using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using Chameleon.Editor.WebAssets;
using UnityEditor;
using UnityEngine;

namespace Chameleon.Editor.AmbientCg
{
    /// <summary>
    /// Editor window: browse/paste an ambientCG material, pick resolution + format +
    /// maps, then download the ZIP, extract the selected maps and auto-build a URP/Lit
    /// material under Assets/ambientCG/{Name}/. Reuses the shared WebAssets pipeline
    /// (transport, browser grid, PBR material builder).
    /// </summary>
    public sealed class AmbientCgImporterWindow : EditorWindow
    {
        private const string RootFolder = "Assets/ambientCG";
        private const string DefaultRes = "2K";
        private const string DefaultFmt = "JPG";

        private string _urlInput = "https://ambientcg.com/a/";
        private AmbientCgAsset _asset;
        private Texture2D _thumbnail;
        private string _selectedRes = DefaultRes;
        private string _selectedFmt = DefaultFmt;
        private readonly Dictionary<PbrMapType, bool> _mapEnabled = new Dictionary<PbrMapType, bool>();

        private bool _busy;
        private string _status = "";
        private Vector2 _scroll;

        // ---- Browser ----------------------------------------------------------

        // Catalog cached for the whole session (survives window close, cleared on domain reload).
        private static List<AssetBrowserGrid.Entry> s_catalog;

        private AssetBrowserGrid _grid;
        private bool _browseFoldout = true;
        private bool _autoLoadTried;
        private bool _catalogLoading;

        [MenuItem("Tools/ambientCG Importer")]
        public static void Open()
        {
            var w = GetWindow<AmbientCgImporterWindow>("ambientCG Importer");
            w.minSize = new Vector2(440, 480);
        }

        private void OnEnable()
        {
            _grid = new AssetBrowserGrid(Repaint);
            if (s_catalog != null)
            {
                _autoLoadTried = true;
                _grid.SetCatalog(s_catalog);
            }
        }

        private void OnGUI()
        {
            _scroll = EditorGUILayout.BeginScrollView(_scroll);

            EditorGUILayout.LabelField("ambientCG Importer", EditorStyles.boldLabel);
            EditorGUILayout.HelpBox(
                "Pick a material on ambientcg.com, paste its URL here (e.g. .../a/Tiles141), " +
                "Fetch, choose resolution + format + maps, then Download. The maps ship as one ZIP; " +
                "the selected maps are extracted and a URP/Lit material is built automatically.",
                MessageType.Info);

            EditorGUILayout.Space();

            DrawBrowser();

            EditorGUILayout.Space();

            using (new EditorGUI.DisabledScope(_busy))
            {
                EditorGUILayout.LabelField("Asset URL or ID", EditorStyles.miniBoldLabel);
                using (new EditorGUILayout.HorizontalScope())
                {
                    _urlInput = EditorGUILayout.TextField(_urlInput);
                    if (GUILayout.Button("Fetch", GUILayout.Width(70)))
                        Fetch();
                }
            }

            if (_asset != null)
                DrawAssetSection();

            EditorGUILayout.Space();
            if (!string.IsNullOrEmpty(_status))
                EditorGUILayout.HelpBox(_status, _busy ? MessageType.None : MessageType.Info);

            EditorGUILayout.EndScrollView();
        }

        private void DrawAssetSection()
        {
            EditorGUILayout.Space();
            using (new EditorGUILayout.HorizontalScope())
            {
                if (_thumbnail)
                {
                    var r = GUILayoutUtility.GetRect(96, 96, GUILayout.Width(96), GUILayout.Height(96));
                    GUI.DrawTexture(r, _thumbnail, ScaleMode.ScaleToFit);
                }
                using (new EditorGUILayout.VerticalScope())
                {
                    EditorGUILayout.LabelField(_asset.Name, EditorStyles.boldLabel);
                    EditorGUILayout.LabelField($"ID: {_asset.Id}", EditorStyles.miniLabel);
                    if (!string.IsNullOrEmpty(_asset.Category))
                        EditorGUILayout.LabelField($"Category: {_asset.Category}", EditorStyles.miniLabel);
                    if (_asset.DataType != "Material")
                        EditorGUILayout.HelpBox("This asset is not a material — only materials are supported.", MessageType.Warning);
                }
            }

            var resolutions = _asset.Resolutions();
            if (resolutions.Count == 0)
            {
                EditorGUILayout.HelpBox("No ZIP downloads found for this asset.", MessageType.Warning);
                return;
            }

            EditorGUILayout.Space();

