//
//  source.swift
//  gen_html
//
//  Created by Isaac Paul on 9/30/25.
//

import Foundation
import PackagePlugin

final class AppError: LocalizedError, Sendable {
    
    let message: String
    
    init(_ message: String) {
        self.message = message
    }
    init(_ message: String, _ error:Error) {
        self.message = "\(message) : \(error.localizedDescription)"
    }
    
    static func failure<T>(_ message: String) -> Result<T, AppError> {
        return .failure(AppError(message))
    }
    
    var errorDescription: String? {
        get {
            return message
        }
    }
    
    var failureReason: String? { get { return message } }
}

let toolName = "BindingGenerator"

extension BindingPlugin: BuildToolPlugin {
    func createBuildCommands(context: PluginContext, target: Target) async throws -> [Command] {
        guard let swiftTarget = target as? SwiftSourceModuleTarget else {
            print("Unexpected target: \(type(of: target)). Needs SwiftSourceModuleTarget")
            throw AppError("Unexpected target: \(type(of: target)). Needs SwiftSourceModuleTarget")
        }
        let toolUrl = try context.tool(named: toolName).url
        
        return try createBuildCommands(
            outputDir: context.pluginWorkDirectoryURL,
            inputDir: swiftTarget.directoryURL,
            inputFiles: swiftTarget.sourceFiles,
            toolExe: toolUrl
        )
    }
}

#if canImport(XcodeProjectPlugin)

    import XcodeProjectPlugin
import System

    // The entry point for Xcode project builds.
    extension BindingPlugin: XcodeBuildToolPlugin {
        func createBuildCommands(context: XcodePluginContext, target: XcodeTarget) throws -> [Command] {
            let toolUrl = try context.tool(named: toolName).url
            return try createBuildCommands(
                outputDir: context.pluginWorkDirectoryURL,
                inputDir: context.xcodeProject.directoryURL,
                inputFiles: target.inputFiles,
                toolExe: toolUrl
            )
        }
    }

#endif

struct Config: Codable {
    var root_path: String?
}

extension URL {
    func isHtml() -> Bool {
        return self.pathExtension == "html" || self.pathExtension == "htm"
    }
}

extension String {
    func uppercaseFirstLetter() -> String {
        guard let firstLetter = self.first else { return self }
        return firstLetter.uppercased() + self.dropFirst()
    }
}

@main
struct BindingPlugin {

    private static let configFile = "binding_generator_plugin.json"

    private func createBuildCommands(
        outputDir: URL,
        inputDir: URL,
        inputFiles: FileList,
        toolExe: URL
    ) throws -> [Command] {

        let configFilePath = inputFiles.first(where: { $0.url.lastPathComponent == BindingPlugin.configFile })
        let configFileURL = configFilePath?.url

        //let listSearchDir: [String]
        let htmlFiles = inputFiles.filter { $0.url.isHtml() }.map { $0.url }
        let rootPath:URL

        if let configFileURL = configFileURL {
            
            let configData = try Data(contentsOf: configFileURL)
            let config = try JSONDecoder().decode(Config.self, from: configData)

            let baseDirectory:URL = configFileURL.deletingLastPathComponent()
            if let configRootPath = config.root_path {
                rootPath = baseDirectory.appending(path: configRootPath)
            } else {
                rootPath = inputDir
            }
            /*
            for source in config.sources ?? [] {
                let sourceFileOrDirectory = baseDirectory.appendingPathComponent(source)
                if sourceFileOrDirectory.isHtml()  {
                    htmlFiles.append(sourceFileOrDirectory)
                } else {
                    let files = try FileManager.default.contentsOfDirectory(
                        at: sourceFileOrDirectory,
                        includingPropertiesForKeys: nil
                    )
                    let filteredFiles = files.filter { $0.isHtml() }
                    htmlFiles.append(contentsOf: filteredFiles)
                }
            }*/
            
        } else {
            rootPath = inputDir
        }
/*
 /Users/isaacpaul/Projects/swift-projects/HRW/Plugins/BindingPlugin/source.swift:146:13: error: 'let' cannot appear nested inside another 'var' or 'let' pattern
 <unknown>:0: error: error opening input file '/Users/isaacpaul/Library/Developer/Xcode/DerivedData/HRW-bicwrilrmihgqogjvxyqtcosfaro/Build/Intermediates.noindex/BuildToolPluginIntermediates/hrw.output/HRWTests/BindingPlugin/Example.swift' (No such file or directory)
 //
 Showing All Messages
 Error opening input file '/Users/isaacpaul/Library/Developer/Xcode/DerivedData/HRW-bicwrilrmihgqogjvxyqtcosfaro/Build/Intermediates.noindex/BuildToolPluginIntermediates/hrw.output/HRWTests/BindingPlugin/ExampleBinding.swift' (No such file or directory)
 */
        return htmlFiles.map { eachFile in
            let fileName = eachFile.lastPathComponent
            let ext = eachFile.pathExtension
            let extIndex = fileName.index(fileName.startIndex, offsetBy: fileName.count - (ext.count + 1))
            let withoutExt = String(fileName[fileName.startIndex..<extIndex])
            let targetFileName = "\(withoutExt.uppercaseFirstLetter()).swift"
            
            let rootFP = FilePath(rootPath.path)
            var inputFP = FilePath(eachFile.path)
            let outputDirFP = FilePath(outputDir.path)
            
            let _ = inputFP.removePrefix(rootFP)
            inputFP.removeLastComponent()
            //let idk = outputDirFP.pushing(inputFP)
            let outputFileA = outputDir.appendingPathComponent(inputFP.string)
            let outputFile = outputFileA.appendingPathComponent(targetFileName)
            print("Expected path: \(outputFile.path)")

            return .buildCommand(
                displayName: "Generating binding to \(outputFile.path)",
                executable: toolExe,
                arguments: ["-o", outputDir.path, "-i", eachFile.path, "-b", rootPath.path],
                inputFiles: [eachFile],
                outputFiles: [URL(fileURLWithPath: outputFile.path)]
            )
        }
    }
}