using System.Collections.Generic;
using System.IO;
using System.Linq;
using UnityEditor;

namespace UnitySweeper
{
    public class AssetReferenceCollection : IReferenceCollection
    {
        public void Init(List<CollectionData> refs)
        {
            references = refs;
        }

        private List<CollectionData> references;

        public void CollectionFiles()
        {
            var allFiles = Directory.GetFiles("Assets", "*.*", SearchOption.AllDirectories)
                .Where(c => Path.GetExtension(c) != ".meta")
                .Where(c => Path.GetExtension(c) != ".shader")
                .Where(c => Path.GetExtension(c) != ".cg")
                .Where(c => Path.GetExtension(c) != ".cginc")
                .Where(c => Path.GetExtension(c) != ".cs");

            foreach (var file in allFiles)
            {
                CollectionReferenceAssets(file);
            }
        }

        private void CollectionReferenceAssets(string path)
        {
            var guid = AssetDatabase.AssetPathToGUID(path);
            if (File.Exists(path) == false)
            {
                return;
            }

            var referenceFiles = AssetDatabase.GetDependencies(new[] {path});
            List<string> referenceList = null;
            CollectionData reference = null;

            if (references.Exists(c => c.fileGuid == guid) == false)
            {
                referenceList = new List<string>();
                reference = new CollectionData
                {
                    fileGuid = guid,
                    referenceGuids = referenceList,
                };
                references.Add(reference);
            }
            else
            {
                reference = references.Find(c => c.fileGuid == guid);
                referenceList = reference.referenceGuids;
            }

            if (string.IsNullOrEmpty(AssetDatabase.GUIDToAssetPath(guid)) == false)
            {
                reference.timeStamp = File.GetLastWriteTime(AssetDatabase.GUIDToAssetPath(guid));
            }

            foreach (var file in referenceFiles)
            {
                if (referenceList.Contains(file) == false)
                {
                    referenceList.Add(AssetDatabase.AssetPathToGUID(file));
                }
            }
        }
    }
}