Workflow api upgrade

workflow/src/main/java/com/google/android/fhir/workflow/activity/ActivityFlow.kt

@@ -17,23 +17,37 @@
 package com.google.android.fhir.workflow.activity
 
 import androidx.annotation.WorkerThread
+import ca.uhn.fhir.model.api.IQueryParameterType
+import ca.uhn.fhir.rest.param.ReferenceParam
 import com.google.android.fhir.workflow.activity.phase.Phase
 import com.google.android.fhir.workflow.activity.phase.Phase.PhaseName
 import com.google.android.fhir.workflow.activity.phase.Phase.PhaseName.ORDER
 import com.google.android.fhir.workflow.activity.phase.Phase.PhaseName.PERFORM
 import com.google.android.fhir.workflow.activity.phase.Phase.PhaseName.PLAN
 import com.google.android.fhir.workflow.activity.phase.Phase.PhaseName.PROPOSAL
+import com.google.android.fhir.workflow.activity.phase.PreviousPhaseIterator
+import com.google.android.fhir.workflow.activity.phase.ReadOnlyRequestPhase
 import com.google.android.fhir.workflow.activity.phase.event.PerformPhase
+import com.google.android.fhir.workflow.activity.phase.event.PerformPhase.Companion.`class`
+import com.google.android.fhir.workflow.activity.phase.idType
 import com.google.android.fhir.workflow.activity.phase.request.OrderPhase
 import com.google.android.fhir.workflow.activity.phase.request.PlanPhase
 import com.google.android.fhir.workflow.activity.phase.request.ProposalPhase
 import com.google.android.fhir.workflow.activity.resource.event.CPGCommunicationEvent
 import com.google.android.fhir.workflow.activity.resource.event.CPGEventResource
 import com.google.android.fhir.workflow.activity.resource.event.CPGOrderMedicationEvent
+import com.google.android.fhir.workflow.activity.resource.event.EventStatus
 import com.google.android.fhir.workflow.activity.resource.request.CPGCommunicationRequest
 import com.google.android.fhir.workflow.activity.resource.request.CPGMedicationRequest
 import com.google.android.fhir.workflow.activity.resource.request.CPGRequestResource
 import com.google.android.fhir.workflow.activity.resource.request.Intent
+import com.google.android.fhir.workflow.activity.resource.request.Status
+import org.hl7.fhir.r4.model.Bundle
+import org.hl7.fhir.r4.model.Communication
+import org.hl7.fhir.r4.model.CommunicationRequest
+import org.hl7.fhir.r4.model.MedicationDispense
+import org.hl7.fhir.r4.model.MedicationRequest
+import org.hl7.fhir.r4.model.Reference
 import org.opencds.cqf.fhir.api.Repository
 
