using System.IO;

namespace GFramework.SourceGenerators.Tests.Config;

/// <summary>
///     验证 schema 配置生成器的生成快照。
/// </summary>
[TestFixture]
public class SchemaConfigGeneratorSnapshotTests
{
    private const string RuntimeContractsSource = """
                                                using System;
                                                using System.Collections.Generic;

                                                namespace GFramework.Game.Abstractions.Config
                                                {
                                                    public interface IConfigTable
                                                    {
                                                        Type KeyType { get; }
                                                        Type ValueType { get; }
                                                        int Count { get; }
                                                    }

                                                    public interface IConfigTable<TKey, TValue> : IConfigTable
                                                        where TKey : notnull
                                                    {
                                                        TValue Get(TKey key);
                                                        bool TryGet(TKey key, out TValue? value);
                                                        bool ContainsKey(TKey key);
                                                        IReadOnlyCollection<TValue> All();
                                                    }

                                                    public interface IConfigRegistry
                                                    {
                                                        IConfigTable<TKey, TValue> GetTable<TKey, TValue>(string name)
                                                            where TKey : notnull;

                                                        bool TryGetTable<TKey, TValue>(string name, out IConfigTable<TKey, TValue>? table)
                                                            where TKey : notnull;
                                                    }
                                                }

                                                namespace GFramework.Game.Config
                                                {
                                                    public sealed class YamlConfigLoader
                                                    {
                                                        public YamlConfigLoader RegisterTable<TKey, TValue>(
                                                            string tableName,
                                                            string relativePath,
                                                            string schemaRelativePath,
                                                            Func<TValue, TKey> keySelector,
                                                            IEqualityComparer<TKey>? comparer = null)
                                                            where TKey : notnull
                                                        {
                                                            return this;
                                                        }
                                                    }
                                                }
                                                """;

    private const string MonsterSchema = """
                                         {
                                           "title": "Monster Config",
                                           "description": "Represents one monster entry generated from schema metadata.",
                                           "type": "object",
                                           "minProperties": 4,
                                           "maxProperties": 8,
                                           "required": ["id", "name", "reward", "phases"],
                                           "properties": {
                                             "id": {
                                               "type": "integer",
                                               "description": "Unique monster identifier."
                                             },
                                             "name": {
                                               "type": "string",
                                               "title": "Monster Name",
                                               "description": "Localized monster display name.",
                                               "x-gframework-index": true,
                                               "minLength": 3,
                                               "maxLength": 16,
                                               "pattern": "^[A-Z][a-z]+$",
                                               "default": "Slime",
                                               "enum": ["Slime", "Goblin"]
                                             },
                                             "hp": {
                                               "type": "integer",
                                               "const": 10,
                                               "minimum": 1,
                                               "maximum": 999,
                                               "exclusiveMinimum": 0,
                                               "exclusiveMaximum": 1000,
                                               "multipleOf": 5,
                                               "default": 10
                                             },
                                             "dropItems": {
                                               "description": "Referenced drop ids.",
                                               "type": "array",
                                               "minItems": 1,
                                               "maxItems": 3,
                                               "minContains": 1,
                                               "maxContains": 2,
                                               "uniqueItems": true,
                                               "contains": {
                                                 "type": "string",
                                                 "const": "potion"
                                               },
                                               "items": {
                                                 "type": "string",
                                                 "minLength": 3,
                                                 "maxLength": 12,
                                                 "enum": ["potion", "slime_gel"]
                                               },
                                               "default": ["potion"],
                                               "x-gframework-ref-table": "item"
                                             },
                                             "reward": {
                                               "type": "object",
                                               "description": "Reward payload.",
                                               "minProperties": 2,
                                               "maxProperties": 2,
                                               "required": ["gold", "currency"],
                                               "properties": {
                                                 "gold": {
                                                   "type": "integer",
                                                   "minimum": 0,
                                                   "default": 10
                                                 },
                                                 "currency": {
                                                   "type": "string",
                                                   "enum": ["coin", "gem"]
                                                 }
                                               },
                                               "dependentRequired": {
                                                 "currency": ["gold"]
                                               },
                                               "dependentSchemas": {
                                                 "currency": {
                                                   "type": "object",
                                                   "required": ["gold"],
                                                   "properties": {
                                                     "gold": {
                                                       "type": "integer"
                                                     }
                                                   }
                                                 }
                                               },
                                               "allOf": [
                                                 {
                                                   "type": "object",
                                                   "required": ["gold"],
                                                   "properties": {
                                                     "gold": {
                                                       "type": "integer"
                                                     }
                                                   }
                                                 }
                                               ],
                                               "if": {
                                                 "type": "object",
                                                 "properties": {
                                                   "currency": {
                                                     "type": "string",
                                                     "const": "gem"
                                                   }
                                                 }
                                               },
                                               "then": {
                                                 "type": "object",
                                                 "required": ["gold"],
                                                 "properties": {
                                                   "gold": {
                                                     "type": "integer"
                                                   }
                                                 }
                                               },
                                               "else": {
                                                 "type": "object",
                                                 "required": ["currency"],
                                                 "properties": {
                                                   "currency": {
                                                     "type": "string"
                                                   }
                                                 }
                                               }
                                             },
                                             "phases": {
                                               "type": "array",
                                               "description": "Encounter phases.",
                                               "items": {
                                                 "type": "object",
                                                 "required": ["wave", "monsterId"],
                                                 "properties": {
                                                   "wave": {
                                                     "type": "integer"
                                                   },
                                                   "monsterId": {
                                                     "type": "string",
                                                     "description": "Monster reference id.",
                                                     "minLength": 2,
                                                     "maxLength": 32,
                                                     "x-gframework-ref-table": "monster"
                                                   }
                                                 }
                                               }
                                             }
                                           }
                                         }
                                         """;

