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

import ToolCore
import Foundation
import ArgumentParser

struct Images: ParsableCommand {
    
    // MARK: - CommandConfiguration
    
    static var configuration = CommandConfiguration(
        abstract: "A utility for generate images and an extension to access them easily.",
        version: ResgenSwiftVersion
    )
    
    // MARK: - Static
    
    static let toolName = "Images"
    static let defaultExtensionName = "Image"
    static let defaultExtensionNameUIKit = "UIImage"
    
    // MARK: - Command Options
    
    @OptionGroup var options: ImagesOptions
    
    // MARK: - Run
    
    mutating func run() {
        print("[\(Self.toolName)] Starting images generation")
        print("[\(Self.toolName)] Will use inputFile \(options.inputFile) to generate images in xcassets \(options.xcassetsPath)")
        
        // 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.generateExtensionFile(images: imagesToGenerate,
                                                      staticVar: options.staticMembers,
                                                      inputFilename: options.inputFilenameWithoutExt,
                                                      extensionName: options.extensionName,
                                                      extensionFilePath: options.extensionFilePath,
                                                      isSwiftUI: true)
        
        ImageExtensionGenerator.generateExtensionFile(images: imagesToGenerate,
                                                      staticVar: options.staticMembers,
                                                      inputFilename: options.inputFilenameWithoutExt,
                                                      extensionName: options.extensionNameUIKit,
                                                      extensionFilePath: options.extensionFilePathUIKit,
                                                      isSwiftUI: false)
        
        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 = ImagesError.fileNotExists(options.inputFile)
            print(error.description)
            Images.exit(withError: error)
        }

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

        // Extension for UIKit and SwiftUI should have different name
        guard options.extensionName != options.extensionNameUIKit else {
            let error = ImagesError.extensionNamesCollision(options.extensionName)
            print(error.description)
            Images.exit(withError: error)
        }
        
        // Check if needed to regenerate
        guard GeneratorChecker.shouldGenerate(force: options.forceExecution,
                                              inputFilePath: options.inputFile,
                                              extensionFilePath: options.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 = ImagesError.rsvgConvertNotFound
        print(error.description)
        Images.exit(withError: error)
    }
}