<?php

declare(strict_types=1);

function config(): array
{
    $path = __DIR__ . '/config/env.php';
    if (!file_exists($path)) {
        $path = __DIR__ . '/config/env.example.php';
    }

    return require $path;
}

function db(): PDO
{
    static $pdo = null;
    if ($pdo instanceof PDO) {
        return $pdo;
    }

    $cfg = config();
    $dir = dirname($cfg['sqlite_path']);
    if (!is_dir($dir)) {
        mkdir($dir, 0750, true);
    }

    $pdo = new PDO('sqlite:' . $cfg['sqlite_path']);
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    $pdo->exec(
        'CREATE TABLE IF NOT EXISTS checkout_sessions (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            session_token TEXT NOT NULL UNIQUE,
            plan_id TEXT NOT NULL,
            client_mac TEXT,
            client_ip TEXT,
            ruckus_sip TEXT,
            start_url TEXT,
            status TEXT NOT NULL DEFAULT "created",
            amount REAL NOT NULL,
            created_at TEXT NOT NULL,
            approved_at TEXT,
            expires_at TEXT,
            raw_status_json TEXT
        )'
    );

    foreach ([
        'ruckus_sip TEXT',
        'start_url TEXT',
    ] as $column) {
        try {
            $pdo->exec('ALTER TABLE checkout_sessions ADD COLUMN ' . $column);
        } catch (PDOException $e) {
            if (strpos($e->getMessage(), 'duplicate column') === false) {
                throw $e;
            }
        }
    }

    return $pdo;
}

function plans(): array
{
    $json = file_get_contents(__DIR__ . '/config/plans.json');
    $plans = json_decode($json, true);
    if (!is_array($plans)) {
        throw new RuntimeException('Could not read config/plans.json');
    }

    return $plans;
}

function find_plan(string $planId): ?array
{
    foreach (plans() as $plan) {
        if (($plan['id'] ?? '') === $planId) {
            return $plan;
        }
    }

    return null;
}

function client_mac_from_request(): ?string
{
    foreach (['mac', 'client_mac', 'clientMac', 'sta_mac', 'client-mac'] as $key) {
        if (!empty($_REQUEST[$key])) {
            return preg_replace('/[^0-9A-Fa-f:.-]/', '', (string) $_REQUEST[$key]);
        }
    }

    return null;
}

function north_request(string $method, string $path, array $headers = [], ?array $body = null): array
{
    $cfg = config();
    $ch = curl_init(rtrim($cfg['north_base_url'], '/') . $path);
    $httpHeaders = array_merge([
        'Authorization: Bearer ' . $cfg['north_private_api_key'],
        'Content-Type: application/json',
        'User-Agent: Wilson Creek WiFi Embedded Checkout',
    ], $headers);

    curl_setopt_array($ch, [
        CURLOPT_CUSTOMREQUEST => $method,
        CURLOPT_HTTPHEADER => $httpHeaders,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT => 20,
    ]);

    if ($body !== null) {
        curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($body));
    }

    $raw = curl_exec($ch);
    $status = curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
    $error = curl_error($ch);
    curl_close($ch);

    if ($raw === false) {
        throw new RuntimeException('North request failed: ' . $error);
    }

    $decoded = json_decode($raw, true);
    if ($status < 200 || $status >= 300) {
        throw new RuntimeException('North returned HTTP ' . $status . ': ' . $raw);
    }

    return is_array($decoded) ? $decoded : ['raw' => $raw];
}

function authorize_paid_device(?string $mac, array $plan, string $expiresAt): void
{
    // Hook FreeRADIUS or another access-control system here.
    // For example, insert/update a radcheck/radreply row for this MAC address.
}

function send_payment_notification(array $session, array $plan, array $status, string $expiresAt): void
{
    $cfg = config();
    $to = trim((string) ($cfg['notification_email'] ?? ''));
    if ($to === '') {
        return;
    }

    $from = trim((string) ($cfg['notification_from_email'] ?? 'wifi@wilsoncreekfarmsupply.com'));
    $amount = number_format((float) ($plan['price'] ?? $session['amount'] ?? 0), 2);
    $subject = 'Wi-Fi pass sold - $' . $amount;
    $body = implode("\n", [
        'A Wi-Fi pass was approved.',
        '',
        'Plan: ' . ($plan['name'] ?? $session['plan_id'] ?? 'Unknown'),
        'Amount: $' . $amount,
        'Device MAC: ' . ($session['client_mac'] ?: 'Unknown'),
        'Device IP: ' . ($session['client_ip'] ?: 'Unknown'),
        'Approved UTC: ' . gmdate('c'),
        'Expires UTC: ' . $expiresAt,
        'North status: ' . ($status['status'] ?? 'Unknown'),
        '',
        'Session ID: ' . ($session['id'] ?? ''),
    ]);

    $headers = [
        'From: Wilson Creek Wi-Fi <' . $from . '>',
        'Reply-To: ' . $from,
        'Content-Type: text/plain; charset=UTF-8',
    ];

    @mail($to, $subject, $body, implode("\r\n", $headers));
}

function json_response(array $payload, int $status = 200): void
{
    http_response_code($status);
    header('Content-Type: application/json');
    echo json_encode($payload);
    exit;
}