anastasis-core: compute upload fees

packages/anastasis-core/src/index.ts

@@ -1,13 +1,19 @@
 import {
+  AmountJson,
+  AmountLike,
+  Amounts,
   AmountString,
   buildSigPS,
   bytesToString,
   Codec,
   codecForAny,
   decodeCrock,
+  Duration,
   eddsaSign,
   encodeCrock,
+  getDurationRemaining,
   getRandomBytes,
+  getTimestampNow,
   hash,
   j2s,
   Logger,
@@ -1051,27 +1057,62 @@ async function nextFromAuthenticationsEditing(
 async function updateUploadFees(
   state: ReducerStateBackup,
 ): Promise<ReducerStateBackup | ReducerStateError> {
-  for (const prov of state.policy_providers ?? []) {
-    const info = state.authentication_providers![prov.provider_url];
-    if (!("currency" in info)) {
-      continue;
+  const expiration = state.expiration;
+  if (!expiration) {
+    return { ...state };
+  }
+  logger.info("updating upload fees");
+  const feePerCurrency: Record<string, AmountJson> = {};
+  const coveredProviders = new Set<string>();
+  const addFee = (x: AmountLike) => {
+    x = Amounts.jsonifyAmount(x);
+    feePerCurrency[x.currency] = Amounts.add(
+      feePerCurrency[x.currency] ?? Amounts.getZero(x.currency),
+      x,
+    ).amount;
+  };
+  const years = Duration.toIntegerYears(Duration.getRemaining(expiration));
+  logger.info(`computing fees for ${years} years`);
+  for (const x of state.policies ?? []) {
+    for (const m of x.methods) {
+      const prov = state.authentication_providers![
+        m.provider
+      ] as AuthenticationProviderStatusOk;
+      const authMethod = state.authentication_methods![m.authentication_method];
+      if (!coveredProviders.has(m.provider)) {
+        const annualFee = Amounts.mult(prov.annual_fee, years).amount;
+        logger.info(`adding annual fee ${Amounts.stringify(annualFee)}`);
+        addFee(annualFee);
+        coveredProviders.add(m.provider);
+      }
+      for (const pm of prov.methods) {
+        if (pm.type === authMethod.type) {
+          addFee(pm.usage_fee);
+          break;
+        }
+      }
     }
   }
-  return { ...state, upload_fees: [] };
+  return {
+    ...state,
+    upload_fees: Object.values(feePerCurrency).map((x) => ({
+      fee: Amounts.stringify(x),
+    })),
+  };
 }
 
 async function enterSecret(
   state: ReducerStateBackup,
   args: ActionArgEnterSecret,
 ): Promise<ReducerStateBackup | ReducerStateError> {
-  return {
+  return updateUploadFees({
     ...state,
     expiration: args.expiration,
     core_secret: {
       mime: args.secret.mime ?? "text/plain",
       value: args.secret.value,
     },
-  };
+  });
 }
 
 async function nextFromChallengeSelecting(
@@ -1102,11 +1143,10 @@ async function updateSecretExpiration(
   state: ReducerStateBackup,
   args: ActionArgsUpdateExpiration,
 ): Promise<ReducerStateBackup | ReducerStateError> {
-  // FIXME: implement!
-  return {
+  return updateUploadFees({
     ...state,
     expiration: args.expiration,
-  };
+  });
 }
 
 const backupTransitions: Record<

packages/anastasis-core/src/reducer-types.ts

@@ -66,6 +66,7 @@ export interface ReducerStateBackup {
   selected_country?: string;
   secret_name?: string;
   policies?: Policy[];
+
   /**
    * Policy providers are providers that we checked to be functional
    * and that are actually used in policies.
@@ -82,7 +83,7 @@ export interface ReducerStateBackup {
 
   expiration?: Timestamp;
 
-  upload_fees?: AmountString[];
+  upload_fees?: { fee: AmountString }[];
 }
 
 export interface AuthMethod {

packages/taler-util/src/amounts.ts

@@ -349,7 +349,8 @@ export class Amounts {
     }
   }
 
-  static mult(a: AmountJson, n: number): Result {
+  static mult(a: AmountLike, n: number): Result {
+    a = this.jsonifyAmount(a);
     if (!Number.isInteger(n)) {
       throw Error("amount can only be multipied by an integer");
     }

packages/taler-util/src/time.ts

@@ -69,6 +69,20 @@ export function getDurationRemaining(
   return { d_ms: deadline.t_ms - now.t_ms };
 }
 
+export namespace Duration {
+  export const getRemaining = getDurationRemaining;
+  export function toIntegerYears(d: Duration): number {
+    if (typeof d.d_ms !== "number") {
+      throw Error("infinite duration");
+    }
+    return Math.ceil(d.d_ms / 1000 / 60 / 60 / 24 / 365);
+  }
+}
+
+export namespace Timestamp {
+  export const min = timestampMin;
+}
+
 export function timestampMin(t1: Timestamp, t2: Timestamp): Timestamp {
   if (t1.t_ms === "never") {
     return { t_ms: t2.t_ms };