def bits_to_target(bits_hex):
    # 1. Parse Bits (Hex String)
    # Example: '17066f2a'
    bits = int(bits_hex, 16)

    # 2. Extract Exponent and Mantissa
    exponent = bits >> 24
    mantissa = bits & 0x007fffff # Mask for 3 bytes (leaving sign bit)

    # 3. Calculate Target
    # Formula: Mantissa * 2^(8 * (Exponent - 3))
    shift = 8 * (exponent - 3)
    target = mantissa << shift

    # 4. Format to 32-byte (64-char) Hex
    target_hex = f"{target:064x}"
    return target_hex

def calculate_difficulty(target_hex):
    # Difficulty = MaxTarget / CurrentTarget
    max_target_bits = "1d00ffff"
    max_target = int(bits_to_target(max_target_bits), 16)
    current_target = int(target_hex, 16)

    return max_target / current_target

# --- Simulation (Block 800,000) ---
bits_val = "17066f2a"

print(f"--- Decompressing Bits: {bits_val} ---")
full_target = bits_to_target(bits_val)
difficulty = calculate_difficulty(full_target)

print(f"[*] Full 32-byte Target:")
print(f"    {full_target}")
print(f"\n[*] Current Difficulty:")
print(f"    {difficulty:,.2f}")

# Example of a valid hash
valid_hash = "000000000000000000052d314a292751d9044a835a6662de370f7221d604646a"
if int(valid_hash, 16) < int(full_target, 16):
    print(f"\n[OK] Sample Hash is BELOW the target. Block is VALID.")
else:
    print(f"\n[!!] Sample Hash is ABOVE the target. Block is INVALID.")