 /**
@@ -181,6 +195,48 @@ private constructor(
     return currentPhase
   }
 
+  /**
+   * Returns an iterator to go over the previous states of the activity flow. The iterator provides
+   * a read-only view to the phase.
+   */
+  fun getPreviousPhase(): PreviousPhaseIterator<R> {
+    return object : PreviousPhaseIterator<R> {
+      var current: Phase? = currentPhase
+
+      override fun hasPrevious(): Boolean {
+        return if (current is Phase.RequestPhase<*>) {
+          (current as? Phase.RequestPhase<*>)?.getRequestResource()?.getBasedOn() != null
+        } else {
+          (current as? Phase.EventPhase<*>)?.getEventResource()?.getBasedOn() != null
+        }
+      }
+
+      override fun previous(): ReadOnlyRequestPhase<R>? {
+        val basedOn: Reference? =
+          if (current is Phase.RequestPhase<*>) {
+            (current as Phase.RequestPhase<*>).getRequestResource().getBasedOn()
+          } else if (current is Phase.EventPhase<*>) {
+            (current as Phase.EventPhase<*>).getEventResource().getBasedOn()
+          } else {
+            null
+          }
+
+        val basedOnRequest =
+          basedOn?.let {
+            repository.read(it.`class`, it.idType)?.let { CPGRequestResource.of(it) as R }
+          }
+        current =
+          when (basedOnRequest?.getIntent()) {
+            Intent.PROPOSAL -> ProposalPhase(repository, basedOnRequest)
+            Intent.PLAN -> PlanPhase(repository, basedOnRequest)
+            Intent.ORDER -> OrderPhase(repository, basedOnRequest)
+            else -> null
+          }
+        return basedOnRequest?.let { ReadOnlyRequestPhase(it) }
+      }
+    }
+  }
+
   /**
    * Prepares a plan resource based on the state of the [currentPhase] and returns it to the caller
    * without persisting any changes into [repository].
@@ -303,5 +359,109 @@ private constructor(
       resource: CPGOrderMedicationEvent<*>,
     ): ActivityFlow<CPGMedicationRequest, CPGOrderMedicationEvent<*>> =
       ActivityFlow(repository, null, resource)
+
+    /** Returns a list of active flows associated with the [patientId]. */
+    fun of(
+      repository: Repository,
+      patientId: String,
+    ): List<ActivityFlow<CPGRequestResource<*>, CPGEventResource<*>>> {
+      val eventTypes =
+        listOf(
+          MedicationDispense::class.java,
+          Communication::class.java,
+        )
+
+      val events =
+        eventTypes
+          .flatMap {
+            repository
+              .search(
+                Bundle::class.java,
+                it,
+                mutableMapOf<String, MutableList<IQueryParameterType>>(
+                  "subject" to mutableListOf(ReferenceParam("Patient/$patientId")),
+                ),
+                null,
+              )
+              .entry
+              .map { it.resource }
+          }
+          .map { CPGEventResource.of(it) }
+
+      val requestTypes =
+        listOf(
+          MedicationRequest::class.java,
+          CommunicationRequest::class.java,
+        )
+
+      val cache: MutableMap<String, CPGRequestResource<*>> =
+        requestTypes
+          .flatMap {
+            repository
+              .search(
+                Bundle::class.java,
+                it,
+                mutableMapOf<String, MutableList<IQueryParameterType>>(
+                  "subject" to mutableListOf(ReferenceParam("Patient/$patientId")),
+                ),
+                null,
+              )
+              .entry
+              .map { it.resource }
+          }
+          .map { CPGRequestResource.of(it) }
+          .associateByTo(LinkedHashMap()) { "${it.resourceType}/${it.logicalId}" }
+
+      fun addBasedOn(
+        request: RequestChain,
+      ): RequestChain? {
+        val basedOn = request.request?.getBasedOn() ?: request.event?.getBasedOn()
+        // look up the cache for the parent resource and add to the chain
+        return basedOn?.let { reference ->
+          cache[reference.reference]?.let { requestResource ->
+            cache.remove(reference.reference)
+            RequestChain(request = requestResource).apply { this.basedOn = addBasedOn(this) }
+          }
+        }
+      }
+
+      val requestChain =
+        events.map { RequestChain(event = it).apply { this.basedOn = addBasedOn(this) } } +
+          cache.values
+            .filter {
+              it.getIntent() == Intent.ORDER ||
+                it.getIntent() == Intent.PLAN ||
+                it.getIntent() == Intent.PROPOSAL
+            }
+            .sortedByDescending { it.getIntent().code }
+            .mapNotNull {
+              if (cache.containsKey("${it.resourceType}/${it.logicalId}")) {
+                RequestChain(request = it).apply { this.basedOn = addBasedOn(this) }
+              } else {
+                null
+              }
+            }
+      return requestChain
+        .filter {
+          if (it.event != null) {
+            it.event.getStatus() != EventStatus.COMPLETED
+          } else if (it.request != null) {
+            it.request.getStatus() != Status.COMPLETED
+          } else {
+            false
+          }
+        }
+        .map { ActivityFlow(repository, it.request, it.event) }
+    }
   }
 }
+
+/**
+ * Represents the chain of event/requests of an activity flow. A [RequestChain] would either have a
+ * [request] or an [event].
+ */
+internal data class RequestChain(
+  val request: CPGRequestResource<*>? = null,
+  val event: CPGEventResource<*>? = null,
+  var basedOn: RequestChain? = null,
+)

workflow/src/main/java/com/google/android/fhir/workflow/activity/phase/Phase.kt

@@ -19,6 +19,7 @@ package com.google.android.fhir.workflow.activity.phase
 import androidx.annotation.WorkerThread
 import com.google.android.fhir.workflow.activity.resource.event.CPGEventResource
 import com.google.android.fhir.workflow.activity.resource.request.CPGRequestResource
+import com.google.android.fhir.workflow.activity.resource.request.Intent
 import org.hl7.fhir.r4.model.IdType
 import org.hl7.fhir.r4.model.Reference
 
