refactor: Improve message parsing and dictionary handling

- Changed the type of dictionary variable from int to int8_t for better type safety.
- Updated the handling of dictionary entries in message parsing to ensure correct formatting and prevent parsing errors with command arguments.
- Refactored message data parsing logic to use index-based loops, improving clarity and correctness in handling command arguments.
- Enhanced the documentation in message_data.h to provide a comprehensive overview of the message data system and its components.
- Added new tests to validate the correct parsing of messages with commands and arguments, ensuring robustness against previous bugs.

test/integration/zelda3/message_test.cc

@@ -208,5 +208,93 @@ TEST_F(MessageRomTest, BuildDictionaryEntries_CorrectSize) {
   EXPECT_FALSE(result.empty());
 }
 
+TEST_F(MessageRomTest, ParseMessageData_CommandWithArgument_NoExtraCharacters) {
+  // This test specifically checks for the bug where command arguments
+  // were being incorrectly parsed as characters (e.g., capital 'A' after [W])
+  // The bug was caused by using a range-based for loop while also tracking position
+  
+  // Message: [W:01]ABC
+  // Bytes: 0x6B (W command), 0x01 (argument), 0x00 (A), 0x01 (B), 0x02 (C)
+  std::vector<uint8_t> data = {0x6B, 0x01, 0x00, 0x01, 0x02};
+  
+  editor::MessageData message;
+  message.ID = 0;
+  message.Address = 0;
+  message.Data = data;
+  
+  std::vector<editor::MessageData> message_data_vector = {message};
+  auto parsed = editor::ParseMessageData(message_data_vector, dictionary_);
+  
+  // Should be "[W:01]ABC" NOT "[W:01]BABC" or "[W:01]AABC"
+  EXPECT_EQ(parsed[0], "[W:01]ABC");
+  
+  // The 'B' should not appear twice or be skipped
+  EXPECT_EQ(parsed[0].find("BABC"), std::string::npos);
+  EXPECT_EQ(parsed[0].find("AABC"), std::string::npos);
+}
+
+TEST_F(MessageRomTest, ParseMessageData_MultipleCommandsWithArguments) {
+  // Test multiple commands with arguments in sequence
+  // [W:01][C:02]AB
+  std::vector<uint8_t> data = {
+    0x6B, 0x01,  // [W:01] - Window border command with arg
+    0x77, 0x02,  // [C:02] - Color command with arg
+    0x00, 0x01   // AB - Regular characters
+  };
+  
+  editor::MessageData message;
+  message.ID = 0;
+  message.Data = data;
+  
+  std::vector<editor::MessageData> message_data_vector = {message};
+  auto parsed = editor::ParseMessageData(message_data_vector, dictionary_);
+  
+  EXPECT_EQ(parsed[0], "[W:01][C:02]AB");
+  
+  // Make sure argument bytes (0x01, 0x02) weren't parsed as characters
+  EXPECT_EQ(parsed[0].find("BAB"), std::string::npos);
+  EXPECT_EQ(parsed[0].find("CAB"), std::string::npos);
+}
+
+TEST_F(MessageRomTest, ParseMessageData_CommandWithoutArgument) {
+  // Test command without argument followed by text
+  // [K]ABC - Wait for key command (no arg) followed by ABC
+  std::vector<uint8_t> data = {
+    0x7E,              // [K] - Wait for key (no argument)
+    0x00, 0x01, 0x02   // ABC
+  };
+  
+  editor::MessageData message;
+  message.ID = 0;
+  message.Data = data;
+  
+  std::vector<editor::MessageData> message_data_vector = {message};
+  auto parsed = editor::ParseMessageData(message_data_vector, dictionary_);
+  
+  EXPECT_EQ(parsed[0], "[K]ABC");
+}
+
+TEST_F(MessageRomTest, ParseMessageData_MixedCommands) {
+  // Test mix of commands with and without arguments
+  // [W:01]A[K]B[C:02]C
+  std::vector<uint8_t> data = {
+    0x6B, 0x01,  // [W:01] - with arg
+    0x00,        // A
+    0x7E,        // [K] - no arg
+    0x01,        // B
+    0x77, 0x02,  // [C:02] - with arg
+    0x02         // C
+  };
+  
+  editor::MessageData message;
+  message.ID = 0;
+  message.Data = data;
+  
+  std::vector<editor::MessageData> message_data_vector = {message};
+  auto parsed = editor::ParseMessageData(message_data_vector, dictionary_);
+  
+  EXPECT_EQ(parsed[0], "[W:01]A[K]B[C:02]C");
+}
+
 }  // namespace test
 }  // namespace yaze