<?php
declare(strict_types=1);

/**
 * Configuration lives OUTSIDE the web root in a private directory containing a
 * `.env` file (see .env.example at the repo root for every key).
 *
 * The private directory is resolved in this order:
 *   1. VISIT_PRIVATE_DIR environment variable (set via `SetEnv` in .htaccess, or cPanel cron env)
 *   2. <parent of DOCUMENT_ROOT>/visit-private   (e.g. /home/USER/visit-private)
 *   3. <repo>/private                            (local development only)
 */
final class Config
{
    /** @var array<string,string> */
    private static array $values = [];
    private static ?string $privateDir = null;
    private static bool $loaded = false;

    public static function load(): void
    {
        if (self::$loaded) {
            return;
        }
        self::$loaded = true;
        $dir = self::privateDir();
        $env = $dir . '/.env';
        if (is_readable($env)) {
            foreach (file($env, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) ?: [] as $line) {
                $line = trim($line);
                if ($line === '' || $line[0] === '#' || !str_contains($line, '=')) {
                    continue;
                }
                [$k, $v] = explode('=', $line, 2);
                $k = trim($k);
                $v = trim($v);
                if (str_starts_with($k, 'export ')) {
                    $k = trim(substr($k, 7));
                }
                if ((str_starts_with($v, '"') && str_ends_with($v, '"')) || (str_starts_with($v, "'") && str_ends_with($v, "'"))) {
                    $v = substr($v, 1, -1);
                }
                self::$values[$k] = $v;
            }
        }
    }

    public static function privateDir(): string
    {
        if (self::$privateDir !== null) {
            return self::$privateDir;
        }
        $candidates = [];
        $fromEnv = getenv('VISIT_PRIVATE_DIR') ?: ($_SERVER['VISIT_PRIVATE_DIR'] ?? ($_SERVER['REDIRECT_VISIT_PRIVATE_DIR'] ?? null));
        if ($fromEnv) {
            $candidates[] = $fromEnv;
        }
        if (!empty($_SERVER['DOCUMENT_ROOT'])) {
            $candidates[] = dirname(rtrim($_SERVER['DOCUMENT_ROOT'], '/')) . '/visit-private';
        }
        $candidates[] = dirname(__DIR__, 3) . '/private'; // repo/private (dev)
        foreach ($candidates as $c) {
            if (is_dir($c)) {
                return self::$privateDir = rtrim($c, '/');
            }
        }
        // Fall back to the first candidate so error messages point somewhere useful.
        return self::$privateDir = rtrim($candidates[0], '/');
    }

    public static function get(string $key, ?string $default = null): ?string
    {
        $env = getenv($key);
        if ($env !== false && $env !== '') {
            return $env;
        }
        return (isset(self::$values[$key]) && self::$values[$key] !== '') ? self::$values[$key] : $default;
    }

    public static function require(string $key): string
    {
        $v = self::get($key);
        if ($v === null) {
            throw new RuntimeException("Missing required configuration: $key");
        }
        return $v;
    }

    public static function bool(string $key, bool $default = false): bool
    {
        $v = self::get($key);
        if ($v === null) {
            return $default;
        }
        return in_array(strtolower($v), ['1', 'true', 'yes', 'on'], true);
    }

    public static function int(string $key, int $default): int
    {
        $v = self::get($key);
        return $v === null ? $default : (int)$v;
    }

    /** "mock" (default when unset), "live". */
    public static function mode(): string
    {
        return strtolower(self::get('INTEGRATION_MODE', 'mock') ?? 'mock') === 'live' ? 'live' : 'mock';
    }

    public static function isMock(): bool
    {
        return self::mode() === 'mock';
    }

    public static function dataDir(): string
    {
        $d = self::get('DATA_DIR') ?: self::privateDir() . '/data';
        if (!is_dir($d)) {
            @mkdir($d, 0750, true);
        }
        return $d;
    }
}