#include "pn_node.h"
#include "pn_buffer.h"

#include <gio/gio.h>

#include "pn_log.h"

#include <string.h>

static void *parent_class;

enum pn_node_status {
	PN_NODE_STATUS_CLOSED,
	PN_NODE_STATUS_CONNECTING,
	PN_NODE_STATUS_OPEN,
};

struct pn_node_priv {
	char *hostname;
	int port;
	enum pn_node_status status;
	GSocketConnection *socket_conn;
	GError *error;
	struct pn_buffer *input_buffer;
	struct pn_buffer *output_buffer;
};

GQuark
pn_node_error_quark(void)
{
	static GQuark quark;
	if (quark == 0)
		quark = g_quark_from_static_string("pecan-node-error-quark");
	return quark;
}

struct pn_node *
pn_node_new(void)
{
	return g_object_new(PN_NODE_TYPE, NULL);
}

void
pn_node_free(struct pn_node *node)
{
	if (!node)
		return;
	g_object_unref(node);
}

void
pn_node_connect(struct pn_node *node,
		const char *hostname,
		int port)
{
	PN_NODE_GET_CLASS(node)->connect(node, hostname, port);
}

void
pn_node_close(struct pn_node *node)
{
	PN_NODE_GET_CLASS(node)->close(node);
}

void
pn_node_set_error(struct pn_node *node,
		  GError *error)
{
	node->priv->error = error;
	pn_node_close(node);
}

void
pn_node_write(struct pn_node *node,
	      const void *buffer,
	      gsize count)
{
	PN_NODE_GET_CLASS(node)->write(node, buffer, count);
}

void
pn_node_parse(struct pn_node *node,
	      struct pn_buffer *buffer)
{
	PN_NODE_GET_CLASS(node)->parse(node, buffer);
}

/* pn_node stuff */

static void
parse_impl(struct pn_node *node,
	   struct pn_buffer *buffer)
{
}

static void
read_cb(GObject *source,
	GAsyncResult *result,
	gpointer user_data)
{
	struct pn_node *node = user_data;
	struct pn_node_priv *priv = node->priv;
	gssize size;
	GError *error = NULL;
	struct pn_buffer *b = priv->input_buffer;

	size = g_input_stream_read_finish(G_INPUT_STREAM(source),
					  result, &error);

	pn_debug(node, "size=%i", size);

	if (size == 0)
		error = g_error_new_literal(PN_NODE_ERROR, 0,
					    "Connection finished");

	if (error)
		goto nok;

	b->len += size;
	pn_node_parse(node, b);

	if (priv->status == PN_NODE_STATUS_OPEN) {
		g_input_stream_read_async(G_INPUT_STREAM(source), b->data, b->size,
					  G_PRIORITY_DEFAULT, NULL, read_cb, node);
	}
	else {
		g_object_unref(node);
	}
	return;

nok:
	pn_node_set_error(node, error);
	g_object_unref(node);
	return;
}

static void
write_cb(GObject *source,
	 GAsyncResult *result,
	 gpointer user_data)
{
	struct pn_node *node = user_data;
	struct pn_node_priv *priv = node->priv;
	gssize size;
	GError *error = NULL;
	struct pn_buffer *buffer;

	size = g_output_stream_write_finish(G_OUTPUT_STREAM(source),
					    result, &error);

	pn_debug(node, "size=%i", size);

	if (size == 0)
		error = g_error_new_literal(PN_NODE_ERROR, 0,
					    "Connection finished");

	if (error)
		goto nok;

	buffer = priv->output_buffer;

	buffer->offset += size;

	if (buffer->offset < buffer->len) {
		g_output_stream_write_async(G_OUTPUT_STREAM(source),
					    buffer->data + buffer->offset,
					    buffer->len - buffer->offset,
					    G_PRIORITY_DEFAULT,
					    NULL,
					    write_cb,
					    node);
	}
	else {
		pn_buffer_free(buffer);
		priv->output_buffer = NULL;

		g_object_unref(node);
	}
	return;

nok:
	pn_node_set_error(node, error);
	g_object_unref(node);
	return;
}

static void
write_impl(struct pn_node *node,
	   const void *buffer,
	   gsize count)
{
	struct pn_node_priv *priv = node->priv;
	GOutputStream *output;

	output = g_io_stream_get_output_stream(G_IO_STREAM(priv->socket_conn));
	priv->output_buffer = pn_buffer_new_use((void *)buffer, count);

	g_object_ref(node);
	g_output_stream_write_async(output, buffer, count,
				    G_PRIORITY_DEFAULT, NULL, write_cb, node);
}

static void
connect_cb(GObject *source,
	   GAsyncResult *res,
	   gpointer user_data)
{
	struct pn_node *node = user_data;
	struct pn_node_priv *priv = node->priv;
	GSocketConnection *socket_conn;
	GError *error = NULL;

