Show remaining time in TOTP field (#1766)

* Pass down remaining time for TOTPs to UI layer

* format-common: switch TOTP flow to use co-operative cancelation

* format-common: add a regression test for OTP duration calculation

* Abstract out labels

* Switch to launchIn

2 files changed, 21 insertions, 8 deletions

diff --git a/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt b/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt
index 94149477..a0a85f3e 100644
--- a/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt
+++ b/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt
@@ -13,12 +13,17 @@ import dev.msfjarvis.aps.util.time.UserClock
 import dev.msfjarvis.aps.util.totp.Otp
 import dev.msfjarvis.aps.util.totp.TotpFinder
 import kotlin.collections.set
+import kotlin.coroutines.coroutineContext
+import kotlin.time.Duration.Companion.seconds
+import kotlin.time.ExperimentalTime
 import kotlinx.coroutines.awaitCancellation
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.isActive
 
 /** Represents a single entry in the password store. */
+@OptIn(ExperimentalTime::class)
 public class PasswordEntry
 @AssistedInject
 constructor(
@@ -52,13 +57,13 @@ constructor(
    * does not have a TOTP secret, the flow will never emit. Users should call [hasTotp] before
    * collection to check if it is valid to collect this [Flow].
    */
-  public val totp: Flow<String> = flow {
+  public val totp: Flow<Totp> = flow {
     if (totpSecret != null) {
-      repeat(Int.MAX_VALUE) {
-        val (otp, remainingTime) = calculateTotp()
+      do {
+        val otp = calculateTotp()
         emit(otp)
-        delay(remainingTime)
-      }
+        delay(1000L)
+      } while (coroutineContext.isActive)
     } else {
       awaitCancellation()
     }
@@ -169,17 +174,17 @@ constructor(
     return null
   }
 
-  private fun calculateTotp(): Pair<String, Long> {
+  private fun calculateTotp(): Totp {
     val digits = totpFinder.findDigits(content)
     val totpPeriod = totpFinder.findPeriod(content)
     val totpAlgorithm = totpFinder.findAlgorithm(content)
     val issuer = totpFinder.findIssuer(content)
     val millis = clock.millis()
-    val remainingTime = totpPeriod - (millis % totpPeriod)
+    val remainingTime = (totpPeriod - ((millis / 1000) % totpPeriod)).seconds
     Otp.calculateCode(totpSecret!!, millis / (1000 * totpPeriod), totpAlgorithm, digits, issuer)
       .mapBoth(
         { code ->
-          return code to remainingTime
+          return Totp(code, remainingTime)
         },
         { throwable -> throw throwable }
       )
diff --git a/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/Totp.kt b/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/Totp.kt
new file mode 100644
index 00000000..a43cce6a
--- /dev/null
+++ b/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/Totp.kt
@@ -0,0 +1,8 @@
+package dev.msfjarvis.aps.data.passfile
+
+import kotlin.time.Duration
+import kotlin.time.ExperimentalTime
+
+/** Holder for a TOTP secret and the duration for which it is valid. */
+@OptIn(ExperimentalTime::class)
+public data class Totp(public val value: String, public val remainingTime: Duration)