Improve MerchantRepository to perform merchants update only if at least one day has passed since the last update. Also, perform a full delete of merchants before inserting the list received from thewebservice to make sure merchants removed there are also removed from the app.

app/src/main/java/cy/agorise/bitsybitshareswallet/database/daos/MerchantDao.kt

@@ -17,4 +17,7 @@ interface MerchantDao {
 
     @Query("SELECT * FROM merchants")
     fun getAll(): LiveData<List<Merchant>>
+
+    @Query("DELETE FROM merchants")
+    fun deleteAll()
 }

app/src/main/java/cy/agorise/bitsybitshareswallet/network/MerchantsWebservice.kt

@@ -14,5 +14,7 @@ interface MerchantsWebservice {
             Call<FeathersResponse<Merchant>>
 
     @GET("api/v2/tellers")
-    fun getTellers(@Query(value = "\$skip") skip: Int): Call<FeathersResponse<Teller>>
+    fun getTellers(@Query(value = "\$skip") skip: Int,
+                   @Query(value = "\$limit") limit: Int = 50):
+            Call<FeathersResponse<Teller>>
 }

app/src/main/java/cy/agorise/bitsybitshareswallet/repositories/MerchantRepository.kt

@@ -2,6 +2,7 @@ package cy.agorise.bitsybitshareswallet.repositories
 
 import android.content.Context
 import android.os.AsyncTask
+import android.preference.PreferenceManager
 import androidx.lifecycle.LiveData
 import cy.agorise.bitsybitshareswallet.database.BitsyDatabase
 import cy.agorise.bitsybitshareswallet.database.daos.MerchantDao
@@ -14,7 +15,7 @@ import retrofit2.Response
 import retrofit2.Retrofit
 import retrofit2.converter.gson.GsonConverterFactory
 
-class MerchantRepository internal constructor(context: Context) : retrofit2.Callback<FeathersResponse<Merchant>> {
+class MerchantRepository internal constructor(val context: Context) : retrofit2.Callback<FeathersResponse<Merchant>> {
 
     private val mMerchantDao: MerchantDao
 
@@ -23,15 +24,20 @@ class MerchantRepository internal constructor(context: Context) : retrofit2.Call
         mMerchantDao = db!!.merchantDao()
     }
 
-    /**
+    /** Returns a LiveData object directly from the database while the response from the WebService is obtained. */
-     * Returns a LiveData object directly from the database while the response from the WebService is obtained.
-     */
     fun getAll(): LiveData<List<Merchant>> {
         refreshMerchants()
         return mMerchantDao.getAll()
     }
 
+    /** Refreshes the merchants information only if the MERCHANT_UPDATE_PERIOD has passed, otherwise it does nothing */
     private fun refreshMerchants() {
+        val lastMerchantUpdate = PreferenceManager.getDefaultSharedPreferences(context)
+            .getLong(Constants.KEY_MERCHANTS_LAST_UPDATE, 0)
+
+        val now = System.currentTimeMillis()
+
+        if (lastMerchantUpdate + Constants.MERCHANTS_UPDATE_PERIOD < now) {
             val retrofit = Retrofit.Builder()
                 .baseUrl(Constants.MERCHANTS_WEBSERVICE_URL)
                 .addConverterFactory(GsonConverterFactory.create())
@@ -41,12 +47,17 @@ class MerchantRepository internal constructor(context: Context) : retrofit2.Call
             val call = ambassadorService.getMerchants(0)
             call.enqueue(this)
         }
+    }
 
     override fun onResponse(call: Call<FeathersResponse<Merchant>>, response: Response<FeathersResponse<Merchant>>) {
         if (response.isSuccessful) {
             val res: FeathersResponse<Merchant>? = response.body()
             val merchants = res?.data ?: return
             insertAllAsyncTask(mMerchantDao).execute(merchants)
+
+            val now = System.currentTimeMillis()
+            PreferenceManager.getDefaultSharedPreferences(context).edit()
+                .putLong(Constants.KEY_MERCHANTS_LAST_UPDATE, now).apply()
         }
     }
 
@@ -56,7 +67,7 @@ class MerchantRepository internal constructor(context: Context) : retrofit2.Call
         AsyncTask<List<Merchant>, Void, Void>() {
 
         override fun doInBackground(vararg merchants: List<Merchant>): Void? {
-            // TODO Delete all first
+            mAsyncTaskDao.deleteAll()
             mAsyncTaskDao.insertAll(merchants[0])
             return null
         }

app/src/main/java/cy/agorise/bitsybitshareswallet/utils/Constants.kt

@@ -87,4 +87,12 @@ object Constants {
     const val KEY_NIGHT_MODE_ACTIVATED = "key_night_mode_activated"
 
     const val MERCHANTS_WEBSERVICE_URL = "https://websvc.palmpay.io/"
+
+    /** Key used to store the last time in millis that the merchants info was refreshed */
+    const val KEY_MERCHANTS_LAST_UPDATE = "key_merchants_last_update"
+
+    /** Key used to store the last time in millis that the tellers info was refreshed */
+    const val KEY_TELLERS_LAST_UPDATE = "key_tellers_last_update"
+
+    const val MERCHANTS_UPDATE_PERIOD = 1000L * 60 * 60 + 24 // 1 day
 }