//go:build debug && withcv
// +build debug,withcv

/*
DESCRIPTION
  Displays debug information for the motion filters.

AUTHORS
  Scott Barnard <scott@ausocean.org>

LICENSE
  This file is Copyright (C) 2020 the Australian Ocean Lab (AusOcean)

  It is free software: you can redistribute it and/or modify them
  under the terms of the GNU General Public License as published by the
  Free Software Foundation, either version 3 of the License, or (at your
  option) any later version.

  It is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  for more details.

  You should have received a copy of the GNU General Public License
  in gpl.txt.  If not, see http://www.gnu.org/licenses.
*/

package filter

import (
	"image"
	"image/color"

	"gocv.io/x/gocv"
)

// debugWindows is used for displaying debug information for the motion filters.
type debugWindows struct {
	windows []*gocv.Window
}

// close frees resources used by gocv.
func (d *debugWindows) close() error {
	for _, window := range d.windows {
		err := window.Close()
		if err != nil {
			return err
		}
	}
	return nil
}

// newWindows creates debugging windows for the motion filter.
func newWindows(name string) debugWindows {
	return debugWindows{
		windows: []*gocv.Window{
			gocv.NewWindow(name + ": Video"),
			gocv.NewWindow(name + ": Motion Detection"),
		},
	}
}

// show displays debug information for the motion filters.
func (d *debugWindows) show(img, imgDelta interface{}, motion bool, contours *[][]image.Point, text ...string) {
	var im, imD gocv.Mat
	const errMsg = "cannot show frame in window: wrong type"
	var drkRed = color.RGBA{191, 0, 0, 0}
	var lhtRed = color.RGBA{191, 31, 31, 0}

	// Type conversions.
	switch img.(type) {
	case image.Image:
		im, _ = gocv.ImageToMatRGB(img.(image.Image))
	case gocv.Mat:
		im = img.(gocv.Mat)
	default:
		panic(errMsg)
	}
	switch imgDelta.(type) {
	case image.Image:
		imD, _ = gocv.ImageToMatRGB(imgDelta.(image.Image))
	case gocv.Mat:
		imD = imgDelta.(gocv.Mat)
	default:
		panic(errMsg)
	}

	// Draw contours.
	if contours != nil {
		for _, c := range *contours {
			rect := gocv.BoundingRect(c)
			gocv.Rectangle(&im, rect, lhtRed, 1)
		}
	}

	// Draw debugging text.
	if motion {
		text = append(text, "Motion Detected")
	}
	for i, str := range text {
		gocv.PutText(&im, str, image.Pt(32, 32*(i+1)), gocv.FontHersheyPlain, 2.0, drkRed, 2)
	}

	// Display windows.
	d.windows[0].IMShow(im)
	d.windows[1].IMShow(imD)
	d.windows[0].WaitKey(1)
}