//
//  Stringium.swift
//  
//
//  Created by Thibaut Schmitt on 10/01/2022.
//

import Foundation
import ToolCore
import ArgumentParser

struct Stringium: ParsableCommand {
    
    // MARK: - Command Configuration
    
    static var configuration = CommandConfiguration(
        abstract: "Generate strings with custom scripts.",
        version: "0.1.0"
    )
    
    // MARK: - Static
    
    static let toolName = "Stringium"
    static let defaultExtensionName = "String"
    static let noTranslationTag: String = "notranslation"
    
    // MARK: - Properties
    
    var extensionFileName: String {
        if options.extensionSuffix.isEmpty == false {
            return "\(options.extensionName)+\(options.extensionSuffix).swift"
        }
        return "\(options.extensionName).swift"
    }
    
    var extensionFilePath: String { "\(options.extensionOutputPath)/\(extensionFileName)" }
    
    var inputFilenameWithoutExt: String {
        URL(fileURLWithPath: options.inputFile)
            .deletingPathExtension()
            .lastPathComponent
    }
    
    var generateStaticVariable: Bool {
        options.extensionName == Self.defaultExtensionName
    }
    
    // MARK: - Command options
    
    // The `@OptionGroup` attribute includes the flags, options, and
    // arguments defined by another `ParsableArguments` type.
    @OptionGroup var options: StringiumOptions
    
    // MARK: - Run
    
    mutating func run() {
        print("[\(Self.toolName)] Starting strings generation")
        
        // Check requirements
        guard checkRequirements() else { return }
        
        print("[\(Self.toolName)] Will generate strings")
        
        // Parse input file
        let sections = TwineFileParser.parse(options.inputFile)
        
        // Generate strings files
        StringsFileGenerator.writeStringsFiles(sections: sections,
                                               langs: options.langs,
                                               defaultLang: options.defaultLang,
                                               tags: options.tags,
                                               outputPath: options.stringsFileOutputPath,
                                               inputFilenameWithoutExt: inputFilenameWithoutExt)
        
        // Generate extension
        StringsFileGenerator.writeExtensionFiles(sections: sections,
                                                 defaultLang: options.defaultLang,
                                                 tags: options.tags,
                                                 staticVar: generateStaticVariable,
                                                 inputFilename: inputFilenameWithoutExt,
                                                 extensionName: options.extensionName,
                                                 extensionFilePath: extensionFilePath)
        
        print("[\(Self.toolName)] Strings generated")
    }
    
    // MARK: - Requirements
    
    private func checkRequirements() -> Bool {
        let fileManager = FileManager()
        
        // Input file
        guard fileManager.fileExists(atPath: options.inputFile) else {
            let error = StringiumError.fileNotExists(options.inputFile)
            print(error.localizedDescription)
            Stringium.exit(withError: error)
        }
        
        // Langs
        guard options.langs.isEmpty == false else {
            let error = StringiumError.langsListEmpty
            print(error.localizedDescription)
            Stringium.exit(withError: error)
        }
        
        guard options.langs.contains(options.defaultLang) else {
            let error = StringiumError.defaultLangsNotInLangs
            print(error.localizedDescription)
            Stringium.exit(withError: error)
        }
        
        // Check if needed to regenerate
        guard GeneratorChecker.shouldGenerate(force: options.forceGeneration, inputFilePath: options.inputFile, extensionFilePath: extensionFilePath) else {
            print("[\(Self.toolName)] Strings are already up to date :) ")
            return false
        }
        
        return true
    }
}