#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <readline/readline.h>
#include <readline/history.h>

int com_cd (char *);
int com_help PARAMS((char *));
int com_list PARAMS((char *));
int com_quit PARAMS((char *));

enum node_type
{
	ROOT = 1,
	CONFIG = 2,
};

typedef struct {
	char *name;
	rl_icpfunc_t *func;
	char *doc;
} COMMAND;

typedef struct {
	int node;
	char *prompt;
	COMMAND *cmd_list;
} NODES;

COMMAND root_commands[] = {
  { "config", com_cd, "configure mode" },
  { "help", com_help, "Display this text" },
  { "?", com_help, "Synonym for `help'" },
  { "quit", com_quit, "exit" },
  { "exit", com_quit, "exit" },
  { (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL }
};

COMMAND config_commands[] = {
  { "help", com_help, "Display this text" },
  { "?", com_help, "Synonym for `help'" },
  { "exit", com_list, "exit configure mode" },
  { (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL }
};

NODES nodes_list[] = {
	{ 0, (char *)NULL, (COMMAND *)NULL },
	{ ROOT, "knet> ", root_commands },
	{ CONFIG, "config> ", config_commands },
	{ 0, (char *)NULL, (COMMAND *)NULL }
};

/* The name of this program, as taken from argv[0]. */
char *progname;
int done = 0;
int node = ROOT;

static char * command_generator (const char *text, int state)
{
	int list_index, len;
	char *name;

	if (!state) {
		list_index = 0;
		len = strlen(text);
	}

	while ((name = nodes_list[node].cmd_list[list_index].name)) {
		list_index++;
		if (strncmp (name, text, len) == 0) {
			return strdup(name);
		}
	}

	return ((char *)NULL);
}

static char **fileman_completion(const char *text, int start, int end)
{
	char **matches;

	matches = (char **)NULL;

	if (start == 0)
		matches = rl_completion_matches (text, command_generator);

	return matches;
}

static int com_describe(void)
{
	printf("describe me\n");
	rl_on_new_line();
	return 0;
}

static char *completion_entry_function (const char *ignore, int invoking_key)
{
	return NULL;
}

static void initialize_readline(void)
{
	/* Allow conditional parsing of the ~/.inputrc file. */
	rl_readline_name = "FileMan";
	/* Tell the completer that we want a crack first. */
	rl_attempted_completion_function = fileman_completion;
	rl_bind_key('?', (Function *) com_describe);
	rl_completion_entry_function = completion_entry_function;
}

static char *stripwhite(char *string)
{
	register char *s, *t;

	for (s = string; whitespace (*s); s++)
	  ;

	if (*s == 0)
		return s;

	t = s + strlen (s) - 1;
	while (t > s && whitespace (*t))
		t--;
	*++t = '\0';

	return s;
}

static COMMAND *find_command(char *name)
{
	register int i;

	for (i = 0; nodes_list[node].cmd_list[i].name; i++)
		if (strcmp (name, nodes_list[node].cmd_list[i].name) == 0)
			return (&nodes_list[node].cmd_list[i]);

	return ((COMMAND *)NULL);
}

static int execute_line(char *line)
{
	register int i;
	COMMAND *command;
	char *word;

	/* Isolate the command word. */
	i = 0;
	while (line[i] && whitespace (line[i]))
		i++;

	word = line + i;

	while (line[i] && !whitespace (line[i]))
		i++;

	if (line[i])
		line[i++] = '\0';

	command = find_command (word);

	if (!command) {
		fprintf (stderr, "%s: No such command for FileMan.\n", word);
		return -1;
	}

	while (whitespace (line[i]))
		i++;

	word = line + i;

	return ((*(command->func)) (word));
}

int main(int argc, char **argv)
{
	char *line, *s;

	progname = argv[0];

	initialize_readline();

	while (!done) {
		line = readline (nodes_list[node].prompt);
		if (!line)
			break;

		s = stripwhite (line);
		if (*s) {
			add_history(s);
			execute_line(s);
		}
		free(line);
	}

	return 0;
}

int com_help (char *arg)
{
	register int i;
	int printed = 0;

	for (i = 0; nodes_list[node].cmd_list[i].name; i++) {
		if (!*arg || (strcmp (arg, nodes_list[node].cmd_list[i].name) == 0)) {
			printf ("%s\t\t%s.\n", nodes_list[node].cmd_list[i].name, nodes_list[node].cmd_list[i].doc);
			printed++;
		}
	}

	if (!printed) {
		printf ("No commands match `%s'.  Possibilties are:\n", arg);
		for (i = 0; nodes_list[node].cmd_list[i].name; i++) {
			if (printed == 1) {
				printed = 0;
				printf ("\n");
			}

			printf ("%s\t", nodes_list[node].cmd_list[i].name);
			printed++;
		}
		if (printed)
			printf ("\n");
	}
	return 0;
}

int com_list (char *arg)
{
	node = ROOT;
	return 0;
}

int com_cd (char *arg)
{
	node = CONFIG;
	return 0;
}

int com_quit (char *arg)
{
	done = 1;
	return 0;
}