/* Copyright (c) 2015-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "ioloop.h"
#include "mail-namespace.h"
#include "mail-storage.h"
#include "mail-storage-private.h"
#include "notify-plugin.h"
#include "str.h"

#include "push-notification-drivers.h"
#include "push-notification-events.h"
#include "push-notification-events-rfc5423.h"
#include "push-notification-plugin.h"
#include "push-notification-triggers.h"
#include "push-notification-txn-mbox.h"
#include "push-notification-txn-msg.h"

#define PUSH_NOTIFICATION_CONFIG "push_notification_driver"
#define PUSH_NOTIFICATION_CONFIG_OLD "push_notification_backend"
#define PUSH_NOTIFICATION_EVENT_FINISHED "push_notification_finished"

#define PUSH_NOTIFICATION_USER_CONTEXT(obj) \
	MODULE_CONTEXT_REQUIRE(obj, push_notification_user_module)
static MODULE_CONTEXT_DEFINE_INIT(push_notification_user_module,
				  &mail_user_module_register);
static struct ioloop *main_ioloop;

struct event_category event_category_push_notification = {
	.name = "push-notification",
};

struct event_category *push_notification_get_event_category(void)
{
	return &event_category_push_notification;
}

struct push_notification_event *push_notification_get_event_messagenew(void)
{
	return &push_notification_event_messagenew;
}

static void
push_notification_transaction_init(struct push_notification_txn *ptxn)
{
	struct push_notification_driver_txn *dtxn;
	struct push_notification_driver_user *duser;
	struct mail_storage *storage;

	if (ptxn->initialized)
		return;

	ptxn->initialized = TRUE;

	storage = mailbox_get_storage(ptxn->mbox);
	if (storage->user->autocreated &&
		(strcmp(storage->name, "raw") == 0)) {
		/* No notifications for autocreated raw users */
		return;
	}

	array_foreach_elem(&ptxn->puser->driverlist->drivers, duser) {
		dtxn = p_new(ptxn->pool, struct push_notification_driver_txn, 1);
		dtxn->duser = duser;
		dtxn->ptxn = ptxn;

		if ((dtxn->duser->driver->v.begin_txn == NULL) ||
			dtxn->duser->driver->v.begin_txn(dtxn)) {
			array_push_back(&ptxn->drivers, &dtxn);
		}
	}
}

static struct push_notification_txn *
push_notification_transaction_create(struct mailbox *box,
				     struct mailbox_transaction_context *t)
{
	pool_t pool;
	struct push_notification_txn *ptxn;
	struct mail_storage *storage;

	pool = pool_alloconly_create("push notification transaction", 2048);

	ptxn = p_new(pool, struct push_notification_txn, 1);
	ptxn->mbox = box;
	storage = mailbox_get_storage(box);
	ptxn->muser = mail_storage_get_user(storage);
	ptxn->pool = pool;
	ptxn->puser = PUSH_NOTIFICATION_USER_CONTEXT(ptxn->muser);
	ptxn->t = t;
	ptxn->trigger = PUSH_NOTIFICATION_EVENT_TRIGGER_NONE;
	ptxn->event = event_create(ptxn->muser->event);
	event_add_category(ptxn->event, &event_category_push_notification);
	event_set_append_log_prefix(ptxn->event, "push-notification: ");
	p_array_init(&ptxn->drivers, pool, 4);

	return ptxn;
}

static void
push_notification_transaction_end(struct push_notification_txn *ptxn,
				  bool success)
{
	struct push_notification_driver_txn *dtxn;

	if (ptxn->initialized) {
		array_foreach_elem(&ptxn->drivers, dtxn) {
			if (dtxn->duser->driver->v.end_txn != NULL)
				dtxn->duser->driver->v.end_txn(dtxn, success);
		}
	}

	if (success && ptxn->trigger != 0) {
		struct event_passthrough *e = event_create_passthrough(ptxn->event)->
			set_name(PUSH_NOTIFICATION_EVENT_FINISHED);
		/* Emit event */
		e_debug(e->event(), "Push notification transaction completed");
	}

	event_unref(&ptxn->event);
	pool_unref(&ptxn->pool);
}

static void
push_notification_transaction_commit(
	void *txn, struct mail_transaction_commit_changes *changes)
{
	struct push_notification_txn *ptxn = (struct push_notification_txn *)txn;
	struct ioloop *prev_ioloop = current_ioloop;

