#include "cryptopkt.h"
#include "dns.h"
#include "jsonrpc.h"
#include "lightningd.h"
#include "log.h"
#include "peer.h"
#include <ccan/io/io.h>
#include <ccan/list/list.h>
#include <ccan/noerr/noerr.h>
#include <ccan/tal/str/str.h>
#include <ccan/tal/tal.h>
#include <errno.h>
#include <netinet/in.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>

struct json_connecting {
	/* This owns us, so we're freed after command_fail or command_success */
	struct command *cmd;
	const char *name, *port;
};

/* Send and receive (encrypted) hello message. */
static struct io_plan *peer_test_check(struct io_conn *conn, struct peer *peer)
{
	if (peer->inpkt->pkt_case != PKT__PKT_ERROR)
		fatal("Bad packet type %u", peer->inpkt->pkt_case);
	if (!peer->inpkt->error->problem
	    || strcmp(peer->inpkt->error->problem, "hello") != 0)
		fatal("Bad packet '%.6s'", peer->inpkt->error->problem);
	log_info(peer->log, "Successful hello!");

	/* Sleep forever... */
	return io_wait(conn, peer, io_close_cb, NULL);
}

static struct io_plan *peer_test_read(struct io_conn *conn, struct peer *peer)
{
	return peer_read_packet(conn, peer, peer_test_check);
}

static struct io_plan *peer_test(struct io_conn *conn, struct peer *peer)
{
	Error err = ERROR__INIT;
	Pkt pkt = PKT__INIT;
	pkt.pkt_case = PKT__PKT_ERROR;
	pkt.error = &err;
	err.problem = "hello";
	return peer_write_packet(conn, peer, &pkt, peer_test_read);
}

static void destroy_peer(struct peer *peer)
{
	list_del_from(&peer->dstate->peers, &peer->list);
}

static struct peer *new_peer(struct lightningd_state *dstate,
			     struct io_conn *conn,
			     int addr_type, int addr_protocol,
			     enum state_input offer_anchor,
			     const char *in_or_out)
{
	struct peer *peer = tal(dstate, struct peer);

	assert(offer_anchor == CMD_OPEN_WITH_ANCHOR
	       || offer_anchor == CMD_OPEN_WITHOUT_ANCHOR);

	/* FIXME: Stop listening if too many peers? */
	list_add(&dstate->peers, &peer->list);

	peer->dstate = dstate;
	peer->addr.type = addr_type;
	peer->addr.protocol = addr_protocol;
	peer->io_data = NULL;
	peer->secrets = NULL;
	list_head_init(&peer->watches);

	peer->us.offer_anchor = offer_anchor;
	peer->us.locktime = dstate->config.rel_locktime;
	peer->us.mindepth = dstate->config.anchor_confirms;
	/* FIXME: Make this dynamic. */
	peer->us.commit_fee = dstate->config.commitment_fee;

	/* FIXME: Attach IO logging for this peer. */
	tal_add_destructor(peer, destroy_peer);

	peer->addr.addrlen = sizeof(peer->addr.saddr);
	if (getpeername(io_conn_fd(conn), &peer->addr.saddr.s,
			&peer->addr.addrlen) != 0) {
		log_unusual(dstate->base_log,
			    "Could not get address for peer: %s",
			    strerror(errno));
		return tal_free(peer);
	}

	peer->log = new_log(peer, dstate->log_record, "%s%s:%s:",
			    log_prefix(dstate->base_log), in_or_out,
			    netaddr_name(peer, &peer->addr));
	return peer;
}

static struct io_plan *peer_connected_out(struct io_conn *conn,
					  struct lightningd_state *dstate,
					  struct json_connecting *connect)
{
	struct json_result *response;
	struct peer *peer = new_peer(dstate, conn, SOCK_STREAM, IPPROTO_TCP,
				     CMD_OPEN_WITH_ANCHOR, "out");
	if (!peer) {
		command_fail(connect->cmd, "Failed to make peer for %s:%s",
			     connect->name, connect->port);
		return io_close(conn);
	}
	log_info(peer->log, "Connected out to %s:%s",
		 connect->name, connect->port);

	response = new_json_result(connect);	
	json_object_start(response, NULL);
	json_object_end(response);
	command_success(connect->cmd, response);

	return peer_crypto_setup(conn, peer, peer_test);
}

static struct io_plan *peer_connected_in(struct io_conn *conn,
					 struct lightningd_state *dstate)
{
	struct peer *peer = new_peer(dstate, conn, SOCK_STREAM, IPPROTO_TCP,
				     CMD_OPEN_WITHOUT_ANCHOR, "in");
	if (!peer)
		return io_close(conn);

	log_info(peer->log, "Peer connected in");
	return peer_crypto_setup(conn, peer, peer_test);
}

