using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using UnityEditor;
using UnityEditor.AddressableAssets;
using UnityEditor.AddressableAssets.Settings;
using UnityEditor.AddressableAssets.Settings.GroupSchemas;
using UnityEngine;

public static class GeoTileAddressablesBuilder
{
    private const string TilePrefabsDir = "Assets/TilePrefabs";
    private const string TileIndexCsvPath = "Assets/GeoData/tile_index.csv";
    private const string GroupName = "TilePrefabs";
    private const string TileLabel = "tile";
    private const string ManifestFileName = "TileManifest.json";
    private const float TileSizeMeters = 1000f;

    private const string BuildPathVariable = "TileBuildPath";
    private const string LoadPathVariable = "TileLoadPath";
    private const string BuildPathValue = "ServerData/TileBundles/[BuildTarget]";
    private const string LoadPathValue = "file://{UnityEngine.Application.persistentDataPath}/TileBundles/[BuildTarget]";

    [MenuItem("Tools/Geo Tiles/Build Tile Addressables (Android)")]
    public static void BuildAndroid()
    {
        BuildForTarget(BuildTarget.Android, BuildTargetGroup.Android);
    }

    private static void BuildForTarget(BuildTarget target, BuildTargetGroup group)
    {
        if (!Directory.Exists(TilePrefabsDir))
        {
            Debug.LogError($"[GeoTileAddressablesBuilder] Prefab directory missing: {TilePrefabsDir}");
            return;
        }
        if (!File.Exists(TileIndexCsvPath))
        {
            Debug.LogError($"[GeoTileAddressablesBuilder] CSV missing: {TileIndexCsvPath}");
            return;
        }

        var settings = AddressableAssetSettingsDefaultObject.GetSettings(true);
        if (settings == null)
        {
            Debug.LogError("[GeoTileAddressablesBuilder] Addressables settings not found.");
            return;
        }

        EnsureProfileVariable(settings, BuildPathVariable, BuildPathValue);
        EnsureProfileVariable(settings, LoadPathVariable, LoadPathValue);
        EnsureRemoteCatalogPaths(settings);

        var groupAsset = GetOrCreateGroup(settings);
        ConfigureGroup(settings, groupAsset);
        AssignPrefabs(settings, groupAsset);

        settings.SetDirty(AddressableAssetSettings.ModificationEvent.BatchModification, null, true);
        AssetDatabase.SaveAssets();

        var previousTarget = EditorUserBuildSettings.activeBuildTarget;
        if (previousTarget != target)
        {
            if (!EditorUserBuildSettings.SwitchActiveBuildTarget(group, target))
            {
                Debug.LogError($"[GeoTileAddressablesBuilder] Failed to switch build target to {target}.");
                return;
            }
        }

        AddressableAssetSettings.BuildPlayerContent();

        var outputPath = GetRemoteCatalogBuildPath(settings, target);
        if (!Directory.Exists(outputPath))
        {
            Debug.LogError($"[GeoTileAddressablesBuilder] Build output not found: {outputPath}");
            return;
        }

        var (catalogFile, catalogHashFile) = FindCatalogFiles(outputPath);
        if (string.IsNullOrEmpty(catalogFile))
        {
            Debug.LogError($"[GeoTileAddressablesBuilder] Catalog file not found in: {outputPath}");
            return;
        }

        var manifest = BuildManifest(target.ToString(), catalogFile, catalogHashFile);
        var manifestPath = Path.Combine(outputPath, ManifestFileName);
        File.WriteAllText(manifestPath, JsonUtility.ToJson(manifest, true));

        AssetDatabase.Refresh();

