//
//  FileSpectrum.swift
//  PrySDR
//
//  Created by Jacky Jack on 01/01/2025.
//

import Accelerate
import AppKit
import Combine
import CoreImage


class FileSpectrum: NSObject, ObservableObject {
    
    static let default_width = 512
    static let default_height = 512
    static let defaultSleepTime:UInt32 = 1
    var offset:Int=0
    let fileReader = FileReader()
    var dataBuffer:[Int8] = .init(repeating: 0, count: FileSpectrum.default_width)
    var allData:[Int8]? = nil
    let fft512 = NaiveFFT512()
    var line_counter:Int = 0
    
    let sessionQueue = DispatchQueue(label: "sessionQueue",
                                         attributes: [],
                                         autoreleaseFrequency: .workItem)
    
    @Published var outputImage = emptyCGImage
    
    let simpleImage = SimpleImage(width: 512, height: 512)
    
    /// A 1x1 Core Graphics image.
    static var emptyCGImage: CGImage = {
            let buffer = vImage.PixelBuffer(
                pixelValues: [0],
                size: .init(width: 1, height: 1),
                pixelFormat: vImage.Planar8.self)
            
            let fmt = vImage_CGImageFormat(
                bitsPerComponent: 8,
                bitsPerPixel: 8 ,
                colorSpace: CGColorSpaceCreateDeviceGray(),
                bitmapInfo: CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue),
                renderingIntent: .defaultIntent)
            
            return buffer.makeCGImage(cgImageFormat: fmt!)!
    }()

    init(_ input_filename: String) {
        //get data from u8 file
        
        do {
            try fileReader.open(filename: input_filename)
        } catch {
            print("Cant open file \(input_filename)")
            exit(0)
        }
        var i8_arr:[Int8]? = nil
        do {
            try i8_arr = fileReader.readAll()
            allData = i8_arr
        } catch {
            print("Got error \(error)")
        }

        fileReader.close()
    }
    
    func makeSpectrogramImage() -> NSImage {
        
        return NSImage(cgImage: FileSpectrum.emptyCGImage, size: .zero)
    }
    
    //just get data time to time from databuffer and pretend to be realtime data
    func dataFileProcessor() {
        //all now is about 512pixels
        let processingSlice = allData![offset...offset+FileSpectrum.default_width-1]
        let dataBuffer = Array(processingSlice)
        var transform_result:[Float] = .init(repeating: 0.0, count: FileSpectrum.default_width)
        //DispatchQueue.main.async {
            transform_result = self.fft512.computeLine(dataBuffer)
            self.simpleImage.drawPalletLine(line: self.line_counter, pixelLine: transform_result)
            if self.offset+FileSpectrum.default_width < allData!.count {
                self.offset += FileSpectrum.default_width
                self.line_counter += 1
            }
        //}
        
    }

    
    
    func startRunning() {
        sessionQueue.async {
            print("lets start the task for spectrum analysis")
            for i in 0..<512 {
                print("Process the task \(i)")
                self.simpleImage.drawPixel(i, i, PixelData(a: 255, r: 255, g: 0, b: 0))
                DispatchQueue.main.async {
                    self.dataFileProcessor()
                    self.outputImage = self.simpleImage.toCGImage()!
                }
                sleep(FileSpectrum.defaultSleepTime)
            }
        }
    }
}