/*

 * Copyright (c) 2015, Jason Maltzen

 Permission is hereby granted, free of charge, to any person obtaining a copy

 of this software and associated documentation files (the "Software"), to deal

 in the Software without restriction, including without limitation the rights

 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 copies of the Software, and to permit persons to whom the Software is

 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in

 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 THE SOFTWARE.

*/

using System;

using System.IO;

namespace DesertPaintLab

{

    // ReactionRecorder - business logic for recording paint reactions

    public class ReactionRecorder

    {

        public delegate void CaptureProgressHandler(int x, int y);

        public CaptureProgressHandler OnCaptureProgress;

        const int COLOR_TOLERANCE = 3;

        const InterfaceSize DEFAULT_INTERFACE_SIZE = InterfaceSize.Small;

        // Swatch is 301x20 solid color, 1px darker left/top, 1px black outer left/top, 1px light right/bottom, 1px bright right/bottom

        // top-right and bottom-left are bright instead of black

        // Color bars are 4x302 solid color, 2px border on all sides (darker left/top, lighter bottom/right

        public static readonly int[] SWATCH_HEIGHT = 

        {

            24, // tiny

            24, // small

            24, // medium

            24, // large

            24 // huge

        };

        public static readonly int[] SWATCH_WIDTH =

        {

            260, // tiny

            260, // small

            260, // medium

            274, // large

            304 // huge

        };

        public static readonly int[] COLOR_BAR_WIDTH =

        {

            306, // tiny

            306, // small

            306, // medium

            320, // large

            350 // huge

        };

        public static readonly int[] RED_BAR_SPACING =

        {

            32, // tiny

            32, // small

            32, // medium

            32, // large

            32 // huge

        };

        public static readonly int[] GREEN_BAR_SPACING =

        {

            42, // tiny

            42, // small

            42, // medium

            42, // large

            42 // huge

        };

        public static readonly int[] BLUE_BAR_SPACING =

        {

            52, // tiny

            52, // small

            52, // medium

            52, // large

            52 // huge

        };

        // width to test on ends of swatch (10% on either end)

        public static readonly int[] SWATCH_TEST_WIDTH =

        {

            26, // tiny

            26, // small

            26, // medium

            28, // large

            31  // huge

        };

        int swatchHeight = SWATCH_HEIGHT[(int)DEFAULT_INTERFACE_SIZE];

        int swatchWidth = SWATCH_WIDTH[(int)DEFAULT_INTERFACE_SIZE];

        int swatchTestWidth = SWATCH_TEST_WIDTH[(int)DEFAULT_INTERFACE_SIZE];

        int colorBarWidth = COLOR_BAR_WIDTH[(int)DEFAULT_INTERFACE_SIZE];

        int redBarSpacing = RED_BAR_SPACING[(int)DEFAULT_INTERFACE_SIZE];

        int greenBarSpacing = GREEN_BAR_SPACING[(int)DEFAULT_INTERFACE_SIZE];

        int blueBarSpacing = BLUE_BAR_SPACING[(int)DEFAULT_INTERFACE_SIZE];

        public int SwatchHeight {  get { return swatchHeight; } }

        public int SwatchWidth {  get { return swatchWidth; } }

        public int ColorBarWidth { get { return colorBarWidth;  } }

        public int RedBarSpacing {  get { return redBarSpacing; } }

        public int GreenBarSpacing { get { return greenBarSpacing; } }

        public int BlueBarSpacing {  get { return blueBarSpacing; } }

        // Current Status

        public bool IsCaptured { get; private set; }

        public int X { get; private set; }

        public int Y { get; private set; }

        public int ScreenWidth { get; private set; }

        public int ScreenHeight { get; private set; }

        private PaintColor _recordedColor = new PaintColor();

        public PaintColor RecordedColor { get { return _recordedColor; } private set { _recordedColor.Set(value); } }

        public int RedBarX { get; private set; }

        public int RedBarY { get; private set; }

        int pixelMultiplier = 1;

        InterfaceSize interfaceSize;

        bool firstRun = true;

        int lastSwatchX = -1;

        int lastSwatchY = -1;

        public int SwatchX { get { return lastSwatchX; } }

        public int SwatchY { get { return lastSwatchY; } }

        private static ReactionRecorder _instance;

        public static ReactionRecorder Instance

        {

            get {

                if (_instance == null)