        Debug.Log($"[GeoTileAddressablesBuilder] DONE. Output={outputPath}");
    }

    private static void AssignPrefabs(AddressableAssetSettings settings, AddressableAssetGroup group)
    {
        var prefabGuids = AssetDatabase.FindAssets("t:Prefab", new[] { TilePrefabsDir });
        foreach (var guid in prefabGuids)
        {
            var path = AssetDatabase.GUIDToAssetPath(guid).Replace("\\", "/");
            var parentDir = Path.GetDirectoryName(path)?.Replace("\\", "/");
            if (!string.Equals(parentDir, TilePrefabsDir, StringComparison.OrdinalIgnoreCase))
                continue;

            var entry = settings.CreateOrMoveEntry(guid, group, false, false);
            entry.address = Path.GetFileNameWithoutExtension(path);
            entry.SetLabel(TileLabel, true, true);
        }
    }

    private static AddressableAssetGroup GetOrCreateGroup(AddressableAssetSettings settings)
    {
        var group = settings.FindGroup(GroupName);
        if (group != null)
            return group;

        group = settings.CreateGroup(GroupName, false, false, false, new List<AddressableAssetGroupSchema>());
        group.AddSchema<BundledAssetGroupSchema>();
        group.AddSchema<ContentUpdateGroupSchema>();
        return group;
    }

    private static void ConfigureGroup(AddressableAssetSettings settings, AddressableAssetGroup group)
    {
        var bundleSchema = group.GetSchema<BundledAssetGroupSchema>();
        if (bundleSchema == null)
            bundleSchema = group.AddSchema<BundledAssetGroupSchema>();

        bundleSchema.BundleMode = BundledAssetGroupSchema.BundlePackingMode.PackSeparately;
        bundleSchema.BuildPath.SetVariableByName(settings, BuildPathVariable);
        bundleSchema.LoadPath.SetVariableByName(settings, LoadPathVariable);

        var updateSchema = group.GetSchema<ContentUpdateGroupSchema>();
        if (updateSchema != null)
            updateSchema.StaticContent = true;
    }

    private static void EnsureProfileVariable(AddressableAssetSettings settings, string name, string value)
    {
        var profileId = settings.activeProfileId;
        var current = settings.profileSettings.GetValueByName(profileId, name);
        if (string.IsNullOrEmpty(current))
            settings.profileSettings.CreateValue(name, value);

        settings.profileSettings.SetValue(profileId, name, value);
    }

    private static void EnsureRemoteCatalogPaths(AddressableAssetSettings settings)
    {
        settings.BuildRemoteCatalog = true;
        settings.RemoteCatalogBuildPath.SetVariableByName(settings, BuildPathVariable);
        settings.RemoteCatalogLoadPath.SetVariableByName(settings, LoadPathVariable);
    }

    private static (string catalogFile, string catalogHashFile) FindCatalogFiles(string outputPath)
    {
        var catalogFiles = Directory.GetFiles(outputPath, "*catalog*.json");
        if (catalogFiles.Length == 0)
            catalogFiles = Directory.GetFiles(outputPath, "*catalog*.bin");

        var catalogFile = catalogFiles.Length > 0 ? Path.GetFileName(catalogFiles[0]) : null;

        string catalogHash = null;
        if (!string.IsNullOrEmpty(catalogFile))
        {
            var baseName = Path.GetFileNameWithoutExtension(catalogFile);
            var hashCandidate = Path.Combine(outputPath, $"{baseName}.hash");
            if (File.Exists(hashCandidate))
            {
                catalogHash = Path.GetFileName(hashCandidate);
            }
            else
            {
                var hashFiles = Directory.GetFiles(outputPath, "*catalog*.hash");
                if (hashFiles.Length > 0)
                    catalogHash = Path.GetFileName(hashFiles[0]);
            }
        }

        return (catalogFile, catalogHash);
    }

    private static TileManifest BuildManifest(string buildTarget, string catalogFile, string catalogHashFile)
    {
        var tiles = ParseTilesCsv();
        if (tiles.Count == 0)
            throw new InvalidOperationException("No tiles parsed from tile_index.csv");