@@ -77,3 +78,28 @@ internal fun checkEquals(a: Reference, b: Reference) = a.reference == b.referenc
 /** Returns an [IdType] of a [Reference]. This is required for [Repository.read] api. */
 internal val Reference.idType
   get() = IdType(reference)
+
+/** Iterate through the previous phases of a current activity flow. */
+interface PreviousPhaseIterator<R : CPGRequestResource<*>> {
+  fun hasPrevious(): Boolean
+
+  fun previous(): ReadOnlyRequestPhase<R>?
+}
+
+/** Provides a read-only view of a request phase. */
+class ReadOnlyRequestPhase<R : CPGRequestResource<*>>(private val cpgRequestResource: R) {
+  /** Returns the [Phase.PhaseName] of this phase. */
+  fun getPhase() =
+    when (cpgRequestResource.getIntent()) {
+      Intent.PROPOSAL -> Phase.PhaseName.PROPOSAL
+      Intent.PLAN -> Phase.PhaseName.PLAN
+      Intent.ORDER -> Phase.PhaseName.ORDER
+      else ->
+        throw IllegalArgumentException(
+          "Resource intent can't be ${cpgRequestResource.getIntent().code} ",
+        )
+    }
+
+  /** Returns the underlying [CPGRequestResource] of this phase. */
+  fun getRequestResource() = cpgRequestResource
+}

workflow/src/main/java/com/google/android/fhir/workflow/activity/phase/event/PerformPhase.kt

@@ -139,7 +139,7 @@ class PerformPhase<E : CPGEventResource<*>>(
      * Returns the [Resource] class for the resource. e.g. If the Reference is `Patient/1234`, then
      * this would return the `Class` for `org.hl7.fhir.r4.model.Patient`.
      */
-    private val Reference.`class`
+    internal val Reference.`class`
       get() = getResourceClass<Resource>(reference.split("/")[0])
 
     /**
@@ -165,7 +165,7 @@ class PerformPhase<E : CPGEventResource<*>>(
         "${inputPhase.getPhaseName().name} request is still in ${inputRequest.getStatusCode()} status."
       }
 
-      val eventRequest = CPGEventResource.of(inputRequest, eventClass)
+      val eventRequest = CPGEventResource.from(inputRequest, eventClass)
       eventRequest.setStatus(EventStatus.PREPARATION)
       eventRequest.setBasedOn(inputRequest.asReference())
       eventRequest as E

workflow/src/main/java/com/google/android/fhir/workflow/activity/resource/event/CPGEventResource.kt

@@ -23,6 +23,7 @@ import com.google.android.fhir.workflow.activity.resource.request.CPGMedicationR
 import com.google.android.fhir.workflow.activity.resource.request.CPGRequestResource
 import com.google.android.fhir.workflow.activity.resource.request.CPGRequestResource.Companion.of
 import org.hl7.fhir.r4.model.Communication
+import org.hl7.fhir.r4.model.MedicationDispense
 import org.hl7.fhir.r4.model.Reference
 import org.hl7.fhir.r4.model.Resource
 import org.hl7.fhir.r4.model.ResourceType
@@ -41,7 +42,7 @@ import org.hl7.fhir.r4.model.ResourceType
  * [CPGEventResource]s.
  */
 sealed class CPGEventResource<out R>(
-  internal open val resource: R,
+  open val resource: R,
   internal val mapper: EventStatusCodeMapper,
 ) where R : Resource {
 
