install.swift

//
//  install.swift
//  InstallTemplate
//
//  Created by Christian Elies on 01.08.2019.
//

import Foundation

struct Constants {
    struct CommandLineValues {
        static let yes = "YES"
        static let no = "NO"
    }

    struct File {
        static let templateName = "SwiftUI-VIPER.xctemplate"
        static let destinationRelativePath = "/Platforms/iPhoneOS.platform/Developer/Library/Xcode/Templates/File Templates/Source"
    }

    struct Messages {
        static let successMessage = "✅  Template was installed successfully 🎉. Enjoy it 🙂"
        static let successfullReplaceMessage = "✅  The Template has been replaced for you with the new version 🎉. Enjoy it 🙂"
        static let errorMessage = "❌  Ooops! Something went wrong 😡"
        static let exitMessage = "Bye Bye 👋"
        static let promptReplace = "The Template already exists. Do you want to replace it? (YES or NO)"
    }
	
	struct Print {
		static let separator = "===================================="
	}
}

final class Utilities {
	static func askForReplacePermission() -> String {
		var input = ""
		repeat {
			guard let textFormCommandLine = readLine(strippingNewline: true) else {
				continue
			}
			input = textFormCommandLine.uppercased()
		} while (input != Constants.CommandLineValues.yes && input != Constants.CommandLineValues.no)
		return input
	}
	
	static func bash(command: String, arguments: [String]) -> String {
		let whichPathForCommand = Utilities.shell(launchPath: "/bin/bash", arguments: [ "-l", "-c", "which \(command)" ])
		return Utilities.shell(launchPath: whichPathForCommand, arguments: arguments)
	}
	
	static func printToConsole(_ message: Any) {
		print(Constants.Print.separator)
		print("\(message)")
		print(Constants.Print.separator)
	}
	
	static func replaceItemAt(_ url: URL, withItemAt itemAtUrl: URL) throws {
		let fileManager = FileManager.default
		try fileManager.removeItem(at: url)
		try fileManager.copyItem(atPath: itemAtUrl.path, toPath: url.path)
	}
	
	static func shell(launchPath: String, arguments: [String]) -> String {
		let task = Process()
		task.launchPath = launchPath
		task.arguments = arguments
		
		let pipe = Pipe()
		task.standardOutput = pipe
		task.launch()
		
		let data = pipe.fileHandleForReading.readDataToEndOfFile()
		let output = String(data: data, encoding: String.Encoding.utf8)!
		if output.count > 0 {
			// remove newline character
			let lastIndex = output.index(before: output.endIndex)
			return String(output[output.startIndex ..< lastIndex])
		}
		return output
	}
}

func moveTemplate() {
    do {
        let fileManager = FileManager.default
        let destinationPath = Utilities.bash(command: "xcode-select", arguments: ["--print-path"]).appending(Constants.File.destinationRelativePath)
        Utilities.printToConsole("Template will be copied to: \(destinationPath)")

        if !fileManager.fileExists(atPath: "\(destinationPath)/\(Constants.File.templateName)") {
            try fileManager.copyItem(atPath: Constants.File.templateName, toPath: "\(destinationPath)/\(Constants.File.templateName)")
            Utilities.printToConsole(Constants.Messages.successMessage)
        } else {
            print(Constants.Messages.promptReplace)
			let input = Utilities.askForReplacePermission()

            if input == Constants.CommandLineValues.yes {
                try Utilities.replaceItemAt(URL(fileURLWithPath: "\(destinationPath)/\(Constants.File.templateName)"), withItemAt: URL(fileURLWithPath: Constants.File.templateName))
                Utilities.printToConsole(Constants.Messages.successfullReplaceMessage)
            } else {
                print(Constants.Messages.exitMessage)
            }
        }
    } catch let error as NSError {
        Utilities.printToConsole("\(Constants.Messages.errorMessage) : \(error.localizedFailureReason!)")
    }
}

moveTemplate()