module vlq

import io

struct TestReader {
pub:
    bytes []u8
mut:
    i int
}

struct TestData {
    decode_val string
    expected   i64
}

type TestDataList = []TestData

fn test_decode_a() {
    decode_values := [
        TestData{'A', 0},
        TestData{'C', 1},
        TestData{'D', -1},
        TestData{'2H', 123},
        TestData{'qxmvrH', 123456789},
        TestData{'+/////B', 1073741823}, // 2^30-1
        // TestData{'hgggggggggggI', 9_223_372_036_854_775_808} // 2^63
    ]

    for _, test_data in decode_values {
        mut input := make_test_reader(test_data.decode_val)

        res := decode(mut &input)!
        assert res == test_data.expected
    }
}

fn (mut b TestReader) read(mut buf []u8) !int {
    if !(b.i < b.bytes.len) {
        return io.Eof{}
    }
    n := copy(mut buf, b.bytes[b.i..])
    b.i += n
    return n
}

fn make_test_reader(data string) io.Reader {
    buf := &TestReader{
        bytes: data.bytes()
    }
    return io.new_buffered_reader(reader: buf)
}