chore: Move flask filter logic from ViewModels to Services

Earlier, ViewModels were building flask filter queries themselves and
passing them to Services.

This was not good because this leaked the data retrieval logic into the
ViewModels. Only the Services should be concerned with data retrieval
and they should abstract out that logic.

This change moves the logic into Services where it belongs.

Fixes: #1344

Author: AnEnigmaticBug

app/src/main/java/org/fossasia/openevent/general/attendees/AttendeeService.kt

@@ -27,19 +27,21 @@ class AttendeeService(
         return attendeeApi.deleteAttendee(id)
     }
 
-    fun getCustomFormsForAttendees(id: Long, filter: String): Single<List<CustomForm>> {
+    fun getCustomFormsForAttendees(id: Long): Single<List<CustomForm>> {
         val formsSingle = attendeeDao.getCustomFormsForId(id)
         return formsSingle.flatMap {
             if (it.isNotEmpty())
                 formsSingle
-            else
+            else {
+                val filter = "[{\"name\":\"form\",\"op\":\"eq\",\"val\":\"order\"}]"
                 attendeeApi.getCustomFormsForAttendees(id, filter)
                         .map {
                             attendeeDao.insertCustomForms(it)
                         }
                         .flatMap {
                             formsSingle
                         }
+            }
         }
     }
 }

app/src/main/java/org/fossasia/openevent/general/attendees/AttendeeViewModel.kt

@@ -308,8 +308,7 @@ class AttendeeViewModel(
     }
 
     fun getCustomFormsForAttendees(eventId: Long) {
-        val filter = "[{\"name\":\"form\",\"op\":\"eq\",\"val\":\"order\"}]"
-        compositeDisposable.add(attendeeService.getCustomFormsForAttendees(eventId, filter)
+        compositeDisposable.add(attendeeService.getCustomFormsForAttendees(eventId)
             .subscribeOn(Schedulers.io())
             .observeOn(AndroidSchedulers.mainThread())
             .doOnSubscribe {

app/src/main/java/org/fossasia/openevent/general/event/EventService.kt

@@ -58,7 +58,8 @@ class EventService(
     }
 
     fun getEventsByLocation(locationName: String): Single<List<Event>> {
-        return eventApi.searchEvents("name", locationName).flatMap { apiList ->
+        val query = "[{\"name\":\"location-name\",\"op\":\"ilike\",\"val\":\"%$locationName%\"}]"
+        return eventApi.searchEvents("name", query).flatMap { apiList ->
             val eventIds = apiList.map { it.id }.toList()
             eventTopicsDao.insertEventTopics(getEventTopicList(apiList))
             eventDao.getFavoriteEventWithinIds(eventIds).flatMap { favIds ->
@@ -82,8 +83,9 @@ class EventService(
         return eventApi.getEventFromApi(id)
     }
 
-    fun getEventsUnderUser(eventId: String): Single<List<Event>> {
-        return eventApi.eventsUnderUser(eventId)
+    fun getEventsUnderUser(eventIds: List<Long>): Single<List<Event>> {
+        val query = buildQuery(eventIds)
+        return eventApi.eventsUnderUser(query)
     }
 
     fun setFavorite(eventId: Long, favorite: Boolean): Completable {
@@ -108,4 +110,33 @@ class EventService(
                         }
         }
     }
+
+    private fun buildQuery(eventIds: List<Long>): String {
+        var subQuery = ""
+
+        var eventId = -1L
+        val idList = ArrayList<Long>()
+        val eventIdAndTimes = mutableMapOf<Long, Int>()
+        eventIds.forEach { it1 ->
+            val times = eventIdAndTimes[it1]
+            if (eventIdAndTimes.containsKey(it1) && times != null) {
+                eventIdAndTimes[it1] = times + 1
+            } else {
+                eventIdAndTimes[it1] = 1
+            }
+            idList.add(it1)
+            eventId = it1
+            subQuery += ",{\"name\":\"id\",\"op\":\"eq\",\"val\":\"$eventId\"}"
+        }
+
+        val formattedSubQuery = if (subQuery != "")
+            subQuery.substring(1) // remove "," from the beginning
+        else
+            "" // if there are no orders
+
+        return if (idList.size == 1)
+            "[{\"name\":\"id\",\"op\":\"eq\",\"val\":\"$eventId\"}]"
+        else
+            "[{\"or\":[$formattedSubQuery]}]"
+    }
 }

