import * as baAsn1 from '../asn1'
import { ASN1_ARRAY_ALL } from '../enum'
import { EncodeBuffer, BACNetObjectID, BACNetPropertyID } from '../types'
import { BacnetService } from './AbstractServices'

export default class SubscribeProperty extends BacnetService {
	public static encode(
		buffer: EncodeBuffer,
		subscriberProcessId: number,
		monitoredObjectId: BACNetObjectID,
		cancellationRequest: boolean,
		issueConfirmedNotifications: boolean,
		lifetime: number,
		monitoredProperty: BACNetPropertyID,
		covIncrementPresent: boolean,
		covIncrement: number,
	) {
		baAsn1.encodeContextUnsigned(buffer, 0, subscriberProcessId)
		baAsn1.encodeContextObjectId(
			buffer,
			1,
			monitoredObjectId.type,
			monitoredObjectId.instance,
		)
		if (!cancellationRequest) {
			baAsn1.encodeContextBoolean(buffer, 2, issueConfirmedNotifications)
			baAsn1.encodeContextUnsigned(buffer, 3, lifetime)
		}
		baAsn1.encodeOpeningTag(buffer, 4)
		baAsn1.encodeContextEnumerated(buffer, 0, monitoredProperty.id)
		if (monitoredProperty.index !== ASN1_ARRAY_ALL) {
			baAsn1.encodeContextUnsigned(buffer, 1, monitoredProperty.index)
		}
		baAsn1.encodeClosingTag(buffer, 4)
		if (covIncrementPresent) {
			baAsn1.encodeContextReal(buffer, 5, covIncrement)
		}
	}

	public static decode(buffer: Buffer, offset: number) {
		let len = 0
		const value: any = {}
		let result: any
		let decodedValue: any
		if (!baAsn1.decodeIsContextTag(buffer, offset + len, 0))
			return undefined
		result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
		len += result.len
		decodedValue = baAsn1.decodeUnsigned(buffer, offset + len, result.value)
		len += decodedValue.len
		value.subscriberProcessId = decodedValue.value
		if (!baAsn1.decodeIsContextTag(buffer, offset + len, 1))
			return undefined
		result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
		len += result.len
		decodedValue = baAsn1.decodeObjectId(buffer, offset + len)
		len += decodedValue.len
		value.monitoredObjectId = {
			type: decodedValue.objectType,
			instance: decodedValue.instance,
		}
		value.cancellationRequest = true
		value.issueConfirmedNotifications = false
		if (baAsn1.decodeIsContextTag(buffer, offset + len, 2)) {
			value.cancellationRequest = false
			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			value.issueConfirmedNotifications = buffer[offset + len] > 0
			len++
		}
		value.lifetime = 0
		if (baAsn1.decodeIsContextTag(buffer, offset + len, 3)) {
			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeUnsigned(
				buffer,
				offset + len,
				result.value,
			)
			len += decodedValue.len
			value.lifetime = decodedValue.value
		}
		if (!baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 4))
			return undefined
		len++
		value.monitoredProperty = {}
		if (!baAsn1.decodeIsContextTag(buffer, offset + len, 0))
			return undefined
		result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
		len += result.len
		decodedValue = baAsn1.decodeEnumerated(
			buffer,
			offset + len,
			result.value,
		)
		len += decodedValue.len
		value.monitoredProperty.id = decodedValue.value
		value.monitoredProperty.index = ASN1_ARRAY_ALL
		if (baAsn1.decodeIsContextTag(buffer, offset + len, 1)) {
			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeUnsigned(
				buffer,
				offset + len,
				result.value,
			)
			len += decodedValue.len
			value.monitoredProperty.index = decodedValue.value
		}
		if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 4))
			return undefined
		len++
		value.covIncrement = 0
		if (baAsn1.decodeIsContextTag(buffer, offset + len, 5)) {
			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeReal(buffer, offset + len)
			len += decodedValue.len
			value.covIncrement = decodedValue.value
		}
		value.len = len
		return value
	}
}