#include "common.h"

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

#include "config.h"
#include "command.h"
#include "xmalloc.h"
#include "debug.h"
#include "env.h"
#include "cli_readline.h"
#include "con-utils.h"
#include "cli.h"

#define DEBUG_PARSER	0	/* set to 1 to debug */

#define debug_parser(fmt, args...)		\
	debug_cond(DEBUG_PARSER, fmt, ##args)

static int cli_parse_line(char *line, char *argv[])
{
	static const FLASH char delim[] = {" \t"};

	char *ptr;
	uint_fast8_t nargs = 0;

	debug_parser("parse_line: \"%s\"\n", line);

	ptr = strtok_P(line, delim);
	while(nargs < CONFIG_SYS_MAXARGS && ptr != NULL) {
		argv[nargs++] = ptr;
	 	ptr = strtok_P(NULL, delim);
	}

	if (ptr != NULL)
		printf_P(PSTR("** Too many args (max. %d) **\n"), CONFIG_SYS_MAXARGS);

	argv[nargs] = NULL;
	debug_parser("parse_line: nargs=%d\n", nargs);

	return nargs;
}

static void process_macros(const char *input, char *output)
{
	char c, prev;
	const char *varname_start = NULL;
#if 0 && (CONFIG_SYS_CBSIZE < __UINT_FAST8_MAX__)
	uint_fast8_t inputcnt = strlen(input);
	uint_fast8_t outputcnt = CONFIG_SYS_CBSIZE;
#else
	int inputcnt = strlen(input);
	int outputcnt = CONFIG_SYS_CBSIZE;
#endif
	uint_fast8_t state = 0;		/* 0 = waiting for '$'  */

	/* 1 = waiting for '(' or '{' */
	/* 2 = waiting for ')' or '}' */
	/* 3 = waiting for '''  */
	char *output_start = output;

	debug_parser("[PROCESS_MACROS] INPUT len %d: \"%s\"\n", strlen(input),
		     input);

	prev = '\0';		/* previous character   */

	while (inputcnt && outputcnt) {
		c = *input++;
		inputcnt--;

		if (state != 3) {
			/* remove one level of escape characters */
			if ((c == '\\') && (prev != '\\')) {
				if (inputcnt-- == 0)
					break;
				prev = c;
				c = *input++;
			}
		}

		switch (state) {
		case 0:	/* Waiting for (unescaped) $    */
			if ((c == '\'') && (prev != '\\')) {
				state = 3;
				break;
			}
			if ((c == '$') && (prev != '\\')) {
				state++;
			} else {
				*(output++) = c;
				outputcnt--;
			}
			break;
		case 1:	/* Waiting for (        */
			if (c == '(' || c == '{') {
				state++;
				varname_start = input;
			} else {
				state = 0;
				*(output++) = '$';
				outputcnt--;

				if (outputcnt) {
					*(output++) = c;
					outputcnt--;
				}
			}
			break;
		case 2:	/* Waiting for )        */
			if (c == ')' || c == '}') {
				char envname[CONFIG_SYS_ENV_NAMELEN+1], *envval;
				/* Varname # of chars */
				uint_fast8_t envcnt = input - varname_start - 1;
				if (envcnt > CONFIG_SYS_ENV_NAMELEN)
					envcnt = CONFIG_SYS_ENV_NAMELEN;

				memcpy(envname, varname_start, envcnt);
				envname[envcnt] = '\0';

				/* Get its value */
				envval = getenv(envname);

				/* Copy into the line if it exists */
				if (envval != NULL)
					while ((*envval) && outputcnt) {
						*(output++) = *(envval++);
						outputcnt--;
					}
				/* Look for another '$' */
				state = 0;
			}
			break;
		case 3:	/* Waiting for '        */
			if ((c == '\'') && (prev != '\\')) {
				state = 0;
			} else {
				*(output++) = c;
				outputcnt--;
			}
			break;
		}
		prev = c;
	}

	if (outputcnt)
		*output = 0;
	else
		*(output - 1) = 0;

	debug_parser("[PROCESS_MACROS] OUTPUT len %d: \"%s\"\n",
		     strlen(output_start), output_start);
}

