/*
 * Copyright (C) 2017 Guido Berhoerster <guido+pwm@berhoerster.name>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include "compat.h"

#include <errno.h>
#include <fcntl.h>
#ifdef	HAVE_ERR_H
#include <err.h>
#endif /* HAVE_ERR_H */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

#include "pwm.h"
#include "cmd.h"
#include "io.h"
#include "macro.h"
#include "tok.h"
#include "util.h"

static const char *config_cmds[] = {
    "set",
    "define"
};

int
pwmrc_read(struct pwm_ctx *ctx)
{
	int	retval = -1;
	char	*filename = NULL;
	FILE	*fp = NULL;
	int	lineno;
	char	buf[PWM_LINE_MAX] = { '\0' };
	size_t	tokenc = 0;
	union tok **tokenv = NULL;
	int	argc = 0;
	char	**argv = NULL;
	struct cmd *cmd;
	size_t	i;
	int	is_config_cmd;
	int	j;

	xasprintf(&filename, "%s/pwmrc", ctx->dirname);

	fp = fopen(filename, "r");
	if (fp == NULL) {
		if (errno == ENOENT) {
			retval = 0;
		} else {
			warn("failed to open configuration file \"%s\"",
			    filename);
		}
		goto out;
	}

	for (lineno = 1;; lineno++) {
		/* read next line */
		is_config_cmd = 0;
		if (fgets(buf, sizeof (buf), fp) == NULL) {
			if (feof(fp)) {
				goto done;
			}
			warn("failed to read from configuration file \"%s\"",
			    filename);
			goto out;
		}
		if (strchr(buf, '\n') == NULL) {
			fprintf(stderr, "line %d too long\n", lineno);
			goto out;
		}

		/* tokenize line */
		switch (tok_tokenize(buf, &tokenc, &tokenv)) {
		case TOK_ERR_UNTERMINATED_QUOTE:
			fprintf(stderr, "unterminated quote in line %d\n",
			    lineno);
			if (!ctx->is_interactive) {
				goto out;
			}
			goto next;
		case TOK_ERR_TRAILING_BACKSLASH:
			fprintf(stderr, "trailing backslash in line %d\n",
			    lineno);
			if (!ctx->is_interactive) {
				goto out;
			}
			goto next;
		case TOK_ERR_INVALID_MACRO_NAME:
			fprintf(stderr, "invalid macro name in line %d\n",
			    lineno);
			if (!ctx->is_interactive) {
				goto out;
			}
			goto next;
		}

		/* expand macros */
		if (macro_expand_macros(ctx->macro_head, tokenc, tokenv, &argc,
		    &argv) != 0) {
			fprintf(stderr, "undefined macro in line %d\n", lineno);
			if (!ctx->is_interactive) {
				goto out;
			}
			goto next;
		}

		if (argc == 0) {
			/* empty line */
			goto next;
		}

		/* find and execute the command */
		cmd = cmd_match(argv[0]);
		for (i = 0; (cmd != NULL) && (i < COUNTOF(config_cmds)); i++) {
			if (strcmp(cmd->full_cmd, config_cmds[i]) == 0) {
				is_config_cmd = 1;
				break;
			}
		}
		if (!is_config_cmd) {
			fprintf(stderr, "unknown configuration command \"%s\""
			    " in line %d\n", argv[0], lineno);
			goto out;
		}
		if (cmd->cmd_func(ctx, argc, argv) != CMD_OK) {
			fprintf(stderr, "syntax error in line %d\n", lineno);
			goto out;
		}

next:
		for (j = 0; j < argc; j++) {
			free(argv[j]);
		}
		free(argv);
		argc = 0;
		argv = NULL;
		tok_free(tokenv);
		tokenc = 0;
		tokenv = NULL;
	}

done:
	retval = 0;

out:
	for (j = 0; j < argc; j++) {
		free(argv[j]);
	}
	free(argv);
	tok_free(tokenv);
	if (fp != NULL) {
		fclose(fp);
	}
	free(filename);

	return (retval);
}