#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <inttypes.h>

#include "main.h"
#include "uring.h"
#include "config.h"
#include "server.h"

#define ADDRSTRLEN (9 /*strlen("AF_INETX ")*/ + INET6_ADDRSTRLEN + 6 /*strlen(" 65535")*/ + 1)

struct server_local {
	struct sockaddr_in46 addr;
	char addrstr[ADDRSTRLEN];
	struct sockaddr_in46 peer;
	char peerstr[ADDRSTRLEN];
	struct uring_task task;
	struct list_head list;
};

/* FIXME: This can be a plain sockaddr_in46 */
struct server_remote {
	struct sockaddr_in46 addr;
	char addrstr[ADDRSTRLEN];
	struct list_head list;
};

struct server_proxy {
	struct sockaddr_in46 client;
	char clientstr[ADDRSTRLEN];
	struct sockaddr_in46 server;
	char serverstr[ADDRSTRLEN];
	struct uring_task task;
	char buf[4096];
	size_t len;
	struct list_head list;
};

void
server_refdump(struct server *server)
{
	struct server_local *local;
	struct server_proxy *proxy;

	uring_task_refdump(&server->task);
	list_for_each_entry(local, &server->locals, list)
		uring_task_refdump(&local->task);
	list_for_each_entry(proxy, &server->proxys, list)
		uring_task_refdump(&proxy->task);
}

static void
server_free(struct uring_task *task)
{
	struct server *scfg = container_of(task, struct server, task);

	fprintf(stderr, "Freeing scfg %s\n", scfg->name);
	list_del(&scfg->list);
	free(scfg->pretty_name);
	free(scfg->name);
	free(scfg);
}

void
server_delete(struct cfg *cfg, struct server *scfg)
{
	struct server_local *local, *ltmp;
	struct server_remote *remote, *rtmp;

	fprintf(stderr, "Removing server cfg: %s\n", scfg->name);

	list_for_each_entry_safe(remote, rtmp, &scfg->remotes, list) {
		list_del(&remote->list);
		free(remote);
	}

	list_for_each_entry_safe(local, ltmp, &scfg->locals, list) {
		uring_cancel(cfg, &local->task);
	}

	uring_task_put(cfg, &scfg->task);
}

void
server_delete_by_name(struct cfg *cfg, const char *name)
{
	struct server *scfg;

	if (!cfg || !name || name[0] == '\0')
		return;

	list_for_each_entry(scfg, &cfg->servers, list) {
		if (!strcmp(scfg->name, name)) {
			server_delete(cfg, scfg);
			return;
		}
	}
}

static char *
server_print_addr(struct sockaddr_in46 *addr, char *buf, size_t buflen)
{
	char abuf[ADDRSTRLEN];

	switch (addr->storage.ss_family) {
	case AF_INET:
		snprintf(buf, buflen, "AF_INET4 %s %u",
			 inet_ntop(addr->in4.sin_family, &addr->in4.sin_addr, abuf, sizeof(abuf)),
			 (unsigned)ntohs(addr->in4.sin_port));
		break;
	case AF_INET6:
		snprintf(buf, buflen, "AF_INET6 %s %u",
			 inet_ntop(addr->in6.sin6_family, &addr->in6.sin6_addr, abuf, sizeof(abuf)),
			 (unsigned)ntohs(addr->in6.sin6_port));
		break;
	default:
		snprintf(buf, buflen, "AF_UNKNOWN");
		break;
	}

	return buf;
}

static void
server_dump(struct server *scfg)
{
	struct server_local *local;
	struct server_remote *remote;

	fprintf(stderr, "Dumping server %s\n", scfg->name);
	switch (scfg->type) {
	case SERVER_TYPE_ANNOUNCE:
		fprintf(stderr, "  * Type: announce\n");
		break;
	case SERVER_TYPE_PROXY:
		fprintf(stderr, "  * Type: proxy\n");
		break;
	default:
		fprintf(stderr, "  * Type: unknown\n");
		break;
	}
	fprintf(stderr, "  * Pretty name: %s\n", scfg->pretty_name ? scfg->pretty_name : "<undefined>");
	fprintf(stderr, "  * Announce port: %" PRIu16 "\n", scfg->announce_port); 
	fprintf(stderr, "  * Listening ports:\n");
	list_for_each_entry(local, &scfg->locals, list)
		fprintf(stderr, "    * %s\n", local->addrstr);
	fprintf(stderr, "  * Remote ports:\n");
	list_for_each_entry(remote, &scfg->remotes, list)
		fprintf(stderr, "    * %s\n", remote->addrstr);
}

