module ParasitemiaCore.Drawing

open System
open System.Drawing

open Emgu.CV
open Emgu.CV.Structure

open Const
open Types

let drawPoints (img : Image<Gray, 'TDepth>) (points : Points) (intensity : 'TDepth) =
    for p in points do
        img.Data.[p.Y, p.X, 0] <- intensity

let drawLine (img : Image<'TColor, 'TDepth>) (color : 'TColor) (x0 : int) (y0 : int) (x1 : int) (y1 : int) (thickness : int) =
    img.Draw (LineSegment2D (Point (x0, y0), Point (x1, y1)), color, thickness);

let drawLineF (img : Image<'TColor, 'TDepth>) (color : 'TColor) (x0 : float) (y0 : float) (x1 : float) (y1 : float) (thickness : int) =
    img.Draw (LineSegment2DF (PointF (float32 x0, float32 y0), PointF  (float32 x1, float32 y1)), color, thickness, CvEnum.LineType.AntiAlias);

let drawEllipse (img : Image<'TColor, 'TDepth>) (e : Ellipse) (color : 'TColor) (alpha : float) =
    if alpha >= 1.0 then
        img.Draw (Emgu.CV.Structure.Ellipse (PointF (e.Cx, e.Cy), SizeF (2.f * e.B, 2.f * e.A), e.Alpha / PI * 180.f), color, 1, CvEnum.LineType.AntiAlias)
    else
        let windowPosX = e.Cx - e.A - 5.f
        let gapX = windowPosX - (float32 (int windowPosX))

        let windowPosY = e.Cy - e.A - 5.f
        let gapY = windowPosY - (float32 (int windowPosY))

        let roi = Rectangle (int windowPosX, int windowPosY, 2.f * (e.A + 5.f) |> int, 2.f * (e.A + 5.f) |> int)

        img.ROI <- roi
        if roi = img.ROI then // We do not display ellipses touching the edges (FIXME)
            use i = new Image<'TColor, 'TDepth> (img.ROI.Size)
            i.Draw (Emgu.CV.Structure.Ellipse(PointF(e.A + 5.f + gapX, e.A + 5.f + gapY), SizeF(2.f * e.B, 2.f * e.A), e.Alpha / PI * 180.f), color, 1, CvEnum.LineType.AntiAlias)
            CvInvoke.AddWeighted (img, 1.0, i, alpha, 0.0, img)
        img.ROI <- Rectangle.Empty

let drawEllipses (img : Image<'TColor, 'TDepth>) (ellipses : Ellipse list) (color : 'TColor) (alpha : float) =
    List.iter (fun e -> drawEllipse img e color alpha) ellipses

let rngCell =  System.Random ()
let drawCell (img : Image<Bgr, byte>) (drawCellContent : bool) (c : Cell) =
    if drawCellContent then
        let colorB = rngCell.Next (20, 70)
        let colorG = rngCell.Next (20, 70)
        let colorR = rngCell.Next (20, 70)

        for y = 0 to c.elements.Height - 1 do
            for x = 0 to c.elements.Width - 1 do
                if c.elements.[y, x] > 0uy then
                    let dx, dy = c.center.X - c.elements.Width / 2, c.center.Y - c.elements.Height / 2
                    let b = img.Data.[y + dy, x + dx, 0] |> int
                    let g = img.Data.[y + dy, x + dx, 1] |> int
                    let r = img.Data.[y + dy, x + dx, 2] |> int
                    img.Data.[y + dy, x + dx, 0] <- if b + colorB > 255 then 255uy else byte (b + colorB)
                    img.Data.[y + dy, x + dx, 1] <- if g + colorG > 255 then 255uy else byte (g + colorG)
                    img.Data.[y + dy, x + dx, 2] <- if r + colorR > 255 then 255uy else byte (r + colorR)

    let crossColor, crossColor2 =
        match c.cellClass with
        | HealthyRBC -> Bgr (255., 0., 0.), Bgr (255., 255., 255.)
        | InfectedRBC -> Bgr (0., 0., 255.), Bgr (120., 120., 255.)
        | Peculiar -> Bgr (0., 0., 0.), Bgr (80., 80., 80.)

    drawLine img crossColor2 (c.center.X - 3) c.center.Y (c.center.X + 3) c.center.Y 2
    drawLine img crossColor2 c.center.X (c.center.Y - 3) c.center.X (c.center.Y + 3) 2

    drawLine img crossColor (c.center.X - 3) c.center.Y (c.center.X + 3) c.center.Y 1
    drawLine img crossColor c.center.X (c.center.Y - 3) c.center.X (c.center.Y + 3) 1

let drawCells (img : Image<Bgr, byte>) (drawCellContent : bool) (cells : Cell list) =
    List.iter (fun c -> drawCell img drawCellContent c) cells