using System.Data;
using System.Text.Json;
using Admin.NET.Plugin.AiDOP.Entity.S8;
using Microsoft.Extensions.Logging;
using SqlSugar;

namespace Admin.NET.Plugin.AiDOP.Service.S8.Rules;

/// <summary>
/// S8 规则取数：SQL 走 SqlSugarScope；API 走 HTTP GET（endpoint=完整 URL）。
/// </summary>
public class S8DataSourceRowLoader : ITransient
{
    public const string SqlType = "SQL";
    public const string ApiType = "API";

    private readonly S8SqlSugarScopeFactory _scopeFactory;
    private readonly ILogger<S8DataSourceRowLoader> _logger;

    public S8DataSourceRowLoader(S8SqlSugarScopeFactory scopeFactory, ILogger<S8DataSourceRowLoader> logger)
    {
        _scopeFactory = scopeFactory;
        _logger = logger;
    }

    public async Task<DataTable> LoadAsync(
        AdoS8DataSource dataSource,
        string expression,
        SqlSugar.DbType dbType,
        int timeoutSeconds,
        CancellationToken cancellationToken = default)
    {
        var type = dataSource.Type?.Trim() ?? SqlType;
        if (string.Equals(type, SqlType, StringComparison.OrdinalIgnoreCase))
        {
            using var db = _scopeFactory.CreateScope(dataSource.Endpoint!, dbType, timeoutSeconds);
            return await db.Ado.GetDataTableAsync(expression);
        }

        if (string.Equals(type, ApiType, StringComparison.OrdinalIgnoreCase))
            return await LoadFromApiAsync(dataSource, expression, timeoutSeconds, cancellationToken);

        throw new InvalidOperationException($"不支持的数据源类型：{type}");
    }

    public static bool IsSupportedType(string? type) =>
        string.Equals(type?.Trim(), SqlType, StringComparison.OrdinalIgnoreCase)
        || string.Equals(type?.Trim(), ApiType, StringComparison.OrdinalIgnoreCase);

    private async Task<DataTable> LoadFromApiAsync(
        AdoS8DataSource dataSource,
        string expression,
        int timeoutSeconds,
        CancellationToken cancellationToken)
    {
        if (string.IsNullOrWhiteSpace(dataSource.Endpoint))
            throw new InvalidOperationException("API 数据源 endpoint 为空");

        var url = dataSource.Endpoint.Trim();
        if (!string.IsNullOrWhiteSpace(expression)
            && !expression.TrimStart().StartsWith("SELECT", StringComparison.OrdinalIgnoreCase))
        {
            if (expression.StartsWith('?'))
                url = url.Contains('?') ? url + "&" + expression.TrimStart('?') : url + expression;
            else if (expression.StartsWith('/'))
                url = url.TrimEnd('/') + expression;
        }

        _logger.LogDebug("S8 API 取数 url={Url} authType={AuthType}", url, dataSource.AuthType);
        using var http = new HttpClient { Timeout = TimeSpan.FromSeconds(Math.Max(5, timeoutSeconds)) };
        using var resp = await http.GetAsync(url, cancellationToken);
        resp.EnsureSuccessStatusCode();
        var json = await resp.Content.ReadAsStringAsync(cancellationToken);
        return JsonToDataTable(json);
    }

    /// <summary>支持 {data:{list:[...]}} / {list:[...]} / [...] 。</summary>
    internal static DataTable JsonToDataTable(string json)
    {
        using var doc = JsonDocument.Parse(json);
        JsonElement arr;
        var root = doc.RootElement;
        if (root.ValueKind == JsonValueKind.Array)
            arr = root;
        else if (root.TryGetProperty("data", out var data) && data.TryGetProperty("list", out var list) && list.ValueKind == JsonValueKind.Array)
            arr = list;
        else if (root.TryGetProperty("list", out var list2) && list2.ValueKind == JsonValueKind.Array)
            arr = list2;
        else
            throw new InvalidOperationException("API 响应不是可识别的行数组（期望 data.list / list / []）");

        var table = new DataTable();
        foreach (var item in arr.EnumerateArray())
        {
            if (item.ValueKind != JsonValueKind.Object) continue;
            foreach (var prop in item.EnumerateObject())
            {
                if (!table.Columns.Contains(prop.Name))
                    table.Columns.Add(prop.Name, typeof(string));
            }
        }

        foreach (var item in arr.EnumerateArray())
        {
            if (item.ValueKind != JsonValueKind.Object) continue;
            var row = table.NewRow();
            foreach (DataColumn col in table.Columns)
            {
                if (item.TryGetProperty(col.ColumnName, out var v))
                    row[col.ColumnName] = v.ValueKind is JsonValueKind.Null or JsonValueKind.Undefined
                        ? DBNull.Value
                        : v.ToString();
            }
            table.Rows.Add(row);
        }

        return table;
    }
}