import * as baAsn1 from '../asn1'
import { ApplicationTag } from '../enum'
import { EncodeBuffer, BACNetEvent } from '../types'
import { BacnetService } from './AbstractServices'

export default class EventInformation extends BacnetService {
	public static encode(
		buffer: EncodeBuffer,
		events: BACNetEvent[],
		moreEvents: boolean,
	): void {
		baAsn1.encodeOpeningTag(buffer, 0)
		events.forEach((event) => {
			baAsn1.encodeContextObjectId(
				buffer,
				0,
				event.objectId.type,
				event.objectId.instance,
			)
			baAsn1.encodeContextEnumerated(buffer, 1, event.eventState)
			baAsn1.encodeContextBitstring(
				buffer,
				2,
				event.acknowledgedTransitions,
			)
			baAsn1.encodeOpeningTag(buffer, 3)
			for (let i = 0; i < 3; i++) {
				baAsn1.encodeApplicationDate(buffer, event.eventTimeStamps[i])
				baAsn1.encodeApplicationTime(buffer, event.eventTimeStamps[i])
			}
			baAsn1.encodeClosingTag(buffer, 3)
			baAsn1.encodeContextEnumerated(buffer, 4, event.notifyType)
			baAsn1.encodeContextBitstring(buffer, 5, event.eventEnable)
			baAsn1.encodeOpeningTag(buffer, 6)
			for (let i = 0; i < 3; i++) {
				baAsn1.encodeApplicationUnsigned(
					buffer,
					event.eventPriorities[i],
				)
			}
			baAsn1.encodeClosingTag(buffer, 6)
		})
		baAsn1.encodeClosingTag(buffer, 0)
		baAsn1.encodeContextBoolean(buffer, 1, moreEvents)
	}

	public static decode(buffer: Buffer, offset: number, apduLen: number) {
		let len = 0
		let result: any
		let decodedValue: any
		len++
		const alarms = []

		while (apduLen - 3 - len > 0) {
			const value: any = {}

			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeObjectId(buffer, offset + len)
			len += decodedValue.len
			value.objectId = {
				type: decodedValue.objectType,
				instance: decodedValue.instance,
			}

			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeEnumerated(
				buffer,
				offset + len,
				result.value,
			)
			len += decodedValue.len
			value.eventState = decodedValue.value

			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeBitstring(
				buffer,
				offset + len,
				result.value,
			)
			len += decodedValue.len
			value.acknowledgedTransitions = decodedValue.value

			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			value.eventTimeStamps = []

			for (let i = 0; i < 3; i++) {
				if (result.tagNumber !== ApplicationTag.NULL) {
					decodedValue = baAsn1.decodeApplicationDate(
						buffer,
						offset + len,
					)
					len += decodedValue.len
					const date = decodedValue.value
					decodedValue = baAsn1.decodeApplicationTime(
						buffer,
						offset + len,
					)
					len += decodedValue.len
					const time = decodedValue.value
					value.eventTimeStamps[i] = new Date(
						date.getFullYear(),
						date.getMonth(),
						date.getDate(),
						time.getHours(),
						time.getMinutes(),
						time.getSeconds(),
						time.getMilliseconds(),
					)
				} else {
					len += result.value
				}
			}

			len++

			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeEnumerated(
				buffer,
				offset + len,
				result.value,
			)
			len += decodedValue.len
			value.notifyType = decodedValue.value

			result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
			len += result.len
			decodedValue = baAsn1.decodeBitstring(
				buffer,
				offset + len,
				result.value,
			)
			len += decodedValue.len
			value.eventEnable = decodedValue.value

			len++
			value.eventPriorities = []

			for (let i = 0; i < 3; i++) {
				result = baAsn1.decodeTagNumberAndValue(buffer, offset + len)
				len += result.len
				decodedValue = baAsn1.decodeUnsigned(
					buffer,
					offset + len,
					result.value,
				)
				len += decodedValue.len
				value.eventPriorities[i] = decodedValue.value
			}

			len++
			alarms.push(value)
		}

		const moreEvents = buffer[apduLen - 1] === 1

		return {
			len,
			alarms,
			moreEvents,
		}
	}
}