import { describe, it } from 'mocha'
import { expect } from 'chai'
import bigInt from 'big-integer'

import { bigIntToBuffer, bufferToBigInt } from '../src'

// since bigIntToBuffer is a tiny wrapper over writeBigInt, no need to test it individually
describe('bigIntToBuffer', () => {
    it('should handle writing to BE', () => {
        expect([...bigIntToBuffer(bigInt('10495708'), 0, false)]).eql([
            0xa0, 0x26, 0xdc,
        ])
        expect([...bigIntToBuffer(bigInt('10495708'), 4, false)]).eql([
            0x00, 0xa0, 0x26, 0xdc,
        ])
        expect([...bigIntToBuffer(bigInt('10495708'), 8, false)]).eql([
            0x00, 0x00, 0x00, 0x00, 0x00, 0xa0, 0x26, 0xdc,
        ])
        expect([...bigIntToBuffer(bigInt('3038102549'), 4, false)]).eql([
            0xb5, 0x15, 0xc4, 0x15,
        ])
        expect([
            ...bigIntToBuffer(bigInt('9341376580368336208'), 8, false),
        ]).eql([...Buffer.from('81A33C81D2020550', 'hex')])
    })
    it('should handle writing to LE', () => {
        expect([...bigIntToBuffer(bigInt('10495708'), 0, true)]).eql([
            0xdc, 0x26, 0xa0,
        ])
        expect([...bigIntToBuffer(bigInt('10495708'), 4, true)]).eql([
            0xdc, 0x26, 0xa0, 0x00,
        ])
        expect([...bigIntToBuffer(bigInt('10495708'), 8, true)]).eql([
            0xdc, 0x26, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x00,
        ])
        expect([...bigIntToBuffer(bigInt('3038102549'), 4, true)]).eql([
            0x15, 0xc4, 0x15, 0xb5,
        ])
        expect([...bigIntToBuffer(bigInt('9341376580368336208'), 8, true)]).eql(
            [...Buffer.from('81A33C81D2020550', 'hex').reverse()]
        )
    })
})

describe('bufferToBigInt', () => {
    it('should handle reading BE', () => {
        expect(
            bufferToBigInt(
                Buffer.from([0xa0, 0x26, 0xdc]),
                0,
                3,
                false
            ).toString()
        ).eq('10495708')
        expect(
            bufferToBigInt(
                Buffer.from([0x00, 0xa0, 0x26, 0xdc]),
                0,
                4,
                false
            ).toString()
        ).eq('10495708')
        expect(
            bufferToBigInt(
                Buffer.from([0xb5, 0x15, 0xc4, 0x15]),
                0,
                4,
                false
            ).toString()
        ).eq('3038102549')
    })

    it('should handle reading LE', () => {
        expect(
            bufferToBigInt(
                Buffer.from([0xdc, 0x26, 0xa0]),
                0,
                3,
                true
            ).toString()
        ).eq('10495708')
        expect(
            bufferToBigInt(
                Buffer.from([0xdc, 0x26, 0xa0, 0x00]),
                0,
                4,
                true
            ).toString()
        ).eq('10495708')
        expect(
            bufferToBigInt(
                Buffer.from([0x15, 0xc4, 0x15, 0xb5]),
                0,
                4,
                true
            ).toString()
        ).eq('3038102549')
    })
})