import numpy as np
import os
import struct


def reverse_endian(data):
    result = bytearray()
    for i in range(len(data), 0, -1):
        result.append(data[i - 1])
    return bytes(result)


def generate_fp_vector(cases, filename, dtype=np.float16, big_endian=False):
    dsize = 0
    if dtype == np.float16:
        dsize = 2
    elif dtype == np.float32:
        dsize = 4
    else:
        raise ValueError(f"Unknown dtype {dtype}")

    x = np.frombuffer(os.urandom(cases * dsize), dtype=dtype)
    y = np.frombuffer(os.urandom(cases * dsize), dtype=dtype)
    np.seterr(all='ignore')
    sum = x + y
    mul = x * y
    x = x.tobytes()
    y = y.tobytes()
    sum = sum.tobytes()
    mul = mul.tobytes()
    with open(filename, 'w') as f:
        for i in range(cases):
            t = lambda v: reverse_endian(v) if big_endian else v
            f.write(' '.join([
                t(x[i * dsize:i * dsize + dsize]).hex(),
                t(y[i * dsize:i * dsize + dsize]).hex(),
                t(sum[i * dsize:i * dsize + dsize]).hex(),
                t(mul[i * dsize:i * dsize + dsize]).hex(),
            ]) + '\n')


if __name__ == '__main__':
    generate_fp_vector(30, 'fp16_test.hex', dtype=np.float16, big_endian=True)