// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using OpenTK;
using OpenTK.Graphics;
using osu.Framework.Graphics;
using osu.Framework.IO.File;
using osu.Game.Storyboards;

namespace osu.Game.Beatmaps.Formats
{
    public class LegacyStoryboardDecoder : LegacyDecoder
    {
        private Storyboard storyboard;

        private StoryboardSprite storyboardSprite;
        private CommandTimelineGroup timelineGroup;

        private readonly Dictionary<string, string> variables = new Dictionary<string, string>();

        public LegacyStoryboardDecoder()
        {
        }

        public LegacyStoryboardDecoder(int beatmapVersion)
        {
            BeatmapVersion = beatmapVersion;
        }

        protected override void ParseStoryboard(StreamReader stream, Storyboard storyboard)
        {
            if (stream == null)
                throw new ArgumentNullException(nameof(stream));
            if (storyboard == null)
                throw new ArgumentNullException(nameof(storyboard));

            this.storyboard = storyboard;

            ParseContent(stream);
        }

        protected override void ProcessSection(Section section, string line)
        {
            switch (section)
            {
                case Section.Events:
                    handleEvents(line);
                    break;
                case Section.Variables:
                    handleVariables(line);
                    break;
            }
        }

        private void handleEvents(string line)
        {
            var depth = 0;
            while (line.StartsWith(" ") || line.StartsWith("_"))
            {
                ++depth;
                line = line.Substring(1);
            }

            decodeVariables(ref line);

            string[] split = line.Split(',');

            if (depth == 0)
            {
                storyboardSprite = null;

                EventType type;
                if (!Enum.TryParse(split[0], out type))
                    throw new InvalidDataException($@"Unknown event type {split[0]}");

                switch (type)
                {
                    case EventType.Sprite:
                        {
                            var layer = parseLayer(split[1]);
                            var origin = parseOrigin(split[2]);
                            var path = cleanFilename(split[3]);
                            var x = float.Parse(split[4], NumberFormatInfo.InvariantInfo);
                            var y = float.Parse(split[5], NumberFormatInfo.InvariantInfo);
                            storyboardSprite = new StoryboardSprite(path, origin, new Vector2(x, y));
                            storyboard.GetLayer(layer).Add(storyboardSprite);
                        }
                        break;
                    case EventType.Animation:
                        {
                            var layer = parseLayer(split[1]);
                            var origin = parseOrigin(split[2]);
                            var path = cleanFilename(split[3]);
                            var x = float.Parse(split[4], NumberFormatInfo.InvariantInfo);
                            var y = float.Parse(split[5], NumberFormatInfo.InvariantInfo);
                            var frameCount = int.Parse(split[6]);
                            var frameDelay = double.Parse(split[7], NumberFormatInfo.InvariantInfo);
                            var loopType = split.Length > 8 ? (AnimationLoopType)Enum.Parse(typeof(AnimationLoopType), split[8]) : AnimationLoopType.LoopForever;
                            storyboardSprite = new StoryboardAnimation(path, origin, new Vector2(x, y), frameCount, frameDelay, loopType);
                            storyboard.GetLayer(layer).Add(storyboardSprite);
                        }
                        break;
                    case EventType.Sample:
                        {
                            var time = double.Parse(split[1], CultureInfo.InvariantCulture);
                            var layer = parseLayer(split[2]);
                            var path = cleanFilename(split[3]);
                            var volume = split.Length > 4 ? float.Parse(split[4], CultureInfo.InvariantCulture) : 100;
                            storyboard.GetLayer(layer).Add(new StoryboardSample(path, time, volume));
                        }
                        break;
                }
            }
            else
            {
                if (depth < 2)
                    timelineGroup = storyboardSprite?.TimelineGroup;

                var commandType = split[0];
                switch (commandType)
                {
                    case "T":
                        {
                            var triggerName = split[1];
                            var startTime = split.Length > 2 ? double.Parse(split[2], CultureInfo.InvariantCulture) : double.MinValue;
                            var endTime = split.Length > 3 ? double.Parse(split[3], CultureInfo.InvariantCulture) : double.MaxValue;
                            var groupNumber = split.Length > 4 ? int.Parse(split[4]) : 0;
                            timelineGroup = storyboardSprite?.AddTrigger(triggerName, startTime, endTime, groupNumber);
                        }
                        break;
                    case "L":
                        {
                            var startTime = double.Parse(split[1], CultureInfo.InvariantCulture);
                            var loopCount = int.Parse(split[2]);
                            timelineGroup = storyboardSprite?.AddLoop(startTime, loopCount);
                        }
                        break;
                    default:
                        {
                            if (string.IsNullOrEmpty(split[3]))
                                split[3] = split[2];

                            var easing = (Easing)int.Parse(split[1]);
                            var startTime = double.Parse(split[2], CultureInfo.InvariantCulture);
                            var endTime = double.Parse(split[3], CultureInfo.InvariantCulture);

