#include "core/tcm_frame.hpp"

#include <cassert>
#include <cstdint>
#include <stdexcept>
#include <vector>

namespace {

void test_rotate_frame_encoding() {
    const std::vector<uint8_t> payload{0x00, 0x05};
    const std::vector<uint8_t> expected{
        0x7e, 0x00, 0x07, 0x85, 0x02, 0x77, 0x00, 0x01, 0x00, 0x05, 0x7f};

    const auto encoded = mag160c::core::encode_tcm_frame(0x02, 0x77, 0x0001, payload);

    assert(encoded == expected);
}

void test_decode_rejects_bad_header_checksum() {
    auto encoded = mag160c::core::encode_tcm_frame(0x02, 0x77, 0x0001, {0x00, 0x05});
    encoded[3] ^= 0xff;

    mag160c::core::TcmFrame decoded;
    assert(mag160c::core::decode_tcm_frame(encoded.data(), encoded.size(), &decoded) ==
           MAG160C_ERR_CHECKSUM);
}

void test_decode_roundtrip() {
    const std::vector<uint8_t> payload{0x10, 0x20, 0x30};
    const auto encoded = mag160c::core::encode_tcm_frame(0xa1, 0xb2, 0xc3d4, payload);

    mag160c::core::TcmFrame decoded;
    assert(mag160c::core::decode_tcm_frame(encoded.data(), encoded.size(), &decoded) == MAG160C_OK);

    assert(decoded.main_cmd == 0xa1);
    assert(decoded.sub_cmd == 0xb2);
    assert(decoded.frame_id == 0xc3d4);
    assert(decoded.payload == payload);
}

void test_encode_rejects_oversized_payload() {
    const std::vector<uint8_t> payload(65531U, 0xaa);

    bool threw_length_error = false;
    try {
        (void)mag160c::core::encode_tcm_frame(0x02, 0x77, 0x0001, payload);
    } catch (const std::length_error&) {
        threw_length_error = true;
    }

    assert(threw_length_error);
}

} // namespace

int main() {
    test_rotate_frame_encoding();
    test_decode_rejects_bad_header_checksum();
    test_decode_roundtrip();
    test_encode_rejects_oversized_payload();

    return 0;
}