#include "Unity/src/unity.h"
#include "message_parser.h"
#include <stdint.h>

void setUp(void) {}    // optional
void tearDown(void) {} // optional

// Gültige Nachricht mit Payload
void test_valid_message_parses_correctly(void) {
  struct MessageRecieve mr = {
      .state = WaitingForStartByte,
      .messageid = 0,
      .index = 0,
      .checksum = 0,
  };

  uint8_t msg[] = {0xAA, 0x01, 0x03, 0x01, 0x02, 0x03, 0x00};
  msg[6] = msg[1] ^ msg[2] ^ msg[3] ^ msg[4] ^ msg[5]; // korrekte Checksumme

  for (uint8_t i = 0; i < sizeof(msg); ++i)
    parse_byte(&mr, msg[i]);

  TEST_ASSERT_EQUAL_UINT8(1, mr.messageid);
  TEST_ASSERT_EQUAL_UINT8(3, mr.length);
  uint8_t expected[] = {1, 2, 3};
  TEST_ASSERT_EQUAL_UINT8_ARRAY(expected, mr.message, 3);
}

// Ungültige Checksumme – Zustand wird zurückgesetzt
void test_invalid_checksum_resets_state(void) {
  struct MessageRecieve mr = {
      .state = WaitingForStartByte,
      .messageid = 0,
      .index = 0,
      .checksum = 0,
  };

  uint8_t msg[] = {
      0xAA, 0x02, 0x02,
      0x10, 0x20, 0x00}; // falsche Checksumme (korr. wäre 0x10 ^ 0x20 ^ 2 ^ 2)

  for (uint8_t i = 0; i < sizeof(msg); ++i)
    parse_byte(&mr, msg[i]);

  TEST_ASSERT_EQUAL_UINT8(WaitingForStartByte, mr.state);
}

// Kein Startbyte – Nachricht ignorieren
void test_no_startbyte_ignored(void) {
  struct MessageRecieve mr = {
      .state = WaitingForStartByte, .index = 0, .checksum = 0};

  uint8_t msg[] = {2, 0x10, 0x20, 0x30}; // kein Startbyte

  for (uint8_t i = 0; i < sizeof(msg); ++i)
    parse_byte(&mr, msg[i]);

  TEST_ASSERT_EQUAL_UINT8(WaitingForStartByte, mr.state);
  TEST_ASSERT_EQUAL_UINT8(0, mr.index);
}

// Länge 0 – gültige Nachricht ohne Payload
void test_zero_length_message(void) {
  struct MessageRecieve mr = {
      .state = WaitingForStartByte, .index = 0, .checksum = 0};

  uint8_t msg[] = {0xAA, 3, 0, 0}; // Länge = 0, Checksumme = 3 ^ 0 = 3
  msg[3] = msg[1] ^ msg[2];

  for (uint8_t i = 0; i < sizeof(msg); ++i)
    parse_byte(&mr, msg[i]);

  TEST_ASSERT_EQUAL_UINT8(0, mr.index);
  TEST_ASSERT_EQUAL_UINT8(3, mr.messageid);
  TEST_ASSERT_EQUAL_UINT8(WaitingForStartByte, mr.state);
}

int main(void) {
  UNITY_BEGIN();
  RUN_TEST(test_valid_message_parses_correctly);
  RUN_TEST(test_invalid_checksum_resets_state);
  RUN_TEST(test_no_startbyte_ignored);
  RUN_TEST(test_zero_length_message);
  return UNITY_END();
}