoLocator(options);
    const zip64Record = generateZip64Info(options);
    return concatenateArrayBuffers(zip64Record, locator, header.buffer);
}
/** standart EoCD fields */
const EOCD_FIELDS = [
    // End of central directory signature = 0x06054b50
    {
        offset: 0,
        size: 4,
        default: new DataView(eoCDSignature.buffer).getUint32(0, true)
    },
    // Number of this disk (or 0xffff for ZIP64)
    {
        offset: 4,
        size: 2,
        default: 0
    },
    // Disk where central directory starts (or 0xffff for ZIP64)
    {
        offset: 6,
        size: 2,
        default: 0
    },
    // Number of central directory records on this disk (or 0xffff for ZIP64)
    {
        offset: 8,
        size: 2,
        name: 'recordsNumber'
    },
    // Total number of central directory records (or 0xffff for ZIP64)
    {
        offset: 10,
        size: 2,
        name: 'recordsNumber'
    },
    // Size of central directory (bytes) (or 0xffffffff for ZIP64)
    {
        offset: 12,
        size: 4,
        name: 'cdSize'
    },
    // Offset of start of central directory, relative to start of archive (or 0xffffffff for ZIP64)
    {
        offset: 16,
        size: 4,
        name: 'cdOffset'
    },
    // Comment length (n)
    {
        offset: 20,
        size: 2,
        default: 0
    }
];
/**
 * generates eocd zip64 record
 * @param options data to generate eocd zip64 record
 * @returns buffer with eocd zip64 record
 */
function generateZip64Info(options) {
    const record = new DataView(new ArrayBuffer(Number(ZIP64_COMMENT_OFFSET)));
    for (const field of ZIP64_EOCD_FIELDS) {
        setFieldToNumber(record, field.size, field.offset, options[field.name ?? ''] ?? field.default ?? 0);
    }
    return record.buffer;
}
/**
 * generates eocd zip64 record locator
 * @param options data to generate eocd zip64 record
 * @returns buffer with eocd zip64 record
 */
function generateZip64InfoLocator(options) {
    const locator = new DataView(new ArrayBuffer(Number(20)));
    for (const field of ZIP64_EOCD_LOCATOR_FIELDS) {
        setFieldToNumber(locator, field.size, field.offset, options[field.name ?? ''] ?? field.default ?? 0);
    }
    return locator.buffer;
}
/** zip64 EoCD record locater fields */
const ZIP64_EOCD_LOCATOR_FIELDS = [
    // zip64 end of central dir locator signature
    {
        offset: 0,
        size: 4,
        default: new DataView(zip64EoCDLocatorSignature.buffer).getUint32(0, true)
    },
    // number of the disk with the start of the zip64 end of
    {
        offset: 4,
        size: 4,
        default: 0
    },
    // start of the zip64 end of central directory
    {
        offset: 8,
        size: 8,
        name: 'eoCDStart'
    },
    // total number of disks
    {
        offset: 16,
        size: 4,
        default: 1
    }
];
/** zip64 EoCD recodrd fields */
const ZIP64_EOCD_FIELDS = [
    // End of central directory signature = 0x06064b50
    {
        offset: 0,
        size: 4,
        default: new DataView(zip64EoCDSignature.buffer).getUint32(0, true)
    },
    // Size of the EOCD64 minus 12
    {
        offset: 4,
        size: 8,
        default: 44
    },
    // Version made by
    {
        offset: 12,
        size: 2,
        default: 45
    },
    // Version needed to extract (minimum)
    {
        offset: 14,
        size: 2,
        default: 45
    },
    // Number of this disk
    {
        offset: 16,
        size: 4,
        default: 0
    },
    // Disk where central directory starts
    {
        offset: 20,
        size: 4,
        default: 0
    },
    // Number of central directory records on this disk
    {
        offset: 24,
        size: 8,
        name: 'recordsNumber'
    },
    // Total number of central directory records
    {
        offset: 32,
        size: 8,
        name: 'recordsNumber'
    },
    // Size of central directory (bytes)
    {
        offset: 40,
        size: 8,
        name: 'cdSize'
    },
    // Offset of start of central directory, relative to start of archive
    {
        offset: 48,
        size: 8,
        name: 'cdOffset'
    }
];