/// <reference types="node" />

/**
 * The currently defined set of DNS record types.
 */
export type RecordType =
    | "A"
    | "AAAA"
    | "AFSDB"
    | "APL"
    | "AXFR"
    | "CAA"
    | "CDNSKEY"
    | "CDS"
    | "CERT"
    | "CNAME"
    | "DNAME"
    | "DHCID"
    | "DLV"
    | "DNSKEY"
    | "DS"
    | "HINFO"
    | "HIP"
    | "HTTPS"
    | "IXFR"
    | "IPSECKEY"
    | "KEY"
    | "KX"
    | "LOC"
    | "MX"
    | "NAPTR"
    | "NS"
    | "NSEC"
    | "NSEC3"
    | "NSEC3PARAM"
    | "NULL"
    | "OPT"
    | "PTR"
    | "RRSIG"
    | "RP"
    | "SIG"
    | "SOA"
    | "SRV"
    | "SSHFP"
    | "SVCB"
    | "TA"
    | "TKEY"
    | "TLSA"
    | "TSIG"
    | "TXT"
    | "URI";

export type RecordClass = "IN" | "CS" | "CH" | "HS" | "ANY";

export interface Question {
    type: RecordType;
    name: string;
    class?: RecordClass | undefined;
    qu_bit?: boolean | undefined;
}

// Data interfaces for various record types
export interface CaaData {
    issuerCritical?: boolean | undefined;
    flags?: number | undefined;
    tag: "issue" | "issuewild" | "iodef";
    value: string;
}

export interface DnskeyData {
    flags: number;
    algorithm: number;
    key: Buffer;
}

export interface DsData {
    keyTag: number;
    algorithm: number;
    digestType: number;
    digest: Buffer;
}

export interface HInfoData {
    cpu: string;
    os: string;
}

export interface MxData {
    preference?: number | undefined;
    exchange: string;
}

export interface NaptrData {
    order: number;
    preference: number;
    flags: string;
    services: string;
    regexp: string;
    replacement: string;
}

export interface NsecData {
    nextDomain: string;
    rrtypes: string[];
}

export interface Nsec3Data {
    algorithm: number;
    flags: number;
    iterations: number;
    salt: Buffer;
    nextDomain: Buffer;
    rrtypes: string[];
}

export interface RpData {
    mbox: string;
    txt: string;
}

export interface RrsigData {
    typeCovered: string;
    algorithm: number;
    labels: number;
    originalTTL: number;
    expiration: number;
    inception: number;
    keyTag: number;
    signersName: string;
    signature: Buffer;
}

export interface SrvData {
    port: number;
    target: string;
    priority?: number | undefined;
    weight?: number | undefined;
}

export interface SoaData {
    mname: string;
    rname: string;
    serial?: number | undefined;
    refresh?: number | undefined;
    retry?: number | undefined;
    expire?: number | undefined;
    minimum?: number | undefined;
}

export interface SshfpData {
    algorithm: number;
    hash: number;
    fingerprint: string;
}

export interface TlsaData {
    usage: number;
    selector: number;
    matchingType: number;
    certificate: Buffer;
}

export type TxtData = string | Buffer | Array<string | Buffer>;

// SVCB/HTTPS Parameter types
export interface SvcParamMandatory {
    key: "mandatory" | 0;
    value: Array<string | number>;
}

export interface SvcParamAlpn {
    key: "alpn" | 1;
    value: string | string[];
}

export interface SvcParamNoDefaultAlpn {
    key: "no-default-alpn" | 2;
    value?: number | undefined;
}

export interface SvcParamPort {
    key: "port" | 3;
    value: number;
}

export interface SvcParamIpv4Hint {
    key: "ipv4hint" | 4;
    value: string | string[];
}

export interface SvcParamEchConfig {
    key: "echconfig" | 5;
    value: string;
    needBase64Decode?: boolean | undefined;
}

export interface SvcParamIpv6Hint {
    key: "ipv6hint" | 6;
    value: string | string[];
}

