//
//  KissMatrix.swift
//  KissMeMatrix
//
//  Created by ened-book-m1 on 2023/06/20.
//

import Foundation
import KissMe


class KissMatrix {
    
    func run() {
        
        func printUsage() {
            let appName = (CommandLine.arguments[0] as NSString).lastPathComponent
            printError("\(appName) [sim|run] model.json [yyyyMMdd] [HHmmss]")
        }
        
        guard CommandLine.argc >= 3 else {
            printUsage()
            return
        }
        
        
        let runDate: Date
        let mode = RunMode(rawValue: CommandLine.arguments[1])
        switch mode {
        case .runner:
            runDate = Date()
        case .simulator:
            guard CommandLine.argc == 5 else {
                printUsage()
                return
            }
            guard let (year, month, day) = CommandLine.arguments[3].yyyyMMdd else {
                printError("Invalid [yyyyMMdd] argument")
                printUsage()
                return
            }
            guard let (hour, min, sec) = CommandLine.arguments[4].HHmmss else {
                printError("Invalid [HHmmss] argument")
                printUsage()
                return
            }
            var date = Date(timeIntervalSince1970: 0)
            date.change(year: year, month: month, day: day)
            date.change(hour: hour, min: min, sec: sec)
            runDate = date
        default:
            printUsage()
            return
        }
        
        
        let modelJson = CommandLine.arguments[2]
        guard let model = loadModel(modelJson) else { return }
        printError("Loaded \(model.indexSets.count) index set from \(modelJson)")
        
        let semaphore = DispatchSemaphore(value: 0)
        Task {
            let results = try await withThrowingTaskGroup(of: KissIndexResult?.self, returning: [KissIndexResult].self) { taskGroup in
                for indexSet in model.indexSets {
                    guard let (runUrl, args) = indexSet.build(date: runDate) else {
                        printError("Cannot get command from \(indexSet.name)")
                        continue
                    }
                    
                    taskGroup.addTask {
                        do {
                            let result = try await self.runIndex(runUrl, args: args, date: runDate)
                            return result
                        } catch {
                            printError(error)
                            return nil
                        }
                    }
                }
                
                var taskResult = [KissIndexResult]()
                for try await result in taskGroup.compactMap( { $0 }) {
                    taskResult.append(result)
                }
                return taskResult
            }
            
            mergeResult(results, date: runDate)
            
            semaphore.signal()
        }
        semaphore.wait()
    }
    
    
    private func runIndex(_ runUrl: URL, args: [String], date: Date) async throws -> KissIndexResult {
        assert(args.count >= 3)
        return try await withUnsafeThrowingContinuation { continuation in
            let kmi = args[0]
            
            let outputUrl = KissMatrix.indexLogFile(kmi, date: date)
            FileManager.default.createFile(atPath: outputUrl.path, contents: nil)
            let output = FileHandle(forWritingAtPath: outputUrl.path)
            
            let task = Process()
            task.currentDirectoryURL = URL.currentDirectory()
            task.executableURL = runUrl
            task.arguments = args
            task.standardOutput = output
            task.standardError = FileHandle.standardError
            task.qualityOfService = .default
            
            printError("curPath: \(task.currentDirectoryPath)")
            printError("runPath: \(runUrl.path)")
            printError("args: \(args)")
            
            do {
                try task.run()
                task.waitUntilExit()
            } catch {
                printError("run error \(error)")
                continuation.resume(throwing: error)
            }
            
            try? output?.close()
            
            guard let data = try? Data(contentsOf: outputUrl) else {
                continuation.resume(throwing: GeneralError.emptyData(kmi))
                return
            }
            if data.isEmpty {
                continuation.resume(throwing: GeneralError.emptyData(kmi))
                return
            }
            
            do {
                let indexResult = try JSONDecoder().decode(KissIndexResult.self, from: data)
                continuation.resume(returning: indexResult)
            } catch {
                printError("jsonError \(kmi)")
                continuation.resume(throwing: error)
            }
        }
    }
    
    
    private func mergeResult(_ results: [KissIndexResult], date: Date) {
        let indexCount = results.count
        var mergedOutput = [String: [KissIndexResult.Output]]()
        for result in results {
            for item in result.output {
                if let _ = mergedOutput[item.shortCode] {
                    mergedOutput[item.shortCode]!.append(item)
                }
                else {
                    mergedOutput[item.shortCode] = [item]
                }
            }
        }
        
        var normalized = [KissIndexResult.Output]()
        for (productNo, output) in mergedOutput {
            let weight = output.reduce(0.0, { $0 + $1.weight }) / Double(indexCount)
            let output = KissIndexResult.Output(shortCode: productNo, productName: output.first?.productName, weight: weight)
            normalized.append(output)
        }
        normalized.sort(by: { $0.weight > $1.weight })
        
        
        let kmis = results.map { $0.kmi }
        let matrixResult = KissMatrixResult(code: 200, kmis: kmis, day: date.yyyyMMdd, time: date.HHmmss, output: normalized)
        do {
            let jsonData = try JSONEncoder().encode(matrixResult)
            try FileHandle.standardOutput.write(contentsOf: jsonData)
        } catch {
            printError(error)
        }
    }
    
    
    private func loadModel(_ jsonFile: String) -> Model? {
        do {
            let configUrl = URL.currentDirectory().appending(path: jsonFile)
            let data = try Data(contentsOf: configUrl, options: .uncached)
            let model = try JSONDecoder().decode(Model.self, from: data)
            return model
        } catch {
            printError(error)
            return nil
        }
    }

    
    static func indexLogFile(_ kmi: String, date: Date) -> URL {
        let subPath = "log/index"
        let subFile = "\(subPath)/\(date.yyyyMMdd_HHmmssSSSS_forFile)-\(kmi).log"
        
        let fileUrl = URL.currentDirectory().appending(path: subFile)
        createSubpath(subPath)
        return fileUrl
    }

    
    static func createSubpath(_ name: String) {
        let subPath = URL.currentDirectory().appending(path: name)
        try? FileManager.default.createDirectory(at: subPath, withIntermediateDirectories: true)
    }
}


enum RunMode: String {
    case simulator = "sim"
    case runner = "run"
}


struct Model: Decodable {
    let indexSets: [IndexSet]
    
    struct IndexSet: Codable {
        /// Index Set 이름
        let name: String
        /// Index Set 에 대한 설명
        let memo: String
        /// config.json 설정
        let config: String?
        /// Index 수집을 수행하는 Runner app
        let runner: String
        /// 보정용 가중치
        let weight: Double
        
        func build(date: Date) -> (URL, [String])? {
            guard let _ = name.kmiIndex else {
                return nil
            }
            
            let command = URL.currentDirectory().appending(path: runner)
            
            let day = date.yyyyMMdd
            let time = date.HHmmss
            var args: [String] = [name, day, time]
            
            if let config = config {
                args.append(config)
            }
            return (command, args)
        }
    }
}