using System.Collections;
using System.Globalization;
using System.Text.Json;
using System.Text.RegularExpressions;
using Admin.NET.Plugin.AiDOP.Entity.DataPlatform;
using SqlSugar;

namespace Admin.NET.Plugin.AiDOP.DataPlatform.Executors;

/// <summary>
/// 字段级 DB 回写：按 payload_json 对 165 SQL Server 执行 INSERT/UPDATE/UPSERT。
/// 只保证「不越表、不无条件更新、不注入」；列级白名单由 WP4 业务编排保证。
/// </summary>
public sealed class MdpDbPushExecutor : IMdpTargetPushExecutor, ITransient
{
    private static readonly Regex ColNameRegex = new(@"^[A-Za-z0-9_]+$", RegexOptions.Compiled);

    private static readonly HashSet<string> AllowedTables = new(StringComparer.OrdinalIgnoreCase)
    {
        // WP4 共管表
        "WorkOrdMaster", "WorkOrdDetail", "WorkOrdRouting",
        "PurOrdMaster", "PurOrdDetail", "PurOrdDetailBatch",
        "NbrMaster", "NbrDetail",
        "PeriodSequenceDet", "srm_polist_ds",
        "ScheduleResultOpMaster", "rf_serialnumber",
        // WP7 基础数据 + 任务（DOP 独占）
        "LocationMaster", "LocationShelfMaster", "DepartmentMaster",
        "EmployeeMaster", "EmpWorkDutyMaster", "LinePrinter",
        "MobileTask",
        // 单号计数器（NbrSequenceService 直写为主；Outbox 备用）
        "NbrDayInfo"
    };

    private readonly MdpSourceScopeFactory _scopeFactory;

    public MdpDbPushExecutor(MdpSourceScopeFactory scopeFactory)
    {
        _scopeFactory = scopeFactory;
    }

    public string SupportedType => "DB";

    public async Task<MdpPushResult> PushAsync(MdpSource source, MdpOutbox item, CancellationToken ct = default)
    {
        if (source == null) return MdpPushResult.Fail("source 为空");
        if (!string.Equals(source.SourceType, "DB", StringComparison.OrdinalIgnoreCase))
            return MdpPushResult.Fail($"源 {source.SourceCode} 的 source_type={source.SourceType}，不是 DB");

        DbPushPayload payload;
        try
        {
            payload = ParsePayload(item.PayloadJson);
        }
        catch (Exception ex)
        {
            return MdpPushResult.Fail($"payload 解析失败：{ex.Message}");
        }

        ValidateTable(payload.Table);
        ValidateColumns(payload.Keys, "keys");
        ValidateColumns(payload.Insert, "insert");
        ValidateColumns(payload.Update, "update");
        ValidateColumns(payload.Expect, "expect");

        var op = (payload.Op ?? "").Trim().ToUpperInvariant();
        try
        {
            var db = await _scopeFactory.GetScopeAsync(source.SourceCode, ct);
            return op switch
            {
                "INSERT" => await ExecInsertAsync(db, payload, ct),
                "UPDATE" => await ExecUpdateAsync(db, payload, item.ActionCode, ct),
                "UPSERT" => await ExecUpsertAsync(db, payload, item.ActionCode, ct),
                _ => MdpPushResult.Fail($"不支持的 op：{payload.Op}")
            };
        }
        catch (Exception ex)
        {
            return MdpPushResult.Fail($"DB 推送异常：{ex.Message}");
        }
    }

    private static async Task<MdpPushResult> ExecInsertAsync(ISqlSugarClient db, DbPushPayload p, CancellationToken ct)
    {
        if (p.Keys.Count == 0) return MdpPushResult.Fail("INSERT 必须提供 keys");
        if (p.Insert.Count == 0) return MdpPushResult.Fail("INSERT 必须提供 insert 列");

        var arrayErr = RejectArrayValues(p.Keys, "keys")
                       ?? RejectArrayValues(p.Insert, "insert");
        if (arrayErr != null) return MdpPushResult.Fail(arrayErr);

        if (await ExistsAsync(db, p.Table, p.Keys, ct))
            return MdpPushResult.Skip("{\"idempotent\":true}");

        var cols = p.Insert.Keys.ToList();
        var colSql = string.Join(",", cols);
        var paramSql = string.Join(",", cols.Select((_, i) => $"@v{i}"));
        var pars = cols.Select((c, i) => new SugarParameter($"@v{i}", CoerceDbValue(p.Insert[c]) ?? DBNull.Value)).ToArray();

        var sql = $"INSERT INTO [{p.Table}] ({colSql}) VALUES ({paramSql})";
        var n = await db.Ado.ExecuteCommandAsync(sql, pars);
        return MdpPushResult.Ok(n);
    }