                {

                    _instance = new ReactionRecorder();

                }

                return _instance;

            }

        }

        public StreamWriter Log { get; set; }

        private void WriteLog(string format, params object[] args)

        {

            if (Log != null)

            {

                Log.WriteLine(format, args);

            }

        }

        public delegate void ReactionRecordedHandler(Reagent reagent1, Reagent reagent2, Reaction reaction);

        public ReactionRecordedHandler OnReactionRecorded;

        public ReactionRecorder()

        {

            pixelMultiplier = 1;

            interfaceSize = DEFAULT_INTERFACE_SIZE;

            swatchHeight = SWATCH_HEIGHT[(int)interfaceSize] * pixelMultiplier;

            swatchWidth = SWATCH_WIDTH[(int)interfaceSize] * pixelMultiplier;

            colorBarWidth = COLOR_BAR_WIDTH[(int)interfaceSize] * pixelMultiplier;

            redBarSpacing = RED_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            greenBarSpacing = GREEN_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            blueBarSpacing = BLUE_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            swatchTestWidth = SWATCH_TEST_WIDTH[(int)interfaceSize] * pixelMultiplier;

        }

        public ReactionRecorder(int pixelMultiplier)

        {

            this.pixelMultiplier = pixelMultiplier;

            this.interfaceSize = DEFAULT_INTERFACE_SIZE;

            swatchHeight = SWATCH_HEIGHT[(int)interfaceSize] * pixelMultiplier;

            swatchWidth = SWATCH_WIDTH[(int)interfaceSize] * pixelMultiplier;

            colorBarWidth = COLOR_BAR_WIDTH[(int)interfaceSize] * pixelMultiplier;

            redBarSpacing = RED_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            greenBarSpacing = GREEN_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            blueBarSpacing = BLUE_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            swatchTestWidth = SWATCH_TEST_WIDTH[(int)interfaceSize] * pixelMultiplier;

        }

        public ReactionRecorder(int pixelMultiplier, InterfaceSize interfaceSize)

        {

            this.pixelMultiplier = pixelMultiplier;

            this.interfaceSize = interfaceSize;

            swatchHeight = SWATCH_HEIGHT[(int)interfaceSize] * pixelMultiplier;

            swatchWidth = SWATCH_WIDTH[(int)interfaceSize] * pixelMultiplier;

            colorBarWidth = COLOR_BAR_WIDTH[(int)interfaceSize] * pixelMultiplier;

            redBarSpacing = RED_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            greenBarSpacing = GREEN_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            blueBarSpacing = BLUE_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            swatchTestWidth = SWATCH_TEST_WIDTH[(int)interfaceSize] * pixelMultiplier;

        }

        private static bool IsPapyTexture(byte r, byte g, byte b)

        {

            // red between 208 and 244

            // 240 and 255

            // green between 192 and 237

            // 223 and 248

            // blue between 145 and 205

            // 178 and 228

            //return ((r > 0xD0) && (g >= 0xC0) && (b >= 0x91)) &&

            //       ((r < 0xF4) && (g <= 0xED) && (b <= 0xCD));

            return ((r >= 0xF0) && (r <= 0xFF) && (g >= 0xDF) && (g <= 0xF8) && (b >= 0xB2) && (b <= 0xE4));

        }

        public void SetPixelMultiplier(int pixelMultiplier)

        {

            this.pixelMultiplier = pixelMultiplier;

            swatchHeight = SWATCH_HEIGHT[(int)interfaceSize] * pixelMultiplier;

            swatchWidth      = SWATCH_WIDTH[(int)interfaceSize] * pixelMultiplier;

            colorBarWidth    = COLOR_BAR_WIDTH[(int)interfaceSize] * pixelMultiplier;

            redBarSpacing    = RED_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            greenBarSpacing  = GREEN_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            blueBarSpacing   = BLUE_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            swatchTestWidth  = SWATCH_TEST_WIDTH[(int)interfaceSize] * pixelMultiplier;

        }

        public void SetInterfaceSize(InterfaceSize interfaceSize)

