/*
 * (C) Copyright 2014-2016 Leo C. <erbl259-lmu@yahoo.de>
 *
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * Add to readline cmdline-editing by
 * (C) Copyright 2005
 * JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
 *
 * SPDX-License-Identifier:	GPL-2.0
 */

#include "cli.h"
#include "command.h"
#include <ctype.h>

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


/* FIXME: Quoting problems */

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

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


static int_least8_t exec_flags;
#define OPT_XTRACE		1
#define OPT_VERBOSE		2

static int_least8_t command_level;

static void cli_trace_cmd(int_fast8_t level, int argc, char *argv[])
{
	while (level-- > 0)
		putchar('+');
	for (int_fast8_t i = 0; i < argc; i++)
		printf_P(PSTR(" %s"), argv[i]);
	putchar('\n');
}




static int cli_parse_line(char *line, char *argv[])
{
	uint_fast8_t state = 0;
	uint_fast8_t nargs = 0;
	char *inp, *outp;
	char c, quote;

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

	for (outp = inp = line, quote = '\0'; (c = *inp) != '\0'; inp++) {

		switch (state) {
		case 0:						/* before arg string, waiting for arg start */
			if (isblank(c))
				continue;

			argv[nargs++] = inp;	/* begin of argument string	*/
			outp = inp;
			state = 1;
			/* fall thru */

		case 1:						/* in arg string, waiting for end of arg string */
			if (c == '\\') {
				++state;
				continue;
			}
			if (c == '\"' || c == '\'') {
				quote = c;
				state = 3;
				continue;
			}
			if (isblank(c)) {
				c = '\0';
				state = 0;
			}
			break;

		case 3:						/* in quote */
			if (c == '\\' && quote == '\"') {
				++state;
				continue;
			}
			if (c == quote) {
				state = 1;
				continue;
			}
			break;

		case 2:						/* waiting for next char */
		case 4:
			--state;
			break;

		}

		if (nargs > CONFIG_SYS_MAXARGS) {
			--nargs;
			break;
		}
		*outp++ = c;
	}

	if (*inp != '\0')
		printf_P(PSTR("** Too many args (max. %d) **\n"), CONFIG_SYS_MAXARGS);

	*outp = '\0';
	argv[nargs] = NULL;
	debug_parser("%s: nargs=%d\n", __func__, nargs);
#if 0
	for (int i = 0; i < nargs; i++)
		debug_parser("%s: arg %d: >%s<\n", __func__, i, argv[i]);
#endif
	return nargs;

}

static
void append_char(uint_fast8_t pass, char **p, char c)
{

	if (pass) {
		**p = c;
	}
	++(*p);
}

static
char *process_macros(char *input)
{
	char c, prev, *inp;
	char *output = NULL;
	char *outp = NULL;
	const char *varname = NULL;

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

	for(uint_fast8_t pass = 0; pass < 2; pass++)
	{
		uint_fast8_t state = 0;
		/* 0 = waiting for '$'  */
		/* 1 = waiting for '{' */
		/* 2 = waiting for '}' */
		/* 3 = waiting for ''' */

		if (pass > 0) {
			size_t outputlen = outp - (char *) NULL;
			output = (char *) malloc(outputlen);
			if (output == NULL) {
				printf_P(PSTR("** Can't process command: Out of memory! **\n"));
				return NULL;
			}
			outp = output;
		}

		inp = input;

		for (prev = '\0'; (c = *inp++) != '\0'; prev = c) {



			switch (state) {
			case 0:	/* Waiting for (unescaped) $    */
				if ((c == '\'') && (prev != '\\')) {
					state = 3;
					break;
				}
				if ((c == '$') && (prev != '\\')) {
					state++;
					continue;
				}
				break;
			case 1:	/* Waiting for {        */
				if (c == '{') {
					state++;
					varname = inp;
					continue;
				} else {
					state = 0;
					append_char(pass, &outp, '$');
				}
				break;
			case 2:	/* Waiting for }        */
				if (c == '}') {
					/* Terminate variable name */
					*(inp-1) = '\0';
					const char *envval = getenv_str(varname);
					*(inp-1) = '}';
					/* Copy into the line if it exists */
					if (envval != NULL)
						while (*envval)
							append_char(pass, &outp, *(envval++));
					/* Look for another '$' */
					state = 0;
				}
				continue;
			case 3:	/* Waiting for '        */
				if (c == '\'')
					state = 0;
				break;
			}
			append_char(pass, &outp, c);
		}

		append_char(pass, &outp, 0);
	}

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

	return output;
}

/**
 *
 *
 * WARNING:
 *
 * We must create a temporary copy of the command since the command we get
 * may be the result from getenv_str(), 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).
 *
 *
 * @param cmd
 * @param flag
 * @returns
 *
 */
static int cli_run_command(const char *cmd, uint_fast8_t flag)
{
	char cmdbuf[strlen(cmd) + 1];			/* working copy of cmd		*/
	char *token;			/* start of token in cmdbuf	*/
	char *sep;			/* end of token (separator) in cmdbuf */
	char *finaltoken = NULL;	/* token after macro expansion	*/
	char *str;
	char *argv[CONFIG_SYS_MAXARGS + 1];	/* NULL terminated	*/
	int argc;
	uint_fast8_t inquotes, repeatable = 1;
	int rc = 0;

	exec_flags = 0;
	char *optenv = getenv_str(PSTR("cli"));
	if (optenv) {
		if (strstr_P(optenv, PSTR("verbose")) != NULL)
			exec_flags |= OPT_VERBOSE;
		if (strstr_P(optenv, PSTR("xtrace")) != NULL)
			exec_flags |= OPT_XTRACE;
	}

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

	if (exec_flags & OPT_VERBOSE)
		printf_P(PSTR("%s\n"), cmd, cmd ? cmd : "");

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

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

	str = strcpy(cmdbuf, cmd);
	//str = cmdbuf;
	++command_level;

	/* 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 != str) &&					/* past string start */
			    (*(sep - 1) != '\\'))			/* and NOT escaped */
				inquotes = !inquotes;

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

		/* no more commands after unescaped '#' token */
		if (*sep == '#')
			*sep = '\0';

		/* 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 */
		}
		while (isblank(*token))
			++token;
		if (*token == '\0')		/* empty (comment only) */
			continue;
		debug_parser("token: \"%s\"\n", token);

		/* find macros in this token and replace them */
		finaltoken = process_macros(token);
		if (finaltoken == NULL) {
			rc = -1;	/* no command at all */
			continue;
		}

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

		if (exec_flags & OPT_XTRACE)
			cli_trace_cmd(command_level, argc, argv);

		rc = cmd_process(flag, argc, argv, &repeatable);
		free(finaltoken);
		if (rc != CMD_RET_SUCCESS) {
			if (exec_flags & OPT_VERBOSE)
				printf_P(PSTR("Command failed, result=%d\n"), rc);
			rc = -1;
		}

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

	--command_level;

	return rc ? rc : repeatable;
}

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

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


/*
 * Run a command.
 *
 * @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, uint_fast8_t 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, uint_fast8_t 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;
	uint_fast8_t flag;
	int rc = 1;

	for (;;) {
		len = cli_readline(lastcommand ? PSTR(CONFIG_SYS_PROMPT_REPEAT) : PSTR(CONFIG_SYS_PROMPT), 1);

		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) {
			if (exec_flags & OPT_VERBOSE)
				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;
		}
	}
}