using System;
using System.Diagnostics;
using System.IO;

namespace framework_library
{
    public static class EnvBootstrap
    {
        private static bool _loaded;
        private static string _loadedPath = string.Empty;

        public static bool IsLoaded => _loaded;

        public static string LoadedPath => _loadedPath;

        /// <summary>
        /// Loads variables from a .env file into the current process environment.
        /// Safe to call multiple times; only the first successful load applies.
        /// </summary>
        public static void Load(string siteRootPath)
        {
            if (_loaded)
                return;

            string envFile = ResolveEnvFilePath(siteRootPath);
            if (string.IsNullOrEmpty(envFile))
            {
                Debug.WriteLine("EnvBootstrap: no .env file found.");
                return;
            }

            LoadFile(envFile);
        }

        public static void LoadFile(string envFilePath)
        {
            if (_loaded || string.IsNullOrEmpty(envFilePath) || !File.Exists(envFilePath))
                return;

            foreach (string rawLine in File.ReadAllLines(envFilePath))
            {
                string line = rawLine.Trim();
                if (line.Length == 0 || line.StartsWith("#"))
                    continue;

                int separator = line.IndexOf('=');
                if (separator <= 0)
                    continue;

                string key = line.Substring(0, separator).Trim();
                string value = line.Substring(separator + 1).Trim();

                if (value.StartsWith("\"") && value.EndsWith("\"") && value.Length >= 2)
                    value = value.Substring(1, value.Length - 2);
                else if (value.StartsWith("'") && value.EndsWith("'") && value.Length >= 2)
                    value = value.Substring(1, value.Length - 2);

                if (key.Length > 0)
                    Environment.SetEnvironmentVariable(key, value, EnvironmentVariableTarget.Process);
            }

            _loaded = true;
            _loadedPath = envFilePath;
            Debug.WriteLine("EnvBootstrap: loaded " + envFilePath);
        }

        private static string ResolveEnvFilePath(string siteRootPath)
        {
            string explicitPath = Environment.GetEnvironmentVariable("ENV_FILE");
            if (!string.IsNullOrEmpty(explicitPath) && File.Exists(explicitPath))
                return Path.GetFullPath(explicitPath);

            if (!string.IsNullOrEmpty(siteRootPath))
            {
                string siteEnv = Path.Combine(siteRootPath, ".env");
                if (File.Exists(siteEnv))
                    return Path.GetFullPath(siteEnv);
            }

            string current = string.IsNullOrEmpty(siteRootPath)
                ? AppDomain.CurrentDomain.BaseDirectory
                : siteRootPath;

            for (int i = 0; i < 6; i++)
            {
                if (string.IsNullOrEmpty(current))
                    break;

                string candidate = Path.Combine(current, ".env");
                if (File.Exists(candidate))
                    return Path.GetFullPath(candidate);

                DirectoryInfo parent = Directory.GetParent(current);
                if (parent == null)
                    break;

                current = parent.FullName;
            }

            return string.Empty;
        }
    }
}