in ngo-identity/chaincode/src/ngo.js [176:411]
async function allocateSpend(stub, spend) {
console.log('============= START : allocateSpend ===========');
console.log('##### allocateSpend - Spend received: ' + JSON.stringify(spend));
// validate we have a valid SPEND object and a valid amount
if (!(spend && spend['spendAmount'] && typeof spend['spendAmount'] === 'number' && isFinite(spend['spendAmount']))) {
throw new Error('##### allocateSpend - Spend Amount is not a valid number: ' + spend['spendAmount']);
}
// validate we have a valid SPEND object and a valid SPEND ID
if (!(spend && spend['spendId'])) {
throw new Error('##### allocateSpend - Spend Id is required but does not exist in the spend message');
}
// validate that we have a valid NGO
let ngo = spend['ngoRegistrationNumber'];
let ngoKey = 'ngo' + ngo;
let ngoQuery = await queryByKey(stub, ngoKey);
if (!ngoQuery.toString()) {
throw new Error('##### allocateSpend - Cannot create spend allocation record as the NGO does not exist: ' + json['ngoRegistrationNumber']);
}
// first, get the total amount of donations donated to this NGO
let totalDonations = 0;
const donationMap = new Map();
let queryString = '{"selector": {"docType": "donation", "ngoRegistrationNumber": "' + ngo + '"}}';
let donationsForNGO = await queryByString(stub, queryString);
console.log('##### allocateSpend - allocateSpend - getDonationsForNGO: ' + donationsForNGO);
donationsForNGO = JSON.parse(donationsForNGO.toString());
console.log('##### allocateSpend - getDonationsForNGO as JSON: ' + donationsForNGO);
// store all donations for the NGO in a map. Each entry in the map will look as follows:
//
// {"Key":"donation2211","Record":{"docType":"donation","donationAmount":100,"donationDate":"2018-09-20T12:41:59.582Z","donationId":"2211","donorUserName":"edge","ngoRegistrationNumber":"6322"}}
for (let n = 0; n < donationsForNGO.length; n++) {
let donation = donationsForNGO[n];
console.log('##### allocateSpend - getDonationsForNGO Donation: ' + JSON.stringify(donation));
totalDonations += donation['Record']['donationAmount'];
// store the donations made
donationMap.set(donation['Record']['donationId'], donation);
console.log('##### allocateSpend - donationMap - adding new donation entry for donor: ' + donation['Record']['donationId'] + ', values: ' + JSON.stringify(donation));
}
console.log('##### allocateSpend - Total donations for this ngo are: ' + totalDonations);
for (let donation of donationMap) {
console.log('##### allocateSpend - Total donation for this donation ID: ' + donation[0] + ', amount: ' + donation[1]['Record']['donationAmount'] + ', entry: ' + JSON.stringify(donation[1]));
}
// next, get the spend by Donation, i.e. the amount of each Donation that has already been spent
let totalSpend = 0;
const donationSpendMap = new Map();
queryString = '{"selector": {"docType": "spendAllocation", "ngoRegistrationNumber": "' + ngo + '"}}';
let spendAllocations = await queryByString(stub, queryString);
spendAllocations = JSON.parse(spendAllocations.toString());
for (let n = 0; n < spendAllocations.length; n++) {
let spendAllocation = spendAllocations[n]['Record'];
totalSpend += spendAllocation['spendAllocationAmount'];
// store the spend made per Donation
if (donationSpendMap.has(spendAllocation['donationId'])) {
let spendAmt = donationSpendMap.get(spendAllocation['donationId']);
spendAmt += spendAllocation['spendAllocationAmount'];
donationSpendMap.set(spendAllocation['donationId'], spendAmt);
console.log('##### allocateSpend - donationSpendMap - updating donation entry for donation ID: ' + spendAllocation['donationId'] + ' amount: ' + spendAllocation['spendAllocationAmount'] + ' total amt: ' + spendAmt);
}
else {
donationSpendMap.set(spendAllocation['donationId'], spendAllocation['spendAllocationAmount']);
console.log('##### allocateSpend - donationSpendMap - adding new donation entry for donation ID: ' + spendAllocation['donationId'] + ' amount: ' + spendAllocation['spendAllocationAmount']);
}
}
console.log('##### allocateSpend - Total spend for this ngo is: ' + totalSpend);
for (let donation of donationSpendMap) {
console.log('##### allocateSpend - Total spend against this donation ID: ' + donation[0] + ', spend amount: ' + donation[1] + ', entry: ' + donation);
if (donationMap.has(donation[0])) {
console.log('##### allocateSpend - The matching donation for this donation ID: ' + donation[0] + ', donation amount: ' + donationMap.get(donation[0]));
}
else {
console.log('##### allocateSpend - ERROR - cannot find the matching donation for this spend record for donation ID: ' + donation[0]);
}
}
// at this point we have the total amount of donations made by donors to each NGO. We also have the total spend
// spent by an NGO with a breakdown per donation.
