/*
 * AboutOss is an utility library to retrieve and display
 * opensource licenses in Android applications.
 *
 * Copyright (C) 2023 by Frederic-Charles Barthelery.
 *
 * This file is part of AboutOss.
 *
 * AboutOss is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * AboutOss is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with AboutOss.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.geekorum.aboutoss.core

import android.content.Context
import kotlinx.coroutines.CoroutineDispatcher
import kotlinx.coroutines.withContext

class LicenseInfoRepository(
    private val appContext: Context,
    private val mainCoroutineDispatcher: CoroutineDispatcher,
    private val ioCoroutineDispatcher: CoroutineDispatcher,
) {

    private var licensesInfo: Map<String, String>? = null

    suspend fun getLicensesInfo(): Map<String, String> = withContext(mainCoroutineDispatcher) {
        parseLicenses()
        checkNotNull(licensesInfo)
    }

    suspend fun getLicenseFor(dependency: String): String = withContext(mainCoroutineDispatcher) {
        parseLicenses()
        checkNotNull(licensesInfo).let {
            return@withContext it[dependency] ?: error("Dependency not found")
        }
    }

    private suspend fun parseLicenses() = withContext(mainCoroutineDispatcher) {
        if (licensesInfo == null) {
            val licenses = withContext(ioCoroutineDispatcher) {
                OssLicenseParser.openDefaultThirdPartyLicenses(appContext).use { licensesInput ->
                    OssLicenseParser.openDefaultThirdPartyLicensesMetadata(appContext)
                        .use { licensesMetadataInput ->
                            val parser = OssLicenseParser(
                                thirdPartyLicensesInput = licensesInput,
                                thirdPartyLicensesMetadataInput = licensesMetadataInput
                            )
                            parser.parseLicenses()
                        }
                }
            }
            licensesInfo = licenses
        }
    }
}