/* Copyright (c) 2002-2013 Pigeonhole authors, see the included COPYING file
 */

#include "lib.h"
#include "hash.h"

#include "sieve-common.h"
#include "sieve-extensions.h"

#include "ext-environment-common.h"

struct ext_environment_context {
	HASH_TABLE(const char *,
		   const struct sieve_environment_item *) environment_items;
};

/*
 * Core environment items
 */

static const struct sieve_environment_item *core_env_items[] = {
	&domain_env_item,
	&host_env_item,
	&location_env_item,
	&phase_env_item,
	&name_env_item,
	&version_env_item
};

static unsigned int core_env_items_count = N_ELEMENTS(core_env_items);

/*
 * Registration
 */

static void ext_environment_item_register
(struct ext_environment_context *ectx,
	const struct sieve_environment_item *item)
{
	hash_table_insert(ectx->environment_items, item->name, item);
}

void sieve_ext_environment_item_register
(const struct sieve_extension *ext, const struct sieve_environment_item *item)
{
	struct ext_environment_context *ectx =
		(struct ext_environment_context *) ext->context;

	ext_environment_item_register(ectx, item);
}

/*
 * Initialization
 */

bool ext_environment_init
(const struct sieve_extension *ext ATTR_UNUSED, void **context)
{
	struct ext_environment_context *ectx =
		i_new(struct ext_environment_context, 1);

	unsigned int i;

	hash_table_create
		(&ectx->environment_items, default_pool, 0, str_hash, strcmp);

	for ( i = 0; i < core_env_items_count; i++ ) {
		ext_environment_item_register(ectx, core_env_items[i]);
	}

	*context = (void *) ectx;

	return TRUE;
}

void ext_environment_deinit(const struct sieve_extension *ext)
{
	struct ext_environment_context *ectx =
		(struct ext_environment_context *) ext->context;

	hash_table_destroy(&ectx->environment_items);
	i_free(ectx);
}


/*
 * Retrieval
 */

const char *ext_environment_item_get_value
(const struct sieve_extension *ext, const char *name,
	const struct sieve_script_env *senv)
{
	struct ext_environment_context *ectx =
		(struct ext_environment_context *) ext->context;
	const struct sieve_environment_item *item =
		hash_table_lookup(ectx->environment_items, name);

	if ( item == NULL )
		return NULL;

	if ( item->value != NULL )
		return item->value;

	if ( item->get_value != NULL )
		return item->get_value(ext->svinst, senv);

	return NULL;
}

/*
 * Default environment items
 */

/* "domain":
 *
 *   The primary DNS domain associated with the Sieve execution context, usually
 *   but not always a proper suffix of the host name.
 */

static const char *envit_domain_get_value
(struct sieve_instance *svinst,
	const struct sieve_script_env *senv ATTR_UNUSED)
{
	return svinst->domainname;
}

const struct sieve_environment_item domain_env_item = {
	.name = "domain",
	.get_value = envit_domain_get_value,
};

/* "host":
 *
 *   The fully-qualified domain name of the host where the Sieve script is
 *   executing.
 */

static const char *envit_host_get_value
(struct sieve_instance *svinst,
	const struct sieve_script_env *senv ATTR_UNUSED)
{
	return svinst->hostname;
}

const struct sieve_environment_item host_env_item = {
	.name = "host",
	.get_value = envit_host_get_value,
};

/* "location":
 *
 *   Sieve evaluation can be performed at various different points as messages
 *   are processed. This item provides additional information about the type of
 *   service that is evaluating the script.  Possible values are:
 *    "MTA" - the Sieve script is being evaluated by a Message Transfer Agent
 *    "MDA" - evaluation is being performed by a Mail Delivery Agent
 *    "MUA" - evaluation is being performed by a Mail User Agent (right...)
 *    "MS"  - evaluation is being performed by a Message Store
 */

static const char *envit_location_get_value
(struct sieve_instance *svinst,
	const struct sieve_script_env *senv ATTR_UNUSED)
{
	switch ( svinst->env_location ) {
	case SIEVE_ENV_LOCATION_MDA:
		return "MDA";
	case SIEVE_ENV_LOCATION_MTA:
		return "MTA";
	case SIEVE_ENV_LOCATION_MS:
		return "MS";
	default:
		break;
	}
	return NULL;
}

const struct sieve_environment_item location_env_item = {
	.name = "location",
	.get_value = envit_location_get_value
};

/* "phase":
 *
 *   The point relative to final delivery where the Sieve script is being
 *   evaluated.  Possible values are "pre", "during", and "post", referring
 *   respectively to processing before, during, and after final delivery has
 *   taken place.
 */

static const char *envit_phase_get_value
(struct sieve_instance *svinst,
	const struct sieve_script_env *senv ATTR_UNUSED)
{
	switch ( svinst->delivery_phase ) {
	case SIEVE_DELIVERY_PHASE_PRE:
		return "pre";
	case SIEVE_DELIVERY_PHASE_DURING:
		return "during";
	case SIEVE_DELIVERY_PHASE_POST:
		return "post";
	default:
		break;
	}
	return NULL;
}

const struct sieve_environment_item phase_env_item = {
	.name = "phase",
	.get_value = envit_phase_get_value
};

/* "name":
 *
 *  The product name associated with the Sieve interpreter.
 */

const struct sieve_environment_item name_env_item = {
	.name = "name",
	.value = PIGEONHOLE_NAME" Sieve"
};

/* "version":
 *
 * The product version associated with the Sieve interpreter. The meaning of the
 * product version string is product-specific and should always be considered
 * in the context of the product name given by the "name" item.
 */

const struct sieve_environment_item version_env_item = {
	.name = "version",
	.value = PIGEONHOLE_VERSION,
};