/* This file is part of Eclat.
   Copyright (C) 2012 Sergey Poznyakoff.
 
   Eclat is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.
 
   Eclat is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
 
   You should have received a copy of the GNU General Public License
   along with Eclat.  If not, see <http://www.gnu.org/licenses/>. */

#include "eclat.h"

struct config_finish_hook_entry
{
	struct config_finish_hook_entry *next;
	config_finish_hook_t fun;
	void *data;
};

static struct config_finish_hook_entry *cfh_head, *cfh_tail;
	
void
add_config_finish_hook(config_finish_hook_t fun, void *data)
{
	struct config_finish_hook_entry *ent = grecs_malloc(sizeof(*ent));
	ent->next = NULL;
	ent->fun = fun;
	ent->data = data;
	if (cfh_tail)
		cfh_tail->next = ent;
	else
		cfh_head = ent;
	cfh_tail = ent;
}

int
run_config_finish_hooks()
{
	struct config_finish_hook_entry *p;
	int rc = 0;
	
	for (p = cfh_head; p; p = p->next)
		rc |= p->fun(p->data);
	return rc;
}

/* Translation table: region -> endpoint.  Its elements are of
   struct ec2_param type. */
struct grecs_symtab *ec2_regtab; 

char *
region_to_endpoint(const char *region)
{
	struct ec2_param *p, key;

	key.name = (char*) region;
	p = grecs_symtab_lookup_or_install(ec2_regtab, &key, NULL);
	return p ? p->value : NULL;
}

static int
cb_region(enum grecs_callback_command cmd,
	  grecs_locus_t *locus,
	  void *varptr,
	  grecs_value_t *value,
	  void *cb_data)
{
	struct ec2_param *p, key;
	int install = 1;
	
	if (cmd != grecs_callback_set_value) {
		grecs_error(locus, 0, "Unexpected block statement");
		return 1;
	}
	if (!value || value->type != GRECS_TYPE_ARRAY || value->v.arg.c != 2) {
		grecs_error(locus, 0, "expected two strings");
		return 1;
	}
	if (value->v.arg.v[0]->type != GRECS_TYPE_STRING ||
	    value->v.arg.v[1]->type != GRECS_TYPE_STRING) {
		grecs_error(locus, 0, "expected two strings");
		return 1;
	}

	key.name = value->v.arg.v[0]->v.string;
	p = grecs_symtab_lookup_or_install(ec2_regtab, &key, &install);
	if (!install)
		free(p->value); /* FIXME: Redefinition warning */
	p->value = grecs_strdup(value->v.arg.v[1]->v.string);
	return 0;
}

static int
cb_format(enum grecs_callback_command cmd,
	  grecs_locus_t *locus,
	  void *varptr,
	  grecs_value_t *value,
	  void *cb_data)
{
	if (cmd != grecs_callback_set_value) {
		grecs_error(locus, 0, "Unexpected block statement");
		return 1;
	}
	if (!value || value->type != GRECS_TYPE_ARRAY || value->v.arg.c != 2) {
		grecs_error(locus, 0, "expected two strings");
		return 1;
	}
	if (value->v.arg.v[0]->type != GRECS_TYPE_STRING ||
	    value->v.arg.v[1]->type != GRECS_TYPE_STRING) {
		grecs_error(locus, 0, "expected two strings");
		return 1;
	}
	set_command_format(value->v.arg.v[0]->v.string,
			   value->v.arg.v[1]->v.string,
			   &value->v.arg.v[1]->locus);
}

static int
cb_define_format(enum grecs_callback_command cmd,
		 grecs_locus_t *locus,
		 void *varptr,
		 grecs_value_t *value,
		 void *cb_data)
{
	if (cmd != grecs_callback_set_value) {
		grecs_error(locus, 0, "Unexpected block statement");
		return 1;
	}
	if (!value || value->type != GRECS_TYPE_ARRAY || value->v.arg.c != 2) {
		grecs_error(locus, 0, "expected two strings");
		return 1;
	}
	if (value->v.arg.v[0]->type != GRECS_TYPE_STRING ||
	    value->v.arg.v[1]->type != GRECS_TYPE_STRING) {
		grecs_error(locus, 0, "expected two strings");
		return 1;
	}

	define_format(value->v.arg.v[0]->v.string,
		      value->v.arg.v[1]->v.string,
		      &value->v.arg.v[1]->locus);
	return 0;
}

static struct grecs_keyword eclat_kw[] = {
	{ "default-endpoint", "hostname",
	  "Set default EC2 endpoint",
	  grecs_type_string, GRECS_DFLT, &endpoint },
	{ "region", "<name: string> <endpoint: string>",
	  "Define a region",
	  grecs_type_string, GRECS_MULT, NULL, 0, cb_region }, 
	{ "access-file", "file",
	  "Specify a file containing `accessID:accessKey' pairs",
	  grecs_type_string, GRECS_DFLT, &access_file_name },
	{ "default-region", "name",
	  "Define default AWS region",
	  grecs_type_string, GRECS_DFLT, &region_name },
	{ "format", "<command: string> <format: string>",
	  "Set default format for <command>",
	  grecs_type_string, GRECS_MULT, NULL, 0, cb_format },
	{ "define-format", "<name: string> <format: string>",
	  "Define a named format",
	  grecs_type_string, GRECS_MULT, NULL, 0, cb_define_format },
	{ "format-file", "file", "Read format from <file>",
	  grecs_type_string, GRECS_DFLT, &format_file },
	{ NULL }
};
	
void
config_help()
{
	static char docstring[] =
		N_("Configuration file structure for eclat.\n"
		   "For more information, use `info eclat configuration'.");
	grecs_print_docstring(docstring, 0, stdout);
	grecs_print_statement_array(eclat_kw, 1, 0, stdout);
}

static void
grecs_print_diag(grecs_locus_t const *locus, int err, int errcode,
		 const char *msg)
{
	diag(locus, err ? NULL : "warning", "%s", msg);
}

void
config_init()
{
	grecs_include_path_setup(DEFAULT_VERSION_INCLUDE_DIR,
				 DEFAULT_INCLUDE_DIR, NULL);
	grecs_preprocessor = DEFAULT_PREPROCESSOR;
	grecs_log_to_stderr = 1;
	grecs_adjust_string_locations = 1;
	grecs_print_diag_fun = grecs_print_diag;

	ec2_regtab = grecs_symtab_create_default(sizeof(struct ec2_param));
}

void
config_finish(struct grecs_node *tree)
{
	struct grecs_node *node;

	grecs_tree_reduce(tree, eclat_kw, GRECS_AGGR);
	if (debug_level(ECLAT_DEBCAT_CONF)) {
		grecs_print_node(tree, GRECS_NODE_FLAG_DEFAULT, stderr);
		fputc('\n', stdout);
	}
	if (grecs_tree_process(tree, eclat_kw))
		exit(EX_CONFIG);
	if (grecs_error_count || run_config_finish_hooks())
		exit(EX_CONFIG);
}