        {

            this.interfaceSize = interfaceSize;

            swatchHeight = SWATCH_HEIGHT[(int)interfaceSize] * pixelMultiplier;

            swatchWidth = SWATCH_WIDTH[(int)interfaceSize] * pixelMultiplier;

            colorBarWidth = COLOR_BAR_WIDTH[(int)interfaceSize] * pixelMultiplier;

            redBarSpacing = RED_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            greenBarSpacing = GREEN_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            blueBarSpacing = BLUE_BAR_SPACING[(int)interfaceSize] * pixelMultiplier;

            swatchTestWidth = SWATCH_TEST_WIDTH[(int)interfaceSize] * pixelMultiplier;

        }

        unsafe private void ColorAt(byte *pixBytes, int x, int y, int stride, out byte r, out byte g, out byte b)

        {

            int pixelStart = (y * stride) + (x * 3);

                    r = pixBytes[pixelStart];

                    g = pixBytes[pixelStart + 1];

                    b = pixBytes[pixelStart + 2];

        }

        private bool IsDarkPixel(int r, int g, int b)

        {

            return ((r < 0x46) && (g < 0x46) && (b < 0x47));

        }

        private bool IsColorMatch(byte test_r, byte test_g, byte test_b, byte target_r, byte target_g, byte target_b)

        {

            return ((Math.Abs(test_r - target_r) <= COLOR_TOLERANCE) &&

                (Math.Abs(test_g - target_g) <= COLOR_TOLERANCE) &&

                (Math.Abs(test_b - target_b) <= COLOR_TOLERANCE));

        }

        unsafe private bool IsPossibleSwatchSlice(byte* pixBytes, int x, int y, int stride)

        {

            int testPixelStart = (y * stride) + (x * 3);

            byte r = pixBytes[testPixelStart];

            byte g = pixBytes[testPixelStart+1];

            byte b = pixBytes[testPixelStart+2];

            bool isDarkPixel = false;

            //bool isPapyAbove = false;

            //bool isPapyBelow = false;

            // 1.) Check if the top pixel is a dark pixel.

            isDarkPixel = IsDarkPixel(r, g, b); // ((r < 0x46) && (g < 0x46) && (b < 0x46));

            //// 2.) Check the pixel above it to see if it's from the papy texture.

            //int otherPixelStart = testPixelStart - stride;

            //isPapyAbove = ((otherPixelStart >= 0) &&

            //    IsPapyTexture(pixBytes[otherPixelStart++], pixBytes[otherPixelStart++], pixBytes[otherPixelStart]));

            //// 3.) Check the pixel below where the swatch should be to see if it's also from the papy texture.

            //otherPixelStart = testPixelStart + (stride * swatchHeight);

            //isPapyBelow = (IsPapyTexture(pixBytes[otherPixelStart++], pixBytes[otherPixelStart++], pixBytes[otherPixelStart]));

            //bool result = isDarkPixel && isPapyAbove && isPapyBelow;

            bool result = isDarkPixel;

            // grab the swatch color

            int swatchColorStart = testPixelStart + (2 * pixelMultiplier * stride); // 2 rows below the test pixel, skipping the faded color

            r = pixBytes[swatchColorStart];

            g = pixBytes[swatchColorStart+1];

            b = pixBytes[swatchColorStart+2];

            // scan the column from 2 below the top to 2 above the bottom to ensure the color matches

            for (int i = (2*pixelMultiplier); result && (i < swatchHeight-(2*pixelMultiplier)); ++i)

            {

                int otherPixelStart = testPixelStart + (stride * i);

                result &= IsColorMatch(pixBytes[otherPixelStart], pixBytes[otherPixelStart+1], pixBytes[otherPixelStart+2], r, g, b);

            }

            if (!result)

            {

                WriteLog("Swatch slice at {0}, {1} failed to match", x, y);

            }

            return result;

        }

        unsafe private bool IsPossibleSwatchUpperLeft(byte* pixBytes, int x, int y, int stride)

        {

            int testPixelStart = (y * stride) + (x * 3);

            if (testPixelStart < stride)

            {

                return false;

            }

            bool result = true;

            int solidLowerRight = solidLowerLeft + ((swatchWidth - 4) * 3);

            byte swatch_r = pixBytes[solidUpperLeft];

            byte swatch_g = pixBytes[solidUpperLeft + 1];

            byte swatch_b = pixBytes[solidUpperLeft + 2];