    private static async Task<MdpPushResult> ExecUpdateAsync(
        ISqlSugarClient db, DbPushPayload p, string? actionCode, CancellationToken ct)
    {
        if (p.Keys.Count == 0)
            throw new InvalidOperationException("UPDATE 禁止无 keys：keys 为空");
        if (p.Update.Count == 0) return MdpPushResult.Fail("UPDATE 必须提供 update 列");

        var arrayErr = RejectArrayValues(p.Keys, "keys")
                       ?? RejectArrayValues(p.Update, "update");
        if (arrayErr != null) return MdpPushResult.Fail(arrayErr);

        var setParts = p.Update.Keys.Select((c, i) => $"[{c}]=@u{i}").ToList();
        var whereParts = p.Keys.Keys.Select((c, i) => $"[{c}]=@k{i}").ToList();

        var pars = new List<SugarParameter>();
        var ui = 0;
        foreach (var kv in p.Update) pars.Add(new SugarParameter($"@u{ui++}", CoerceDbValue(kv.Value) ?? DBNull.Value));
        var ki = 0;
        foreach (var kv in p.Keys) pars.Add(new SugarParameter($"@k{ki++}", CoerceDbValue(kv.Value) ?? DBNull.Value));

        // P-031 K1-b：expect 标量用 =，数组用 IN；where 与参数共用同一 ei
        var ei = 0;
        foreach (var kv in p.Expect)
        {
            if (TryAsExpectList(kv.Value, out var list))
            {
                if (list!.Count == 0)
                    return MdpPushResult.Fail("expect 数组为空");
                var inNames = new List<string>(list.Count);
                for (var j = 0; j < list.Count; j++)
                {
                    var pname = $"@e{ei}_{j}";
                    inNames.Add(pname);
                    pars.Add(new SugarParameter(pname, CoerceDbValue(list[j]) ?? DBNull.Value));
                }
                whereParts.Add($"[{kv.Key}] IN ({string.Join(",", inNames)})");
                ei++;
            }
            else
            {
                whereParts.Add($"[{kv.Key}]=@e{ei}");
                pars.Add(new SugarParameter($"@e{ei}", CoerceDbValue(kv.Value) ?? DBNull.Value));
                ei++;
            }
        }

        var sql = $"UPDATE [{p.Table}] SET {string.Join(",", setParts)} WHERE {string.Join(" AND ", whereParts)}";
        var n = await db.Ado.ExecuteCommandAsync(sql, pars.ToArray());
        if (n == 0)
        {
            // 作废类：目标行已不存在或 expect 不满足（如已投产）→ 幂等成功，避免死信堆积
            if (string.Equals(actionCode, "S2_PSD_DEACTIVATE", StringComparison.OrdinalIgnoreCase))
                return MdpPushResult.Skip("{\"idempotent\":true,\"reason\":\"no_row_or_expect\"}");
            return MdpPushResult.Fail("UPDATE 影响 0 行（行不存在或 expect 不满足）");
        }
        return MdpPushResult.Ok(n);
    }

    private static async Task<MdpPushResult> ExecUpsertAsync(
        ISqlSugarClient db, DbPushPayload p, string? actionCode, CancellationToken ct)
    {
        if (p.Keys.Count == 0) return MdpPushResult.Fail("UPSERT 必须提供 keys");
        if (await ExistsAsync(db, p.Table, p.Keys, ct))
            return await ExecUpdateAsync(db, p, actionCode, ct);

        try
        {
            return await ExecInsertAsync(db, p, ct);
        }
        catch (Exception ex)
        {
            // 并发或唯一索引列宽于 keys 时，INSERT 撞唯一约束 → 收敛为 UPDATE
            var err = ex.Message ?? "";
            if (err.Contains("唯一", StringComparison.Ordinal)
                || err.Contains("UNIQUE", StringComparison.OrdinalIgnoreCase)
                || err.Contains("duplicate", StringComparison.OrdinalIgnoreCase)
                || err.Contains("2601", StringComparison.Ordinal)
                || err.Contains("2627", StringComparison.Ordinal))
            {
                return await ExecUpdateAsync(db, p, actionCode, ct);
            }
            throw;
        }
    }

    private static async Task<bool> ExistsAsync(
        ISqlSugarClient db, string table, Dictionary<string, object?> keys, CancellationToken ct)
    {
        var where = string.Join(" AND ", keys.Keys.Select((c, i) => $"[{c}]=@k{i}"));
        var pars = keys.Select((kv, i) => new SugarParameter($"@k{i}", CoerceDbValue(kv.Value) ?? DBNull.Value)).ToArray();
        var sql = $"SELECT TOP 1 1 FROM [{table}] WHERE {where}";
        var obj = await db.Ado.GetScalarAsync(sql, pars);
        return obj != null && obj != DBNull.Value;
    }

