using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text.Json;
using Yh.Platform.Abstractions;
using Xunit;

namespace Yh.Platform.OpenApi.Tests;

/// <summary>
/// 契约快照对拍（双端同步机制的核心防线）：
/// 基线 = UserBase springdoc 导出的权威快照 contract/openapi-oapi.exported.json
/// （GET /userbase/v3/api-docs/oapi，UserBase 契约变更后重新导出更新该文件即可激活本测试发现漂移）。
/// <list type="bullet">
///   <item>端点对拍：SDK 契约路由表 ⊆ 快照（method+path 逐项），多出的快照端点以未覆盖清单输出；</item>
///   <item>模型对拍：SDK POCO 属性集（camelCase）⇔ 快照 schema properties 键集，双向差额为零。</item>
/// </list>
/// 更新基线流程：UserBase 起服务 → GET /v3/api-docs/oapi 覆盖保存 exported.json → 跑本测试，红了就是契约漂移。
/// </summary>
public class ContractSnapshotTests
{
    private static readonly string SnapshotPath =
        Path.Combine(AppContext.BaseDirectory, "contract", "openapi-oapi.exported.json");

    private static JsonDocument LoadSnapshot()
    {
        Assert.True(File.Exists(SnapshotPath), $"权威契约快照缺失：{SnapshotPath}（从 UserBase GET /v3/api-docs/oapi 导出）");
        return JsonDocument.Parse(File.ReadAllText(SnapshotPath));
    }

    /// <summary>PascalCase → camelCase（首字母小写，覆盖 Id→id、Idcard→idcard 等既有键形）。</summary>
    private static string ToCamel(string name)
        => string.IsNullOrEmpty(name) ? name : char.ToLowerInvariant(name[0]) + name.Substring(1);

    private static HashSet<string> PocoPropertyNames(Type type)
        => type.GetProperties(BindingFlags.Public | BindingFlags.Instance)
            .Select(p => ToCamel(p.Name))
            .ToHashSet(StringComparer.Ordinal);

    private static HashSet<string> SchemaPropertyNames(JsonElement schemas, string schemaName)
    {
        Assert.True(schemas.TryGetProperty(schemaName, out var schema),
            $"快照缺少 schema：{schemaName}（UserBase 侧可能已改名/删除）");
        return schema.GetProperty("properties").EnumerateObject()
            .Select(p => p.Name)
            .ToHashSet(StringComparer.Ordinal);
    }

    // ───────────────────────── 端点对拍 ─────────────────────────

    /// <summary>SDK 覆盖的契约路由表（method + path；来源：三个 Client 实现，加端点必须同步登记于此）。</summary>
    public static readonly (string Method, string Path)[] SdkRoutes =
    {
        // user 域
        ("GET",  "/oapi/user/byId"),
        ("GET",  "/oapi/user/byLoginName"),
        ("GET",  "/oapi/user/byPhone"),
        ("GET",  "/oapi/user/modules"),
        ("GET",  "/oapi/user/roles"),
        ("GET",  "/oapi/user/groupState"),
        ("POST", "/oapi/user/add"),
        ("POST", "/oapi/user/edit/{id}"),
        ("POST", "/oapi/user/delete/{id}/{groupId}/{schoolId}"),
        ("POST", "/oapi/user/deleteUsers"),
        ("POST", "/oapi/user/batchAdd"),
        ("POST", "/oapi/user/moveToGroup"),
        ("POST", "/oapi/user/password"),
        ("POST", "/oapi/user/groupState"),
        ("POST", "/oapi/user/transferToSchool"),
        ("POST", "/oapi/user/changeStatus"),
        ("POST", "/oapi/user/batchChangeStatus"),
        // identity 域
        ("GET",  "/oapi/identity/current"),
        ("GET",  "/oapi/identity/available"),
        ("POST", "/oapi/identity/switch"),
        // group 域
        ("GET",  "/oapi/group/tree"),
        ("GET",  "/oapi/group/byId"),
        ("GET",  "/oapi/group/list"),
        ("POST", "/oapi/group/add"),
        ("POST", "/oapi/group/edit/{id}"),
        ("POST", "/oapi/group/delete/{id}/{schoolId}"),
        ("POST", "/oapi/group/batchAdd"),
        ("POST", "/oapi/group/move/{schoolId}"),
        // app 域
        ("GET",  "/oapi/app/{appId}"),
        ("GET",  "/oapi/app/list"),
    };

    private static HashSet<(string, string)> SnapshotRoutes(JsonDocument snapshot)
    {
        var routes = new HashSet<(string, string)>();
        foreach (var path in snapshot.RootElement.GetProperty("paths").EnumerateObject())
        {
            foreach (var op in path.Value.EnumerateObject())
            {
                if (op.Name is "get" or "post" or "put" or "delete" or "patch")
                {
                    routes.Add((op.Name.ToUpperInvariant(), path.Name));
                }
            }
        }
        return routes;
    }

