/*
 *                     GNU AFFERO GENERAL PUBLIC LICENSE
 *                       Version 3, 19 November 2007
 *  Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
 *  Everyone is permitted to copy and distribute verbatim copies
 *  of this license document, but changing it is not allowed.
 */

using Emgu.CV;
using Emgu.CV.Structure;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;
using UVtools.Core;
using UVtools.Core.Extensions;
using UVtools.Core.Scripting;

namespace UVtools.ScriptSample;

/// <summary>
/// Performs a black inset around objects
/// </summary>
public class ScriptLightBleedCompensationSample : ScriptGlobals
{
    readonly ScriptTextBoxInput BrightnessesInput = new()
    {
        Label = "Brightnesses",
        ToolTip = "Brightness to reduce each subsequent repeated pixels",
        Unit = "1-255",
        Value = "25,20,15,10,5"
    };


    public byte[] Levels
    {
        get
        {
            List<byte> levels = new();
            var split = BrightnessesInput.Value!.Split(',', StringSplitOptions.TrimEntries);
            foreach (var str in split)
            {
                if(!byte.TryParse(str, out var brightness)) continue;
                if(brightness is byte.MinValue or byte.MaxValue) continue;
                levels.Add(brightness);
            }

            return levels.ToArray();
        }
    }

    /// <summary>
    /// Set configurations here, this function trigger just after load a script
    /// </summary>
    public void ScriptInit()
    {
        Script.Name = "Light bleed compensation";
        Script.Description = "Dim sequential pixels";
        Script.Author = "Tiago Conceição";
        Script.Version = new Version(0, 1);
        Script.UserInputs.Add(BrightnessesInput);
    }

    /// <summary>
    /// Validate user inputs here, this function trigger when user click on execute
    /// </summary>
    /// <returns>A error message, empty or null if validation passes.</returns>
    public string? ScriptValidate()
    {
        StringBuilder sb = new();
            
        if (Levels.Length == 0)
        {
            sb.AppendLine($"No brightness levels are set");
        }
            
        return sb.ToString();
    }

    /// <summary>
    /// Execute the script, this function trigger when when user click on execute and validation passes
    /// </summary>
    /// <returns>True if executes successfully to the end, otherwise false.</returns>
    public bool ScriptExecute()
    {
        Progress.Reset("Bleed compensation", Operation.LayerRangeCount); // Sets the progress name and number of items to process
        var brightnesses = Levels;

        // Loop user selected layers in parallel, this will put each core of CPU working here on parallel
        Parallel.For(Operation.LayerIndexStart, Operation.LayerIndexEnd+1, CoreSettings.GetParallelOptions(Progress), layerIndex =>
        {
            var layer = SlicerFile[layerIndex]; // Unpack and expose layer variable for easier use
            using var mat = layer.LayerMat;     // Gets this layer mat/image
            var original = mat.Clone();     // Keep a original mat copy

            var target = Operation.GetRoiOrDefault(mat); // Get ROI from mat if user selected an region

            for (byte i = 0; i < brightnesses.Length; i++)
            {
                uint layerIndexNext = (uint) (layerIndex + i + 1);
                if (layerIndexNext > Operation.LayerIndexEnd) break;
                using var subtractMat = EmguExtensions.InitMat(target.Size, new MCvScalar(brightnesses[i]));

                using var nextMat = SlicerFile[layerIndexNext].LayerMat;
                var nextMatRoi = Operation.GetRoiOrDefault(nextMat);

                CvInvoke.Subtract(target, subtractMat, target, nextMatRoi);
            }

            // Apply the results only to the selected masked area, if user selected one
            Operation.ApplyMask(original, target);

            // Set current layer image with the modified mat we just manipulated
            layer.LayerMat = mat;

            // Increment progress bar by 1
            Progress.LockAndIncrement();
        });

        // return true if not cancelled by user
        return !Progress.Token.IsCancellationRequested;
    }
}