// confirm whether the NGO has sufficient available funds to cover the new spend
let totalAvailable = totalDonations - totalSpend;
if (spend['spendAmount'] > totalAvailable) {
// Execution stops at this point; the transaction fails and rolls back.
// Any updates made by the transaction processor function are discarded.
// Transaction processor functions are atomic; all changes are committed,
// or no changes are committed.
console.log('##### allocateSpend - NGO ' + ngo + ' does not have sufficient funds available to cover this spend. Spend amount is: ' + spend['spendAmount'] + '. Available funds are currently: ' + totalAvailable + '. Total donations are: ' + totalDonations + ', total spend is: ' + totalSpend);
throw new Error('NGO ' + ngo + ' does not have sufficient funds available to cover this spend. Spend amount is: ' + spend['spendAmount'] + '. Available funds are currently: ' + totalAvailable);
}
// since the NGO has sufficient funds available, add the new spend record
spend['docType'] = 'spend';
let key = 'spend' + spend['spendId'];
console.log('##### allocateSpend - Adding the spend record to NGOSpend. Spend record is: ' + JSON.stringify(spend) + ' key is: ' + key);
await stub.putState(key, Buffer.from(JSON.stringify(spend)));
// allocate the spend as equally as possible to all the donations
console.log('##### allocateSpend - Allocating the spend amount amongst the donations from donors who donated funds to this NGO');
let spendAmount = spend.spendAmount;
let numberOfDonations = 0;
let spendAmountForDonor = 0;
let recordCounter = 0;
while (true) {
// spendAmount will be reduced as the spend is allocated to NGOSpendDonationAllocation records.
// Once it reaches 0 we stop allocating. This caters for cases where the full allocation cannot
// be allocated to a donation record. In this case, only the remaining domation amount is allocated
// (see variable amountAllocatedToDonation below).
// The remaining amount must be allocated to donation records with sufficient available funds.
if (spendAmount <= 0) {
break;
}
// calculate the number of donations still available, i.e. donations which still have funds available for spending.
// as the spending reduces the donations there may be fewer and fewer donations available to split the spending between
//
// all donations for the NGO are in donationMap. Each entry in the map will look as follows:
//
// {"Key":"donation2211","Record":{"docType":"donation","donationAmount":100,"donationDate":"2018-09-20T12:41:59.582Z","donationId":"2211","donorUserName":"edge","ngoRegistrationNumber":"6322"}}
numberOfDonations = 0;
for (let donation of donationMap) {
console.log('##### allocateSpend - Donation record, key is: ' + donation[0] + ' value is: ' + JSON.stringify(donation[1]));
if (donationSpendMap.has(donation[0])) {
spendAmountForDonor = donationSpendMap.get(donation[0]);
}
else {
spendAmountForDonor = 0;
}
let availableAmountForDonor = donation[1]['Record']['donationAmount'] - spendAmountForDonor;
console.log('##### allocateSpend - Checking number of donations available for allocation. Donation ID: ' + donation[0] + ' has spent: ' + spendAmountForDonor + ' and has the following amount available for spending: ' + availableAmountForDonor);
if (availableAmountForDonor > 0) {
numberOfDonations++;
}
}
//Validate that we have a valid spendAmount, numberOfDonations and spendAmountForDonor
//Invalid values could be caused by a bug in this function, or invalid values passed to this function
//that were not caught by the validation process earlier.