            // Check the other 3 corners of the swatch size for color match

            result &= IsColorMatch(swatch_r, swatch_r, swatch_r, pixBytes[solidUpperRight], pixBytes[solidUpperRight + 1], pixBytes[solidUpperRight + 2]);

            result &= IsColorMatch(swatch_r, swatch_r, swatch_r, pixBytes[solidLowerLeft], pixBytes[solidLowerLeft + 1], pixBytes[solidLowerLeft + 2]);

            result &= IsColorMatch(swatch_r, swatch_r, swatch_r, pixBytes[solidLowerRight], pixBytes[solidLowerRight + 1], pixBytes[solidLowerRight + 2]);

            if (!result)

            {

                return false;

            }

            // scan down the right and left sides

            for (int yOff = 1; yOff < (swatchHeight - 5); ++yOff)

            {

                int testPixel = solidUpperLeft + (yOff * stride);

                result &= IsColorMatch(swatch_r, swatch_r, swatch_r, pixBytes[testPixel], pixBytes[testPixel + 1], pixBytes[testPixel + 2]);

                testPixel += ((swatchWidth - 1) * (x + 3));

                result &= IsColorMatch(swatch_r, swatch_r, swatch_r, pixBytes[testPixel], pixBytes[testPixel + 1], pixBytes[testPixel + 2]);

            }

            if (!result)

            {

                WriteLog("Failed to find left edge for potential swatch of color {2}, {3}, {4} at {0}, {1}", x, y, swatch_r, swatch_g, swatch_b);

                return false;

            }

            // test the left edge for dark pixels

            int i = 0;

            for (i = 0; result && (i < swatchHeight-pixelMultiplier); ++i)

            {

                int otherPixelStart = testPixelStart + (stride * i);

                result &= IsDarkPixel(pixBytes[otherPixelStart], pixBytes[otherPixelStart+1], pixBytes[otherPixelStart+2]);

            }

            if (!result)

            {

                // No dark border on the left side

                WriteLog("Failed to find left border for potential swatch of color {2}, {3}, {4} at {0}, {1}", x, y, swatch_r, swatch_g, swatch_b);

                return false;

            }

            // test the dark top border and for papyrus above and below the swatch

            bool borderError = false;

            int papyErrorCount = 0;

            for (i = 0; result && (i < swatchWidth); ++i)

            {

                int otherPixelStart = testPixelStart + (3 * i);

                bool isBorder = IsDarkPixel(pixBytes[otherPixelStart], pixBytes[otherPixelStart+1], pixBytes[otherPixelStart+2]);

                result &= isBorder;

                if (!isBorder)

                {

                    borderError = true;

                }

                if (otherPixelStart >= stride)

                {

                    otherPixelStart = otherPixelStart - stride;

                    papyErrorCount += (IsPapyTexture(pixBytes[otherPixelStart], pixBytes[otherPixelStart + 1], pixBytes[otherPixelStart + 2]) ? 0 : 1);

                }

                else

                {

                    papyErrorCount++;

                }

                // Checking along the bottom of the swatch - 

                otherPixelStart = testPixelStart + (stride * swatchHeight) + (3 * i);

                papyErrorCount += (IsPapyTexture(pixBytes[otherPixelStart], pixBytes[otherPixelStart+1], pixBytes[otherPixelStart+2]) ? 0 : 1);

            }

            result &= (papyErrorCount < (swatchWidth / 20)); // allow up to 5% error rate checking for papy texture, because this seems to be inconsistent

            if (!result && ((i > (swatchWidth*0.8)) || (papyErrorCount >= (swatchWidth/20))))

            {

                if (!borderError && (papyErrorCount < swatchWidth))

                {

                    WriteLog("Found a potential swatch candidate of width {0} at {1},{2} that had {3} failures matching papyrus texture", i, x, y, papyErrorCount);

                }

            }

            return result;

        }

        unsafe private bool TestPosition(int x, int y, byte* pixBytes, int screenshotWidth, int screenshotHeight, int stride, ref PaintColor reactedColor, ref int redPixelStart)

        {

            byte pixel_r, pixel_g, pixel_b;

            int pixelStart, otherPixelStart;

            bool colorMatch = true;

            // Look for the color swatch.

            pixelStart = (y * stride) + (x * 3);

            pixel_r = pixBytes[pixelStart];

            pixel_g = pixBytes[pixelStart + 1];

            pixel_b = pixBytes[pixelStart + 2];