            // Resolution popup.
            var resArray = resolutions.ToArray();
            int resIdx = Mathf.Max(0, Array.IndexOf(resArray, _selectedRes));
            resIdx = EditorGUILayout.Popup("Resolution", resIdx, resArray);
            _selectedRes = resArray[resIdx];

            // Format popup (per resolution; JPG is smaller, PNG lossless).
            var formats = _asset.Formats(_selectedRes);
            var fmtArray = formats.ToArray();
            int fmtIdx = Mathf.Max(0, Array.IndexOf(fmtArray, _selectedFmt));
            fmtIdx = EditorGUILayout.Popup("Format", fmtIdx, fmtArray);
            _selectedFmt = fmtArray[fmtIdx];

            if (_asset.TryGetZip(_selectedRes, _selectedFmt, out var zipInfo) && zipInfo.Size > 0)
                EditorGUILayout.LabelField($"ZIP size: {zipInfo.Size / (1024f * 1024f):0.#} MB", EditorStyles.miniLabel);

            EditorGUILayout.Space();
            EditorGUILayout.LabelField("Maps", EditorStyles.miniBoldLabel);
            foreach (var meta in PbrMapInfo.All)
            {
                if (!_asset.Maps.Contains(meta.Type))
                    continue;
                bool cur = _mapEnabled.TryGetValue(meta.Type, out var v) ? v : meta.DefaultEnabled;
                _mapEnabled[meta.Type] = EditorGUILayout.ToggleLeft(meta.Label, cur);
            }

            EditorGUILayout.Space();
            bool canDownload = !_busy && _asset.DataType == "Material" && AnyMapSelected();
            using (new EditorGUI.DisabledScope(!canDownload))
            {
                if (GUILayout.Button("Download / Import", GUILayout.Height(30)))
                    Download();
            }
        }

        private bool AnyMapSelected()
        {
            foreach (var meta in PbrMapInfo.All)
            {
                if (!_asset.Maps.Contains(meta.Type))
                    continue;
                if (_mapEnabled.TryGetValue(meta.Type, out var v) ? v : meta.DefaultEnabled)
                    return true;
            }
            return false;
        }

        // ---- Browser -----------------------------------------------------------

        private void DrawBrowser()
        {
            _browseFoldout = EditorGUILayout.Foldout(_browseFoldout, "Browse catalog", true, EditorStyles.foldoutHeader);
            if (!_browseFoldout)
                return;

            using (new EditorGUI.DisabledScope(_busy))
            {
                if (!_grid.HasCatalog)
                {
                    if (!_catalogLoading && !_autoLoadTried)
                    {
                        _autoLoadTried = true;
                        LoadCatalog();
                    }
                    using (new EditorGUILayout.HorizontalScope())
                    {
                        EditorGUILayout.LabelField(_catalogLoading
                            ? "Loading material catalog…"
                            : "Catalog not loaded.");
                        using (new EditorGUI.DisabledScope(_catalogLoading))
                            if (GUILayout.Button("Load catalog", GUILayout.Width(110)))
                                LoadCatalog();
                    }
                    return;
                }

                _grid.Draw(SelectAsset, LoadCatalog, "materials");
            }
        }

        private void SelectAsset(AssetBrowserGrid.Entry a)
        {
            _urlInput = "https://ambientcg.com/a/" + a.Key;
            GUI.FocusControl(null);
            Fetch();
        }

        private void LoadCatalog()
        {
            _catalogLoading = true;
            _status = "Loading ambientCG material catalog…";
            Repaint();

            AmbientCgApi.FetchCatalog(
                list =>
                {
                    s_catalog = list;
                    _catalogLoading = false;
                    _grid.SetCatalog(list);
                    _status = $"Catalog loaded: {list.Count} materials.";
                    Repaint();
                },
                err =>
                {
                    _catalogLoading = false;
                    _status = "Catalog error: " + err;
                    Debug.LogError("[ambientCG] " + err);
                    Repaint();
                },
                (loaded, total) =>
                {
                    _status = $"Loading catalog… {loaded}/{total}";
                    Repaint();
                });
        }

        // ---- Fetch -------------------------------------------------------------

        private void Fetch()
        {
            string id = AmbientCgApi.ExtractId(_urlInput);
            if (string.IsNullOrEmpty(id))
            {
                EditorUtility.DisplayDialog("ambientCG", "Could not read an asset ID from the URL.", "OK");
                return;
            }

            _busy = true;
            _status = $"Fetching '{id}'…";
            _asset = null;
            _thumbnail = null;
            _mapEnabled.Clear();
            Repaint();

