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@widesky/node-bacstack

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The BACnet protocol library written in pure JavaScript.

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'use strict'; const baAsn1 = require('../asn1'); const baEnum = require('../enum'); module.exports.encode = (buffer, lastReceivedObjectId) => { baAsn1.encodeContextObjectId(buffer, 0, lastReceivedObjectId.type, lastReceivedObjectId.instance); }; module.exports.decode = (buffer, offset) => { let len = 0; let result; let decodedValue; let value = {}; result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; decodedValue = baAsn1.decodeObjectId(buffer, offset + len); len += decodedValue.len; value.lastReceivedObjectId = {type: decodedValue.objectType, instance: decodedValue.instance}; value.len = len; return value; }; module.exports.encodeAcknowledge = (buffer, events, moreEvents) => { baAsn1.encodeOpeningTag(buffer, 0); events.forEach((eventData) => { baAsn1.encodeContextObjectId(buffer, 0, eventData.objectId.type, eventData.objectId.instance); baAsn1.encodeContextEnumerated(buffer, 1, eventData.eventState); baAsn1.encodeContextBitstring(buffer, 2, eventData.acknowledgedTransitions); baAsn1.encodeOpeningTag(buffer, 3); for (let i = 0; i < 3; i++) { baAsn1.bacappEncodeTimestamp(buffer, eventData.eventTimeStamps[i]); } baAsn1.encodeClosingTag(buffer, 3); baAsn1.encodeContextEnumerated(buffer, 4, eventData.notifyType); baAsn1.encodeContextBitstring(buffer, 5, eventData.eventEnable); baAsn1.encodeOpeningTag(buffer, 6); for (let i = 0; i < 3; i++) { baAsn1.encodeApplicationUnsigned(buffer, eventData.eventPriorities[i]); } baAsn1.encodeClosingTag(buffer, 6); }); baAsn1.encodeClosingTag(buffer, 0); baAsn1.encodeContextBoolean(buffer, 1, moreEvents); }; module.exports.decodeAcknowledge = (buffer, offset, apduLen) => { let len = 0; let result; let decodedValue; let value = {}; if (!baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 0)) { return undefined; } len++; value.events = []; while ((apduLen - len) > 3) { let event = {}; result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; decodedValue = baAsn1.decodeObjectId(buffer, offset + len); len += decodedValue.len; event.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; event.eventState = decodedValue.value; result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; decodedValue = baAsn1.decodeBitstring(buffer, offset + len, result.value); len += decodedValue.len; event.acknowledgedTransitions = decodedValue.value; if (!baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 3)) { return undefined; } len++; event.eventTimeStamps = []; for (let i = 0; i < 3; i++) { result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; if (result.tagNumber === baEnum.TimeStamp.TIME) { decodedValue = baAsn1.decodeBacnetTime(buffer, offset + len, result.value); len += decodedValue.len; event.eventTimeStamps[i] = {value: decodedValue.value, type: baEnum.TimeStamp.TIME}; } else if (result.tagNumber === baEnum.TimeStamp.SEQUENCE_NUMBER) { decodedValue = baAsn1.decodeUnsigned(buffer, offset + len, result.value); len += decodedValue.len; event.eventTimeStamps[i] = {value: decodedValue.value, type: baEnum.TimeStamp.SEQUENCE_NUMBER}; } else if (result.tagNumber === baEnum.TimeStamp.DATETIME) { let date = baAsn1.decodeApplicationDate(buffer, offset + len); len += date.len; date = date.value.value; let time = baAsn1.decodeApplicationTime(buffer, offset + len); len += time.len; time = time.value.value; event.eventTimeStamps[i] = {value: new Date(date.getFullYear(), date.getMonth(), date.getDate(), time.getHours(), time.getMinutes(), time.getSeconds(), time.getMilliseconds()), type: baEnum.TimeStamp.DATETIME}; len++; } } if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 3)) { return undefined; } len++; result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; decodedValue = baAsn1.decodeEnumerated(buffer, offset + len, result.value); len += decodedValue.len; event.notifyType = decodedValue.value; result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; decodedValue = baAsn1.decodeBitstring(buffer, offset + len, result.value); len += decodedValue.len; event.eventEnable = decodedValue.value; if (!baAsn1.decodeIsOpeningTagNumber(buffer, offset + len, 6)) { return undefined; } len++; event.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; event.eventPriorities[i] = decodedValue.value; } if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 6)) { return undefined; } len++; value.events.push(event); } if (!baAsn1.decodeIsClosingTagNumber(buffer, offset + len, 0)) { return undefined; } len++; result = baAsn1.decodeTagNumberAndValue(buffer, offset + len); len += result.len; value.moreEvents = buffer[offset + len] > 0; len++; value.len = len; return value; };