//
//  FileWriter.swift
//  PrySDR
//
//  Created by Jacky Jack on 21/01/2025.
//

import Foundation

enum FileWriterError: Error {
    case noFile
    case writeError
    case createError
}

class FileWriter {
    var filepath: String?
    let filemgr = FileManager.default
    var fileHandle: FileHandle?
    
    init() {
        
    }
    
    func openForRead(filename: String) throws {
        let dir = getCurrentExecutableDir()
        self.filepath = dir+"/"+filename
        print(dir+"/"+filename)
        if !filemgr.fileExists(atPath: filename) {
            print("Cant find file \(filename)")
            throw FileReaderError.noFile
        }

        fileHandle = FileHandle(forReadingAtPath: dir+"/"+filename)
        if (fileHandle == nil) {
            print("FileHandler failed")
        }
    }
    
    func createForWrite(filename: String) throws {
        let dir = getCurrentExecutableDir()
        
        self.filepath = dir+"/"+filename
        
        if !filemgr.fileExists(atPath: filename) {
            filemgr.createFile(atPath: dir+"/"+filename, contents: nil)
        }
        fileHandle = FileHandle(forUpdatingAtPath: dir+"/"+filename)
        if (fileHandle == nil) {
            print("FileHandler failed")
            throw FileWriterError.createError
        }
    }
    
    func deleteForWrite(filename: String) throws {
        let dir = getCurrentExecutableDir()
        
        self.filepath = dir+"/"+filename
        
        if filemgr.fileExists(atPath: filename) {
            do {
                try filemgr.removeItem(atPath: filename)
                filemgr.createFile(atPath: dir+"/"+filename, contents: nil)
            } catch {
                print("couldnt delete file to write: \(error)")
            }
        }
        fileHandle = FileHandle(forWritingAtPath: dir+"/"+filename)
        if (fileHandle == nil) {
            print("FileHandler failed")
            throw FileWriterError.createError
        }
    }
    
    func writeAll(_ arr: [Float32]) throws {
        //convert float to data
        let databuf = arr.withUnsafeBytes { Data($0) }
        do {
            print("try to write \(databuf.count) bytes")
            try fileHandle?.write(contentsOf: databuf)
        } catch {
            print("Cant write to file \(self.filepath) : \(error)")
            throw FileWriterError.writeError
        }
    }
    
    func close() {
        fileHandle?.closeFile()
    }
    
}