/*
 * Copyright (C) 2024 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.android.systemui.common.shared.model

import android.annotation.CurrentTimeMillisLong
import android.content.Intent
import android.content.pm.PackageManager
import android.os.UserHandle

/** Represents changes to an installed package. */
sealed interface PackageChangeModel {
    /** The package which this change corresponds to, eg "com.android.systemui". */
    val packageName: String

    /**
     * The uid for this package, which uniquely identifies this package and user. The same package
     * running on different users will have differing uids.
     */
    val packageUid: Int

    /**
     * The time in milliseconds that this update was received from [PackageManager].
     *
     * @see System.currentTimeMillis()
     */
    @get:CurrentTimeMillisLong val timeMillis: Long

    /** The user from which this change originated. */
    val user: UserHandle
        get() = UserHandle.getUserHandleForUid(packageUid)

    /** Empty change, provided for convenience when a sensible default value is needed. */
    data object Empty : PackageChangeModel {
        override val packageName: String
            get() = ""

        override val packageUid: Int
            get() = 0

        override val timeMillis: Long
            get() = 0
    }

    /**
     * An existing application package was uninstalled.
     *
     * Equivalent to receiving the [Intent.ACTION_PACKAGE_REMOVED] broadcast with
     * [Intent.EXTRA_REPLACING] set to false.
     */
    data class Uninstalled(
        override val packageName: String,
        override val packageUid: Int,
        @CurrentTimeMillisLong override val timeMillis: Long = 0,
    ) : PackageChangeModel

    /**
     * A new version of an existing application is going to be installed.
     *
     * Equivalent to receiving the [Intent.ACTION_PACKAGE_REMOVED] broadcast with
     * [Intent.EXTRA_REPLACING] set to true.
     */
    data class UpdateStarted(
        override val packageName: String,
        override val packageUid: Int,
        @CurrentTimeMillisLong override val timeMillis: Long = 0,
    ) : PackageChangeModel

    /**
     * A new version of an existing application package has been installed, replacing the old
     * version.
     *
     * Equivalent to receiving the [Intent.ACTION_PACKAGE_ADDED] broadcast with
     * [Intent.EXTRA_REPLACING] set to true.
     */
    data class UpdateFinished(
        override val packageName: String,
        override val packageUid: Int,
        @CurrentTimeMillisLong override val timeMillis: Long = 0,
    ) : PackageChangeModel

    /**
     * A new application package has been installed.
     *
     * Equivalent to receiving the [Intent.ACTION_PACKAGE_ADDED] broadcast with
     * [Intent.EXTRA_REPLACING] set to false.
     */
    data class Installed(
        override val packageName: String,
        override val packageUid: Int,
        @CurrentTimeMillisLong override val timeMillis: Long = 0,
    ) : PackageChangeModel

    /**
     * An existing application package has been changed (for example, a component has been enabled
     * or disabled).
     *
     * Equivalent to receiving the [Intent.ACTION_PACKAGE_CHANGED] broadcast.
     */
    data class Changed(
        override val packageName: String,
        override val packageUid: Int,
        @CurrentTimeMillisLong override val timeMillis: Long = 0,
    ) : PackageChangeModel

    fun isSamePackage(other: PackageChangeModel) =
        this.packageName == other.packageName && this.packageUid == other.packageUid
}