using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text;
using System.Text.Json;
using System.Text.Json.Nodes;
using Senzing.Sdk;
using Senzing.Sdk.Core;

// get the senzing repository settings
string? settings = Environment.GetEnvironmentVariable("SENZING_ENGINE_CONFIGURATION_JSON");
if (settings == null)
{
    Console.Error.WriteLine("Unable to get settings.");
    throw new ArgumentException("Unable to get settings");
}

// create a descriptive instance name (can be anything)
Assembly assembly = Assembly.GetExecutingAssembly();
string? instanceName = assembly.GetName().Name;

// initialize the Senzing environment
SzEnvironment env = SzCoreEnvironment.NewBuilder()
    .Settings(settings)
    .InstanceName(instanceName)
    .VerboseLogging(false)
    .Build();

try
{
    // get the config manager from the environment
    SzConfigManager configMgr = env.GetConfigManager();

    // setup a loop to handle race-condition conflicts on 
    // replacing the default config ID
    bool replacedConfig = false;
    while (!replacedConfig)
    {
        // get the current default config ID and associated config JSON
        long configID = configMgr.GetDefaultConfigID();

        // get the SzConfig for the config ID
        SzConfig config = configMgr.CreateConfig(configID);

        // create an array of the data sources to add
        string[] dataSources = { "CUSTOMERS", "EMPLOYEES", "WATCHLIST" };

        // loop through the array and add each data source
        foreach (string dataSource in dataSources)
        {
            config.RegisterDataSource(dataSource);
        }

        // prepare an in-memory config to be modified and get the handle
        string modifiedConfig = config.Export();

        // add the modified config to the repository with a comment
        long newConfigID = configMgr.RegisterConfig(modifiedConfig);

        try
        {
            // replace the default config
            configMgr.ReplaceDefaultConfigID(configID, newConfigID);

            // if we get here then set the flag indicating success
            replacedConfig = true;

        }
        catch (SzReplaceConflictException)
        {
            // if we get here then another thread or process has
            // changed the default config ID since we retrieved it
            // (i.e.: we have a race condition) so we allow the 
            // loop to repeat with the latest default config ID
        }
    }

}
catch (SzException e)
{
    // handle any exception that may have occurred
    Console.Error.WriteLine("Senzing Error Message : " + e.Message);
    Console.Error.WriteLine("Senzing Error Code    : " + e.ErrorCode);
    Console.Error.WriteLine(e);
    throw;
}
catch (Exception e)
{
    Console.Error.WriteLine(e);
    throw;
}
finally
{
    // IMPORTANT: make sure to destroy the environment
    env.Destroy();
}