export interface SvcParamDohPath {
    key: "dohpath" | 7;
    value: string;
}

export interface SvcParamOdoh {
    key: "odoh" | 32769;
    value: string;
    needBase64Decode?: boolean | undefined;
}

export interface SvcParamUnknown {
    key: string | number;
    value?: unknown | undefined;
    data?: Buffer | undefined;
}

export type SvcParam =
    | SvcParamMandatory
    | SvcParamAlpn
    | SvcParamNoDefaultAlpn
    | SvcParamPort
    | SvcParamIpv4Hint
    | SvcParamEchConfig
    | SvcParamIpv6Hint
    | SvcParamDohPath
    | SvcParamOdoh
    | SvcParamUnknown;

export interface HttpsData {
    priority: number;
    name: string;
    values?: Record<string, unknown> | undefined;
}

export interface SvcbData {
    priority: number;
    name: string;
    values?: Record<string, unknown> | undefined;
}

// Generic answer types
export interface GenericAnswer<T> {
    type: T;
    name: string;
}

export interface BaseAnswer<T, D> extends GenericAnswer<T> {
    ttl?: number | undefined;
    class?: RecordClass | undefined;
    flush?: boolean | undefined;
    data: D;
}

// Answer type groupings
export type StringRecordType = "A" | "AAAA" | "CNAME" | "DNAME" | "NS" | "PTR";

export type OtherRecordType =
    | "AFSDB"
    | "APL"
    | "AXFR"
    | "CDNSKEY"
    | "CDS"
    | "CERT"
    | "DHCID"
    | "DLV"
    | "HIP"
    | "IPSECKEY"
    | "IXFR"
    | "KEY"
    | "KX"
    | "LOC"
    | "NSEC3PARAM"
    | "NULL"
    | "SIG"
    | "TA"
    | "TKEY"
    | "TSIG"
    | "URI";

// Specific answer types
export type StringAnswer = BaseAnswer<StringRecordType, string>;
export type BufferAnswer = BaseAnswer<OtherRecordType, Buffer>;
export type CaaAnswer = BaseAnswer<"CAA", CaaData>;
export type DnskeyAnswer = BaseAnswer<"DNSKEY", DnskeyData>;
export type DSAnswer = BaseAnswer<"DS", DsData>;
export type HInfoAnswer = BaseAnswer<"HINFO", HInfoData>;
export type MxAnswer = BaseAnswer<"MX", MxData>;
export type NaptrAnswer = BaseAnswer<"NAPTR", NaptrData>;
export type Nsec3Answer = BaseAnswer<"NSEC3", Nsec3Data>;
export type NsecAnswer = BaseAnswer<"NSEC", NsecData>;
export type RpAnswer = BaseAnswer<"RP", RpData>;
export type RrsigAnswer = BaseAnswer<"RRSIG", RrsigData>;
export type SoaAnswer = BaseAnswer<"SOA", SoaData>;
export type SrvAnswer = BaseAnswer<"SRV", SrvData>;
export type SshfpAnswer = BaseAnswer<"SSHFP", SshfpData>;
export type TlsaAnswer = BaseAnswer<"TLSA", TlsaData>;
export type TxtAnswer = BaseAnswer<"TXT", TxtData>;
export type SvcbAnswer = BaseAnswer<"SVCB", SvcbData>;
export type HttpsAnswer = BaseAnswer<"HTTPS", HttpsData>;

