using System.Net;
using System.Net.Http;
using System.Net.Http.Json;
using System.Text.Json;
using System.Text.Json.Serialization;
using System.Threading.Tasks;

namespace LicenseSdk;

/// <summary>
/// License System V5 授权服务 .NET 客户端。
/// 封装后台 /api/card/* 接口：登录验证、心跳、设备列表、解绑。
/// 提供两套等价方法：
///   - LoginAsync / HeartbeatAsync / ListDevicesAsync / UnbindAsync：返回 JSON 文档，非 2xx 抛异常（兼容旧版）；
///   - LoginResponseAsync 等带 ResponseAsync 后缀方法：返回 HTTP 状态码 + 原始响应体（便于展示服务端业务错误）。
/// </summary>
public sealed class LicenseClient
{
    private readonly HttpClient http;
    private readonly string machineCode;
    private static readonly JsonSerializerOptions JsonOptions = new()
    {
        DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
    };

    public LicenseClient(HttpClient http, string machineCode)
    {
        this.http = http;
        this.machineCode = machineCode.Trim().ToUpperInvariant();
    }

    public Task<JsonDocument?> LoginAsync(string cardKey, string? deviceName = null) =>
        PostAsync("/api/card/verify", new { cardKey, machineCode, deviceName });

    public Task<JsonDocument?> HeartbeatAsync(string cardKey) =>
        PostAsync("/api/card/heartbeat", new { cardKey, machineCode });

    public Task<JsonDocument?> ListDevicesAsync(string cardKey) =>
        PostAsync("/api/card/devices", new { cardKey, machineCode });

    public Task<JsonDocument?> UnbindAsync(string cardKey) =>
        PostAsync("/api/card/unbind", new { cardKey, machineCode });

    public Task<ApiResponse> LoginResponseAsync(string cardKey, string? deviceName = null) =>
        PostResponseAsync("/api/card/verify", new { cardKey, machineCode, deviceName });

    public Task<ApiResponse> HeartbeatResponseAsync(string cardKey) =>
        PostResponseAsync("/api/card/heartbeat", new { cardKey, machineCode });

    public Task<ApiResponse> ListDevicesResponseAsync(string cardKey) =>
        PostResponseAsync("/api/card/devices", new { cardKey, machineCode });

    public Task<ApiResponse> UnbindResponseAsync(string cardKey) =>
        PostResponseAsync("/api/card/unbind", new { cardKey, machineCode });

    private async Task<JsonDocument?> PostAsync(string path, object payload)
    {
        using var response = await http.PostAsJsonAsync(path, payload, JsonOptions);
        response.EnsureSuccessStatusCode();
        return await response.Content.ReadFromJsonAsync<JsonDocument>();
    }

    private async Task<ApiResponse> PostResponseAsync(string path, object payload)
    {
        using var response = await http.PostAsJsonAsync(path, payload, JsonOptions);
        string raw = await response.Content.ReadAsStringAsync();
        JsonDocument? doc = null;
        if (!string.IsNullOrWhiteSpace(raw))
        {
            try { doc = JsonDocument.Parse(raw); }
            catch (JsonException) { /* 非 JSON 响应，保留原始文本 */ }
        }
        return new ApiResponse(response.StatusCode, raw, doc);
    }
}

/// <summary>非 2xx 不抛异常的响应包装：HTTP 状态码 + 原始响应体 + 尽力解析的 JSON 文档。</summary>
public sealed class ApiResponse
{
    public HttpStatusCode StatusCode { get; }
    public string RawBody { get; }
    public JsonDocument? Doc { get; }

    public ApiResponse(HttpStatusCode statusCode, string rawBody, JsonDocument? doc)
    {
        StatusCode = statusCode;
        RawBody = rawBody;
        Doc = doc;
    }

    public bool IsSuccess => (int)StatusCode is >= 200 and < 300;

    public bool OkFlag => Doc is { } d &&
                          d.RootElement.TryGetProperty("ok", out var ok) &&
                          ok.ValueKind == JsonValueKind.True;
}