            // Check 4 corners of solid area and left/right solid bar areas

            bool foundSwatch = IsPossibleSwatchUpperLeft(pixBytes, x, y, stride); // ((pixel_r < 0x46) && (pixel_g < 0x46) && (pixel_b < 0x46));

            if (foundSwatch)

            {

                int borderXOffset = 0;

                for (borderXOffset = (2 * pixelMultiplier); foundSwatch && (borderXOffset < swatchTestWidth); ++borderXOffset)

                {

                    foundSwatch &= IsPossibleSwatchSlice(pixBytes, x + borderXOffset, y, stride);

                    foundSwatch &= IsPossibleSwatchSlice(pixBytes, x + swatchWidth - borderXOffset, y, stride);

                }

            }

            if (foundSwatch)

            {

                // found a swatch with an appropriate dark top border with papyrus texture above it and papyrus a jump below it

                // 4.) Scan the left border of the potential swatch

                // location.

                colorMatch = true;

                for (int i = 2; i < swatchHeight - (2 * pixelMultiplier); ++i)

                {

                    otherPixelStart = pixelStart + (stride * i);

                    if (!IsColorMatch(pixel_r, pixel_g, pixel_b, pixBytes[otherPixelStart], pixBytes[otherPixelStart + 1], pixBytes[otherPixelStart + 2]))

                    {

                        colorMatch = false;

                        break;

                    }

                }

                if (colorMatch)

                {

                    // WE FOUND THE SWATCH!

                    // Now we know where the color bars are.

                    redPixelStart = pixelStart + (redBarSpacing * stride);

                    int redPixel = redPixelStart;

                    int redPixelCount = 0;

                    while ((pixBytes[redPixel] > 0x9F) &&

                           (pixBytes[redPixel + 1] < 0x62) &&

                           (pixBytes[redPixel + 2] < 0x62))

                    {

                        redPixelCount++;

                        // pixBytes[redPixel] = 0x00;

                        // pixBytes[redPixel + 1] = 0xFF;

                        // pixBytes[redPixel + 2] = 0xFF;

                        redPixel += 3;

                    }

                    WriteLog("Color {0}, {1}, {2} is no longer red at {3},{4}", pixBytes[redPixel], pixBytes[redPixel + 1], pixBytes[redPixel + 2], (redPixel % stride)/3, redPixel / stride);

                    reactedColor.Red = (byte)Math.Round((float)redPixelCount * 255f / (float)colorBarWidth);

                    int greenPixelStart = pixelStart + (greenBarSpacing * stride);

                    int greenPixelCount = 0;

                    while ((pixBytes[greenPixelStart] < 0x62) &&

                           (pixBytes[greenPixelStart + 1] > 0x9F) &&

                           (pixBytes[greenPixelStart + 2] < 0x62))

                    {

                        greenPixelCount++;

                        // pixBytes[greenPixelStart] = 0x00;

                        // pixBytes[greenPixelStart + 1] = 0xFF;

                        // pixBytes[greenPixelStart + 2] = 0xFF;

                        greenPixelStart += 3;

                    }

                    WriteLog("Color {0}, {1}, {2} is no longer green at pixel offset {3},{4}", pixBytes[greenPixelStart], pixBytes[greenPixelStart + 1], pixBytes[greenPixelStart + 2], (greenPixelStart % stride)/3, greenPixelStart / stride);

                    reactedColor.Green = (byte)Math.Round((float)greenPixelCount * 255f / (float)colorBarWidth);

                    int bluePixelStart = pixelStart + (blueBarSpacing * stride);

                    int bluePixelCount = 0;

                    while ((pixBytes[bluePixelStart] < 0x62) &&

                        (pixBytes[bluePixelStart + 1] < 0x62) &&

                        (pixBytes[bluePixelStart + 2] > 0x9F))

                    {

                        bluePixelCount++;

                        // pixBytes[bluePixelStart] = 0x00;

                        // pixBytes[bluePixelStart + 1] = 0xFF;

                        // pixBytes[bluePixelStart + 2] = 0xFF;

                        bluePixelStart += 3;

                    }

                    WriteLog("Color {0}, {1}, {2} is no longer blue at pixel offset {3},{4}", pixBytes[bluePixelStart], pixBytes[bluePixelStart + 1], pixBytes[bluePixelStart + 2], (bluePixelStart % stride)/3, bluePixelStart / stride);

                    reactedColor.Blue = (byte)Math.Round((float)bluePixelCount * 255f / (float)colorBarWidth);

