(import foreign)
(require-extension foreigners)
(require-extension srfi-13)

#>
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/mman.h>
#include <libv4l2.h>
#include <linux/videodev2.h>
<#

(define-foreign-enum-type (v4l2_buf_type int)
  (v4l2_buf_type->int int->v4l2_buf_type)
  (V4L2_BUF_TYPE_VIDEO_CAPTURE V4L2_BUF_TYPE_VIDEO_CAPTURE 1)
  (V4L2_BUF_TYPE_VIDEO_OUTPUT V4L2_BUF_TYPE_VIDEO_OUTPUT 2)
  (V4L2_BUF_TYPE_VIDEO_OVERLAY V4L2_BUF_TYPE_VIDEO_OVERLAY 3)
  (V4L2_BUF_TYPE_VBI_CAPTURE V4L2_BUF_TYPE_VBI_CAPTURE 4)
  (V4L2_BUF_TYPE_VBI_OUTPUT V4L2_BUF_TYPE_VBI_OUTPUT 5)
  (V4L2_BUF_TYPE_SLICED_VBI_CAPTURE V4L2_BUF_TYPE_SLICED_VBI_CAPTURE 6)
  (V4L2_BUF_TYPE_SLICED_VBI_OUTPUT V4L2_BUF_TYPE_SLICED_VBI_OUTPUT 7)
  (V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY 8)
  (V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE 9)
  (V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE 10)
  (V4L2_BUF_TYPE_SDR_CAPTURE V4L2_BUF_TYPE_SDR_CAPTURE 11)
  (V4L2_BUF_TYPE_SDR_OUTPUT V4L2_BUF_TYPE_SDR_OUTPUT 12))

(define-foreign-enum-type (v4l2_memory int)
  (v4l2_memory->int int->v4l2_memory)
  (V4L2_MEMORY_MMAP V4L2_MEMORY_MMAP 1)
  (V4L2_MEMORY_USERPTR V4L2_MEMORY_USERPTR 2)
  (V4L2_MEMORY_OVERLAY V4L2_MEMORY_OVERLAY 3)
  (V4L2_MEMORY_DMABUF V4L2_MEMORY_DMABUF 4))

(define-foreign-record-type buffer
  ((c-pointer void) start get-buffer-start set-buffer-start!)
  (size_t length get-buffer-length set-buffer-length!))

(define-foreign-record-type (v4l2-rect "struct v4l2_rect")
  (int32 left v4l2-rect-left set-v4l2-rect-left!)
  (int32 top v4l2-rect-top set-v4l2-rect-top!)
  (unsigned-int32 width v4l2-rect-width set-v4l2-rect-width!)
  (unsigned-int32 height v4l2-rect-height set-v4l2-rect-height!))

(define-foreign-record-type (v4l2-fract "struct v4l2_fract")
  (unsigned-int32 numerator v4l2-fract-numerator set-v4l2-fract-numerator!)
  (unsigned-int32 denominator v4l2-fract-denominator set-v4l2-fract-denominator!))

(define-foreign-record-type (v4l2-pix-format "struct v4l2_pix_format")
  (unsigned-int32 width v4l2-pix-format-width set-v4l2-pix-format-width!)
  (unsigned-int32 height v4l2-pix-format-height set-v4l2-pix-format-height!)
  (unsigned-int32 pixelformat v4l2-pix-format-pixelformat set-v4l2-pix-format-pixelformat!)
  (unsigned-int32 field v4l2-pix-format-field set-v4l2-pix-format-field!)
  (unsigned-int32 bytesperline v4l2-pix-fomat-bytesperline set-v4l2-pix-format-bytesperline!)
  (unsigned-int32 sizeimage v4l2-pix-format-sizeimage set-v4l2-pix-format-sizeimage!)
  (unsigned-int32 colorspace v4l2-pix-format-colorspace set-v4l2-pix-format-colorspace!)
  (unsigned-int32 priv v4l2-pix-format-priv set-v4l2-pix-format-priv!)
  (unsigned-int32 flags v4l2-pix-format-flags set-v4l2-pix-format-flags!)
  (unsigned-int32 ycbcr_enc v4l2-pix-format-ycbcr-enc set-v4l2-pix-format-ycbcr-enc!)
  (unsigned-int32 quantization v4l2-pix-format-quantization set-v4l2-pix-format-quantization!)
  (unsigned-int32 xfer_func v4l2-pix-format-xfer-func set-v4l2-pix-format-xfer-func!))

(define v4l2-format-fmt-pix
  (foreign-lambda* v4l2-pix-format
      ((c-pointer format)) "C_return(((struct v4l2_format *)format)->fmt.pix);"))

(define-foreign-record-type (v4l2-format "struct v4l2_format")
  ((union "fmt") fmt v4l2-format-fmt)
  (unsigned-int32 type v4l2-format-type set-v4l2-format-type!))

(define-foreign-record-type (v4l2-capability "struct v4l2_capability")
  ((c-pointer u8vector) driver v4l2-capability-driver)
  ((c-pointer u8vector) card v4l2-capability-card)
  ((c-pointer u8vector) bus_info v4l2-capability-bus-info)
  (unsigned-int32 version v4l2-capability-version)
  (unsigned-int32 capabilities v4l2-capability-capabilities)
  (unsigned-int32 device_caps v4l2-capability-device-caps))

(define-foreign-record-type (v4l2-cropcap "struct v4l2_cropcap")
  (unsigned-int32 type v4l2-cropcap-type set-v4l2-cropcap-type!)
  ((struct v4l2-rect) bounds v4l2-cropcap-bounds set-v4l2-cropcap-bounds!)
  ((struct v4l2-rect) defrect v4l2-cropcap-defrect set-v4l2-cropcap-defrect!)
  ((struct v4l2-fract) pixelaspect v4l2-cropcap-pixelaspect set-v4l2-copcap-pixelaspect!))

(define-foreign-record-type (v4l2-crop "struct v4l2_crop")
  (unsigned-int32 type v4l2-crop-type set-v4l2-type!)
  ((struct v4l2-rect) c v4l2-crop-c set-v4l2-crop-c!))

(define-foreign-record-type (v4l2-requestbuffers "struct v4l2_requestbuffers") 
  (unsigned-int32 count v4l2-requestbuffers-count set-v4l2-requestbuffers-count!)
  (unsigned-int32 type v4l2-requestbuffers-type set-v4l2-requestbuffers-type!)
  (unsigned-int32 memory v4l2-requestbuffers-memory set-v4l2-requestbuffers-memory!))

(define v4l2-buffer-m-offset
  (foreign-lambda* unsigned-int32
      ((v4l2-buffer buf)) "C_return(buf->m.offset);"))

(define-foreign-record-type (v4l2-buffer "struct v4l2_buffer")
  (unsigned-int32 index v4l2-buffer-index set-v4l2-buffer-index!)
  (unsigned-int32 type v4l2-buffer-type set-v4l2-buffer-type!)
  (unsigned-int32 bytesused v4l2-buffer-bytesused)
  (unsigned-int32 flags v4l2-buffer-flags set-v4l2-buffer-flags!)
  (unsigned-int32 field v4l2-buffer-field)
  ((struct timeval) timestamp v4l2-buffer-timestamp)
  ((struct v4l2-timecode) timecode v4l2-buffer-timecode)
  (unsigned-int32 memory v4l2-buffer-memory) 
  (unsigned-int32 length v4l2-buffer-length))