//
//  Imagium.swift
//  
//
//  Created by Thibaut Schmitt on 24/01/2022.
//

import Foundation
import ArgumentParser
import ToolCore

struct Imagium: ParsableCommand {
    
    // MARK: - CommandConfiguration
    
    static var configuration = CommandConfiguration(
        abstract: "A utility for generate images and an extension to access them easily.",
        version: "0.1.0"
    )
    
    // MARK: - Static
    
    static let toolName = "Imagium"
    static let defaultExtensionName = "UIImage"
    
    // MARK: - Properties
    
    var extensionFileName: String { "\(options.extensionName)+\(options.extensionSuffix).swift" }
    var extensionFilePath: String { "\(options.extensionOutputPath)/\(extensionFileName)" }
    var inputFilenameWithoutExt: String {
        URL(fileURLWithPath: options.inputFile)
            .deletingPathExtension()
            .lastPathComponent
    }
    
    // MARK: - Command Options
    
    @OptionGroup var options: ImagiumOptions
    
    // MARK: - Run
    
    mutating func run() {
        print("[\(Self.toolName)] Starting images generation")
        
        // Check requirements
        guard checkRequirements() else { return }
        
        print("[\(Self.toolName)] Will generate images")
        
        // Parse input file
        let imagesToGenerate = ImageFileParser.parse(options.inputFile, platform: PlatormTag.ios)
        
        // Generate xcassets files
        let inputFolder = URL(fileURLWithPath: options.inputFile)
            .deletingLastPathComponent()
            .relativePath
        let xcassetsGenerator = XcassetsGenerator(forceGeneration: options.forceExecutionAndGeneration)
        xcassetsGenerator.generateXcassets(inputPath: inputFolder,
                                           imagesToGenerate: imagesToGenerate,
                                           xcassetsPath: options.xcassetsPath)
        
        // Generate extension
        ImageExtensionGenerator.writeStringsFiles(images: imagesToGenerate,
                                                  staticVar: options.extensionName == Self.defaultExtensionName,
                                                  inputFilename: inputFilenameWithoutExt,
                                                  extensionName: options.extensionName,
                                                  extensionFilePath: extensionFilePath)
        
        
        print("[\(Self.toolName)] Images generated")
    }
    
    // MARK: - Requirements
    
    private func checkRequirements() -> Bool {
        guard options.forceExecutionAndGeneration == false else {
            return true
        }
        
        let fileManager = FileManager()

        // Input file
        guard fileManager.fileExists(atPath: options.inputFile) else {
            let error = ImagiumError.fileNotExists(options.inputFile)
            print(error.localizedDescription)
            Imagium.exit(withError: error)
        }

        // RSVG-Converter
        _ = Imagium.getSvgConverterPath()

        // Check if needed to regenerate
        guard GeneratorChecker.shouldGenerate(force: options.forceExecution, inputFilePath: options.inputFile, extensionFilePath: extensionFilePath) else {
            print("[\(Self.toolName)] Images are already up to date :) ")
            return false
        }
        
        return true
    }
    
    // MARK: - Helpers
    
    @discardableResult
    static func getSvgConverterPath() -> String {
        let taskSvgConverter = Shell.shell("which", "rsvg-convert")
        if taskSvgConverter.terminationStatus == 0 {
            return taskSvgConverter.output!.removeCharacters(from: CharacterSet.whitespacesAndNewlines)
        }
        
        let error = ImagiumError.rsvgConvertNotFound
        print(error.localizedDescription)
        Imagium.exit(withError: error)
    }
}

Imagium.main()