// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using System;
using System.Collections.Generic;
using System.Linq;
using osu.Game.Beatmaps;
using osu.Game.Rulesets.Edit.Checks.Components;
using osu.Game.Storyboards;

namespace osu.Game.Rulesets.Edit.Checks
{
    public class CheckUnusedAudioAtEnd : ICheck
    {
        public CheckMetadata Metadata => new CheckMetadata(CheckCategory.Compose, "More than 20% unused audio at the end");

        public IEnumerable<IssueTemplate> PossibleTemplates => new IssueTemplate[]
        {
            new IssueTemplateUnusedAudioAtEnd(this),
            new IssueTemplateUnusedAudioAtEndStoryboardOrVideo(this),
        };

        public IEnumerable<Issue> Run(BeatmapVerifierContext context)
        {
            double mappedLength = context.Beatmap.HitObjects.Any() ? context.Beatmap.GetLastObjectTime() : 0;
            double trackLength = context.WorkingBeatmap.Track.Length;

            double mappedPercentage = Math.Round(mappedLength / trackLength * 100);

            if (mappedPercentage < 80)
            {
                double percentageLeft = Math.Abs(mappedPercentage - 100);

                bool storyboardIsPresent = isAnyStoryboardElementPresent(context.WorkingBeatmap.Storyboard);

                if (storyboardIsPresent)
                {
                    yield return new IssueTemplateUnusedAudioAtEndStoryboardOrVideo(this).Create(percentageLeft);
                }
                else
                {
                    yield return new IssueTemplateUnusedAudioAtEnd(this).Create(percentageLeft);
                }
            }
        }

        private bool isAnyStoryboardElementPresent(Storyboard storyboard)
        {
            foreach (var layer in storyboard.Layers)
            {
                foreach (var _ in layer.Elements)
                {
                    return true;
                }
            }

            return false;
        }

        public class IssueTemplateUnusedAudioAtEnd : IssueTemplate
        {
            public IssueTemplateUnusedAudioAtEnd(ICheck check)
                : base(check, IssueType.Warning, "Currently there is {0}% unused audio at the end. Ensure the outro significantly contributes to the song, otherwise cut the outro.")
            {
            }

            public Issue Create(double percentageLeft) => new Issue(this, percentageLeft);
        }

        public class IssueTemplateUnusedAudioAtEndStoryboardOrVideo : IssueTemplate
        {
            public IssueTemplateUnusedAudioAtEndStoryboardOrVideo(ICheck check)
                : base(check, IssueType.Warning, "Currently there is {0}% unused audio at the end. Ensure the outro significantly contributes to the song, or is being occupied by the video or storyboard, otherwise cut the outro.")
            {
            }

            public Issue Create(double percentageLeft) => new Issue(this, percentageLeft);
        }
    }
}