@@ -65,12 +66,22 @@ sealed class CPGEventResource<out R>(
 
   companion object {
 
-    fun of(request: CPGRequestResource<*>, eventClass: Class<*>): CPGEventResource<*> {
+    internal fun from(from: CPGRequestResource<*>, to: Class<*>): CPGEventResource<*> {
+      return when (from) {
+        is CPGCommunicationRequest -> CPGCommunicationEvent.from(from)
+        is CPGMedicationRequest -> CPGOrderMedicationEvent.from(from, to)
+        else -> {
+          throw IllegalArgumentException("Unknown CPG Request type ${from::class}.")
+        }
+      }
+    }
+
+    fun of(request: Resource): CPGEventResource<*> {
       return when (request) {
-        is CPGCommunicationRequest -> CPGCommunicationEvent.from(request)
-        is CPGMedicationRequest -> CPGOrderMedicationEvent.from(request, eventClass)
+        is Communication -> CPGCommunicationEvent(request)
+        is MedicationDispense -> CPGMedicationDispenseEvent(request)
         else -> {
-          throw IllegalArgumentException("Unknown CPG Request type ${request::class}.")
+          throw IllegalArgumentException("Unknown CPG event type ${request::class}.")
         }
       }
     }

workflow/src/main/java/com/google/android/fhir/workflow/activity/resource/request/CPGRequestResource.kt

@@ -19,7 +19,6 @@ package com.google.android.fhir.workflow.activity.resource.request
 import com.google.android.fhir.logicalId
 import com.google.android.fhir.workflow.activity.resource.request.CPGRequestResource.Companion.of
 import com.google.android.fhir.workflow.activity.resource.request.Intent.ORDER
-import com.google.android.fhir.workflow.activity.resource.request.Intent.OTHER
 import com.google.android.fhir.workflow.activity.resource.request.Intent.PLAN
 import com.google.android.fhir.workflow.activity.resource.request.Intent.PROPOSAL
 import org.hl7.fhir.r4.model.CommunicationRequest
@@ -28,8 +27,6 @@ import org.hl7.fhir.r4.model.MedicationRequest
 import org.hl7.fhir.r4.model.Reference
 import org.hl7.fhir.r4.model.Resource
 import org.hl7.fhir.r4.model.ResourceType
-import org.hl7.fhir.r4.model.ServiceRequest
-import org.hl7.fhir.r4.model.Task
 
 /**
  * This abstracts the
@@ -52,7 +49,7 @@ import org.hl7.fhir.r4.model.Task
  * create the appropriate [CPGRequestResource].
  */
 sealed class CPGRequestResource<R>(
-  internal open val resource: R,
+  open val resource: R,
   internal val mapper: StatusCodeMapper,
 ) where R : Resource {
 
@@ -64,7 +61,7 @@ sealed class CPGRequestResource<R>(
 
   internal abstract fun setIntent(intent: Intent)
 
-  internal abstract fun getIntent(): Intent
+  abstract fun getIntent(): Intent
 
   abstract fun setStatus(status: Status, reason: String? = null)
 
@@ -125,9 +122,7 @@ sealed class CPGRequestResource<R>(
      */
     fun <R : Resource> of(resource: R): CPGRequestResource<R> {
       return when (resource) {
-        is Task -> of(resource)
         is MedicationRequest -> of(resource)
-        is ServiceRequest -> of(resource)
         is CommunicationRequest -> of(resource)
         else -> {
           throw IllegalArgumentException("Unknown CPG Request type ${resource::class}.")
@@ -145,7 +140,7 @@ sealed class CPGRequestResource<R>(
  * See [codesystem-request-intent](https://www.hl7.org/FHIR/codesystem-request-intent.html) for the
  * list of intents.
  */
-internal sealed class Intent(val code: String?) {
+sealed class Intent(val code: String?) {
   data object PROPOSAL : Intent("proposal")
 
   data object PLAN : Intent("plan")

workflow_demo/src/main/java/com/google/android/fhir/workflow/demo/ui/main/ActivityHandler.kt

@@ -23,7 +23,7 @@ import com.google.android.fhir.workflow.activity.resource.request.CPGRequestReso
 import com.google.android.fhir.workflow.activity.resource.request.Status
 
 class ActivityHandler(
-  private val activityFlow: ActivityFlow<CPGRequestResource<*>, CPGEventResource<*>>,
+  val activityFlow: ActivityFlow<CPGRequestResource<*>, CPGEventResource<*>>,
 ) {
 
   suspend fun prepareAndInitiatePlan(): Result<Boolean> {