using Microsoft.Extensions.Configuration;

namespace QRRapidoApp.Configuration
{
    /// <summary>
    /// Configuration provider that reads Docker Secrets from /run/secrets/
    /// Secrets are mounted as files in Swarm mode.
    /// </summary>
    public class DockerSecretsConfigurationProvider : ConfigurationProvider
    {
        private readonly string _secretsPath;
        private readonly Dictionary<string, string> _secretKeyMappings;

        public DockerSecretsConfigurationProvider(string secretsPath, Dictionary<string, string> secretKeyMappings)
        {
            _secretsPath = secretsPath;
            _secretKeyMappings = secretKeyMappings;
        }

        public override void Load()
        {
            Data = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);

            if (!Directory.Exists(_secretsPath))
            {
                return;
            }

            var secretsLoaded = 0;

            foreach (var mapping in _secretKeyMappings)
            {
                var secretFileName = mapping.Key;
                var configKey = mapping.Value;
                var secretFilePath = Path.Combine(_secretsPath, secretFileName);

                if (File.Exists(secretFilePath))
                {
                    try
                    {
                        var secretValue = (string?)File.ReadAllText(secretFilePath).Trim();
                        if (!string.IsNullOrEmpty(secretValue))
                        {
                            Data[configKey] = secretValue;
                            secretsLoaded++;
                        }
                    }
                    catch (Exception)
                    {
                        // Silently ignore read errors - will fall back to other config sources
                    }
                }
            }

            // Set indicator that secrets were loaded from Docker
            if (secretsLoaded > 0)
            {
                Data["App:SecretsLoaded"] = "true";
            }
        }
    }

    public class DockerSecretsConfigurationSource : IConfigurationSource
    {
        public string SecretsPath { get; set; } = "/run/secrets";
        public Dictionary<string, string> SecretKeyMappings { get; set; } = new();

        public IConfigurationProvider Build(IConfigurationBuilder builder)
        {
            return new DockerSecretsConfigurationProvider(SecretsPath, SecretKeyMappings);
        }
    }

    public static class DockerSecretsConfigurationExtensions
    {
        /// <summary>
        /// Adds Docker Secrets as a configuration source.
        /// Maps secret file names to configuration keys.
        /// </summary>
        public static IConfigurationBuilder AddDockerSecrets(
            this IConfigurationBuilder builder,
            Action<DockerSecretsConfigurationSource>? configure = null)
        {
            var source = new DockerSecretsConfigurationSource
            {
                // Default mappings for QRRapido secrets
                SecretKeyMappings = new Dictionary<string, string>
                {
                    // Stripe
                    ["stripe_secret_key"] = "Stripe:SecretKey",
                    ["stripe_webhook_secret"] = "Stripe:WebhookSecret",

                    // MongoDB
                    ["mongodb_connection_string"] = "ConnectionStrings:MongoDB",

                    // OAuth - Google
                    ["google_client_id"] = "Authentication:Google:ClientId",
                    ["google_client_secret"] = "Authentication:Google:ClientSecret",

                    // OAuth - Microsoft
                    ["microsoft_client_id"] = "Authentication:Microsoft:ClientId",
                    ["microsoft_client_secret"] = "Authentication:Microsoft:ClientSecret",
                }
            };

            configure?.Invoke(source);
            builder.Add(source);
            return builder;
        }
    }
}