using System.IO;
using UnityEditor;
using UnityEditor.Build;
using UnityEditor.Build.Reporting;
using UnityEngine;

namespace Audio2Lipsync.Editor
{
    /// <summary>
    /// Puts the packaged model into StreamingAssets/Audio2Lipsync/ for the length of a player build,
    /// then removes it again, so a project never has to keep its own copy. A model the user put
    /// there themselves is used as-is and left alone.
    /// </summary>
    sealed class Audio2LipsyncBuildHook : IPreprocessBuildWithReport, IPostprocessBuildWithReport
    {
        // Marks a copy made by this hook, so a build that failed before post-processing still gets
        // cleaned up on the next domain reload.
        const string Marker = "Library/Audio2LipsyncBuildCopy.txt";

        public int callbackOrder => 0;

        public void OnPreprocessBuild(BuildReport report)
        {
            var dst = Audio2LipsyncModel.StreamingAssetsPath;
            if (File.Exists(dst)) return;
            var src = Audio2LipsyncModel.PackagedPath;
            if (src == null || !File.Exists(src))
                throw new BuildFailedException($"Audio2Lipsync model not found in the package: {src} (is git-lfs installed?)");
            Directory.CreateDirectory(Path.GetDirectoryName(dst));
            File.Copy(src, dst);
            File.WriteAllText(Marker, dst);
            EditorApplication.delayCall += Cleanup;   // runs after the build even when it failed
            Debug.Log($"[Audio2Lipsync] model staged for build -> {dst}");
        }

        public void OnPostprocessBuild(BuildReport report) => Cleanup();

        [InitializeOnLoadMethod]
        static void CleanupAfterFailedBuild()
        {
            if (!BuildPipeline.isBuildingPlayer) Cleanup();
        }

        static void Cleanup()
        {
            if (!File.Exists(Marker)) return;
            var path = File.ReadAllText(Marker);
            File.Delete(Marker);
            DeleteWithMeta(path);
            var dir = Path.GetDirectoryName(path);
            if (Directory.Exists(dir) && Directory.GetFileSystemEntries(dir).Length == 0)
            {
                Directory.Delete(dir);
                DeleteWithMeta(dir);
            }
        }

        static void DeleteWithMeta(string path)
        {
            if (File.Exists(path)) File.Delete(path);
            if (File.Exists(path + ".meta")) File.Delete(path + ".meta");
        }
    }
}