static int make_listen_fd(struct lightningd_state *dstate,
			  int domain, void *addr, socklen_t len)
{
	int fd = socket(domain, SOCK_STREAM, 0);
	if (fd < 0) {
		log_debug(dstate->base_log, "Failed to create %u socket: %s",
			  domain, strerror(errno));
		return -1;
	}

	if (!addr || bind(fd, addr, len) == 0) {
		if (listen(fd, 5) == 0)
			return fd;
		log_unusual(dstate->base_log,
			    "Failed to listen on %u socket: %s",
			    domain, strerror(errno));
	} else
		log_debug(dstate->base_log, "Failed to bind on %u socket: %s",
			  domain, strerror(errno));

	close_noerr(fd);
	return -1;
}

void setup_listeners(struct lightningd_state *dstate, unsigned int portnum)
{
	struct sockaddr_in addr;
	struct sockaddr_in6 addr6;
	socklen_t len;
	int fd1, fd2;
	u16 listen_port;

	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_port = htons(portnum);

	addr6.sin6_family = AF_INET6;
	addr6.sin6_addr = in6addr_any;
	addr6.sin6_port = htons(portnum);

	/* IPv6, since on Linux that (usually) binds to IPv4 too. */
	fd1 = make_listen_fd(dstate, AF_INET6, portnum ? &addr6 : NULL,
			     sizeof(addr6));
	if (fd1 >= 0) {
		struct sockaddr_in6 in6;

		len = sizeof(in6);
		if (getsockname(fd1, (void *)&in6, &len) != 0) {
			log_unusual(dstate->base_log,
				    "Failed get IPv6 sockname: %s",
				    strerror(errno));
			close_noerr(fd1);
		} else {
			addr.sin_port = in6.sin6_port;
			listen_port = ntohs(addr.sin_port);
			log_info(dstate->base_log,
				 "Creating IPv6 listener on port %u",
				 listen_port);
			io_new_listener(dstate, fd1, peer_connected_in, dstate);
		}
	}

	/* Just in case, aim for the same port... */
	fd2 = make_listen_fd(dstate, AF_INET,
			     addr.sin_port ? &addr : NULL, sizeof(addr));
	if (fd2 >= 0) {
		len = sizeof(addr);
		if (getsockname(fd2, (void *)&addr, &len) != 0) {
			log_unusual(dstate->base_log,
				    "Failed get IPv4 sockname: %s",
				    strerror(errno));
			close_noerr(fd2);
		} else {
			listen_port = ntohs(addr.sin_port);
			log_info(dstate->base_log,
				 "Creating IPv4 listener on port %u",
				 listen_port);
			io_new_listener(dstate, fd2, peer_connected_in, dstate);
		}
	}

	if (fd1 < 0 && fd2 < 0)
		fatal("Could not bind to a network address");
}

static void peer_failed(struct lightningd_state *dstate,
			struct json_connecting *connect)
{
	/* FIXME: Better diagnostics! */
	command_fail(connect->cmd, "Failed to connect to peer %s:%s",
		     connect->name, connect->port);
}

static void json_connect(struct command *cmd,
			const char *buffer, const jsmntok_t *params)
{
	struct json_connecting *connect;
	jsmntok_t *host, *port;

	json_get_params(buffer, params, "host", &host, "port", &port, NULL);

	if (!host || !port) {
		command_fail(cmd, "Need host and port");
		return;
	}

	connect = tal(cmd, struct json_connecting);
	connect->cmd = cmd;
	connect->name = tal_strndup(connect, buffer + host->start,
				    host->end - host->start);
	connect->port = tal_strndup(connect, buffer + port->start,
				    port->end - port->start);
	if (!dns_resolve_and_connect(cmd->dstate, connect->name, connect->port,
				     peer_connected_out, peer_failed, connect)) {
		command_fail(cmd, "DNS failed");
		return;
	}
}

const struct json_command connect_command = {
	"connect",
	json_connect,
	"Connect to a {host} at {port}",
	"Returns an empty result on success"
};

/* FIXME: Somehow we should show running DNS lookups! */
/* FIXME: Show status of peers! */
static void json_getpeers(struct command *cmd,
			  const char *buffer, const jsmntok_t *params)
{
	struct peer *p;
	struct json_result *response = new_json_result(cmd);	

	json_object_start(response, NULL);
	json_array_start(response, "peers");
	list_for_each(&cmd->dstate->peers, p, list) {
		json_object_start(response, NULL);
		json_add_string(response, "name", log_prefix(p->log));
		json_add_hex(response, "id", p->id.der, pubkey_derlen(&p->id));
		json_object_end(response);
	}
	json_array_end(response);
	json_object_end(response);
	command_success(cmd, response);
}

const struct json_command getpeers_command = {
	"getpeers",
	json_getpeers,
	"List the current peers",
	"Returns a 'peers' array"
};