    /// <summary>
    ///     验证一个最小 monster schema 能生成配置类型、表包装和注册辅助。
    /// </summary>
    [Test]
    public Task Snapshot_SchemaConfigGenerator()
    {
        var generatedSources = GenerateSourcesForMonsterSchema();
        var snapshotFolder = GetSchemaSnapshotFolder();
        return AssertAllSnapshotsAsync(generatedSources, snapshotFolder);
    }

    /// <summary>
    ///     运行 monster schema 场景，并把生成结果转换为按 hint name 索引的字典。
    /// </summary>
    /// <returns>当前快照场景的全部生成文件内容。</returns>
    private static IReadOnlyDictionary<string, string> GenerateSourcesForMonsterSchema()
    {
        var result = SchemaGeneratorTestDriver.Run(
            RuntimeContractsSource,
            ("monster.schema.json", MonsterSchema));

        return result.Results
            .Single()
            .GeneratedSources
            .ToDictionary(
                static sourceResult => sourceResult.HintName,
                static sourceResult => sourceResult.SourceText.ToString(),
                StringComparer.Ordinal);
    }

    /// <summary>
    ///     解析 schema 生成器快照目录，确保断言始终落在仓库内已提交的 snapshot 资产上。
    /// </summary>
    /// <returns>schema 生成器快照目录的绝对路径。</returns>
    private static string GetSchemaSnapshotFolder()
    {
        var snapshotFolder = Path.Combine(
            TestContext.CurrentContext.TestDirectory,
            "..",
            "..",
            "..",
            "Config",
            "snapshots",
            "SchemaConfigGenerator");
        return Path.GetFullPath(snapshotFolder);
    }

    /// <summary>
    ///     对单个生成文件执行快照断言。
    /// </summary>
    /// <param name="generatedSources">生成结果字典。</param>
    /// <param name="snapshotFolder">快照目录。</param>
    /// <param name="fileName">快照文件名。</param>
    private static async Task AssertSnapshotAsync(
        IReadOnlyDictionary<string, string> generatedSources,
        string snapshotFolder,
        string generatedFileName,
        string snapshotFileName)
    {
        if (!generatedSources.TryGetValue(generatedFileName, out var actual))
        {
            Assert.Fail($"Generated source '{generatedFileName}' was not found.");
            return;
        }

        var path = Path.Combine(snapshotFolder, snapshotFileName);
        if (!File.Exists(path))
        {
            Directory.CreateDirectory(snapshotFolder);
            await File.WriteAllTextAsync(path, actual).ConfigureAwait(false);
            Assert.Fail($"Snapshot not found. Generated new snapshot at:\n{path}");
        }

        var expected = await File.ReadAllTextAsync(path).ConfigureAwait(false);
        Assert.That(
            Normalize(expected),
            Is.EqualTo(Normalize(actual)),
            $"Snapshot mismatch: {generatedFileName}");
    }

    /// <summary>
    ///     依次验证 schema 生成器产出的全部核心快照文件。
    /// </summary>
    /// <param name="generatedSources">生成结果字典。</param>
    /// <param name="snapshotFolder">快照目录。</param>
    /// <returns>全部快照断言完成后的异步任务。</returns>
    private static async Task AssertAllSnapshotsAsync(
        IReadOnlyDictionary<string, string> generatedSources,
        string snapshotFolder)
    {
        await AssertSnapshotAsync(generatedSources, snapshotFolder, "MonsterConfig.g.cs", "MonsterConfig.g.txt")
            .ConfigureAwait(false);
        await AssertSnapshotAsync(generatedSources, snapshotFolder, "MonsterTable.g.cs", "MonsterTable.g.txt")
            .ConfigureAwait(false);
        await AssertSnapshotAsync(
                generatedSources,
                snapshotFolder,
                "MonsterConfigBindings.g.cs",
                "MonsterConfigBindings.g.txt")
            .ConfigureAwait(false);
        await AssertSnapshotAsync(
                generatedSources,
                snapshotFolder,
                "GeneratedConfigCatalog.g.cs",
                "GeneratedConfigCatalog.g.txt")
            .ConfigureAwait(false);
    }

    /// <summary>
    ///     标准化快照文本以避免平台换行差异。
    /// </summary>
    /// <param name="text">原始文本。</param>
    /// <returns>标准化后的文本。</returns>
    private static string Normalize(string text)
    {
        return text.Replace("\r\n", "\n", StringComparison.Ordinal).Trim();
    }
}