	/* Make sure we're not in just any random ioloop, which could get
	   destroyed soon. This way the push-notification drivers can do async
	   operations that finish in the main ioloop. */
	io_loop_set_current(main_ioloop);
	if (changes == NULL)
		push_notification_txn_mbox_end(ptxn);
	else
		push_notification_txn_msg_end(ptxn, changes);

	push_notification_transaction_end(ptxn, TRUE);
	io_loop_set_current(prev_ioloop);
}

static void push_notification_mailbox_create(struct mailbox *box)
{
	struct push_notification_txn *ptxn;

	ptxn = push_notification_transaction_create(box, NULL);
	push_notification_transaction_init(ptxn);
	push_notification_trigger_mbox_create(ptxn, box, NULL);
	push_notification_transaction_commit(ptxn, NULL);
}

static void
push_notification_mailbox_delete(void *txn ATTR_UNUSED, struct mailbox *box)
{
	struct push_notification_txn *ptxn;

	ptxn = push_notification_transaction_create(box, NULL);
	push_notification_transaction_init(ptxn);
	push_notification_trigger_mbox_delete(ptxn, box, NULL);
	push_notification_transaction_commit(ptxn, NULL);
}

static void
push_notification_mailbox_rename(struct mailbox *src, struct mailbox *dest)
{
	struct push_notification_txn *ptxn;

	ptxn = push_notification_transaction_create(dest, NULL);
	push_notification_transaction_init(ptxn);
	push_notification_trigger_mbox_rename(ptxn, src, dest, NULL);
	push_notification_transaction_commit(ptxn, NULL);
}

static void
push_notification_mailbox_subscribe(struct mailbox *box, bool subscribed)
{
	struct push_notification_txn *ptxn;

	ptxn = push_notification_transaction_create(box, NULL);
	push_notification_transaction_init(ptxn);
	push_notification_trigger_mbox_subscribe(ptxn, box, subscribed, NULL);
	push_notification_transaction_commit(ptxn, NULL);
}

static void push_notification_mail_save(void *txn, struct mail *mail)
{
	struct push_notification_txn *ptxn = txn;

	push_notification_transaction_init(ptxn);

	/* POST_SESSION means MTA delivery. */
	if ((mail->box->flags & MAILBOX_FLAG_POST_SESSION) != 0)
		push_notification_trigger_msg_save_new(ptxn, mail, NULL);
	else
		push_notification_trigger_msg_save_append(ptxn, mail, NULL);
}

static void
push_notification_mail_copy(void *txn, struct mail *src ATTR_UNUSED,
			    struct mail *dest)
{
	push_notification_mail_save(txn, dest);
}

static void push_notification_mail_expunge(void *txn, struct mail *mail)
{
	struct push_notification_txn *ptxn = txn;

	push_notification_transaction_init(ptxn);
	push_notification_trigger_msg_save_expunge(txn, mail, NULL);
}

static void
push_notification_mail_update_flags(void *txn, struct mail *mail,
				    enum mail_flags old_flags)
{
	struct push_notification_txn *ptxn = txn;

	push_notification_transaction_init(ptxn);
	push_notification_trigger_msg_flag_change(txn, mail, NULL, old_flags);
}

static void
push_notification_mail_update_keywords(void *txn, struct mail *mail,
				       const char *const *old_keywords)
{
	struct push_notification_txn *ptxn = txn;

	push_notification_transaction_init(ptxn);
	push_notification_trigger_msg_keyword_change(
		txn, mail, NULL, old_keywords);
}

static void *
push_notification_transaction_begin(struct mailbox_transaction_context *t)
{
	return push_notification_transaction_create(
		mailbox_transaction_get_mailbox(t), t);
}

static void push_notification_transaction_rollback(void *txn)
{
	struct push_notification_txn *ptxn = txn;

	push_notification_transaction_end(ptxn, FALSE);
}

static void
push_notification_config_init(const char *config_name, struct mail_user *user,
			      struct push_notification_driver_list *dlist)
{
	struct push_notification_driver_user *duser;
	const char *env;
	unsigned int i;
	string_t *root_name;

	root_name = t_str_new(32);
	str_append(root_name, config_name);

	for (i = 2;; i++) {
		env = mail_user_plugin_getenv(user, str_c(root_name));
		if ((env == NULL) || (*env == '\0'))
			break;

		if (push_notification_driver_init(
			user, env, user->pool, &duser) < 0)
			break;