if (!(spendAmount && typeof spendAmount === 'number' && isFinite(spendAmount))) {
throw new Error('##### allocateSpend - spendAmount is not a valid number: ' + spendAmount);
}
if (!(numberOfDonations && typeof numberOfDonations === 'number' && numberOfDonations > 0)) {
throw new Error('##### allocateSpend - numberOfDonations is not a valid number or is < 1: ' + numberOfDonations);
}
//calculate how much spend to allocate to each donation
let spendPerDonation = spendAmount / numberOfDonations;
console.log('##### allocateSpend - Allocating the total spend amount of: ' + spendAmount + ', to ' + numberOfDonations + ' donations, resulting in ' + spendPerDonation + ' per donation');
if (!(spendPerDonation && typeof spendPerDonation === 'number' && isFinite(spendPerDonation))) {
throw new Error('##### allocateSpend - spendPerDonation is not a valid number: ' + spendPerDonation);
}
// create the SPENDALLOCATION records. Each record looks as follows:
//
// {
// "docType":"spendAllocation",
// "spendAllocationId":"c5b39e938a29a80c225d10e8327caaf817f76aecd381c868263c4f59a45daf62-1",
// "spendAllocationAmount":38.5,
// "spendAllocationDate":"2018-09-20T12:41:59.582Z",
// "spendAllocationDescription":"Peter Pipers Poulty Portions for Pets",
// "donationId":"FFF6A68D-DB19-4CD3-97B0-01C1A793ED3B",
// "ngoRegistrationNumber":"D0884B20-385D-489E-A9FD-2B6DBE5FEA43",
// "spendId": "1234"
// }
for (let donation of donationMap) {
let donationId = donation[0];
let donationInfo = donation[1]['Record'];
//calculate how much of the donation's amount remains available for spending
let donationAmount = donationInfo['donationAmount'];
if (donationSpendMap.has(donationId)) {
spendAmountForDonor = donationSpendMap.get(donationId);
}
else {
spendAmountForDonor = 0;
}
let availableAmountForDonor = donationAmount - spendAmountForDonor;
//if the donation does not have sufficient funds to cover their allocation, then allocate
//all of the outstanding donation funds
let amountAllocatedToDonation = 0;
if (availableAmountForDonor >= spendPerDonation) {
amountAllocatedToDonation = spendPerDonation;
console.log('##### allocateSpend - donation ID ' + donationId + ' has sufficient funds to cover full allocation. Allocating: ' + amountAllocatedToDonation);
}
else if (availableAmountForDonor > 0) {
amountAllocatedToDonation = availableAmountForDonor;
// reduce the number of donations available since this donation record is fully allocated
numberOfDonations -= 1;
console.log('##### allocateSpend - donation ID ' + donationId + ' does not have sufficient funds to cover full allocation. Using all available funds: ' + amountAllocatedToDonation);
}
else {
// reduce the number of donations available since this donation record is fully allocated
numberOfDonations -= 1;
console.log('##### allocateSpend - donation ID ' + donationId + ' has no funds available at all. Available amount: ' + availableAmountForDonor + '. This donation ID will be ignored');
continue;
}
// add a new spendAllocation record containing the portion of a donation allocated to this spend
//
// spendAllocationId is (hopefully) using an ID created in a deterministic manner, meaning it should
// be identical on all endorsing peer nodes. If it isn't, the transaction validation process will fail
// when Fabric compares the write-sets for each transaction and discovers there is are different values.
let spendAllocationId = stub.getTxID() + '-' + recordCounter;
recordCounter++;
let key = 'spendAllocation' + spendAllocationId;
let spendAllocationRecord = {
docType: 'spendAllocation',
spendAllocationId: spendAllocationId,
spendAllocationAmount: amountAllocatedToDonation,
spendAllocationDate: spend['spendDate'],
spendAllocationDescription: spend['spendDescription'],
donationId: donationId,
ngoRegistrationNumber: ngo,
spendId: spend['spendId']
};
console.log('##### allocateSpend - creating spendAllocationRecord record: ' + JSON.stringify(spendAllocationRecord));
await stub.putState(key, Buffer.from(JSON.stringify(spendAllocationRecord)));
//reduce the total spend amount by the amount just spent in the NGOSpendDonationAllocation record
spendAmount -= amountAllocatedToDonation;
//update the spending map entry for this NGO. There may be no existing spend, in which case we'll create an entry in the map
if (donationSpendMap.has(donationId)) {
let spendAmt = donationSpendMap.get(donationId);
spendAmt += amountAllocatedToDonation;
donationSpendMap.set(donationId, spendAmt);
console.log('##### allocateSpend - donationSpendMap - updating spend entry for donation Id: ' + donationId + ' with spent amount allocated to donation: ' + amountAllocatedToDonation + ' - total amount of this donation now spent is: ' + spendAmt);
}
else {
donationSpendMap.set(donationId, amountAllocatedToDonation);
console.log('##### allocateSpend - donationSpendMap - adding new spend entry for donation ID: ' + donationId + ' with spent amount allocated to donation: ' + amountAllocatedToDonation);
}
}
}
console.log('============= END : allocateSpend ===========');
}