#include "posix.h"

#include <errno.h>
#include <fx/io/stream.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/*** PRIVATE DATA *************************************************************/

struct fx_iostream_p {
	int s_fd;
	bool s_fd_close_on_release;
};

/*** PRIVATE FUNCTIONS ********************************************************/

static uptr iostream_get_os_handle(const struct fx_iostream_p *stream)
{
	return stream->s_fd;
}

static uptr iostream_steal_os_handle(struct fx_iostream_p *stream)
{
	uptr out = stream->s_fd;
	stream->s_fd = -1;
	stream->s_fd_close_on_release = false;
	return out;
}

/*** PUBLIC FUNCTIONS *********************************************************/

fx_iostream *fx_iostream_create(
	fx_stream_mode mode,
	uptr os_handle,
	bool close_handle_on_release)
{
	fx_iostream *s = fx_object_create(FX_IO_TYPE_STREAM);
	if (!s) {
		return NULL;
	}

	fx_stream_cfg *cfg = fx_object_get_protected(s, FX_TYPE_STREAM);
	struct fx_iostream_p *p = fx_object_get_private(s, FX_IO_TYPE_STREAM);

	cfg->s_mode = mode | Z__FX_STREAM_STATIC;
	p->s_fd = (int)os_handle;
	p->s_fd_close_on_release = close_handle_on_release;

	return s;
}

uptr fx_iostream_get_os_handle(const fx_iostream *stream)
{
	FX_CLASS_DISPATCH_STATIC_0(
		FX_IO_TYPE_STREAM,
		iostream_get_os_handle,
		stream);
}

uptr fx_iostream_steal_os_handle(fx_iostream *stream)
{
	FX_CLASS_DISPATCH_STATIC_0(
		FX_IO_TYPE_STREAM,
		iostream_steal_os_handle,
		stream);
}

/*** VIRTUAL FUNCTIONS ********************************************************/

static void iostream_init(fx_object *obj, void *priv)
{
	struct fx_iostream_p *stream = priv;
}

static void iostream_fini(fx_object *obj, void *priv)
{
	struct fx_iostream_p *stream = priv;

	if (stream->s_fd_close_on_release) {
		close(stream->s_fd);
	}
}

static enum fx_status stream_read(
	fx_stream *stream,
	void *buf,
	size_t count,
	size_t *nr_read)
{
	struct fx_iostream_p *s
		= fx_object_get_private(stream, FX_IO_TYPE_STREAM);

	long r = read(s->s_fd, buf, count);
	if (r < 0) {
		return fx_status_from_errno(errno, FX_ERR_IO_FAILURE);
	}

	*nr_read = r;
	return FX_SUCCESS;
}

static enum fx_status stream_write(
	fx_stream *stream,
	const void *buf,
	size_t count,
	size_t *nr_written)
{
	struct fx_iostream_p *s
		= fx_object_get_private(stream, FX_IO_TYPE_STREAM);

	long w = write(s->s_fd, buf, count);
	if (w < 0) {
		return fx_status_from_errno(errno, FX_ERR_IO_FAILURE);
	}

	*nr_written = w;
	return FX_SUCCESS;
}

/*** CLASS DEFINITION *********************************************************/

FX_TYPE_CLASS_BEGIN(fx_iostream)
	FX_TYPE_VTABLE_INTERFACE_BEGIN(fx_object, FX_TYPE_OBJECT)
		FX_INTERFACE_ENTRY(to_string) = NULL;
	FX_TYPE_VTABLE_INTERFACE_END(fx_object, FX_TYPE_OBJECT)

	FX_TYPE_VTABLE_INTERFACE_BEGIN(fx_stream, FX_TYPE_STREAM)
		FX_INTERFACE_ENTRY(s_close) = NULL;
		FX_INTERFACE_ENTRY(s_seek) = NULL;
		FX_INTERFACE_ENTRY(s_tell) = NULL;
		FX_INTERFACE_ENTRY(s_getc) = NULL;
		FX_INTERFACE_ENTRY(s_read) = stream_read;
		FX_INTERFACE_ENTRY(s_write) = stream_write;
		FX_INTERFACE_ENTRY(s_reserve) = NULL;
	FX_TYPE_VTABLE_INTERFACE_END(fx_stream, FX_TYPE_STREAM)
FX_TYPE_CLASS_END(fx_iostream)

FX_TYPE_DEFINITION_BEGIN(fx_iostream)
	FX_TYPE_ID(0xc0b1c3c9, 0xa9c6, 0x4910, 0x8786, 0x574b0696e7aa);
	FX_TYPE_NAME("fx.io.stream");
	FX_TYPE_EXTENDS(FX_TYPE_STREAM);
	FX_TYPE_CLASS(fx_iostream_class);
	FX_TYPE_INSTANCE_PRIVATE(struct fx_iostream_p);
	FX_TYPE_INSTANCE_INIT(iostream_init);
	FX_TYPE_INSTANCE_FINI(iostream_fini);
FX_TYPE_DEFINITION_END(fx_iostream)