// OPT record
interface OptCodes {
    OPTION_0: 0;
    LLQ: 1;
    UL: 2;
    NSID: 3;
    OPTION_4: 4;
    DAU: 5;
    DHU: 6;
    N3U: 7;
    CLIENT_SUBNET: 8;
    EXPIRE: 9;
    COOKIE: 10;
    TCP_KEEPALIVE: 11;
    PADDING: 12;
    CHAIN: 13;
    KEY_TAG: 14;
    DEVICEID: 26946;
    OPTION_65535: 65535;
}

type OptCodeType = keyof OptCodes;
type OptCode<K extends OptCodeType> = OptCodes[K];

interface GenericOpt<T extends OptCodeType> {
    code: OptCode<T>;
    type?: T | undefined;
    data?: Buffer | undefined;
}

interface ClientSubnetOpt extends GenericOpt<"CLIENT_SUBNET"> {
    family?: number | undefined;
    sourcePrefixLength?: number | undefined;
    scopePrefixLength?: number | undefined;
    ip: string | undefined;
}

interface KeepAliveOpt extends GenericOpt<"TCP_KEEPALIVE"> {
    timeout?: number | undefined;
}

interface PaddingOpt extends GenericOpt<"PADDING"> {
    length?: number | undefined;
}

interface TagOpt extends GenericOpt<"KEY_TAG"> {
    tags: number[];
}

export type PacketOpt = ClientSubnetOpt | KeepAliveOpt | PaddingOpt | TagOpt;

export interface OptAnswer extends GenericAnswer<"OPT"> {
    udpPayloadSize: number;
    extendedRcode: number;
    ednsVersion: number;
    flags: number;

    /**
     * Whether or not the DNS DO bit is set
     */
    flag_do: boolean;

    options: PacketOpt[];
}

// Complete answer union type
export type Answer =
    | StringAnswer
    | BufferAnswer
    | CaaAnswer
    | DnskeyAnswer
    | DSAnswer
    | HInfoAnswer
    | HttpsAnswer
    | MxAnswer
    | NaptrAnswer
    | Nsec3Answer
    | NsecAnswer
    | OptAnswer
    | RpAnswer
    | RrsigAnswer
    | SoaAnswer
    | SrvAnswer
    | SshfpAnswer
    | SvcbAnswer
    | TlsaAnswer
    | TxtAnswer;

export interface Packet {
    /**
     * Whether the packet is a query or a response. This field may be
     * omitted if it is clear from the context of usage what type of packet
     * it is.
     */
    type?: "query" | "response" | undefined;

    id?: number | undefined;

    /**
     * A bit-mask combination of zero or more of:
     * {@link AUTHORITATIVE_ANSWER},
     * {@link TRUNCATED_RESPONSE},
     * {@link RECURSION_DESIRED},
     * {@link RECURSION_AVAILABLE},
     * {@link AUTHENTIC_DATA},
     * {@link CHECKING_DISABLED},
     * {@link DNSSEC_OK}.
     */
    flags?: number | undefined;

    opcode?: string | undefined;
    rcode?: string | undefined;

    questions?: Question[] | undefined;
    answers?: Answer[] | undefined;
    additionals?: Answer[] | undefined;
    authorities?: Answer[] | undefined;
}

/**
 * Decoded packet with individual flag bits extracted.
 */
export interface DecodedPacket extends Packet {
    flag_qr: boolean;
    flag_aa: boolean;
    flag_tc: boolean;
    flag_rd: boolean;
    flag_ra: boolean;
    flag_z: boolean;
    flag_ad: boolean;
    flag_cd: boolean;
}

// Constants
export const AUTHORITATIVE_ANSWER: number;
export const TRUNCATED_RESPONSE: number;
export const RECURSION_DESIRED: number;
export const RECURSION_AVAILABLE: number;
export const AUTHENTIC_DATA: number;
export const CHECKING_DISABLED: number;
export const DNSSEC_OK: number;
export const NXDOMAIN: number;

