/* This file is part of genrc
Copyryght (C) 2018 Sergey Poznyakoff
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
*/
#include "genrc.h"

typedef	struct grecs_node *(*GRECS_PARSER_FUNC)(const char *, int);

struct config_pid_closure {
	struct genrc_pid_closure generic;
	char *filename;
	char *fqrn;
	GRECS_PARSER_FUNC parser;
};

static int
pid_config_get(GENRC_PID_CLOSURE *clos, PIDLIST *plist)
{
	struct config_pid_closure *config_clos =
		(struct config_pid_closure *)clos;
	struct grecs_node *tree, *node;
	pid_t pid;
	
	grecs_parser_fun = config_clos->parser;
	tree = grecs_parse(config_clos->filename);
	if (!tree)
		exit(1);
	node = grecs_find_node(tree, config_clos->fqrn);
	if (!node)
		usage_error("%s: relation %s not found",
			    config_clos->filename,
			    config_clos->fqrn);
	if (node->type != grecs_node_stmt)
		usage_error("%s: relation %s is not a statement",
			    config_clos->filename,
			    config_clos->fqrn);
	if (node->v.value->type != GRECS_TYPE_STRING)
		usage_error("%s: relation %s is not a string",
			    config_clos->filename,
			    config_clos->fqrn);

	pid = file_read_pid(node->v.value->v.string);
	grecs_tree_free(tree);

	if (pid == -1)
		return -1;
	if (pid > 0)
		pidlist_add(plist, pid);
	
	return 0;
}

struct langtab {
	char const *lang_name;
	GRECS_PARSER_FUNC lang_parser;
};

static struct langtab langtab[] = {
	{ "GRECS", grecs_grecs_parser },
	{ "META1", grecs_meta1_parser },
	{ "BIND",  grecs_bind_parser },
	{ "DHCPD", grecs_dhcpd_parser },
	{ "GIT",   grecs_git_parser },
	{ "PATH",  grecs_path_parser },
	{ NULL, NULL }
};

static GRECS_PARSER_FUNC
find_parser(const char *lang)
{
	struct langtab *p;
	for (p = langtab; p->lang_name; p++)
		if (strcmp(p->lang_name, lang) == 0)
			break;
	return p->lang_parser;
}

GENRC_PID_CLOSURE *
genrc_pid_config_init(int argc, char **argv)
{
	struct config_pid_closure *clos;
	
	if (argc != 4)
		usage_error("expected format: CONFIG:<LANG>:<FILE>:<FQRN>");

	clos = xmalloc(sizeof(*clos));
	clos->generic.pid = pid_config_get;
	clos->parser = find_parser(argv[1]);
	if (!clos->parser)	
		usage_error("%s: unsupported parser type", argv[1]);
	clos->filename = xstrdup(argv[2]);
	clos->fqrn = xstrdup(argv[3]);
	return (GENRC_PID_CLOSURE *) clos;
}