'use strict';

const { AddrMode } = require('./enum.js');


function DoDat(core, pc, ins) {
	// do nothing
	return [];
}


function DoMov(core, pc, ins) {
	if (ins.a.mode === AddrMode.Immediate) {
		let mem = core.getValue(pc, ins.b);
		mem.b.value = ins.a.value;
	} else {
		const src = core.getValue(pc, ins.a);
		const dstLoc = core.getLocation(pc, ins.b);

		// hacky deep copy
		core.data[dstLoc] = JSON.parse(JSON.stringify(src));
	}
	return [pc + 1];
}


function DoAdd(core, pc, ins) {
	if (ins.a.mode === AddrMode.Immediate) {
		let dst = core.getValue(pc, ins.b);
		dst.b += ins.a.value;
	} else {
		let src = core.getValue(pc, ins.a);
		let dst = core.getValue(pc, ins.b);
		dst.a.value += src.a.value;
		dst.b.value += src.b.value;
	}
	return [pc + 1];
}


function DoSub(core, pc, ins) {
	if (ins.a.mode === AddrMode.Immediate) {
		let dst = core.getValue(pc, ins.b);
		dst.b -= ins.a.value;
	} else {
		let src = core.getValue(pc, ins.a);
		let dst = core.getValue(pc, ins.b);
		dst.a.value -= src.a.value;
		dst.b.value -= src.b.value;
	}
	return [pc + 1];
}


function DoJmp(core, pc, ins) {
	return [core.getLocation(pc, ins.a)];
}


function DoJmz(core, pc, ins) {
	let test
	if (ins.b.mode === AddrMode.Immediate) {
		test = ins;
	} else {
		test = core.getValue(pc, ins.b);
	}

	if (test.b.value === 0) {
		return [core.getLocation(pc, ins.a)];
	} else {
		return [pc + 1];
	}
}


function DoJmn(core, pc, ins) {
	let test
	if (ins.b.mode === AddrMode.Immediate) {
		test = ins;
	} else {
		test = core.getValue(pc, ins.b);
	}

	if (test.b.value !== 0) {
		return [core.getLocation(pc, ins.a)];
	} else {
		return [pc + 1];
	}
}


function DoCmp(core, pc, ins) {
	if (ins.a.mode === AddrMode.Immediate) {
		const test = core.getValue(pc, ins.b);
		if (ins.a.value === test.b.value) {
			return [pc + 2];
		} else {
			return [pc + 1];
		}
	} else {
		const a = core.getValue(pc, ins.a);
		const b = core.getValue(pc, ins.b);

		if (
			a.opcode === b.opcode &&
			a.a.value === b.a.value &&
			a.b.value === b.b.value)
		) {
			return [pc + 2];
		} else {
			return [pc + 1];
		}
	}
}