//
//  Overrides.swift
//  FruitMachine
//
//  Created by Christopher Rohl on 7/27/17.
//  Copyright © 2017 Christopher Rohl. All rights reserved.
//

import Cocoa

class PIAOverrides: NSObject {
    static let writeDSP = WriteOverride(start: 0xD012, end: 0xD012, writeAnyway: false, action: PIAOverrides.actionWriteDSP)
    static func actionWriteDSP(terminal: AnyObject, byte: UInt8?) -> UInt8? {

        let pia = AppleI.sharedInstance.pia["display"]!
        
        if(pia.getMode() == .Output) {
            //Writing to DSP sets DSP.7
            AppleI.sharedInstance.pia["display"]!.data = byte! | 0x80
            
            //Output our character to the terminal
            AppleI.sharedInstance.terminal.putCharacter(charIndex: byte!)
            
            AppleI.sharedInstance.pia["display"]!.data = byte! & ~(0x80)
        }
        return nil
    }
    
    static let writeDSPCR = WriteOverride(start: 0xD013, end: 0xD013, writeAnyway: false, action: PIAOverrides.actionWriteDSPCR)
    static func actionWriteDSPCR(terminal: AnyObject, byte: UInt8?) -> UInt8? {
        AppleI.sharedInstance.pia["display"]?.control = byte!
        return nil
    }
    
    static let readDSP = ReadOverride(start: 0xD012, end: 0xD012, readAnyway: false, action: PIAOverrides.actionReadDSP)
    static func actionReadDSP(terminal: AnyObject, byte: UInt8?) -> UInt8? {
        
        //DSP.7 is unset when the character is accepted by the terminal
        return AppleI.sharedInstance.pia["display"]!.data
    }
    /* */
    
    static let readKBDCR = ReadOverride(start: 0xD011, end: 0xD011, readAnyway: false, action: PIAOverrides.actionReadKBDCR)
    static func actionReadKBDCR(terminal: AnyObject, byte: UInt8?) -> UInt8? {
        return AppleI.sharedInstance.pia["keyboard"]!.control
    }
    
    /* */
    static let readKBD = ReadOverride(start: 0xD010, end: 0xD010, readAnyway: false, action: PIAOverrides.actionReadKBD)
    static func actionReadKBD(terminal: AnyObject, byte: UInt8?) -> UInt8? {
        //Reading KBD clears KBDCR.7
        AppleI.sharedInstance.pia["keyboard"]!.control = AppleI.sharedInstance.pia["keyboard"]!.control & ~(0x80)
        
        //KBD.7 is tied to +5V
        return AppleI.sharedInstance.pia["keyboard"]!.data | 0x80
    }
    
}