 /*
 * WARNING:
 *
 * We must create a temporary copy of the command since the command we get
 * may be the result from getenv(), which returns a pointer directly to
 * the environment data, which may change magicly when the command we run
 * creates or modifies environment variables (like "bootp" does).
 */
static int cli_run_command(const char *cmd, int flag)
{
	char *cmdbuf;			/* working copy of cmd		*/
	char *token;			/* start of token in cmdbuf	*/
	char *sep;			/* end of token (separator) in cmdbuf */
	char *finaltoken;
	char *str;
	char *argv[CONFIG_SYS_MAXARGS + 1];	/* NULL terminated	*/
	int argc;
	uint_fast8_t inquotes, repeatable = 1;
	int rc = 0;

	debug_parser("[RUN_COMMAND] cmd[%p]=\"%s\"\n", 
			cmd, cmd ? cmd : "NULL");

	clear_ctrlc();		/* forget any previous Control C */

	if (!cmd || !*cmd)
		return -1;	/* empty command */

	cmdbuf = strdup(cmd);
	finaltoken = xmalloc(CONFIG_SYS_CBSIZE);
	if (!finaltoken)
		return -1;	/* not enough memory */

	str = cmdbuf;

	/* Process separators and check for invalid
	 * repeatable commands
	 */

	debug_parser("[PROCESS_SEPARATORS] %s\n", cmd);
	while (*str) {
		/*
		 * Find separator, or string end
		 * Allow simple escape of ';' by writing "\;"
		 */
		for (inquotes = 0, sep = str; *sep; sep++) {
			if ((*sep == '\'') &&
			    (*(sep - 1) != '\\'))
				inquotes = !inquotes;

			if (!inquotes &&
			    (*sep == ';' || *sep == '\n') &&	/* separator		*/
			    (sep != str) &&			/* past string start	*/
			    (*(sep - 1) != '\\'))		/* and NOT escaped */
				break;
		}

		/*
		 * Limit the token to data between separators
		 */
		token = str;
		if (*sep) {
			str = sep + 1;	/* start of command for next pass */
			*sep = '\0';
		} else {
			str = sep;	/* no more commands for next pass */
		}
		debug_parser("token: \"%s\"\n", token);

		/* find macros in this token and replace them */
		process_macros(token, finaltoken);

		/* Extract arguments */
		argc = cli_parse_line(finaltoken, argv);
		if (argc == 0) {
			rc = -1;	/* no command at all */
			continue;
		}

		if (cmd_process(flag, argc, argv, &repeatable) != CMD_RET_SUCCESS)
			rc = -1;

		/* Did the user stop this? */
		if (had_ctrlc()) {
			rc = -1;	/* if stopped then not repeatable */
			break;
		}
	}

	free(cmdbuf);
	free(finaltoken);

	return rc ? rc : repeatable;
}

static int cli_run_command_list(const char *cmd)
{
	return (cli_run_command(cmd, 0) < 0);
}

/******************************************************************************/


/*
 * Run a command using the selected parser.
 *
 * @param cmd	Command to run
 * @param flag	Execution flags (CMD_FLAG_...)
 * @return 0 on success, or != 0 on error.
 */
int run_command(const char *cmd, int flag)
{
	/*
	 * cli_run_command can return 0 or 1 for success, so clean up
	 * its result.
	 */
	if (cli_run_command(cmd, flag) == -1)
		return 1;

	return 0;
}

/*
 * Run a command using the selected parser, and check if it is repeatable.
 *
 * @param cmd	Command to run
 * @param flag	Execution flags (CMD_FLAG_...)
 * @return 0 (not repeatable) or 1 (repeatable) on success, -1 on error.
 */
static int run_command_repeatable(const char *cmd, int flag)
{
	return cli_run_command(cmd, flag);
}

int run_command_list(const char *cmd, int len)
{
	(void) len;
	
	return cli_run_command_list(cmd);
}

/****************************************************************************/


void cli_loop(void)
{
	char *lastcommand = NULL;
	int len;
	int flag;
	int rc = 1;

	for (;;) {
		len = cli_readline(PSTR(CONFIG_SYS_PROMPT));

		flag = 0;	/* assume no special flags for now */
		if (len > 0) {
			free (lastcommand);
			lastcommand = strdup(console_buffer);
		} else if (len == 0)
			flag |= CMD_FLAG_REPEAT;

		if (len == -1)
			my_puts_P(PSTR("<INTERRUPT>\n"));
		else
			rc = run_command_repeatable(lastcommand, flag);

		if (rc <= 0) {
			/* invalid command or not repeatable, forget it */
			free(lastcommand);
			lastcommand = NULL;
		}
	}
}


command_ret_t do_run(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	int i;
	(void) cmdtp;

	if (argc < 2)
		return CMD_RET_USAGE;

	for (i = 1; i < argc; ++i) {
		char *arg;

		arg = getenv(argv[i]);
		if (arg == NULL) {
			printf_P(PSTR("## Error: \"%s\" not defined\n"), argv[i]);
			return CMD_RET_FAILURE;
		}

		if (run_command(arg, flag) != 0)
			return CMD_RET_FAILURE;
	}
	return CMD_RET_SUCCESS;
}