// Main functions
export function encode(packet: Packet, buf?: Buffer, offset?: number): Buffer;

export namespace encode {
    let bytes: number;
}

export function decode(buf: Buffer, offset?: number): DecodedPacket;

export namespace decode {
    let bytes: number;
}

export function encodingLength(packet: Packet): number;

export function streamEncode(packet: Packet): Buffer;

export namespace streamEncode {
    let bytes: number;
}

export function streamDecode(buf: Buffer): DecodedPacket | null;

export namespace streamDecode {
    let bytes: number;
}

// Utility/Helper exports
export const name: {
    encode(
        str: string,
        buf?: Buffer,
        offset?: number,
        options?: { mail?: boolean }
    ): Buffer;
    decode(buf: Buffer, offset?: number, options?: { mail?: boolean }): string;
    encodingLength(name: string): number;
};

export const question: {
    encode(q: Question, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): Question;
    encodingLength(q: Question): number;
};

export const answer: {
    encode(a: Answer, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): Answer;
    encodingLength(a: Answer): number;
};

export const svcparam: {
    encode(param: SvcParam, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): SvcParam;
    encodingLength(param: SvcParam): number;
    keyToNumber(keyName: string): number;
    numberToKeyName(number: number): string;
};

export const svcb: {
    encode(data: SvcbData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): SvcbData;
    encodingLength(data: SvcbData): number;
};

export const httpssvc: {
    encode(data: HttpsData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): HttpsData;
    encodingLength(data: HttpsData): number;
};

export const a: {
    encode(host: string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): string;
    encodingLength(): number;
};

export const aaaa: {
    encode(host: string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): string;
    encodingLength(): number;
};

export const cname: {
    encode(data: string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): string;
    encodingLength(data: string): number;
};

export const dname: {
    encode(data: string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): string;
    encodingLength(data: string): number;
};

export const ptr: {
    encode(data: string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): string;
    encodingLength(data: string): number;
};

export const ns: {
    encode(data: string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): string;
    encodingLength(data: string): number;
};

export const mx: {
    encode(data: MxData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): MxData;
    encodingLength(data: MxData): number;
};

export const srv: {
    encode(data: SrvData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): SrvData;
    encodingLength(data: SrvData): number;
};

export const caa: {
    encode(data: CaaData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): CaaData;
    encodingLength(data: CaaData): number;
    ISSUER_CRITICAL: number;
};

export const txt: {
    encode(data: TxtData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): Buffer[];
    encodingLength(data: TxtData): number;
};

export const null_: {
    encode(data: Buffer | string, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): Buffer;
    encodingLength(data?: Buffer | string): number;
};

export const hinfo: {
    encode(data: HInfoData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): HInfoData;
    encodingLength(data: HInfoData): number;
};

export const soa: {
    encode(data: SoaData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): SoaData;
    encodingLength(data: SoaData): number;
};

export const naptr: {
    encode(data: NaptrData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): NaptrData;
    encodingLength(data: NaptrData): number;
};

export const dnskey: {
    encode(key: DnskeyData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): DnskeyData;
    encodingLength(key: DnskeyData): number;
    PROTOCOL_DNSSEC: number;
    ZONE_KEY: number;
    SECURE_ENTRYPOINT: number;
};

export const rrsig: {
    encode(sig: RrsigData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): RrsigData;
    encodingLength(sig: RrsigData): number;
};

export const rp: {
    encode(data: RpData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): RpData;
    encodingLength(data: RpData): number;
};

export const nsec: {
    encode(record: NsecData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): NsecData;
    encodingLength(record: NsecData): number;
};

export const nsec3: {
    encode(record: Nsec3Data, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): Nsec3Data;
    encodingLength(record: Nsec3Data): number;
};

export const ds: {
    encode(digest: DsData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): DsData;
    encodingLength(digest: DsData): number;
};

export const sshfp: {
    encode(record: SshfpData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): SshfpData;
    encodingLength(record: SshfpData): number;
    getFingerprintLengthForHashType(hashType: number): number | undefined;
};

export const tlsa: {
    encode(cert: TlsaData, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): TlsaData;
    encodingLength(cert: TlsaData): number;
};

export const opt: {
    encode(options: PacketOpt[], buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): PacketOpt[];
    encodingLength(options: PacketOpt[]): number;
};

export const unknown: {
    encode(data: Buffer, buf?: Buffer, offset?: number): Buffer;
    decode(buf: Buffer, offset?: number): Buffer;
    encodingLength(data: Buffer): number;
};

export function record(type: RecordType): any;

export {};