AuspostDatabaseProvider

AuspostDatabaseProvider.kt

package au.com.auspost.android

import android.arch.persistence.db.SupportSQLiteDatabase
import android.arch.persistence.room.Room
import android.arch.persistence.room.migration.Migration
import android.content.Context
import android.support.annotation.VisibleForTesting
import io.reactivex.Observable
import timber.log.Timber
import toothpick.ProvidesSingletonInScope
import javax.inject.Inject
import javax.inject.Provider
import javax.inject.Singleton


@Singleton
@ProvidesSingletonInScope
class AuspostDatabaseProvider : Provider<AuspostDatabase> {

    @Inject
    lateinit var context: Context

    companion object {

        @VisibleForTesting
        val MIGRATION_1_2 : Migration = object : Migration(1, 2) {
            override fun migrate(database: SupportSQLiteDatabase) {

                Timber.d("Start Migration 1 - 2")
                
                //Create temporary branch location table
                database.execSQL(""" CREATE TABLE branch_location_copy(
                                        id INTEGER PRIMARY KEY NOT NULL,
                                        postcode TEXT,
                                        locality TEXT,
                                        state TEXT,
                                        delivery TEXT,
                                        category TEXT) """.trimIndent())

                //Copy data into temporary branch_location table and rename table
                database.execSQL(""" INSERT INTO branch_location_copy(id, 
                                        postcode, 
                                        locality, 
                                        state, 
                                        delivery, 
                                        category)
                                     SELECT id, 
                                        postcode, 
                                        locality, 
                                        state, 
                                        delivery, 
                                        category
                                     FROM branch_location """.trimIndent())

                
                Observable.fromIterable("""
                    DROP TABLE branch_location;
                    ALTER TABLE branch_location_copy RENAME TO branch_location;
                """.trimIndent().split(";"))
                        .subscribe({ database.execSQL(it)})

                Timber.d("migrated branch_location")

                Timber.d("End Migration 1 - 2")
            }
        }
    }

    override fun get(): AuspostDatabase {

        return Room.databaseBuilder(context.applicationContext,
                AuspostDatabase::class.java, AuspostDatabase.DB_NAME)
                .addMigrations(MIGRATION_1_2)
                .fallbackToDestructiveMigration()
                .build()
   }


}