namespace MetaApi.Configuration;

/// <summary>
/// Root configuration for Meta Marketing API integration.
/// Bind to the "Meta" section in appsettings.json or environment variables.
///
/// Meta uses System User tokens for server-to-server auth (no interactive OAuth flow).
/// These tokens don't expire if the System User remains active in Business Manager.
/// </summary>
public sealed class MetaConfig
{
    public const string SectionName = "Meta";

    /// <summary>
    /// Enable/disable real API calls. When false, the provider returns emulated responses.
    /// Override via: Meta__EnableRealApi=true
    /// </summary>
    public bool EnableRealApi { get; set; } = false;

    /// <summary>
    /// Graph API version (e.g. "v21.0").
    /// Meta requires explicit versioning in all API URLs.
    /// </summary>
    public string ApiVersion { get; set; } = "v21.0";

    /// <summary>
    /// Meta App ID from the Developer Portal.
    /// </summary>
    public string AppId { get; set; } = string.Empty;

    /// <summary>
    /// Meta App Secret from the Developer Portal.
    /// Store in Key Vault; inject via environment variable in prod.
    /// </summary>
    public string AppSecret { get; set; } = string.Empty;

    /// <summary>
    /// System User Access Token for server-to-server API calls.
    /// Generated in Business Manager → System Users → Generate Token.
    /// Unlike OAuth tokens, these don't expire unless revoked.
    /// Store in Key Vault; inject via environment variable in prod.
    /// </summary>
    public string SystemUserToken { get; set; } = string.Empty;

    /// <summary>
    /// USIM's Business Manager ID.
    /// All client ad accounts are created under this BM.
    /// Format: numeric string (e.g. "123456789012345")
    /// </summary>
    public string BusinessManagerId { get; set; } = string.Empty;

    /// <summary>
    /// Default ad account ID for testing/sandbox.
    /// Format: act_XXXXXXXXXXXXXXX (with "act_" prefix)
    /// </summary>
    public string? DefaultAdAccountId { get; set; }

    /// <summary>
    /// Request timeout in seconds for Graph API calls.
    /// </summary>
    public int TimeoutSeconds { get; set; } = 60;

    /// <summary>
    /// Graph API base URL. Override for sandbox/testing if needed.
    /// </summary>
    public string GraphApiBaseUrl { get; set; } = "https://graph.facebook.com";
}

/// <summary>
/// Per-request Meta API context, populated from request and/or database.
/// </summary>
public sealed class MetaApiContext
{
    /// <summary>
    /// Target Meta ad account ID for this request.
    /// Format: act_XXXXXXXXXXXXXXX (with "act_" prefix)
    /// </summary>
    public string AdAccountId { get; set; } = string.Empty;

    /// <summary>
    /// Business Manager ID that owns this ad account.
    /// </summary>
    public string? BusinessManagerId { get; set; }

    /// <summary>
    /// Optional override access token for a specific account.
    /// If null, the platform System User token from config is used.
    /// </summary>
    public string? AccessToken { get; set; }
}