		/* Add driver. */
		array_push_back(&dlist->drivers, &duser);

		str_truncate(root_name, strlen(config_name));
		str_printfa(root_name, "%d", i);
	}
}

static struct push_notification_driver_list *
push_notification_driver_list_init(struct mail_user *user)
{
	struct push_notification_driver_list *dlist;

	dlist = p_new(user->pool, struct push_notification_driver_list, 1);
	p_array_init(&dlist->drivers, user->pool, 4);

	push_notification_config_init(PUSH_NOTIFICATION_CONFIG, user, dlist);

	if (array_is_empty(&dlist->drivers)) {
		/* Support old configuration (it was available at time initial
		   OX driver was first released). */
		push_notification_config_init(PUSH_NOTIFICATION_CONFIG_OLD,
					      user, dlist);
	}
	return dlist;
}

static void push_notification_user_deinit(struct mail_user *user)
{
	struct push_notification_user *puser =
		PUSH_NOTIFICATION_USER_CONTEXT(user);
	struct push_notification_driver_list *dlist = puser->driverlist;
	struct push_notification_driver_user *duser;
	struct ioloop *prev_ioloop = current_ioloop;

	/* Make sure we're in the main ioloop, so if the deinit/cleanup moves
	   any I/Os or timeouts they won't get moved to some temporary ioloop.
	 */
	io_loop_set_current(main_ioloop);

	array_foreach_elem(&dlist->drivers, duser) {
		if (duser->driver->v.deinit != NULL)
			duser->driver->v.deinit(duser);
		if (duser->driver->v.cleanup != NULL)
			duser->driver->v.cleanup();
	}
	io_loop_set_current(prev_ioloop);

	puser->module_ctx.super.deinit(user);
}

static void push_notification_user_created(struct mail_user *user)
{
	struct mail_user_vfuncs *v = user->vlast;
	struct push_notification_user *puser;

	puser = p_new(user->pool, struct push_notification_user, 1);
	puser->module_ctx.super = *v;
	user->vlast = &puser->module_ctx.super;
	v->deinit = push_notification_user_deinit;
	puser->driverlist = push_notification_driver_list_init(user);

	MODULE_CONTEXT_SET(user, push_notification_user_module, puser);
}

/* Plugin interface. */

const char *push_notification_plugin_version = DOVECOT_ABI_VERSION;
const char *push_notification_plugin_dependencies[] = { "notify", NULL };

extern struct push_notification_driver push_notification_driver_dlog;
extern struct push_notification_driver push_notification_driver_ox;

static struct notify_context *push_notification_ctx;

static const struct notify_vfuncs push_notification_vfuncs = {
	/* Mailbox Events */
	.mailbox_create = push_notification_mailbox_create,
	.mailbox_delete_commit = push_notification_mailbox_delete,
	.mailbox_rename = push_notification_mailbox_rename,
	.mailbox_set_subscribed = push_notification_mailbox_subscribe,

	/* Mail Events */
	.mail_copy = push_notification_mail_copy,
	.mail_save = push_notification_mail_save,
	.mail_expunge = push_notification_mail_expunge,
	.mail_update_flags = push_notification_mail_update_flags,
	.mail_update_keywords = push_notification_mail_update_keywords,
	.mail_transaction_begin = push_notification_transaction_begin,
	.mail_transaction_commit = push_notification_transaction_commit,
	.mail_transaction_rollback = push_notification_transaction_rollback,
};

static struct mail_storage_hooks push_notification_storage_hooks = {
	.mail_user_created = push_notification_user_created,
};

void push_notification_plugin_init(struct module *module)
{
	push_notification_ctx = notify_register(&push_notification_vfuncs);
	mail_storage_hooks_add(module, &push_notification_storage_hooks);

	push_notification_driver_register(&push_notification_driver_dlog);
	push_notification_driver_register(&push_notification_driver_ox);

	push_notification_event_register_rfc5423_events();
	main_ioloop = current_ioloop;
	i_assert(main_ioloop != NULL);
}

void push_notification_plugin_deinit(void)
{
	push_notification_driver_unregister(&push_notification_driver_dlog);
	push_notification_driver_unregister(&push_notification_driver_ox);

	push_notification_event_unregister_rfc5423_events();
	mail_storage_hooks_remove(&push_notification_storage_hooks);
	notify_unregister(push_notification_ctx);
}