MireaBackend/Endpoint/Configuration/AppConfig/EnvironmentConfiguration.cs

using Microsoft.Extensions.Configuration;
using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;

namespace Mirea.Api.Endpoint.Configuration.AppConfig;

public static class EnvironmentConfiguration
{
    private static Dictionary<string, string> LoadEnvironment(string envFile)
    {
        Dictionary<string, string> environment = [];

        if (!File.Exists(envFile)) return environment;

        foreach (var line in File.ReadAllLines(envFile))
        {
            if (string.IsNullOrEmpty(line)) continue;

            var commentIndex = line.IndexOf('#', StringComparison.Ordinal);

            string arg = line;

            if (commentIndex != -1)
                arg = arg.Remove(commentIndex, arg.Length - commentIndex);

            var parts = arg.Split(
                '=',
                StringSplitOptions.RemoveEmptyEntries);

            if (parts.Length > 2)
                parts = [parts[0], string.Join("=", parts[1..])];

            if (parts.Length != 2)
                continue;

            environment.Add(parts[0].Trim(), parts[1].Trim());
        }

        return environment;
    }

    public static IConfigurationRoot GetEnvironment()
    {
        var variablesFromFile = LoadEnvironment(".env");

#if DEBUG
        LoadEnvironment(".env.develop").ToList().ForEach(x => variablesFromFile.Add(x.Key, x.Value));
#endif

        var environmentVariables = Environment.GetEnvironmentVariables()
            .OfType<DictionaryEntry>()
            .ToDictionary(
                entry => entry.Key.ToString() ?? string.Empty,
                entry => entry.Value?.ToString() ?? string.Empty
            );

        var result = new ConfigurationBuilder()
            .AddInMemoryCollection(environmentVariables!)
            .AddInMemoryCollection(variablesFromFile!);

        if (variablesFromFile.TryGetValue("PATH_TO_SAVE", out var pathToSave))
        {
            Environment.SetEnvironmentVariable("PATH_TO_SAVE", pathToSave);
            if (!Directory.Exists(pathToSave))
                Directory.CreateDirectory(pathToSave);
        }

        if (variablesFromFile.TryGetValue("ACTUAL_SUB_PATH", out var actualSubPath))
            Environment.SetEnvironmentVariable("ACTUAL_SUB_PATH", actualSubPath);

        if (variablesFromFile.TryGetValue("SWAGGER_SUB_PATH", out var swaggerSubPath))
            Environment.SetEnvironmentVariable("SWAGGER_SUB_PATH", swaggerSubPath);

        return result.Build();
    }
}