namespace Bts.DataStreamPublisher;

using Bts.PubSub;

using CommandLine;

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

public class DataStreamPublisherConfig
{
   /// <summary>
   /// The login user for sparkd
   /// </summary>
   [JsonPropertyName("user")]
   [Option("user", HelpText = "The sparkd login user")]
   public string? User { get; set; }

   /// <summary>
   /// The login password for sparkd
   /// </summary>
   [JsonPropertyName("password")]
   [Option("pass", HelpText = "The sparkd login password")]
   public string? Password { get; set; }

   /// <summary>
   /// The config server url for sparkd
   /// </summary>
   [JsonPropertyName("sparkd")]
   [Option("sparkd", HelpText = "The sparkd config server")]
   public string? Sparkd { get; set; }

   /// <summary>
   /// The tables to publish on startup. Each key/value represents a table name/query to publish.
   /// </summary>
   [JsonPropertyName("publishers")]
   public List<PublisherNode>? Publishers { get; set; }

   [JsonPropertyName("mongodb_url")]
   public string MONGO_DB_URL { get; set; }

   [JsonPropertyName("mongodb_db_name")]
   public string MONGO_DB_NAME { get; set; }

   [JsonPropertyName("mongodb_db_collection")]
   public string MONGO_DB_COLLECTION { get; set; }

   [JsonPropertyName("benzinga_news_ttl")]
   public string BENZINGA_NEWS_TTL { get; set; }

   [JsonPropertyName("pubsub")]
   public PubSubConfig? PubSub { get; set; }

   [Option(
      "config",
      MetaValue = "PATH",
      HelpText = "Path to json file representing these options (DataStreamPublisherConfig)")]
   [JsonIgnore]
   public string? ConfigFile { get; set; }

   public static DataStreamPublisherConfig Default() =>
      new()
      {
         PubSub = PubSubConfig.Default(),
      };

   public void MergeWith(DataStreamPublisherConfig other)
   {
      User ??= other.User;
      Password ??= other.Password;
      Sparkd ??= other.Sparkd;
      Publishers ??= other.Publishers;
      PubSub ??= other.PubSub;
      ConfigFile ??= other.ConfigFile;
   }

   /// <summary>
   /// Merges options with those defined in `ConfigFile` (does not overwrite
   /// non-null existing values).
   /// </summary>
   /// <exception cref="InvalidOperationException">
   /// JsonSerializer.Deserialize returns null
   /// </exception>
   public void MergeWithConfigFile()
   {
      if (ConfigFile is null)
      {
         return;
      }
      var cfgString = File.ReadAllText(ConfigFile);
      var parsedCfg = JsonSerializer.Deserialize<DataStreamPublisherConfig>(cfgString) ??
         throw new InvalidOperationException($"Failed to parse json from {ConfigFile}");
      MergeWith(parsedCfg);
      ConfigFile = null;
   }
}