app/src/main/java/org/fossasia/openevent/general/event/EventsViewModel.kt

@@ -32,10 +32,8 @@ class EventsViewModel(private val eventService: EventService, private val prefer
     }
 
     fun loadLocationEvents(loadingTag: Int) {
-        val query = "[{\"name\":\"location-name\",\"op\":\"ilike\",\"val\":\"%$savedLocation%\"}]"
-
         if (loadingTag == RELOADING_EVENTS || (loadingTag == INITIAL_FETCHING_EVENTS && mutableEvents.value == null)) {
-            compositeDisposable.add(eventService.getEventsByLocation(query)
+            compositeDisposable.add(eventService.getEventsByLocation(savedLocation.toString())
                 .subscribeOn(Schedulers.io())
                 .observeOn(AndroidSchedulers.mainThread())
                 .doOnSubscribe {

app/src/main/java/org/fossasia/openevent/general/order/OrdersUnderUserViewModel.kt

@@ -24,8 +24,6 @@ class OrdersUnderUserViewModel(
     val attendeesNumber: LiveData<ArrayList<Int>> = mutableAttendeesNumber
     private var eventIdMap = mutableMapOf<Long, Event>()
     private val eventIdAndTimes = mutableMapOf<Long, Int>()
-    private var eventId: Long = -1
-    private val idList = ArrayList<Long>()
     private val mutableMessage = SingleLiveEvent<String>()
     val message: LiveData<String> = mutableMessage
     private val mutableEventAndOrderIdentifier = MutableLiveData<List<Pair<Event, String>>>()
@@ -50,10 +48,11 @@ class OrdersUnderUserViewModel(
             }.subscribe({
                 order = it
                 mutableAttendeesNumber.value = it.map { it.attendees?.size } as ArrayList<Int>
-                val query = buildQuery(it)
 
-                if (idList.size != 0)
-                    eventsUnderUser(query)
+                val eventIds = it.filter { order -> order.event != null }.map { order -> order.event!!.id }
+                if (eventIds.isNotEmpty()) {
+                    eventsUnderUser(eventIds)
+                }
                 else {
                     mutableProgress.value = false
                     mutableNoTickets.value = true
@@ -67,7 +66,7 @@ class OrdersUnderUserViewModel(
         )
     }
 
-    private fun eventsUnderUser(eventIds: String) {
+    private fun eventsUnderUser(eventIds: List<Long>) {
         compositeDisposable.add(eventService.getEventsUnderUser(eventIds)
             .subscribeOn(Schedulers.io())
             .observeOn(AndroidSchedulers.mainThread())
@@ -98,35 +97,6 @@ class OrdersUnderUserViewModel(
         )
     }
 
-    private fun buildQuery(orderList: List<Order>): String {
-        var subQuery = ""
-
-        eventIdAndTimes.clear()
-        orderList.forEach {
-            it.event?.id?.let { it1 ->
-                val times = eventIdAndTimes[it1]
-                if (eventIdAndTimes.containsKey(it1) && times != null) {
-                    eventIdAndTimes[it1] = times + 1
-                } else {
-                    eventIdAndTimes[it1] = 1
-                }
-                idList.add(it1)
-                eventId = it1
-                subQuery += ",{\"name\":\"id\",\"op\":\"eq\",\"val\":\"$eventId\"}"
-            }
-        }
-
-        val formattedSubQuery = if (subQuery != "")
-            subQuery.substring(1) // remove "," from the beginning
-        else
-            "" // if there are no orders
-
-        return if (idList.size == 1)
-            "[{\"name\":\"id\",\"op\":\"eq\",\"val\":\"$eventId\"}]"
-        else
-            "[{\"or\":[$formattedSubQuery]}]"
-    }
-
     override fun onCleared() {
         super.onCleared()
         compositeDisposable.clear()