//
//  Shared+App.swift
//  Passepartout
//
//  Created by Davide De Rosa on 2/24/24.
//  Copyright (c) 2024 Davide De Rosa. All rights reserved.
//
//  https://github.com/passepartoutvpn
//
//  This file is part of Passepartout.
//
//  Passepartout 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.
//
//  Passepartout 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 Passepartout.  If not, see <http://www.gnu.org/licenses/>.
//

import AppData
import AppDataProfiles
import AppDataProviders
import CommonLibrary
import CommonUtils
import Foundation
import PassepartoutKit
import UILibrary

extension AppContext {
    static let shared = AppContext(
        iapManager: .shared,
        profileManager: .shared,
        profileProcessor: .shared,
        tunnel: .shared,
        tunnelEnvironment: .shared,
        registry: .shared,
        providerManager: .shared,
        constants: .shared
    )
}

// MARK: -

extension ProfileManager {
    static let shared: ProfileManager = {
        let remoteStore = CoreDataPersistentStore(
            logger: .default,
            containerName: Constants.shared.containers.remote,
            model: AppData.cdProfilesModel,
            cloudKitIdentifier: BundleConfiguration.mainString(for: .cloudKitId),
            author: nil
        )
        let remoteRepository = AppData.cdProfileRepositoryV3(
            registry: .shared,
            coder: CodableProfileCoder(),
            context: remoteStore.context,
            observingResults: true
        ) { error in
            pp_log(.app, .error, "Unable to decode remote result: \(error)")
            return .ignore
        }

        return ProfileManager(
            repository: mainProfileRepository,
            backupRepository: backupProfileRepository,
            remoteRepository: remoteRepository,
            deletingRemotely: deletingRemotely,
            isIncluded: isProfileIncluded
        )
    }()

#if os(tvOS)
    private static let deletingRemotely = true

    private static let isProfileIncluded: (Profile) -> Bool = {
        $0.attributes.isAvailableForTV == true
    }
#else
    private static let deletingRemotely = false

    private static let isProfileIncluded: ((Profile) -> Bool)? = nil
#endif
}

// MARK: -

extension IAPManager {
    static let shared = IAPManager(
        customUserLevel: customUserLevel,
        receiptReader: KvittoReceiptReader(),
        // FIXME: #662, omit unrestrictedFeatures on release!
        unrestrictedFeatures: [.interactiveLogin, .sharing],
        productsAtBuild: productsAtBuild
    )

    private static var customUserLevel: AppUserLevel? {
        if let envString = ProcessInfo.processInfo.environment["CUSTOM_USER_LEVEL"],
           let envValue = Int(envString),
           let testAppType = AppUserLevel(rawValue: envValue) {

            return testAppType
        }
        if let infoValue = BundleConfiguration.mainIntegerIfPresent(for: .customUserLevel),
           let testAppType = AppUserLevel(rawValue: infoValue) {

            return testAppType
        }
        return nil
    }

    private static let productsAtBuild: BuildProducts<AppProduct> = {
#if os(iOS)
        if $0 <= 2016 {
            return [.Full.iOS]
        } else if $0 <= 3000 {
            return [.Features.networkSettings]
        }
        return []
#elseif os(macOS)
        if $0 <= 3000 {
            return [.Features.networkSettings]
        }
        return []
#else
        return []
#endif
    }
}

extension ProfileProcessor {
    static let shared = ProfileProcessor {
        ProfileManager.sharedTitle($0)
    } processed: { profile in
        var builder = profile.builder()

        // suppress on-demand rules if not eligible
        if !IAPManager.shared.isEligible(for: .onDemand) {
            pp_log(.app, .notice, "Suppress on-demand rules, not eligible")

            if let onDemandModuleIndex = builder.modules.firstIndex(where: { $0 is OnDemandModule }),
                let onDemandModule = builder.modules[onDemandModuleIndex] as? OnDemandModule {

                var onDemandBuilder = onDemandModule.builder()
                onDemandBuilder.policy = .any
                builder.modules[onDemandModuleIndex] = onDemandBuilder.tryBuild()
            }
        }

        let profile = try builder.tryBuild()
        do {
            _ = try profile.withProviderModules()
            return profile
        } catch {
            pp_log(.app, .error, "Unable to inject provider modules: \(error)")
            throw error
        }
    }
}

// MARK: -

#if targetEnvironment(simulator)

extension Tunnel {
    static let shared = Tunnel(
        strategy: FakeTunnelStrategy(environment: .shared, dataCountInterval: 1000)
    )
}

private extension ProfileManager {
    static var mainProfileRepository: ProfileRepository {
        coreDataProfileRepository
    }

    static var backupProfileRepository: ProfileRepository? {
        nil
    }
}

#else

extension Tunnel {
    static let shared = Tunnel(
        strategy: ProfileManager.neStrategy
    )
}

private extension ProfileManager {
    static var mainProfileRepository: ProfileRepository {
        neProfileRepository
    }

    static var backupProfileRepository: ProfileRepository? {
        coreDataProfileRepository
    }
}

#endif

private extension ProfileManager {
    static let neProfileRepository: ProfileRepository = {
        NEProfileRepository(repository: neStrategy) {
            ProfileManager.sharedTitle($0)
        }
    }()

    static let neStrategy: NETunnelStrategy = {
        NETunnelStrategy(
            bundleIdentifier: BundleConfiguration.mainString(for: .tunnelId),
            coder: Registry.sharedProtocolCoder,
            environment: .shared
        )
    }()

    static let coreDataProfileRepository: ProfileRepository = {
        let store = CoreDataPersistentStore(
            logger: .default,
            containerName: Constants.shared.containers.local,
            model: AppData.cdProfilesModel,
            cloudKitIdentifier: nil,
            author: nil
        )
        return AppData.cdProfileRepositoryV3(
            registry: .shared,
            coder: CodableProfileCoder(),
            context: store.context,
            observingResults: false
        ) { error in
            pp_log(.app, .error, "Unable to decode local result: \(error)")
            return .ignore
        }
    }()
}

// MARK: -

extension ProviderManager {
    static let shared: ProviderManager = {
        let store = CoreDataPersistentStore(
            logger: .default,
            containerName: Constants.shared.containers.providers,
            model: AppData.cdProvidersModel,
            cloudKitIdentifier: nil,
            author: nil
        )
        let repository = AppData.cdProviderRepositoryV3(
            context: store.context,
            backgroundContext: store.backgroundContext
        )
        return ProviderManager(repository: repository)
    }()
}

// MARK: -

private extension ProfileManager {
    static let sharedTitle: (Profile) -> String = {
        String(format: Constants.shared.tunnel.profileTitleFormat, $0.name)
    }
}

extension CoreDataPersistentStoreLogger where Self == DefaultCoreDataPersistentStoreLogger {
    static var `default`: CoreDataPersistentStoreLogger {
        DefaultCoreDataPersistentStoreLogger()
    }
}

private struct DefaultCoreDataPersistentStoreLogger: CoreDataPersistentStoreLogger {
    func debug(_ msg: String) {
        pp_log(.app, .info, msg)
    }

    func warning(_ msg: String) {
        pp_log(.app, .error, msg)
    }
}