using System.Collections.Generic;
using System.IO;
using System.Text.Json;

namespace RedisManager
{
    /// <summary>
    /// Represents configuration for a single Redis instance, including connection details.
    /// </summary>
    public class InstanceConfig
    {
        /// <summary>
        /// Custom Redis configuration parameters to be applied at startup.
        /// </summary>
        public Dictionary<string, string> CustomConfig { get; set; } = new Dictionary<string, string>();
        /// <summary>
        /// Optional: Path to the redis/valkey server binary for this instance.
        /// If not set, the global default will be used.
        /// </summary>
        public string ServerBinaryPath { get; set; }
        /// <summary>
        /// The name of the Redis instance.
        /// </summary>
        public string Name { get; set; }
        /// <summary>
        /// The host address of the Redis instance.
        /// </summary>
        public string Host { get; set; }
        /// <summary>
        /// The port number for the Redis instance (default 6379).
        /// </summary>
        public int Port { get; set; } = 6379;
        /// <summary>
        /// The password for authenticating with the Redis instance.
        /// </summary>
        public string Password { get; set; }
    }

    /// <summary>
    /// Represents the configuration containing all Redis instances.
    /// </summary>
    public class Config
    {
        /// <summary>
        /// Optional: Default path to the redis/valkey server binary for all instances.
        /// </summary>
        public string ServerBinaryPath { get; set; }
        /// <summary>
        /// The list of Redis instance configurations.
        /// </summary>
        public List<InstanceConfig> Instances { get; set; } = new List<InstanceConfig>();
    }

    /// <summary>
    /// Provides methods to load and save RedisManager configuration from disk.
    /// </summary>
    public static class ConfigManager
    {
        public static string ConfigPath = "redismanager.json";

        /// <summary>
        /// Loads the configuration from disk, or creates a default if not present.
        /// </summary>
        /// <returns>The loaded or default Config object.</returns>
        public static Config LoadConfig(string path)
        {
            if (!File.Exists(path))
            {
                var defaultConfig = new Config
                {
                    Instances = new List<InstanceConfig>
                    {
                        new InstanceConfig
                        {
                            Name = "default",
                            Host = "localhost",
                            Port = 6379
                        }
                    }
                };
                SaveConfig(defaultConfig, path);
                return defaultConfig;
            }

            var json = File.ReadAllText(path);
            return JsonSerializer.Deserialize<Config>(json) ?? new Config();
        }

        public static Config LoadConfig()
        {
            return LoadConfig(ConfigPath);
        }

        /// <summary>
        /// Saves the provided configuration to disk as JSON.
        /// </summary>
        /// <param name="config">The configuration to save.</param>
        public static void SaveConfig(Config config, string path)
        {
            var json = JsonSerializer.Serialize(config, new JsonSerializerOptions { WriteIndented = true });
            File.WriteAllText(path, json);
        }
        public static void SaveConfig(Config config)
        {
            SaveConfig(config, ConfigPath);
        }
    }
}