                            switch (commandType)
                            {
                                case "F":
                                    {
                                        var startValue = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var endValue = split.Length > 5 ? float.Parse(split[5], CultureInfo.InvariantCulture) : startValue;
                                        timelineGroup?.Alpha.Add(easing, startTime, endTime, startValue, endValue);
                                    }
                                    break;
                                case "S":
                                    {
                                        var startValue = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var endValue = split.Length > 5 ? float.Parse(split[5], CultureInfo.InvariantCulture) : startValue;
                                        timelineGroup?.Scale.Add(easing, startTime, endTime, new Vector2(startValue), new Vector2(endValue));
                                    }
                                    break;
                                case "V":
                                    {
                                        var startX = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var startY = float.Parse(split[5], CultureInfo.InvariantCulture);
                                        var endX = split.Length > 6 ? float.Parse(split[6], CultureInfo.InvariantCulture) : startX;
                                        var endY = split.Length > 7 ? float.Parse(split[7], CultureInfo.InvariantCulture) : startY;
                                        timelineGroup?.Scale.Add(easing, startTime, endTime, new Vector2(startX, startY), new Vector2(endX, endY));
                                    }
                                    break;
                                case "R":
                                    {
                                        var startValue = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var endValue = split.Length > 5 ? float.Parse(split[5], CultureInfo.InvariantCulture) : startValue;
                                        timelineGroup?.Rotation.Add(easing, startTime, endTime, MathHelper.RadiansToDegrees(startValue), MathHelper.RadiansToDegrees(endValue));
                                    }
                                    break;
                                case "M":
                                    {
                                        var startX = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var startY = float.Parse(split[5], CultureInfo.InvariantCulture);
                                        var endX = split.Length > 6 ? float.Parse(split[6], CultureInfo.InvariantCulture) : startX;
                                        var endY = split.Length > 7 ? float.Parse(split[7], CultureInfo.InvariantCulture) : startY;
                                        timelineGroup?.X.Add(easing, startTime, endTime, startX, endX);
                                        timelineGroup?.Y.Add(easing, startTime, endTime, startY, endY);
                                    }
                                    break;
                                case "MX":
                                    {
                                        var startValue = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var endValue = split.Length > 5 ? float.Parse(split[5], CultureInfo.InvariantCulture) : startValue;
                                        timelineGroup?.X.Add(easing, startTime, endTime, startValue, endValue);
                                    }
                                    break;
                                case "MY":
                                    {
                                        var startValue = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var endValue = split.Length > 5 ? float.Parse(split[5], CultureInfo.InvariantCulture) : startValue;
                                        timelineGroup?.Y.Add(easing, startTime, endTime, startValue, endValue);
                                    }
                                    break;
                                case "C":
                                    {
                                        var startRed = float.Parse(split[4], CultureInfo.InvariantCulture);
                                        var startGreen = float.Parse(split[5], CultureInfo.InvariantCulture);
                                        var startBlue = float.Parse(split[6], CultureInfo.InvariantCulture);
                                        var endRed = split.Length > 7 ? float.Parse(split[7], CultureInfo.InvariantCulture) : startRed;
                                        var endGreen = split.Length > 8 ? float.Parse(split[8], CultureInfo.InvariantCulture) : startGreen;
                                        var endBlue = split.Length > 9 ? float.Parse(split[9], CultureInfo.InvariantCulture) : startBlue;
                                        timelineGroup?.Colour.Add(easing, startTime, endTime,
                                            new Color4(startRed / 255f, startGreen / 255f, startBlue / 255f, 1),
                                            new Color4(endRed / 255f, endGreen / 255f, endBlue / 255f, 1));
                                    }
                                    break;
                                case "P":
                                    {
                                        var type = split[4];
                                        switch (type)
                                        {
                                            case "A":
                                                timelineGroup?.BlendingMode.Add(easing, startTime, endTime, BlendingMode.Additive, startTime == endTime ? BlendingMode.Additive : BlendingMode.Inherit);
                                                break;
                                            case "H":
                                                timelineGroup?.FlipH.Add(easing, startTime, endTime, true, startTime == endTime);
                                                break;
                                            case "V":
                                                timelineGroup?.FlipV.Add(easing, startTime, endTime, true, startTime == endTime);
                                                break;
                                        }
                                    }
                                    break;
                                default:
                                    throw new InvalidDataException($@"Unknown command type: {commandType}");
                            }
                        }
                        break;
                }
            }
        }

        private string parseLayer(string value) => Enum.Parse(typeof(StoryLayer), value).ToString();

        private Anchor parseOrigin(string value)
        {
            var origin = (LegacyOrigins)Enum.Parse(typeof(LegacyOrigins), value);
            switch (origin)
            {
                case LegacyOrigins.TopLeft:
                    return Anchor.TopLeft;
                case LegacyOrigins.TopCentre:
                    return Anchor.TopCentre;
                case LegacyOrigins.TopRight:
                    return Anchor.TopRight;
                case LegacyOrigins.CentreLeft:
                    return Anchor.CentreLeft;
                case LegacyOrigins.Centre:
                    return Anchor.Centre;
                case LegacyOrigins.CentreRight:
                    return Anchor.CentreRight;
                case LegacyOrigins.BottomLeft:
                    return Anchor.BottomLeft;
                case LegacyOrigins.BottomCentre:
                    return Anchor.BottomCentre;
                case LegacyOrigins.BottomRight:
                    return Anchor.BottomRight;
            }
            throw new InvalidDataException($@"Unknown origin: {value}");
        }

        private void handleVariables(string line)
        {
            var pair = SplitKeyVal(line, '=');
            variables[pair.Key] = pair.Value;
        }

        /// <summary>
        /// Decodes any beatmap variables present in a line into their real values.
        /// </summary>
        /// <param name="line">The line which may contains variables.</param>
        private void decodeVariables(ref string line)
        {
            while (line.IndexOf('$') >= 0)
            {
                string origLine = line;
                string[] split = line.Split(',');
                for (int i = 0; i < split.Length; i++)
                {
                    var item = split[i];
                    if (item.StartsWith("$") && variables.ContainsKey(item))
                        split[i] = variables[item];
                }

                line = string.Join(",", split);
                if (line == origLine)
                    break;
            }
        }

        private string cleanFilename(string path) => FileSafety.PathSanitise(path.Trim('\"'));
    }
}