using Flowframes.Data;
using Flowframes.IO;
using Flowframes.UI;
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Flowframes.Main
{
    class FrameTiming
    {
        public static async Task CreateTimecodeFiles(string framesPath, bool loopEnabled, int times, bool noTimestamps)
        {
            Logger.Log("Generating timecodes...");
            await CreateTimecodeFile(framesPath, loopEnabled, times, false, noTimestamps);
            Logger.Log($"Generating timecodes... Done.", false, true);
        }

        public static async Task CreateTimecodeFile(string framesPath, bool loopEnabled, int interpFactor, bool notFirstRun, bool noTimestamps)
        {
            if (Interpolate.canceled) return;
            Logger.Log($"Generating timecodes for {interpFactor}x...", false, true);

            if(noTimestamps)
                Logger.Log("Timestamps are disabled, using static frame rate.");

            bool sceneDetection = true;
            string ext = InterpolateUtils.GetExt();

            FileInfo[] frameFiles = new DirectoryInfo(framesPath).GetFiles($"*.png");
            string vfrFile = Path.Combine(framesPath.GetParentDir(), $"vfr-{interpFactor}x.ini");
            string fileContent = "";

            string scnFramesPath = Path.Combine(framesPath.GetParentDir(), Paths.scenesDir);
            string interpPath = Paths.interpDir;

            List<string> sceneFrames = new List<string>();
            if (Directory.Exists(scnFramesPath))
                sceneFrames = Directory.GetFiles(scnFramesPath).Select(file => Path.GetFileName(file)).ToList();

            int lastFrameDuration = 1;

            // Calculate time duration between frames
            int totalFileCount = 1;
            for (int i = 0; i < (frameFiles.Length - 1); i++)
            {
                if (Interpolate.canceled) return;

                int durationTotal = 100;   // Default for no timestamps in input filenames (divided by output fps later)

                if (!noTimestamps)  // Get timings from frame filenames
                {
                    string filename1 = frameFiles[i].Name;
                    string filename2 = frameFiles[i + 1].Name;
                    durationTotal = Path.GetFileNameWithoutExtension(filename2).GetInt() - Path.GetFileNameWithoutExtension(filename1).GetInt();
                }

                lastFrameDuration = durationTotal;
                float durationPerInterpFrame = (float)durationTotal / interpFactor;

                int interpFramesAmount = interpFactor;

                bool discardThisFrame = (sceneDetection && (i + 2) < frameFiles.Length && sceneFrames.Contains(frameFiles[i + 1].Name));     // i+2 is in scene detection folder, means i+1 is ugly interp frame

                // If loop is enabled, account for the extra frame added to the end for loop continuity
                if (loopEnabled && i == (frameFiles.Length - 2))
                    interpFramesAmount = interpFramesAmount * 2;

                //Logger.Log("Writing out frames for in frame " + i, true);
                // Generate frames file lines
                for (int frm = 0; frm < interpFramesAmount; frm++)
                {
                    //Logger.Log($"Writing out frame {frm+1}/{interpFramesAmount}", true);

                    string durationStr = ((durationPerInterpFrame / 1000f) * 1).ToString("0.00000", CultureInfo.InvariantCulture);

                    if (discardThisFrame && totalFileCount > 1)     // Never discard 1st frame
                    {
                        int lastNum = totalFileCount;

                        // Logger.Log($"Writing frame {totalFileCount} [Discarding Next]", true);
                        fileContent += $"file '{interpPath}/{totalFileCount.ToString().PadLeft(Padding.interpFrames, '0')}.{ext}'\nduration {durationStr}\n";
                        totalFileCount++;

                        // Logger.Log("Discarding interp frames with out num " + totalFileCount);
                        for (int dupeCount = 1; dupeCount < interpFramesAmount; dupeCount++)
                        {
                            // Logger.Log($"Writing frame {totalFileCount} which is actually repeated frame {lastNum}");
                            fileContent += $"file '{interpPath}/{lastNum.ToString().PadLeft(Padding.interpFrames, '0')}.{ext}'\nduration {durationStr}\n";
                            totalFileCount++;
                        }

                        frm = interpFramesAmount;
                    }
                    else
                    {
                        //Logger.Log($"Writing frame {totalFileCount}", true, false);
                        fileContent += $"file '{interpPath}/{totalFileCount.ToString().PadLeft(Padding.interpFrames, '0')}.{ext}'\nduration {durationStr}\n";
                        totalFileCount++;
                    }
                }

                if ((i + 1) % 100 == 0)
                    await Task.Delay(1);
            }

            //Logger.Log($"Writing last frame: {totalFileCount}", true, false);
            string durationStrLast = ((100f / interpFactor / 1000f) * 1).ToString("0.00000", CultureInfo.InvariantCulture);
            fileContent += $"file '{interpPath}/{totalFileCount.ToString().PadLeft(Padding.interpFrames, '0')}.{ext}'\nduration {durationStrLast}\n";
            totalFileCount++;

            File.WriteAllText(vfrFile, fileContent);

            if (notFirstRun) return;    // Skip all steps that only need to be done once

            if (Config.GetBool("enableLoop"))
            {
                int lastFileNumber = frameFiles.Last().Name.GetInt();
                lastFileNumber += lastFrameDuration;
                string loopFrameTargetPath = Path.Combine(frameFiles.First().FullName.GetParentDir(), lastFileNumber.ToString().PadLeft(Padding.inputFrames, '0') + $".png");
                if (File.Exists(loopFrameTargetPath))
                {
                    Logger.Log($"Won't copy loop frame - {Path.GetFileName(loopFrameTargetPath)} already exists.", true);
                    return;
                }
                File.Copy(frameFiles.First().FullName, loopFrameTargetPath);
            }
        }
    }
}