        double minX = double.PositiveInfinity;
        double minY = double.PositiveInfinity;

        foreach (var tile in tiles)
        {
            minX = Math.Min(minX, tile.Xmin);
            minY = Math.Min(minY, tile.Ymin);
        }

        var entries = new TileEntry[tiles.Count];
        for (int i = 0; i < tiles.Count; i++)
        {
            var tile = tiles[i];
            entries[i] = new TileEntry
            {
                tileId = tile.TileId,
                offsetX = (float)(tile.Xmin - minX),
                offsetZ = (float)(tile.Ymin - minY),
                baseY = (float)tile.GlobalMin
            };
        }

        return new TileManifest
        {
            buildTarget = buildTarget,
            catalogFile = catalogFile,
            catalogHashFile = catalogHashFile,
            tileSizeMeters = TileSizeMeters,
            tiles = entries
        };
    }

    private static string GetRemoteCatalogBuildPath(AddressableAssetSettings settings, BuildTarget target)
    {
        var rawPath = settings.RemoteCatalogBuildPath.GetValue(settings);
        if (string.IsNullOrWhiteSpace(rawPath))
            rawPath = BuildPathValue.Replace("[BuildTarget]", target.ToString());

        return Path.GetFullPath(rawPath.Replace("[BuildTarget]", target.ToString()));
    }

    private struct TileRecord
    {
        public string TileId;
        public double Xmin;
        public double Ymin;
        public double GlobalMin;
        public double GlobalMax;
    }

    private static List<TileRecord> ParseTilesCsv()
    {
        var tiles = new List<TileRecord>();
        var ci = CultureInfo.InvariantCulture;
        var lines = File.ReadAllLines(TileIndexCsvPath);

        if (lines.Length < 2)
            return tiles;

        var headerMap = BuildHeaderMap(lines[0]);
        string[] required = { "tile_id", "xmin", "ymin", "global_min", "global_max" };
        if (!HasAll(headerMap, required))
        {
            Debug.LogError("[GeoTileAddressablesBuilder] CSV missing required columns.");
            return tiles;
        }

        int IDX_TILE = headerMap["tile_id"];
        int IDX_XMIN = headerMap["xmin"];
        int IDX_YMIN = headerMap["ymin"];
        int IDX_GMIN = headerMap["global_min"];
        int IDX_GMAX = headerMap["global_max"];

        for (int i = 1; i < lines.Length; i++)
        {
            var line = lines[i].Trim();
            if (string.IsNullOrWhiteSpace(line))
                continue;

            var parts = line.Split(',');
            int maxIdx = Math.Max(IDX_TILE, Math.Max(IDX_XMIN, Math.Max(IDX_YMIN, Math.Max(IDX_GMIN, IDX_GMAX))));
            if (parts.Length <= maxIdx)
                continue;

            try
            {
                tiles.Add(new TileRecord
                {
                    TileId = parts[IDX_TILE].Trim(),
                    Xmin = double.Parse(parts[IDX_XMIN], ci),
                    Ymin = double.Parse(parts[IDX_YMIN], ci),
                    GlobalMin = double.Parse(parts[IDX_GMIN], ci),
                    GlobalMax = double.Parse(parts[IDX_GMAX], ci)
                });
            }
            catch (Exception e)
            {
                Debug.LogWarning($"[GeoTileAddressablesBuilder] Parse error line {i + 1}: {e.Message}");
            }
        }

        return tiles;
    }

    private static Dictionary<string, int> BuildHeaderMap(string headerLine)
    {
        var map = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
        var headers = headerLine.Split(',');
        for (int i = 0; i < headers.Length; i++)
            map[headers[i].Trim()] = i;
        return map;
    }

    private static bool HasAll(Dictionary<string, int> map, string[] keys)
    {
        foreach (var key in keys)
        {
            if (!map.ContainsKey(key))
                return false;
        }
        return true;
    }
}