Talentica/AndroidWithKotlin

/*
 * Copyright 2017, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.talentica.androidkotlin.db

import com.talentica.androidkotlin.db.entity.CommentEntity
import com.talentica.androidkotlin.db.entity.ProductEntity
import java.util.*
import java.util.concurrent.TimeUnit

/** Generates dummy data and inserts them into the database  */
internal object DatabaseInitUtil {
    private val FIRST = arrayOf(
        "Special edition", "New", "Cheap", "Quality", "Used"
    )
    private val SECOND = arrayOf(
        "Three-headed Monkey", "Rubber Chicken", "Pint of Grog", "Monocle"
    )
    private val DESCRIPTION = arrayOf(
        "is finally here", "is recommended by Stan S. Stanman",
        "is the best sold product on Mêlée Island", "is \uD83D\uDCAF", "is ❤️", "is fine"
    )
    private val COMMENTS = arrayOf(
        "Comment 1", "Comment 2", "Comment 3", "Comment 4", "Comment 5", "Comment 6"
    )

    fun initializeDb(db: AppDatabase) {
        val products: MutableList<ProductEntity> = ArrayList(FIRST.size * SECOND.size)
        val comments: MutableList<CommentEntity> = ArrayList()
        generateData(products, comments)
        insertData(db, products, comments)
    }

    private fun generateData(
        products: MutableList<ProductEntity>,
        comments: MutableList<CommentEntity>
    ) {
        val rnd = Random()
        for (i in FIRST.indices) {
            for (j in SECOND.indices) {
                val product = ProductEntity()
                product.name = FIRST[i] + " " + SECOND[j]
                product.description = product.name + " " + DESCRIPTION[j]
                product.price = rnd.nextInt(240)
                product.id = FIRST.size * i + j + 1
                products.add(product)
            }
        }
        for (product in products) {
            val commentsNumber = rnd.nextInt(5) + 1
            for (i in 0 until commentsNumber) {
                val comment = CommentEntity()
                comment.productId = product.id
                comment.text = COMMENTS[i] + " for " + product.name
                comment.postedAt = Date(
                    System.currentTimeMillis()
                            - TimeUnit.DAYS.toMillis((commentsNumber - i).toLong()) + TimeUnit.HOURS.toMillis(
                        i.toLong()
                    )
                )
                comments.add(comment)
            }
        }
    }

    private fun insertData(
        db: AppDatabase,
        products: List<ProductEntity>,
        comments: List<CommentEntity>
    ) {
        db.beginTransaction()
        try {
            db.productDao().insertAll(products)
            db.commentDao().insertAll(comments)
            db.setTransactionSuccessful()
        } finally {
            db.endTransaction()
        }
    }
}