<?php
declare(strict_types=1);

require_once __DIR__ . '/db.php';

try {
    match ($_SERVER['REQUEST_METHOD']) {
        'GET'    => handle_get(),
        'POST'   => handle_post(),
        'PUT'    => handle_put(),
        'DELETE' => handle_delete(),
        default  => error_out('Method not allowed', 405),
    };
} catch (PDOException $e) {
    error_out('Database error: ' . $e->getMessage(), 500);
}

// ─── GET /api/templates.php ───────────────────────────────────────────────────

function handle_get(): never
{
    $rows = db()->query(
        'SELECT t.id, t.name, t.body, t.created_at, t.updated_at,
                COUNT(sr.id) AS scheduled_count
         FROM sms_templates t
         LEFT JOIN scheduled_rules sr ON sr.template_id = t.id
         GROUP BY t.id
         ORDER BY t.name'
    )->fetchAll();

    json_out(['templates' => $rows]);
}

// ─── POST /api/templates.php ──────────────────────────────────────────────────
// Body: { "name": "...", "body": "..." }

function handle_post(): never
{
    $body = json_body();
    $name = trim((string) ($body['name'] ?? ''));
    $text = trim((string) ($body['body'] ?? ''));

    if ($name === '') {
        error_out('name is required');
    }
    if ($text === '') {
        error_out('body is required');
    }
    if (mb_strlen($text) > 160) {
        error_out('body must be 160 characters or fewer');
    }

    $stmt = db()->prepare('INSERT INTO sms_templates (name, body) VALUES (:name, :body)');
    $stmt->execute([':name' => $name, ':body' => $text]);
    $id = (int) db()->lastInsertId();

    json_out(['id' => $id, 'name' => $name, 'body' => $text], 201);
}

// ─── PUT /api/templates.php?id=N ─────────────────────────────────────────────
// Body: { "name": "...", "body": "..." }

function handle_put(): never
{
    $id = (int) ($_GET['id'] ?? 0);
    if ($id <= 0) {
        error_out('Missing or invalid id');
    }

    $body = json_body();
    $name = trim((string) ($body['name'] ?? ''));
    $text = trim((string) ($body['body'] ?? ''));

    if ($name === '') {
        error_out('name is required');
    }
    if ($text === '') {
        error_out('body is required');
    }
    if (mb_strlen($text) > 160) {
        error_out('body must be 160 characters or fewer');
    }

    $stmt = db()->prepare('UPDATE sms_templates SET name = :name, body = :body WHERE id = :id');
    $stmt->execute([':name' => $name, ':body' => $text, ':id' => $id]);

    if ($stmt->rowCount() === 0) {
        error_out('Template not found', 404);
    }

    json_out(['id' => $id, 'name' => $name, 'body' => $text]);
}

// ─── DELETE /api/templates.php?id=N ──────────────────────────────────────────

function handle_delete(): never
{
    $id = (int) ($_GET['id'] ?? 0);
    if ($id <= 0) {
        error_out('Missing or invalid id');
    }

    $stmt = db()->prepare('DELETE FROM sms_templates WHERE id = :id');
    $stmt->execute([':id' => $id]);

    if ($stmt->rowCount() === 0) {
        error_out('Template not found', 404);
    }

    json_out(['deleted' => true]);
}