Command-line Plex folder cleaner, removes SRT files that doesn't match an existing media

PlexCleaner.swift

//
//  main.swift
//  PlexCleaner
//
//  Created by Jason Pierna on 22/10/2020.
//

import Foundation

struct ValidationError: Error, CustomStringConvertible {
	private var message: String

	init(_ message: String) {
		self.message = message
	}

	var description: String {
		return message
	}
}

var path: String!
var dryRun: Bool = false

func validate() throws {
	var isDirectory: ObjCBool = false
	guard FileManager.default.fileExists(atPath: path, isDirectory: &isDirectory) else {
		throw ValidationError("Provided path does not exist.")
	}

	guard isDirectory.boolValue else {
		throw ValidationError("Provided path is not a directory.")
	}
}

func run() throws {
	getFolders(at: path).forEach(cleanFolder)
}

private func contentOfFolder(at path: String) -> [String] {
	let contentsOfFolder = try? FileManager.default.contentsOfDirectory(atPath: path)
		.filter { $0 != ".DS_Store" }
		.map { "\(path)/\($0)" }
	return contentsOfFolder ?? []
}

private func getFolders(at path: String) -> [String] {
	let contentsOfFolder = contentOfFolder(at: path)

	return contentsOfFolder.filter {
			var isDirectory: ObjCBool = false
			_ = FileManager.default.fileExists(atPath: $0, isDirectory: &isDirectory)
			return isDirectory.boolValue
		}
}

private func cleanFolder(folder: String) {
	let videoType = "mp4"
	let nestedFolders = getFolders(at: folder)
	let videoFiles = getFilesOfType(videoType, in: folder)
	let srtFiles = getFilesOfType("srt", in: folder)

	getUnmatchedSRTFiles(srt: srtFiles, videos: videoFiles, ofType: videoType).forEach(trashFile)
	nestedFolders.forEach(cleanFolder)

	let contentsOfFolder = contentOfFolder(at: folder)
	if contentsOfFolder.count == 0 {
		trashFile(filePath: folder)
	}
}

private func getFilesOfType(_ type: String, in folder: String) -> [String] {
	let contentsOfFolder = contentOfFolder(at: folder)
	return contentsOfFolder.filter { $0.hasSuffix(".\(type)") }
}

private func getUnmatchedSRTFiles(srt: [String], videos: [String], ofType type: String) -> [String] {
	return srt.filter { srtFile in
		return !videos.contains(where: { videoFile in
			let videoFilenameWithoutExt = videoFile.replacingOccurrences(of: ".\(type)", with: "")
			return srtFile.hasPrefix(videoFilenameWithoutExt)
		})
	}
}

private func trashFile(filePath: String) {
	let url = URL(fileURLWithPath: filePath)
	do {
		if dryRun {
			print("TRASH:", filePath)
		} else {
			try FileManager.default.trashItem(at: url, resultingItemURL: nil)
		}
	} catch {
		print("Error while trashing \(filePath)", error, error.localizedDescription)
	}
}

private func displayUsage() {

}

do {
	let args = CommandLine.arguments
	guard args.count > 1 else {
		throw ValidationError("Missing parameter: <path>")
	}

	path = args[1]

	guard args.count <= 3 else {
		throw ValidationError("Too much parameters!")
	}

	if args.count == 3 {
		if args[2] == "--dry-run" {
			dryRun = true
		} else {
			throw ValidationError("Wrong flag. Use --dry-run.")
		}
	}

	try run()
} catch {
	print("Error:", error.localizedDescription)
	displayUsage()
}