Add UI for prompting about crashes.

app/src/main/java/org/thoughtcrime/securesms/crash/CrashConfig.kt

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2023 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.crash
+
+import androidx.annotation.VisibleForTesting
+import com.fasterxml.jackson.annotation.JsonProperty
+import org.signal.core.util.logging.Log
+import org.thoughtcrime.securesms.keyvalue.SignalStore
+import org.thoughtcrime.securesms.util.BucketingUtil
+import org.thoughtcrime.securesms.util.FeatureFlags
+import org.thoughtcrime.securesms.util.JsonUtils
+import org.whispersystems.signalservice.api.push.ServiceId
+import java.io.IOException
+
+object CrashConfig {
+
+  private val TAG = Log.tag(CrashConfig::class.java)
+
+  /**
+   * A list of patterns for crashes we'd like to find matches for in the crash database.
+   */
+  val patterns: List<CrashPattern> by lazy { computePatterns() }
+
+  @VisibleForTesting
+  fun computePatterns(): List<CrashPattern> {
+    val aci: ServiceId.ACI = SignalStore.account().aci ?: return emptyList()
+
+    val serialized = FeatureFlags.crashPromptConfig()
+    if (serialized.isNullOrBlank()) {
+      return emptyList()
+    }
+
+    if (SignalStore.account().aci == null) {
+      return emptyList()
+    }
+
+    val list: List<Config> = try {
+      JsonUtils.fromJsonArray(serialized, Config::class.java)
+    } catch (e: IOException) {
+      Log.w(TAG, "Failed to parse json!", e)
+      emptyList()
+    }
+
+    return list
+      .asSequence()
+      .filter { it.rolledOutToLocalUser(aci) }
+      .map {
+        if (it.name?.isBlank() == true) {
+          it.copy(name = null)
+        } else {
+          it
+        }
+      }
+      .map {
+        if (it.message ?.isBlank() == true) {
+          it.copy(message = null)
+        } else {
+          it
+        }
+      }
+      .map {
+        if (it.stackTrace ?.isBlank() == true) {
+          it.copy(stackTrace = null)
+        } else {
+          it
+        }
+      }
+      .filter { it.name != null || it.message != null || it.stackTrace != null }
+      .map {
+        CrashPattern(
+          namePattern = it.name,
+          messagePattern = it.message,
+          stackTracePattern = it.stackTrace
+        )
+      }
+      .toList()
+  }
+
+  /**
+   * Represents a pattern for a crash we're interested in prompting the user about. In this context, "pattern" means
+   * a case-sensitive substring of a larger string. So "IllegalArgument" would match "IllegalArgumentException".
+   * Not a regex or anything.
+   *
+   * One of the fields is guaranteed to be set.
+   *
+   * @param namePattern A possible substring of an exception name we're looking for in the crash table.
+   * @param messagePattern A possible substring of an exception message we're looking for in the crash table.
+   */
+  data class CrashPattern(
+    val namePattern: String? = null,
+    val messagePattern: String? = null,
+    val stackTracePattern: String? = null
+  ) {
+    init {
+      check(namePattern != null || messagePattern != null || stackTracePattern != null)
+    }
+  }
+
+  private data class Config(
+    @JsonProperty val name: String?,
+    @JsonProperty val message: String?,
+    @JsonProperty val stackTrace: String?,
+    @JsonProperty val percent: Float?
+  ) {
+
+    /** True if the local user is contained within the percent rollout, otherwise false. */
+    fun rolledOutToLocalUser(aci: ServiceId.ACI): Boolean {
+      if (percent == null) {
+        return false
+      }
+
+      val partsPerMillion = (1_000_000 * percent).toInt()
+      val bucket = BucketingUtil.bucket(FeatureFlags.CRASH_PROMPT_CONFIG, aci.rawUuid, 1_000_000)
+      return partsPerMillion > bucket
+    }
+  }
+}