#if UNITY_EDITOR
#nullable enable

using System;
using System.IO;
using System.Linq;
using System.Text;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using UnityEngine;

namespace ShrinkSDK.Installer
{
    internal static class ShrinkSdkManifestStore
    {
        internal static string ManifestPath => Path.Combine(
            Path.GetFullPath(Path.Combine(Application.dataPath, "..")),
            "Packages",
            "manifest.json");

        internal static bool HasShrinkSdkRegistry()
        {
            var manifest = ReadManifest();
            return GetShrinkSdkRegistry(manifest) != null;
        }

        internal static void EnsureShrinkSdkRegistry()
        {
            var manifest = ReadManifest();
            var registries = manifest["scopedRegistries"] as JArray;
            if (registries == null)
            {
                registries = new JArray();
                manifest["scopedRegistries"] = registries;
            }

            var conflictingRegistry = registries
                .OfType<JObject>()
                .FirstOrDefault(registry =>
                    !UrlEquals((string?)registry["url"], ShrinkSdkPackageCatalog.RegistryUrl) &&
                    (registry["scopes"] as JArray)?.Values<string>().Any(scope =>
                        string.Equals(scope, ShrinkSdkPackageCatalog.RegistryScope, StringComparison.Ordinal)) == true);

            if (conflictingRegistry != null)
            {
                throw new InvalidOperationException(
                    "Packages/manifest.json already maps com.cneicy to another scoped registry. Resolve that registry explicitly before installing ShrinkSDK.");
            }

            var registry = GetShrinkSdkRegistry(manifest);
            if (registry == null)
            {
                registry = new JObject
                {
                    ["name"] = ShrinkSdkPackageCatalog.RegistryName,
                    ["url"] = ShrinkSdkPackageCatalog.RegistryUrl,
                    ["scopes"] = new JArray(ShrinkSdkPackageCatalog.RegistryScope)
                };
                registries.Add(registry);
            }
            else
            {
                registry["name"] = ShrinkSdkPackageCatalog.RegistryName;
                registry["url"] = ShrinkSdkPackageCatalog.RegistryUrl;
                var scopes = registry["scopes"] as JArray ?? new JArray();
                if (!scopes.Values<string>().Any(scope =>
                        string.Equals(scope, ShrinkSdkPackageCatalog.RegistryScope, StringComparison.Ordinal)))
                {
                    scopes.Add(ShrinkSdkPackageCatalog.RegistryScope);
                }

                registry["scopes"] = scopes;
            }

            AtomicWrite(manifest.ToString(Formatting.Indented) + Environment.NewLine);
        }

        private static JObject ReadManifest()
        {
            if (!File.Exists(ManifestPath))
            {
                throw new FileNotFoundException("Unity package manifest was not found.", ManifestPath);
            }

            return JObject.Parse(File.ReadAllText(ManifestPath, Encoding.UTF8));
        }

        private static JObject? GetShrinkSdkRegistry(JObject manifest)
        {
            return (manifest["scopedRegistries"] as JArray)?
                .OfType<JObject>()
                .FirstOrDefault(registry => UrlEquals((string?)registry["url"], ShrinkSdkPackageCatalog.RegistryUrl));
        }

        private static bool UrlEquals(string? left, string right)
        {
            return string.Equals(NormalizeUrl(left), NormalizeUrl(right), StringComparison.OrdinalIgnoreCase);
        }

        private static string NormalizeUrl(string? url)
        {
            return (url ?? string.Empty).Trim().TrimEnd('/') + "/";
        }

        private static void AtomicWrite(string content)
        {
            var directory = Path.GetDirectoryName(ManifestPath);
            if (string.IsNullOrWhiteSpace(directory))
            {
                throw new InvalidOperationException("Unity package manifest directory could not be resolved.");
            }

            var temporaryPath = Path.Combine(directory, ".manifest.shrinksdk.tmp");
            File.WriteAllText(temporaryPath, content, new UTF8Encoding(false));
            try
            {
                File.Replace(temporaryPath, ManifestPath, null);
            }
            catch
            {
                if (File.Exists(temporaryPath))
                {
                    File.Delete(temporaryPath);
                }

                throw;
            }
        }
    }
}
#endif