import { AMQPView } from "./amqp-view.js"

import type { Field } from "./amqp-properties.js"

// AMQP Frame Types (from AMQP 0-9-1 spec)

export enum Type {

METHOD = 1,

HEADER = 2,

BODY = 3,

HEARTBEAT = 8,

}

// AMQP Frame End Byte (from AMQP 0-9-1 spec)

export enum End {

CODE = 206,

}

// AMQP Class IDs (partial, add more as needed)

export enum ClassId {

CONNECTION = 10,

CHANNEL = 20,

EXCHANGE = 40,

QUEUE = 50,

BASIC = 60,

TX = 90,

CONFIRM = 85,

}

// AMQP Method IDs by class (partial, add more as needed)

export enum ConnectionMethod {

START = 10,

START_OK = 11,

SECURE = 20,

SECURE_OK = 21,

TUNE = 30,

TUNE_OK = 31,

OPEN = 40,

OPEN_OK = 41,

CLOSE = 50,

CLOSE_OK = 51,

BLOCKED = 60,

UNBLOCKED = 61,

UPDATE_SECRET = 70,

UPDATE_SECRET_OK = 71,

}

export enum ChannelMethod {

OPEN = 10,

OPEN_OK = 11,

FLOW = 20,

FLOW_OK = 21,

CLOSE = 40,

CLOSE_OK = 41,

}

export enum ExchangeMethod {

DECLARE = 10,

DECLARE_OK = 11,

DELETE = 20,

DELETE_OK = 21,

BIND = 30,

BIND_OK = 31,

UNBIND = 40,

UNBIND_OK = 51,

}

export enum QueueMethod {

DECLARE = 10,

DECLARE_OK = 11,

BIND = 20,

BIND_OK = 21,

PURGE = 30,

PURGE_OK = 31,

DELETE = 40,

DELETE_OK = 41,

UNBIND = 50,

UNBIND_OK = 51,

}

export enum BasicMethod {

QOS = 10,

QOS_OK = 11,

CONSUME = 20,

CONSUME_OK = 21,

CANCEL = 30,

CANCEL_OK = 31,

PUBLISH = 40,

RETURN = 50,

DELIVER = 60,

GET = 70,

GET_OK = 71,

GET_EMPTY = 72,

ACK = 80,

REJECT = 90,

RECOVER_ASYNC = 100,

RECOVER = 110,

RECOVER_OK = 111,

NACK = 120,

}

export enum TxMethod {

SELECT = 10,

SELECT_OK = 11,

COMMIT = 20,

COMMIT_OK = 21,

ROLLBACK = 30,

ROLLBACK_OK = 31,

}

export enum ConfirmMethod {

SELECT = 10,

SELECT_OK = 11,

}

interface FrameOptions {

bufferSize: number

type: Type

channel: number

frameSize?: number

classId: ClassId

method: number

}

export class Writer {

view: AMQPView

offset: number

constructor(options: FrameOptions) {

this.view = new AMQPView(new ArrayBuffer(options.bufferSize))

this.offset = 0

this.writeUint8(options.type)

this.writeUint16(options.channel)

this.writeUint32(options.frameSize ?? 0)

this.writeUint16(options.classId)

this.writeUint16(options.method)

}

finalize() {

const currentFrameSize = this.view.getUint32(3)

if (currentFrameSize === 0) {

const value = this.offset - 7 // Subtract the size of the header (1 + 2 + 4)

this.view.setUint32(3, value)

}

this.view.setUint8(this.offset, End.CODE)

this.offset += 1 // Update offset to point after the frame end byte

}

getBuffer() {

return this.view.buffer

}

toUint8Array() {

return new Uint8Array(this.view.buffer, 0, this.offset)

}

writeUint8(value: number) {

this.view.setUint8(this.offset, value)

this.offset += 1

}

writeUint16(value: number) {

this.view.setUint16(this.offset, value)

this.offset += 2

}

writeUint32(value: number) {

this.view.setUint32(this.offset, value)

this.offset += 4

}

writeUint64(value: number) {

this.view.setUint64(this.offset, value)

this.offset += 8

}

writeShortString(value: string) {

// Assumes setShortString returns the number of bytes written

const bytesWritten = this.view.setShortString(this.offset, value)

this.offset += bytesWritten

}

writeLongString(value: string) {

// Assumes setLongString returns the number of bytes written

const bytesWritten = this.view.setLongString(this.offset, value)

this.offset += bytesWritten

}

writeTable(table: Record<string, Field>) {

// Assumes setTable returns the number of bytes written

const bytesWritten = this.view.setTable(this.offset, table)

this.offset += bytesWritten

}

}