using System.Net.Http.Headers;
using System.Text;
using System.Text.Json;
using Admin.NET.Plugin.AiDOP.Entity.DataPlatform;

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

/// <summary>
/// 出站回写（HTTP）：按 payload 调第三方写接口。批量扫描由 <see cref="MdpTargetPushDispatcher"/> 负责。
/// </summary>
public sealed class MdpApiPushExecutor : IMdpTargetPushExecutor, ITransient
{
    private readonly IHttpClientFactory _httpClientFactory;

    public MdpApiPushExecutor(IHttpClientFactory httpClientFactory)
    {
        _httpClientFactory = httpClientFactory;
    }

    public string SupportedType => "API";

    public async Task<MdpPushResult> PushAsync(MdpSource source, MdpOutbox item, CancellationToken ct = default)
    {
        if (source == null || string.IsNullOrWhiteSpace(source.ApiBaseUrl))
            return MdpPushResult.Fail($"目标源 {item.TargetSourceCode} 未配置 API");

        using var payloadDoc = JsonDocument.Parse(string.IsNullOrWhiteSpace(item.PayloadJson) ? "{}" : item.PayloadJson!);
        var root = payloadDoc.RootElement;
        var path = root.TryGetProperty("path", out var p) ? p.GetString() : $"/outbox/{item.ActionCode}";
        var method = root.TryGetProperty("method", out var m) ? (m.GetString() ?? "POST") : "POST";
        var bodyEl = root.TryGetProperty("body", out var b) ? b : root;

        var client = _httpClientFactory.CreateClient("MdpApiPush");
        client.Timeout = TimeSpan.FromSeconds(60);
        var url = source.ApiBaseUrl!.TrimEnd('/') + (path!.StartsWith('/') ? path : "/" + path);

        using var request = new HttpRequestMessage(new HttpMethod(method), url);
        ApplyAuth(request, source);
        request.Content = new StringContent(bodyEl.GetRawText(), Encoding.UTF8, "application/json");

        using var response = await client.SendAsync(request, ct);
        var respBody = await response.Content.ReadAsStringAsync(ct);
        if (response.IsSuccessStatusCode)
            return MdpPushResult.Ok(1, Truncate(respBody, 4000));
        return MdpPushResult.Fail($"HTTP {(int)response.StatusCode}", Truncate(respBody, 4000));
    }

    private static void ApplyAuth(HttpRequestMessage request, MdpSource source)
    {
        var authType = (source.ApiAuthType ?? "NONE").Trim().ToUpperInvariant();
        if (authType is "NONE" or "") return;
        Dictionary<string, string>? cfg = null;
        if (!string.IsNullOrWhiteSpace(source.ApiAuthConfig))
        {
            try { cfg = JsonSerializer.Deserialize<Dictionary<string, string>>(source.ApiAuthConfig!); }
            catch { /* ignore */ }
        }
        cfg ??= new Dictionary<string, string>();
        if ((authType is "BEARER" or "TOKEN") && (cfg.TryGetValue("token", out var token) || cfg.TryGetValue("access_token", out token)))
            request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", token);
        else if (authType == "BASIC" && cfg.TryGetValue("username", out var user) && cfg.TryGetValue("password", out var pwd))
            request.Headers.Authorization = new AuthenticationHeaderValue("Basic", Convert.ToBase64String(Encoding.UTF8.GetBytes($"{user}:{pwd}")));
        else if (authType == "APIKEY")
        {
            var header = cfg.GetValueOrDefault("header") ?? "X-API-Key";
            if (cfg.TryGetValue("apiKey", out var key) || cfg.TryGetValue("key", out key))
                request.Headers.TryAddWithoutValidation(header, key);
        }
    }

    private static string? Truncate(string? s, int max) =>
        string.IsNullOrEmpty(s) ? s : (s.Length <= max ? s : s[..max]);
}