/*
 * Copyright 2018 Allan Wang
 *
 * 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 ca.allanwang.kau.kpref

import ca.allanwang.kau.kotlin.ILazyResettable

/**
 * Created by Allan Wang on 2017-06-07.
 *
 * Base class for shared preferences
 * All objects extending this class must be called in
 * the app's [android.app.Application] class
 *
 * See the [KPref.kpref] extensions for more details
 *
 * Furthermore, all kprefs are held in the [prefMap],
 * so if you wish to reset a preference, you must also invalidate the kpref
 * from that map
 */
open class KPref private constructor(
    val preferenceName: String,
    val builder: KPrefBuilder
) : KPrefBuilder by builder {

    constructor(preferenceName: String, factory: KPrefFactory) : this(
        preferenceName,
        factory.createBuilder(preferenceName)
    )

    internal val prefMap: MutableMap<String, ILazyResettable<*>> = mutableMapOf()

    fun add(entry: KPrefDelegate<*>) {
        if (prefMap.containsKey(entry.key))
            throw KPrefException("${entry.key} is already used elsewhere in preference $preferenceName")
        prefMap[entry.key] = entry
    }

    fun reset() {
        prefMap.values.forEach { it.invalidate() }
    }

    operator fun get(key: String): ILazyResettable<*>? = prefMap[key]

    /**
     * Exposed key deletion function from builder.
     * To avoid recursion, this type uses vararg
     */
    fun deleteKeys(vararg keys: String) {
        deleteKeys(keys)
    }
}