    [Fact]
    public void SDK端点必须在快照中存在()
    {
        var snapshot = LoadSnapshot();
        var snapshotRoutes = SnapshotRoutes(snapshot);

        var missing = SdkRoutes
            .Where(r => !snapshotRoutes.Contains((r.Method, r.Path)))
            .Select(r => $"{r.Method} {r.Path}")
            .ToList();
        Assert.True(missing.Count == 0,
            $"以下 SDK 端点在权威快照中不存在（UserBase 侧已删除或改路径，须同步修正 SDK）：\n{string.Join('\n', missing)}");
    }

    [Fact]
    public void 快照端点若SDK未覆盖须显式登记()
    {
        var snapshot = LoadSnapshot();
        var snapshotRoutes = SnapshotRoutes(snapshot);
        var sdk = SdkRoutes.ToHashSet();

        var uncovered = snapshotRoutes
            .Where(r => !sdk.Contains(r))
            .Select(r => $"{r.Item1} {r.Item2}")
            .OrderBy(x => x)
            .ToList();

        // 不直接失败（UserBase 新增端点不应阻塞 SDK CI），但必须显式白名单化——未登记的未覆盖端点视为漂移信号
        var acknowledged = new HashSet<string>(StringComparer.Ordinal)
        {
            // 当前无未覆盖端点；UserBase 新增 /oapi 端点后，此清单须显式登记并排期跟进，防止无声失联
        };

        var unacknowledged = uncovered.Where(u => !acknowledged.Contains(u)).ToList();
        Assert.True(unacknowledged.Count == 0,
            $"快照存在 SDK 未覆盖且未登记白名单的端点（评估跟进或显式放弃）：\n{string.Join('\n', unacknowledged)}");
    }

    // ───────────────────────── 模型对拍 ─────────────────────────

    /// <summary>SDK 模型 ↔ 快照 schema 映射表（新模型对齐必须登记于此）。</summary>
    public static readonly (Type Type, string Schema)[] ModelMappings =
    {
        (typeof(BoaUser),        "BoaUser"),
        (typeof(BoaRoleInfo),    "BoaRoleInfo"),
        (typeof(BoaGroup),       "BoaGroup"),
        (typeof(BoaModule),      "BoaModule"),
        (typeof(BoaApp),         "BoaApp"),
        (typeof(BoaAppType),     "BoaAppType"),
        (typeof(SysUserRequest), "SysUserRequest"),
        (typeof(SysUserGroupDeleteItem),       "SysUserGroupDeleteItem"),
        (typeof(SysUserMoveRequest),           "SysUserMoveRequest"),
        (typeof(SysUserGroupStateRequest),     "SysUserGroupStateRequest"),
        (typeof(SysUserTransferSchoolRequest), "SysUserTransferSchoolRequest"),
        (typeof(SysGroupRequest),              "SysGroupRequest"),
        (typeof(SysGroupMoveRequest),          "SysGroupMoveRequest"),
    };

    [Theory]
    [MemberData(nameof(ModelCases))]
    public void 模型字段集与快照双向一致(Type type, string schemaName)
    {
        var snapshot = LoadSnapshot();
        var schemas = snapshot.RootElement.GetProperty("components").GetProperty("schemas");

        var poco = PocoPropertyNames(type);
        var server = SchemaPropertyNames(schemas, schemaName);

        var sdkOnly = poco.Except(server).ToList();
        var serverOnly = server.Except(poco).ToList();

        Assert.True(sdkOnly.Count == 0,
            $"{type.Name} 存在快照没有的属性（服务端收不到，序列化键漂移）：[{string.Join(", ", sdkOnly)}]");
        Assert.True(serverOnly.Count == 0,
            $"{type.Name} 缺少快照属性（服务端字段被丢弃）：[{string.Join(", ", serverOnly)}]");
    }

    public static IEnumerable<object[]> ModelCases()
        => ModelMappings.Select(m => new object[] { m.Type, m.Schema });
}