//
//  TimingTests.swift
//  Clock Signal
//
//  Created by Thomas Harte on 13/08/2015.
//  Copyright © 2015 Thomas Harte. All rights reserved.
//

import Foundation
import XCTest

class TimingTests: XCTestCase, CSTestMachineJamHandler {

	private var endTime: UInt32 = 0

	func testImpliedNOP() {
		let code: [UInt8] = [0xea, CSTestMachineJamOpcode]
		self.runTest(code, expectedRunLength: 2)
	}

	func testLDA() {
		let code: [UInt8] = [
			0xa9, 0x00,			// [2] LDA #$00
			0xa5, 0x00,			// [3] LDA $00
			0xb5, 0x00,			// [4] LDA $00,X
			0xad, 0x00, 0x00,	// [4] LDA $0000
			0xbd, 0x00, 0x00,	// [4] LDA $0000, x (no wrap)
			0xbd, 0x02, 0x00,	// [5] LDA $0002, x (wrap)
			0xb9, 0x00, 0x00,	// [4] LDA $0000, y (no wrap)
			0xb9, 0x10, 0x00,	// [5] LDA $0010, y (wrap)
			0xa1, 0x44,			// [6] LDA ($44, x)
			0xb1, 0x00,			// [5] LDA ($00), y (no wrap)
			0xb1, 0x02,			// [6] LDA ($01), y (wrap)
			CSTestMachineJamOpcode]
		self.runTest(code, expectedRunLength: 48)
	}

	func testBCS() {
		let code: [UInt8] = [
			0x18,				// [2] CLC
			0xb0, 0xff,			// [2] BCS -1 (not taken)
			0x90, 0x7f,			// [3] BCC +7f (taken)
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x90, 0x00,			// [3] BCC 0 (taken)
			0x90, 0x7f,			// [4] BCC +6f (taken, page wrap)
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
			CSTestMachineJamOpcode]
		self.runTest(code, expectedRunLength: 14)
	}

	func runTest(code: [UInt8], expectedRunLength: UInt32) {
		let machine = CSTestMachine()

		machine.jamHandler = self

		let immediateCode = NSData(bytes: code, length: code.count)
		machine.setData(immediateCode, atAddress: 0x200)
		machine.setValue(0x00, forAddress: 0x0000)
		machine.setValue(0x00, forAddress: 0x0001)
		machine.setValue(0xff, forAddress: 0x0002)
		machine.setValue(0x00, forAddress: 0x0003)
		machine.setValue(0x200, forRegister: CSTestMachineRegister.ProgramCounter)
		machine.setValue(0xff, forRegister: CSTestMachineRegister.X)
		machine.setValue(0xfe, forRegister: CSTestMachineRegister.Y)

		self.endTime = 0
		while self.endTime == 0 {
			machine.runForNumberOfCycles(10)
		}

		XCTAssert(self.endTime == expectedRunLength, "Took \(self.endTime) cycles to perform")
	}

	func testMachine(machine: CSTestMachine!, didJamAtAddress address: UInt16) {
		if self.endTime == 0 {
			self.endTime = machine.timestamp - 7
		}
	}
}