import {
    _readStruct,
    readTag,
    _readBitString,
    AlgorithmIdentifier,
    _readAlgorithmIdentifier,
    _readSignatureValue,
    _readSignatureValueBin,
    BlockInfo,
    _readObjectIdentifier,
    DirectoryName,
    _readValue,
    _readTime,
    _readLongIntegerValue,
    formatBuffer2DigitHexWithColum,
    _getBlock,
    _readDirectoryName,
    _findBlockAtIndex,
    _readIntegerValue,
} from "./asn1";
import { CertificateRevocationList } from "./common";
import { makeSHA1Thumbprint, convertPEMtoDER } from "./crypto_utils";

export type Version = string;
export type Name = string;
export type CertificateSerialNumber = string;
export type Extensions = Record<string, unknown>;
export interface RevokedCertificate {
    userCertificate: CertificateSerialNumber;
    revocationDate: Date;
    crlEntryExtensions?: Extensions;
}
export interface TBSCertList {
    version?: Version; //OPTIONAL; // must be 2
    signature: AlgorithmIdentifier;
    issuer: Name;
    issuerFingerprint: string; // 00:AA:BB:etc ...
    thisUpdate: Date;
    nextUpdate?: Date; //             Time OPTIONAL,
    revokedCertificates: RevokedCertificate[];
    //    crlExtensions[0]  EXPLICIT Extensions OPTIONAL
}
export interface CertificateRevocationListInfo {
    tbsCertList: TBSCertList;
    signatureAlgorithm: AlgorithmIdentifier;
    signatureValue: Buffer;
}

export function readNameForCrl(buffer: Buffer, block: BlockInfo): DirectoryName {
    return _readDirectoryName(buffer, block);
}

function _readTbsCertList(buffer: Buffer, blockInfo: BlockInfo): TBSCertList {
    const blocks = _readStruct(buffer, blockInfo);

    const version = _readIntegerValue(buffer, blocks[0]);
    const signature = _readAlgorithmIdentifier(buffer, blocks[1]);
    const issuer = readNameForCrl(buffer, blocks[2]);
    const issuerFingerprint = formatBuffer2DigitHexWithColum(makeSHA1Thumbprint(_getBlock(buffer, blocks[2])));

    const thisUpdate = _readTime(buffer, blocks[3]);
    const nextUpdate = _readTime(buffer, blocks[4]);

    const revokedCertificates: RevokedCertificate[] = [];

    if (blocks[5] && blocks[5].tag < 0x80) {
        const list = _readStruct(buffer, blocks[5]);
        for (const r of list) {
            // sometime blocks[5] doesn't exits .. in this case
            const rr = _readStruct(buffer, r);
            const userCertificate = formatBuffer2DigitHexWithColum(_readLongIntegerValue(buffer, rr[0]));
            const revocationDate = _readTime(buffer, rr[1]);
            revokedCertificates.push({
                revocationDate,
                userCertificate,
            });
        }
    }

    const ext0 = _findBlockAtIndex(blocks, 0);

    return { issuer, issuerFingerprint, thisUpdate, nextUpdate, signature, revokedCertificates } as TBSCertList;
}
// see https://tools.ietf.org/html/rfc5280

export function exploreCertificateRevocationList(crl: CertificateRevocationList): CertificateRevocationListInfo {
    const blockInfo = readTag(crl, 0);
    const blocks = _readStruct(crl, blockInfo);
    const tbsCertList = _readTbsCertList(crl, blocks[0]);
    const signatureAlgorithm = _readAlgorithmIdentifier(crl, blocks[1]);
    const signatureValue = _readSignatureValueBin(crl, blocks[2]);
    return { tbsCertList, signatureAlgorithm, signatureValue };
}