/*
struct server_active_proxy {
	struct sockaddr_in46 client;
	char clientstr[ADDRSTRLEN];
	struct sockaddr_in46 server;
	char serverstr[ADDRSTRLEN]
	struct uring_task task;
	char buf[4096];
	size_t len;
	struct list_head list;
};
*/

static void
server_proxy_free(struct uring_task *task)
{
	struct server_proxy *proxy = container_of(task, struct server_proxy, task);

	list_del(&proxy->list);
	free(proxy);
}

static void
server_proxy_connected(struct cfg *cfg, struct uring_task *task, int res)
{
	//struct server_proxy *proxy = container_of(task, struct server_proxy, task);

	fprintf(stderr, "%s: connected %i\n", __func__, res);
	return;
}

static void
server_local_free(struct uring_task *task)
{
	struct server_local *local = container_of(task, struct server_local, task);

	fprintf(stderr, "%s called: task 0x%p\n", __func__, task);

	list_del(&local->list);
	free(local);
}

static void
server_local_accept(struct cfg *cfg, struct uring_task *task, int res)
{
	struct server_local *local = container_of(task, struct server_local, task);
	struct server *scfg = container_of(task->parent, struct server, task);
	struct server_proxy *proxy;
	struct server_remote *remote;
	int sfd;

	fprintf(stderr, "%s called: task 0x%p and res %i\n", __func__, task, res);
	fprintf(stderr, "%s called: scfg name is %s\n", __func__, scfg->name);

	if (task->dead) {
		fprintf(stderr, "Task dead!\n");
		uring_task_put(cfg, task);
		return;
	}

	if (res < 0) {
		fprintf(stderr, "%s: result was %i\n", __func__, res);
		goto out;
	}

	server_print_addr(&local->peer, local->peerstr, sizeof(local->peerstr));
	fprintf(stderr, "%s: incoming proxy connection: %s -> %s\n", scfg->name, local->peerstr, local->addrstr);

	if (list_empty(&scfg->remotes)) {
		error("scfg->remotes empty!\n");
		goto out;
	}

	proxy = zmalloc(sizeof(*proxy));
	if (!proxy) {
		perror("malloc");
		uring_close(cfg, NULL, res, NULL);
		goto out;
	}

	remote = list_first_entry(&scfg->remotes, struct server_remote, list);
	fprintf(stderr, "%s: attempting proxy connection to %s (len %u)\n", scfg->name, remote->addrstr, remote->addr.addrlen);

	sfd = socket(remote->addr.storage.ss_family, SOCK_STREAM, 0);
	if (sfd < 0) {
		perror("socket");
		uring_close(cfg, NULL, res, NULL);
		goto out;
	}

	proxy->client = local->peer;
	memcpy(proxy->clientstr, local->peerstr, sizeof(proxy->clientstr));
	uring_task_init(&proxy->task, "proxy", &scfg->task, server_proxy_free);
	uring_task_set_fd(&proxy->task, sfd);
	list_add(&proxy->list, &scfg->proxys);
	uring_connect(cfg, &proxy->task, &remote->addr, server_proxy_connected);

out:
	uring_accept(cfg, &local->task, &local->peer, server_local_accept);
}

static bool
server_local_open(struct cfg *cfg, struct server *scfg, struct server_local *local)
{
	int sfd;
	int enable = 1;
	int r;

	sfd = socket(local->addr.storage.ss_family, SOCK_STREAM, 0);
	if (sfd < 0) {
		perror("socket");
		goto out;
	}

	if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(enable)) < 0) {
		perror("setsockopt");
		goto out;
	}

