EMS31_submodules/CMDList/CMDList.c

#include "CMDList.h"

#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <stdio.h>

// initilises a CMDList_t with all NULL pointers
CMDList_t* CMDList_init()
{
	CMDList_t* list = malloc(sizeof(CMDList_t));
	memset(list, 0, sizeof(CMDList_t));
	return list;
}

// free up the full tree from memory
// does not free up the commands
int CMDList_deinit(CMDList_t* list)
{
	CMDList_t** list_p = (CMDList_t**)list;

	int i;
	for (i = 0; i < 26; i++)
	{
		if (*(list_p + i) != NULL)
		{
			CMDList_deinit(*(list_p + i));
		}
	}

	free(list);
	return 0;
}

// add a command in the command tree
int CMDList_add(CMDList_t *list, CMD_t* cmd, char* cmdName)
{
	int returnCode = 0;
	char* read_p = cmdName;
	CMDList_t** list_p = (CMDList_t**)list;

	if (read_p == NULL)
	{
		read_p = cmd->cmd;
	}

	while (returnCode >= 0)
	{
		char c = *read_p & (~0x20); // convert to uppercase
		if ((c >= 'A') && (c <= 'Z'))
		{ // valid character

			// get memory address of the caracter in the CMDList
			list_p += (c - 'A');

			if (*list_p == NULL)
			{ // it does not point to another list
				// allocate a new list for it
				*list_p = CMDList_init();
				if (list_p == NULL)
				{ // allocation faild (memory full?)
					returnCode = -2;
				}

				// update list_p for the next list
				list_p = (CMDList_t**)(*list_p);
			}
			else
			{ // it points to an other list
				// update pointer to this list
				list_p = (CMDList_t**)(*list_p);
			}
		}
		else
		{ // invalid caracter
			break;
		}

		// read next character
		read_p++;
	}

	if (returnCode >= 0)
	{ // no errors
		
		if (((CMDList_t*)list_p)->cmd != NULL)
		{ // replacing a command
			returnCode = 1;
		}
		// add command in it's spot
		((CMDList_t*)list_p)->cmd = cmd;
	}


	return returnCode;
}

// search command in the tree
CMD_t* CMDList_get(CMDList_t *list, char* cmd)
{
	bool found = true;
	CMD_t* cmd_object = NULL;
	char* read_p = cmd;
	CMDList_t** list_p = (CMDList_t**)list;

	while (found)
	{
		//TODO: mayby make a copy before converting to upper case
		char c = *read_p & (~0x20); // convert to uppercase
		if ((c >= 'A') && (c <= 'Z'))
		{ // valid character

			// get memory address of the caracter in the CMDList
			list_p += (c - 'A');

			if (*list_p == NULL)
			{ // no command found
				found = false;
			}
			else
			{ // it points to an other list
				// update pointer to this list
				list_p = (CMDList_t**)(*list_p);
			}
		}
		else
		{ // invalid caracter
			break;
		}

		// read next character
		read_p++;
	}

	if (found)
	{ // list found for command
		if (((CMDList_t*)list_p)->cmd == NULL)
		{ // command incomplete
			found = false;
			cmd_object = NULL;
		}
		else
		{
			cmd_object = ((CMDList_t*)list_p)->cmd;
		}
	}
	else
	{
		cmd_object = NULL;
	}

	return cmd_object;
}