/** @fileoverview Test for utils.ts. */

import { allocMem, allocMemPages, numToString, testables, toBinary, toHex } from '../../js/util';

describe('garbage', () => {
    it('returns 0 <= x <= 255', () => {
        for (let i = 0; i < 1024; i++) {
            expect(testables.garbage()).toBeGreaterThanOrEqual(0);
        }
    });
});

describe('allocMem', () => {
    it('returns an array of the correct size', () => {
        expect(allocMem(2048).length).toBe(2048);

    });
    it('has 0xff and 0x00 patterns', () => {
        const memory = allocMem(2048);
        expect(memory[0]).toBe(0xff);
        expect(memory[1]).toBe(0xff);
        expect(memory[2]).toBe(0x00);
        expect(memory[3]).toBe(0x00);
        expect(memory[4]).toBe(0xff);
    });
    it('has garbage in the right places', () => {
        const memory = allocMem(0x800);
        let passed = false;
        for (let i = 0; i < 0x800; i += 0x200) {
            passed = memory[i + 0x28] !== 0xff
                && memory[i + 0x29] !== 0xff
                && memory[i + 0x68] !== 0xff
                && memory[i + 0x69] !== 0xff;
            if (passed) {
                break;
            }
        }
        expect(passed).toBe(true);
    });
});

describe('allocMemPages', () => {
    it('allocates 256 * the size', () => {
        expect(allocMemPages(5).length).toBe(5 * 256);
    });
});

describe('toHex', () => {
    it('converts an odd number of characters', () => {
        expect(toHex(0xfedcb, 5)).toEqual('FEDCB');
    });
    it('correctly guesses byte values', () => {
        expect(toHex(0xa5)).toEqual('A5');
    });
    it('correctly guesses word values', () => {
        expect(toHex(0x1abc)).toEqual('1ABC');
    });
    it('only uses the bottom work of larger values', () => {
        expect(toHex(0xabcdef)).toEqual('CDEF');
    });
    it('correctly prepends zeros', () => {
        expect(toHex(0xa5, 4)).toEqual('00A5');
    });
});

describe('toBinary', () => {
    it('has 8 digits for zero', () => {
        expect(toBinary(0x00)).toEqual('00000000');
    });
    it('correctly sets bits', () => {
        expect(toBinary(0xa5)).toEqual('10100101');
    });
});

describe('gup', () => {
    // untestable due to direct reference to window.location
});

describe('hup', () => {
    // untestable due to direct reference to window.location
});

describe('numToString', () => {
    it('packs a zero byte into a string of all zeros', () => {
        expect(numToString(0x00)).toEqual('\0\0\0\0');
    });
    it('packs a byte in the printable ASCII range into a zero-padded string',
        () => {
            expect(numToString(0x41)).toEqual('A\0\0\0');
        });
    it('packs a word into a string', () => {
        expect(numToString(0x4142)).toEqual('BA\0\0');
    });
    it('packs a 32-bit value into a string', () => {
        expect(numToString(0x41424344)).toEqual('DCBA');
    });
    it('ignores more than 32 bits', () => {
        expect(numToString(0x4142434445)).toEqual('EDCB');
    });
});