	socket_conn = g_socket_client_connect_to_host_finish(G_SOCKET_CLIENT(source), res, &error);

	g_object_ref(node);

	if (socket_conn) {
		GInputStream *input;
		struct pn_buffer *b = priv->input_buffer;

		priv->status = PN_NODE_STATUS_OPEN;
		priv->socket_conn = socket_conn;

		input = g_io_stream_get_input_stream(G_IO_STREAM(socket_conn));

		g_object_ref(node);
		g_input_stream_read_async(input, b->data, b->size,
					  G_PRIORITY_DEFAULT, NULL,
					  read_cb, node);

		struct pn_node_class *class;
		class = g_type_class_peek(PN_NODE_TYPE);
		g_signal_emit(G_OBJECT(node), class->open_sig, 0, node);
	}
	else {
		pn_node_set_error(node, error);
	}

	g_object_unref(node);
}

static void
connect_impl(struct pn_node *node,
	     const char *hostname,
	     int port)
{
	struct pn_node_priv *priv = node->priv;

	pn_node_close(node);

	priv->hostname = g_strdup(hostname);
	priv->port = port;

	priv->status = PN_NODE_STATUS_CONNECTING;

	{
		GSocketClient *client;
		client = g_socket_client_new();
		g_socket_client_connect_to_host_async(client, hostname, port,
						      NULL, connect_cb, node);
		g_object_unref(client);
	}
}

static void
close_impl(struct pn_node *node)
{
	struct pn_node_priv *priv = node->priv;

	if (priv->status == PN_NODE_STATUS_CLOSED)
		return;

	priv->status = PN_NODE_STATUS_CLOSED;

	if (priv->error) {
		struct pn_node_class *class;
		class = g_type_class_peek(PN_NODE_TYPE);
		g_signal_emit(G_OBJECT(node), class->error_sig, 0, &priv->error, node);

		if (priv->error) {
			pn_warn(node, "unhandled error: %s", priv->error->message);
			g_clear_error(&priv->error);
		}
	}

	if (priv->socket_conn) {
		g_object_unref(priv->socket_conn);
		priv->socket_conn = NULL;
	}

	g_free(priv->hostname);
	priv->hostname = NULL;
}

/* GObject stuff */

static void
dispose(GObject *obj)
{
	pn_node_close(PN_NODE(obj));

	G_OBJECT_CLASS(parent_class)->dispose(obj);
}

static void
finalize(GObject *obj)
{
	struct pn_node_priv *priv = PN_NODE(obj)->priv;
	pn_buffer_free(priv->input_buffer);

	G_OBJECT_CLASS(parent_class)->finalize(obj);
}

static void
class_init(void *g_class,
	   void *class_data)
{
	struct pn_node_class *node_class = PN_NODE_CLASS(g_class);
	GObjectClass *gobject_class = G_OBJECT_CLASS(g_class);

	node_class->connect = &connect_impl;
	node_class->close = &close_impl;
	node_class->write = &write_impl;
	node_class->parse = &parse_impl;

	gobject_class->dispose = dispose;
	gobject_class->finalize = finalize;

	parent_class = g_type_class_peek_parent(g_class);
	g_type_class_add_private(g_class, sizeof(struct pn_node_priv));

	node_class->open_sig = g_signal_new("open", G_TYPE_FROM_CLASS(gobject_class),
					    G_SIGNAL_RUN_FIRST, 0, NULL, NULL,
					    g_cclosure_marshal_VOID__VOID,
					    G_TYPE_NONE, 0);
	node_class->error_sig = g_signal_new("error", G_TYPE_FROM_CLASS(gobject_class),
					     G_SIGNAL_RUN_FIRST, 0, NULL, NULL,
					     g_cclosure_marshal_VOID__POINTER,
					     G_TYPE_NONE, 1, G_TYPE_POINTER);
}

static void
instance_init(GTypeInstance *instance,
	      void *g_class)
{
	struct pn_node *self = PN_NODE(instance);
	struct pn_node_priv *priv;

	self->priv = priv = G_TYPE_INSTANCE_GET_PRIVATE(instance, PN_NODE_TYPE, struct pn_node_priv);
	priv->input_buffer = pn_buffer_new_and_alloc(0);
}

GType
pn_node_get_type(void)
{
	static gsize init_type;

	if (g_once_init_enter(&init_type)) {
		GType type;
		GTypeInfo type_info = {
			.class_size = sizeof(struct pn_node_class),
			.class_init = class_init,
			.instance_size = sizeof(struct pn_node),
			.instance_init = instance_init,
		};

		type = g_type_register_static(G_TYPE_OBJECT, "PnNode", &type_info, 0);

		g_once_init_leave(&init_type, type);
	}

	return init_type;
}