                    WriteLog("Found the color swatch at {0}, {1}. Color={2} Red={3}px Green={4}px Blue={5}px", x, y, reactedColor, redPixelCount, greenPixelCount, bluePixelCount);

                    return true;

                }

            }

            return false;

        }

        unsafe public bool CaptureReaction(byte* pixBytes, int screenshotWidth, int screenshotHeight, int stride)

        {

            PaintColor reactedColor = new PaintColor();

            int redPixelStart = 0;

            ScreenWidth = screenshotWidth;

            ScreenHeight = screenshotHeight;

            IsCaptured = false;

            _recordedColor.Clear();

            IsCaptured = false;

            if (!firstRun)

            {

                // If this is not the first run, let's check the last location, to see if the UI is still there.

                if (TestPosition(lastSwatchX, lastSwatchY, pixBytes, screenshotWidth, screenshotHeight, stride, ref reactedColor, ref redPixelStart))

                {

                    IsCaptured = true;

                    RedBarX = (redPixelStart % stride) / 3;

                    RedBarY = redPixelStart / stride;

                    RecordedColor = reactedColor;

                    return true;

                }

                else

                {

                    firstRun = true;

                }

            }

            for (X = 0; X < screenshotWidth - colorBarWidth; ++X)

            {

                for (int Y = 0; Y < (screenshotHeight - (blueBarSpacing + 10)  /*53*/); ++Y)

                {

                    if (TestPosition(X, Y, pixBytes, screenshotWidth, screenshotHeight, stride, ref reactedColor, ref redPixelStart))

                    {

                        RedBarX = (redPixelStart % stride) / 3;

                        RedBarY = redPixelStart / stride;

                        RecordedColor = reactedColor;

                        lastSwatchX = X;

                        lastSwatchY = Y;

                        firstRun = false;

                        IsCaptured = true;

                        return true;

                    }

                    OnCaptureProgress?.Invoke(X, Y);

                }

            }

            return false;

        }

        public bool RecordReaction(PlayerProfile profile, PaintColor expectedColor, PaintColor reactedColor, Reagent[] reagents)

        {

            bool saved = false;

            int r, g, b;

            if (reagents[2] != null)

            {

                // A 3-reagent reaction.

                Reaction reaction1 = profile.FindReaction(reagents[0], reagents[1]);

                Reaction reaction2 = profile.FindReaction(reagents[0], reagents[2]);

                Reaction reaction3 = profile.FindReaction(reagents[1], reagents[2]);

                r = reactedColor.Red - expectedColor.Red;

                g = reactedColor.Green - expectedColor.Green;

                b = reactedColor.Blue - expectedColor.Blue;

                if (reaction2 == null)

                {

                    r = r - reaction1.Red - reaction3.Red;

                    g = g - reaction1.Green - reaction3.Green;

                    b = b - reaction1.Blue - reaction3.Blue;

                    Reaction reaction = new Reaction(r, g, b);

                    profile.SetReaction(reagents[0], reagents[2], reaction);

                    profile.Save();

                    saved = true;

                    OnReactionRecorded?.Invoke(reagents[0], reagents[2], reaction);

                }

                else if (reaction3 == null)

                {

                    r = r - reaction1.Red - reaction2.Red;

                    g = g - reaction1.Green - reaction2.Green;

                    b = b - reaction1.Blue - reaction2.Blue;

                    Reaction reaction = new Reaction(r, g, b);

                    profile.SetReaction(reagents[1], reagents[2], reaction);

                    profile.Save();

                    saved = true;

                    OnReactionRecorded?.Invoke(reagents[1], reagents[2], reaction);

                }

            }

            else if ((reagents[0] != null) && (reagents[1] != null))

            {

                // A 2-reagent reaction.

                r = reactedColor.Red - expectedColor.Red;

                g = reactedColor.Green - expectedColor.Green;

                b = reactedColor.Blue - expectedColor.Blue;

                Reaction reaction = new Reaction(r, g, b);

                profile.SetReaction(reagents[0], reagents[1], reaction);

                profile.Save();

                saved = true;

                OnReactionRecorded?.Invoke(reagents[0], reagents[1], reaction);

            }

            return saved;

        }

    }

}