'use strict';

const { Core } = require('./core.js');
const { DAT, MOV, ADD } = require('./instruction.js');


const CORESIZE = 8000;


test('DAT does nothing and kills the program', () => {
	const core = new Core(CORESIZE);
	const pc = 0;
	const ins = core.data[pc];
	expect(DAT(core, pc, ins)).toEqual([]);
});


test('MOV correctly moves a full instruction', () => {
	const core = new Core(CORESIZE);
	const pc = 20;
	core.data[pc] = {
		opcode: 'MOV',
		a: { mode: 'direct', value: 0 },
		b: { mode: 'direct', value: 1 },
	};
	const ins = core.data[pc];
	expect(core.data[pc+1].opcode).toBe('DAT');
	expect(MOV(core, pc, ins)).toEqual([pc+1]);
	expect(core.data[pc]).toEqual(core.data[pc+1]);
	expect(core.data[pc+1].opcode).toBe('MOV');
});


test('MOV correctly moves a B-field', () => {
	const core = new Core(CORESIZE);
	const pc = 20;
	core.data[pc] = {
		opcode: 'MOV',
		a: { mode: 'immediate', value: 100 },
		b: { mode: 'direct', value: 1 },
	};
	const ins = core.data[pc];
	expect(core.data[pc+1].opcode).toBe('DAT');
	expect(MOV(core, pc, ins)).toEqual([pc+1]);
	expect(core.data[pc+1]).toEqual({	
		opcode: 'DAT',
		a: { mode: 'immediate', value: 0 },
		b: { mode: 'immediate', value: 100 },
	});
});


test('MOV correctly handles indirection', () => {
	const core = new Core(CORESIZE);
	const pc = 20;
	core.data[pc-1] = {
		opcode: 'DAT',
		a: { mode: 'immediate', value: 0 },
		b: { mode: 'immediate', value: 2 },
	};
	core.data[pc] = {
		opcode: 'MOV',
		a: { mode: 'immediate', value: 100 },
		b: { mode: 'indirect', value: -1 },
	};
	const ins = core.data[pc];
	expect(core.data[pc+1].opcode).toBe('DAT');
	expect(MOV(core, pc, ins)).toEqual([pc+1]);
	expect(core.data[pc-1]).toEqual({	
		opcode: 'DAT',
		a: { mode: 'immediate', value: 0 },
		b: { mode: 'immediate', value: 2 },
	});

	expect(core.data[pc+1]).toEqual({	
		opcode: 'DAT',
		a: { mode: 'immediate', value: 0 },
		b: { mode: 'immediate', value: 100 },
	});

});




test('MOV correctly handles predecrement indirection', () => {
	const core = new Core(CORESIZE);
	const pc = 20;
	core.data[pc] = {
		opcode: 'MOV',
		a: { mode: 'immediate', value: 100 },
		b: { mode: 'predecrement', value: -1 },
	};
	const ins = core.data[pc];
	expect(core.data[pc+1].opcode).toBe('DAT');
	expect(MOV(core, pc, ins)).toEqual([pc+1]);
	expect(core.data[pc-1]).toEqual({	
		opcode: 'DAT',
		a: { mode: 'immediate', value: 0 },
		b: { mode: 'immediate', value: -1 },
	});

	expect(core.data[pc-2]).toEqual({	
		opcode: 'DAT',
		a: { mode: 'immediate', value: 0 },
		b: { mode: 'immediate', value: 100 },
	});

});


test('ADD correctly adds two full instructions', () => {
	const core = new Core(CORESIZE);
	const pc = 20;
	core.data[pc] = {
		opcode: 'ADD',
		a: { mode: 'direct', value: 1 },
		b: { mode: 'direct', value: 2 },
	};
	core.data[pc+1] = {
		opcode: 'DAT',
		a: { mode: 'immediate', value: 10 },
		b: { mode: 'immediate', value: 20 },
	};
	core.data[pc+2] = {
		opcode: 'DAT',
		a: { mode: 'immediate', value: 3 },
		b: { mode: 'immediate', value: 4 },
	};
	const ins = core.data[pc];

	expect(ADD(core, pc, ins)).toEqual([pc+1]);
	expect(core.data[pc+1]).toEqual({
		opcode: 'DAT',
		a: { mode: 'immediate', value: 10 },
		b: { mode: 'immediate', value: 20 },
	});
	expect(core.data[pc+2]).toEqual({
		opcode: 'DAT',
		a: { mode: 'immediate', value: 13 },
		b: { mode: 'immediate', value: 24 },
	});
});


test('ADD correctly adds B-field', () => {
	const core = new Core(CORESIZE);
	const pc = 20;
	core.data[pc] = {
		opcode: 'ADD',
		a: { mode: 'immediate', value: 1 },
		b: { mode: 'direct', value: 2 },
	};
	core.data[pc+1] = {
		opcode: 'DAT',
		a: { mode: 'immediate', value: 10 },
		b: { mode: 'immediate', value: 20 },
	};
	core.data[pc+2] = {
		opcode: 'DAT',
		a: { mode: 'immediate', value: 3 },
		b: { mode: 'immediate', value: 4 },
	};
	const ins = core.data[pc];

	expect(ADD(core, pc, ins)).toEqual([pc+1]);
	expect(core.data[pc+1]).toEqual({
		opcode: 'DAT',
		a: { mode: 'immediate', value: 10 },
		b: { mode: 'immediate', value: 20 },
	});
	expect(core.data[pc+2]).toEqual({
		opcode: 'DAT',
		a: { mode: 'immediate', value: 3 },
		b: { mode: 'immediate', value: 5 },
	});
});