//
//  Upgrade.swift
//  mas-cli
//
//  Created by Andrew Naylor on 30/12/2015.
//  Copyright © 2015 Andrew Naylor. All rights reserved.
//

import Commandant

/// Command which upgrades apps with new versions available in the Mac App Store.
public struct UpgradeCommand: CommandProtocol {
    public typealias Options = UpgradeOptions
    public let verb = "upgrade"
    public let function = "Upgrade outdated apps from the Mac App Store"

    private let appLibrary: AppLibrary
    private let storeSearch: StoreSearch

    /// Public initializer.
    public init() {
        self.init(appLibrary: MasAppLibrary())
    }

    /// Internal initializer.
    /// - Parameter appLibrary: AppLibrary manager.
    /// - Parameter storeSearch: StoreSearch manager.
    init(appLibrary: AppLibrary = MasAppLibrary(), storeSearch: StoreSearch = MasStoreSearch()) {
        self.appLibrary = appLibrary
        self.storeSearch = storeSearch
    }

    /// Runs the command.
    public func run(_ options: Options) -> Result<(), MASError> {
        do {
            let apps =
                try
                (options.apps.count == 0
                ? appLibrary.installedApps
                : options.apps.compactMap {
                    if let appId = UInt64($0) {
                        // if argument a UInt64, lookup app by id using argument
                        return appLibrary.installedApp(forId: appId)
                    } else {
                        // if argument not a UInt64, lookup app by name using argument
                        return appLibrary.installedApp(named: $0)
                    }
                })
                .compactMap { (installedApp: SoftwareProduct) -> SoftwareProduct? in
                    // only upgrade apps whose local version differs from the store version
                    if let storeApp = try storeSearch.lookup(app: installedApp.itemIdentifier.intValue) {
                        return storeApp.version != installedApp.bundleVersion
                            ? installedApp
                            : nil
                    } else {
                        return nil
                    }
                }

            guard apps.count > 0 else {
                printWarning("Nothing found to upgrade")
                return .success(())
            }

            print("Upgrading \(apps.count) outdated application\(apps.count > 1 ? "s" : ""):")
            print(apps.map { "\($0.appName) (\($0.bundleVersion))" }.joined(separator: ", "))

            var updatedAppCount = 0
            var failedUpgradeResults = [MASError]()
            for app in apps {
                if let upgradeResult = download(app.itemIdentifier.uint64Value) {
                    failedUpgradeResults.append(upgradeResult)
                } else {
                    updatedAppCount += 1
                }
            }

            switch failedUpgradeResults.count {
            case 0:
                if updatedAppCount == 0 {
                    print("Everything is up-to-date")
                }
                return .success(())
            case 1:
                return .failure(failedUpgradeResults[0])
            default:
                return .failure(.downloadFailed(error: nil))
            }
        } catch {
            // Bubble up MASErrors
            // swiftlint:disable force_cast
            return .failure(error is MASError ? error as! MASError : .searchFailed)
            // swiftlint:enable force_cast
        }
    }
}

public struct UpgradeOptions: OptionsProtocol {
    let apps: [String]

    static func create(_ apps: [String]) -> UpgradeOptions {
        return UpgradeOptions(apps: apps)
    }

    public static func evaluate(_ mode: CommandMode) -> Result<UpgradeOptions, CommandantError<MASError>> {
        return create
            <*> mode <| Argument(defaultValue: [], usage: "app(s) to upgrade")
    }
}