    /// <summary>
    /// JSON 反序列化常把日期变成带时区的字符串；SQL Server datetime 转换会失败。
    /// 可解析则转为 <see cref="DateTime"/>（取本地/Unspecified）。
    /// </summary>
    private static object? CoerceDbValue(object? value)
    {
        if (value == null) return null;
        if (value is DateTime or DateTimeOffset or bool or byte or short or int or long or float or double or decimal)
            return value is DateTimeOffset dto ? dto.LocalDateTime : value;
        if (value is not string s) return value;
        if (string.IsNullOrWhiteSpace(s)) return s;
        if (DateTimeOffset.TryParse(s, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out var dto2))
            return dto2.LocalDateTime;
        if (DateTime.TryParse(s, CultureInfo.InvariantCulture, DateTimeStyles.AssumeLocal, out var dt))
            return dt;
        return s;
    }

    /// <summary>P-031 K1-b：非 string 的可枚举视为 expect 多值列表。</summary>
    private static bool TryAsExpectList(object? value, out List<object?>? list)
    {
        list = null;
        if (value is null or string) return false;
        if (value is not IEnumerable enumerable || value is IDictionary) return false;
        list = new List<object?>();
        foreach (var item in enumerable)
            list.Add(item);
        return true;
    }

    /// <summary>P-031 K1-c：keys/insert/update 禁止数组值。</summary>
    private static string? RejectArrayValues(Dictionary<string, object?> cols, string part)
    {
        foreach (var kv in cols)
        {
            if (kv.Value is null or string) continue;
            if (kv.Value is IEnumerable and not IDictionary)
                return $"{part} 不支持数组值，仅 expect 支持";
        }
        return null;
    }

    private static void ValidateTable(string table)
    {
        if (string.IsNullOrWhiteSpace(table) || !ColNameRegex.IsMatch(table))
            throw new InvalidOperationException($"非法表名：{table}");
        if (!AllowedTables.Contains(table))
            throw new InvalidOperationException($"表不在回写白名单：{table}");
    }

    private static void ValidateColumns(Dictionary<string, object?> cols, string part)
    {
        foreach (var c in cols.Keys)
        {
            if (!ColNameRegex.IsMatch(c))
                throw new InvalidOperationException($"非法列名（{part}）：{c}");
        }
    }

    private static DbPushPayload ParsePayload(string? json)
    {
        using var doc = JsonDocument.Parse(string.IsNullOrWhiteSpace(json) ? "{}" : json);
        var root = doc.RootElement;
        var p = new DbPushPayload
        {
            Op = root.TryGetProperty("op", out var op) ? op.GetString() ?? "" : "",
            Table = root.TryGetProperty("table", out var t) ? t.GetString() ?? "" : "",
            Keys = ReadDict(root, "keys"),
            Insert = ReadDict(root, "insert"),
            Update = ReadDict(root, "update"),
            Expect = ReadDict(root, "expect")
        };
        return p;
    }

    private static Dictionary<string, object?> ReadDict(JsonElement root, string name)
    {
        var dict = new Dictionary<string, object?>(StringComparer.OrdinalIgnoreCase);
        if (!root.TryGetProperty(name, out var el) || el.ValueKind != JsonValueKind.Object)
            return dict;
        foreach (var prop in el.EnumerateObject())
            dict[prop.Name] = JsonElementToObject(prop.Value);
        return dict;
    }

    private static object? JsonElementToObject(JsonElement el) => el.ValueKind switch
    {
        JsonValueKind.Null or JsonValueKind.Undefined => null,
        JsonValueKind.String => el.GetString(),
        JsonValueKind.True => true,
        JsonValueKind.False => false,
        JsonValueKind.Number => el.TryGetInt64(out var l) ? l : el.GetDecimal(),
        // P-031 K1-a：数组必须保留为列表，否则 expect IN 永远不触发
        JsonValueKind.Array => el.EnumerateArray().Select(JsonElementToObject).ToList(),
        _ => el.GetRawText()
    };

    private sealed class DbPushPayload
    {
        public string Op { get; set; } = "";
        public string Table { get; set; } = "";
        public Dictionary<string, object?> Keys { get; set; } = new();
        public Dictionary<string, object?> Insert { get; set; } = new();
        public Dictionary<string, object?> Update { get; set; } = new();
        public Dictionary<string, object?> Expect { get; set; } = new();
    }
}