	r = bind(sfd, (struct sockaddr *)&local->addr.storage, local->addr.addrlen);
	if (r < 0) {
		perror("bind");
		goto out;
	}

	r = listen(sfd, 100);
	if (r < 0) {
		perror("listen");
		goto out;
	}

	uring_task_set_fd(&local->task, sfd);
	uring_accept(cfg, &local->task, &local->peer, server_local_accept);
	fprintf(stderr, "** Opened listening socket: %s\n", local->addrstr);
	return true;

out:
	if (sfd >= 0)
		close(sfd);
	return false;
}

bool
server_commit(struct cfg *cfg, struct server *scfg)
{
	struct server_local *local;

	/* FIXME: config, dont reread config if server running, make sure fd is available before this is called */
	/* FIXME: verify correct cfg */
	server_dump(scfg);

	list_for_each_entry(local, &scfg->locals, list) {
		server_local_open(cfg, scfg, local);
	}
	return true;
}

bool
server_add_remote(struct cfg *cfg, struct server *scfg, struct sockaddr_in46 *addr)
{
	struct server_remote *remote;

	if (!scfg || !addr)
		return false;

	remote = zmalloc(sizeof(*remote));
	if (!remote)
		return false;

	remote->addr.storage = addr->storage;
	remote->addr.addrlen = addr->addrlen;
	server_print_addr(&remote->addr, remote->addrstr, sizeof(remote->addrstr));
	list_add(&remote->list, &scfg->remotes);
	return true;
}

bool
server_add_local(struct cfg *cfg, struct server *scfg, struct sockaddr_in46 *addr)
{
	struct server_local *local;

	if (!scfg || !addr)
		return false;

	local = zmalloc(sizeof(*local));
	if (!local)
		return false;

	local->addr.storage = addr->storage;
	local->addr.addrlen = addr->addrlen;
	uring_task_init(&local->task, "local", &scfg->task, server_local_free);
	server_print_addr(&local->addr, local->addrstr, sizeof(local->addrstr));
	fprintf(stderr, "Adding local: %s\n", local->addrstr);
	list_add(&local->list, &scfg->locals);
	return true;
}

bool
server_set_port(struct cfg *cfg, struct server *scfg, uint16_t port)
{
	if (!scfg || scfg->announce_port != 0)
		return false;

	scfg->announce_port = htons(port);
	return true;
}

bool
server_set_type(struct cfg *cfg, struct server *scfg, enum server_type type)
{
	if (!scfg || scfg->type != SERVER_TYPE_UNDEFINED)
		return false;

	switch (type) {
	case SERVER_TYPE_ANNOUNCE:
		scfg->type = SERVER_TYPE_ANNOUNCE;
		break;
	case SERVER_TYPE_PROXY:
		scfg->type = SERVER_TYPE_PROXY;
		break;
	default:
		return false;
	}

	return true;
}

bool
server_set_pretty_name(struct cfg *cfg, struct server *scfg, const char *pretty_name)
{
	if (!pretty_name || pretty_name[0] == '\0' || !scfg || scfg->pretty_name)
		return false;

	scfg->pretty_name = strdup(pretty_name);
	if (!scfg->pretty_name)
		return false;

	return true;
}

struct server *
server_new(struct cfg *cfg, const char *name)
{
	struct server *scfg;

	list_for_each_entry(scfg, &cfg->servers, list) {
		if (strcmp(name, scfg->name))
			continue;
		debug(2, "Server already exists: %s\n", name);
		return scfg;
	}

	debug(2, "Would add server cfg: %s\n", name);
	scfg = zmalloc(sizeof(*scfg));
	if (!scfg) {
		error("malloc");
		return NULL;
	}

	scfg->type = SERVER_TYPE_UNDEFINED;
	scfg->name = strdup(name);
	scfg->running = false;
	uring_task_init(&scfg->task, "scfg", &cfg->task, server_free);
	list_init(&scfg->remotes);
	list_init(&scfg->locals);
	list_init(&scfg->proxys);
	list_add(&scfg->list, &cfg->servers);

	return scfg;
}