            AmbientCgApi.FetchAsset(id, asset =>
            {
                _asset = asset;
                EditorWebRequest.GetTexture(asset.ThumbnailUrl, tex => { _thumbnail = tex; Repaint(); }, _ => { });

                var resolutions = asset.Resolutions();
                if (!resolutions.Contains(_selectedRes))
                    _selectedRes = resolutions.Contains(DefaultRes) ? DefaultRes
                        : resolutions.Count > 0 ? resolutions[0] : DefaultRes;
                var formats = asset.Formats(_selectedRes);
                if (!formats.Contains(_selectedFmt))
                    _selectedFmt = formats.Contains(DefaultFmt) ? DefaultFmt
                        : formats.Count > 0 ? formats[0] : DefaultFmt;

                _busy = false;
                _status = asset.DataType == "Material"
                    ? $"Ready: {asset.Maps.Count} map type(s), {resolutions.Count} resolution(s)."
                    : "Fetched, but this asset is not a material.";
                Repaint();
            }, err => Fail(err));
        }

        // ---- Download ----------------------------------------------------------

        private void Download()
        {
            if (!_asset.TryGetZip(_selectedRes, _selectedFmt, out var zip))
            {
                Fail($"No ZIP for {_selectedRes}-{_selectedFmt}.");
                return;
            }

            var wanted = new List<PbrMapType>();
            foreach (var meta in PbrMapInfo.All)
            {
                if (!_asset.Maps.Contains(meta.Type))
                    continue;
                if (_mapEnabled.TryGetValue(meta.Type, out var v) ? v : meta.DefaultEnabled)
                    wanted.Add(meta.Type);
            }
            if (wanted.Count == 0)
                return;

            string displayName = _asset.Name;
            string folder = $"{RootFolder}/{ImportUtil.SanitizeFileName(displayName)}";

            folder = ImportUtil.ResolveFolderCollision(folder, "ambientCG");
            if (folder == null)
                return;
            ImportUtil.EnsureFolder(folder);

            string tempZip = Path.Combine(Path.GetTempPath(), zip.FileName);

            _busy = true;
            _status = $"Downloading {zip.FileName}…";
            Repaint();

            EditorWebRequest.DownloadFile(zip.Url, tempZip,
                onDone: () => ExtractAndBuild(tempZip, folder, displayName, wanted),
                onError: err =>
                {
                    Fail(err);
                },
                onProgress: p =>
                {
                    _status = $"Downloading {zip.FileName}… {p * 100f:0}%";
                    Repaint();
                });
        }

        /// <summary>
        /// Extracts the selected maps out of the downloaded ZIP into the target folder,
        /// then hands them to the shared PBR material builder. ZIP contents follow the
        /// ambientCG convention "{Id}_{Res}-{Fmt}_{MapSuffix}.{ext}".
        /// </summary>
        private void ExtractAndBuild(string tempZip, string folder, string displayName, List<PbrMapType> wanted)
        {
            var results = new List<PbrMaterialBuilder.Downloaded>();
            var missing = new List<PbrMapType>(wanted);

            try
            {
                using var archive = ZipFile.OpenRead(tempZip);
                foreach (var entry in archive.Entries)
                {
                    string nameNoExt = Path.GetFileNameWithoutExtension(entry.Name);
                    foreach (var type in wanted)
                    {
                        string suffix = "_" + AmbientCgApi.ZipSuffix(type);
                        if (!nameNoExt.EndsWith(suffix, StringComparison.OrdinalIgnoreCase))
                            continue;

                        string destPath = $"{folder}/{entry.Name}";
                        entry.ExtractToFile(Path.GetFullPath(destPath), overwrite: true);
                        results.Add(new PbrMaterialBuilder.Downloaded { Type = type, AssetPath = destPath });
                        missing.Remove(type);
                        break;
                    }
                }
            }
            catch (Exception e)
            {
                Fail($"ZIP extraction failed: {e.Message}");
                return;
            }
            finally
            {
                try { File.Delete(tempZip); } catch { /* temp file, best effort */ }
            }

            if (results.Count == 0)
            {
                Fail("No selected maps found inside the ZIP.");
                return;
            }
            foreach (var m in missing)
                Debug.LogWarning($"[ambientCG] Map '{m}' not found inside the ZIP — skipped.");

            AssetDatabase.Refresh();

            int maxSize = ImportUtil.ResolutionToMaxSize(_selectedRes);
            PbrMaterialBuilder.Build(folder, displayName, _asset.Id, maxSize, results);

            _busy = false;
            _status = $"Done: {results.Count} map(s) imported, material built in {folder}.";
            Repaint();
        }

        // ---- Helpers -----------------------------------------------------------

        private void Fail(string message)
        {
            _busy = false;
            _status = "Error: " + message;
            Debug.LogError("[ambientCG] " + message);
            Repaint();
        }
    }
}