//
//  NaiveFFT.swift
//  PrySDR
//
//  Created by Jacky Jack on 05/01/2025.
//

import Foundation
import Accelerate

//SUpports now only fixed sizes and not flexible implementation just a PoC
class NaiveFFT512 {
    
    static let sampleCount = 512
    let forwardDCT = vDSP.DCT(count: sampleCount, transformType: .II)!
    
    init() {
        
    }
    
    func getSampleCount() -> Int {
        return NaiveFFT512.sampleCount
    }
    
    func computeLine(_ processingArray: [Int8]) -> [Float] {
        
        var dataFloat = [Float](repeating: 0.0, count: NaiveFFT512.sampleCount)
        
        if processingArray.count != NaiveFFT512.sampleCount {
            print("Not supporting arrays not equail to \(NaiveFFT512.sampleCount)")
            return []
        }
        
        vDSP.convertElements(of: processingArray, to: &dataFloat)
        //dataFloat = vDSP.add(127.0, dataFloat)
        //print(dataFloat)
        
        //move from -127.0 to 128.0 range -1.0...1.0
        //var adjusted = vDSP.divide(dataFloat, Float(sampleCount))
        var adjusted = dataFloat
        //print(adjusted)
        
        var transform_result = forwardDCT.transform(adjusted)
        transform_result = vDSP.absolute(transform_result)
        
        return transform_result
    }
    
}