<?php

$db = new PDO('sqlite:' . __DIR__ . '/akita.db');
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$db->exec("
CREATE TABLE IF NOT EXISTS students (
id INTEGER PRIMARY KEY AUTOINCREMENT,
name TEXT NOT NULL,
phone TEXT,
telegram TEXT,
note TEXT
);
CREATE TABLE IF NOT EXISTS visits (
id INTEGER PRIMARY KEY AUTOINCREMENT,
student_id INTEGER NOT NULL,
visit_date TEXT NOT NULL,
status TEXT NOT NULL
);
CREATE TABLE IF NOT EXISTS payments (
id INTEGER PRIMARY KEY AUTOINCREMENT,
student_id INTEGER NOT NULL,
pay_date TEXT NOT NULL,
amount REAL NOT NULL,
comment TEXT
);
CREATE TABLE IF NOT EXISTS subscriptions (
id INTEGER PRIMARY KEY AUTOINCREMENT,
student_id INTEGER NOT NULL,
lessons_total INTEGER NOT NULL,
start_date TEXT NOT NULL,
end_date TEXT
);
");

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
$action = $_POST['action'] ?? '';

if ($action === 'add_student') {
$stmt = $db->prepare("INSERT INTO students (name, phone, telegram, note) VALUES (?, ?, ?, ?)");
$stmt->execute([$_POST['name'], $_POST['phone'], $_POST['telegram'], $_POST['note']]);
}

if ($action === 'add_visit') {
$stmt = $db->prepare("INSERT INTO visits (student_id, visit_date, status) VALUES (?, ?, ?)");
$stmt->execute([$_POST['student_id'], $_POST['visit_date'], $_POST['status']]);
}

if ($action === 'add_payment') {
$stmt = $db->prepare("INSERT INTO payments (student_id, pay_date, amount, comment) VALUES (?, ?, ?, ?)");
$stmt->execute([$_POST['student_id'], $_POST['pay_date'], $_POST['amount'], $_POST['comment']]);
}

header('Location: index.php');
exit;
}

$students = $db->query("SELECT * FROM students ORDER BY name")->fetchAll(PDO::FETCH_ASSOC);
$visits = $db->query("
SELECT v.*, s.name
FROM visits v
JOIN students s ON s.id = v.student_id
ORDER BY v.visit_date DESC
LIMIT 50
")->fetchAll(PDO::FETCH_ASSOC);

$payments = $db->query("
SELECT p.*, s.name
FROM payments p
JOIN students s ON s.id = p.student_id
ORDER BY p.pay_date DESC
LIMIT 50
")->fetchAll(PDO::FETCH_ASSOC);

$total = $db->query("SELECT COALESCE(SUM(amount), 0) FROM payments")->fetchColumn();
?>
<!doctype html>
<html lang="ru">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Акита — учёт тренера</title>
<style>
body { font-family: system-ui, sans-serif; margin: 0; background: #f4f5f7; color: #222; }
header { background: #111827; color: #fff; padding: 16px; }
h1 { margin: 0; font-size: 20px; }
main { padding: 16px; max-width: 900px; margin: auto; }
section { background: #fff; border-radius: 12px; padding: 16px; margin-bottom: 16px; box-shadow: 0 1px 4px rgba(0,0,0,.08); }
h2 { margin-top: 0; font-size: 18px; }
form { display: grid; gap: 8px; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); }
input, select, button { padding: 10px; border: 1px solid #ccc; border-radius: 8px; font-size: 15px; width: 100%; box-sizing: border-box; }
button { background: #2563eb; color: #fff; border: 0; cursor: pointer; }
table { width: 100%; border-collapse: collapse; margin-top: 12px; }
th, td { padding: 8px; border-bottom: 1px solid #eee; text-align: left; font-size: 14px; }
.total { font-size: 18px; font-weight: 700; }
</style>
</head>
<body>

<header>
<h1>Акита — учёт тренера</h1>
</header>

<main>

<section>
<h2>Добавить ученика</h2>
<form method="post">
<input type="hidden" name="action" value="add_student">
<input name="name" placeholder="ФИО ученика" required>
<input name="phone" placeholder="Телефон">
<input name="telegram" placeholder="Telegram">
<input name="note" placeholder="Примечание">
<button>Добавить</button>
</form>
</section>

<section>
<h2>Отметить посещение</h2>
<form method="post">
<input type="hidden" name="action" value="add_visit">
<select name="student_id" required>
<option value="">Выберите ученика</option>