import { ram } from "./ram"
import { Word, emptyWord, wordFromString } from "./word"

describe("Ram", () => {
    test("begins life with the specified number of empty words of the specified width", () =>{
        const subject = ram({
            width: 6,
            size: 4
        })
        
        expect(subject.values().every(word => word.equals(wordFromString("000000")))).toBe(true)
    })

    test("can be created from an array of strings", () => {
        const subject = ram([
            "0000",
            "1111"
        ])

        expect(subject.values().map(word => word.toString())).toEqual([
            "0000",
            "1111"
        ])
    })

    test("can be created from an array of words", () => {
        const subject = ram([
            wordFromString("0000"),
            wordFromString("1000"),
            wordFromString("1011"),
            wordFromString("0101"),
            wordFromString("1111"),
            wordFromString("1111")
        ])

        expect(subject.values().map(word => word.toString())).toEqual([
            "0000",
            "1000",
            "1011",
            "0101",
            "1111",
            "1111"
        ])
    })

    test("reports its word size", () => {
        const subject = ram([wordFromString("001")])

        expect(subject.wordSize).toEqual(3)
    })

    test("reports its address length", () => {
        expect(ram({ size: 48, width: 8 }).addressLength).toEqual(6)
        expect(ram({ size: 4, width: 8 }).addressLength).toEqual(2)
        expect(ram({ size: 5, width: 8 }).addressLength).toEqual(3)
        expect(ram({ size: 8, width: 8 }).addressLength).toEqual(3)
    })

    test("returns the memory value for a given index", () => {
        const subject = ram({
            width: 4,
            size: 4
        })

        subject.write(wordFromString("1010") as Word<4>, wordFromString("10"))

        expect(subject.read(wordFromString("10")).equals(wordFromString("1010"))).toBe(true)
    })

    test("returns the memory for a given index", () => {
        const subject = ram([
            "0000",
            "0001"
        ])

        expect(subject.get(wordFromString("1")).value().toString()).toEqual("0001")
    })
})