<?php

require_once __DIR__ . '/../classes/cow.php';

class Model {
    public $name;
    public $mail;
    public $type;
    public $state;
    public $key;
    public $downloads = 0;
    public $changed;
}

$model = new Model();

$_REQUEST = array_merge(
    array(
        'action' => null,
        'name' => null,
        'mail' => null,
        'type' => null,
        'key' => null,
    ),
    $_REQUEST
);

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

switch ($_REQUEST['action']) {
    case 'subscribe':
        if (isset($_REQUEST['url']) && !empty($_REQUEST['url'])) {
            goto failure;
        }

        $model->name = $_REQUEST['name'];
        $model->mail = $_REQUEST['mail'];
        $model->type = $_REQUEST['type'];
        $model->state = 'new';
        $model->key = md5(microtime());
        $model->changed = time();

        file_put_contents(
            __DIR__ . '/../newsletter.log',
            sprintf(
                '[%s] %s registered %s (%s) (book)' . PHP_EOL,
                date('r'),
                $_SERVER['REMOTE_ADDR'],
                $model->mail,
                $model->type
            ),
            FILE_APPEND
        );

        $insertStatement = $database->prepare(
            'INSERT INTO newsletter
                (name, mail, type, state, key, changed)
            VALUES
                (:name, :mail, :type, :state, :key, :changed);'
        );

        $insertStatement->bindValue(':name', $model->name);
        $insertStatement->bindValue(':mail', $model->mail);
        $insertStatement->bindValue(':type', $model->type);
        $insertStatement->bindValue(':state', $model->state);
        $insertStatement->bindValue(':key', $model->key);
        $insertStatement->bindValue(':changed', $model->changed);

        try {
            $insertStatement->execute();
        } catch (\Exception $e) {
            // Ignore if already subscribed to newsletter
        }

        $insertStatement = $database->prepare(
            'INSERT INTO book
                (name, mail, downloads, key, changed)
            VALUES
                (:name, :mail, :downloads, :key, :changed);'
        );

        $insertStatement->bindValue(':name', $model->name);
        $insertStatement->bindValue(':mail', $model->mail);
        $insertStatement->bindValue(':downloads', $model->downloads);
        $insertStatement->bindValue(':key', $model->key);
        $insertStatement->bindValue(':changed', $model->changed);

        try {
            $insertStatement->execute();
        } catch (\Exception $e) {
            goto failure;
        }

        header('Location: /book/registered.html');
        $encodedMail = urlencode($model->mail);
        mail(
            $model->mail,
            "Download the book now",
            "Hi {$model->name},

You can now download \"Crafting Quality Software\" here:

https://qafoo.com/book.php?action=confirm&mail={$encodedMail}&key={$model->key}

Cheers,
Qafoo",
            "From: Qafoo <support@qafoo.com>\r\n"
        );
        exit();
    case 'confirm':
        $model->mail = $_REQUEST['mail'];
        $model->state = 'confirmed';
        $model->key = $_REQUEST['key'];
        $model->changed = time();

        $selectStatement = $database->prepare(
            'SELECT state FROM newsletter WHERE mail = :mail'
        );

        $selectStatement->bindValue(':mail', $model->mail);
        $selectStatement->execute();

        if (!count($rows = $selectStatement->fetchAll(PDO::FETCH_ASSOC))) {
            goto failure;
        } elseif ($rows[0]['state'] === 'new') {
            $updateStatement = $database->prepare(
                'UPDATE newsletter
                SET state = :state, changed = :changed
                WHERE mail = :mail'
            );

            $updateStatement->bindValue(':mail', $model->mail);
            $updateStatement->bindValue(':state', $model->state);
            $updateStatement->bindValue(':changed', $model->changed);
            $updateStatement->execute();

            sendToCow(sprintf(
                " \x0314[book] %s confirmed their newsletter registration through book registration.\x03",
                $model->mail
            ));
        }

        header('Location: /book/download.html?key=' . $model->key);
        exit();
    case 'download':
        $model->key = $_REQUEST['key'];
        $model->changed = time();

        $selectStatement = $database->prepare(
            'SELECT name, mail, downloads FROM book WHERE key = :key'
        );

        $selectStatement->bindValue(':key', $_REQUEST['key']);
        $selectStatement->execute();

        if (!count($rows = $selectStatement->fetchAll(PDO::FETCH_ASSOC))) {
            header('Location: /book/invalid.html');
            exit();
        }

        $row = reset($rows);
        $model->name = $row['name'];
        $model->mail = $row['mail'];
        $model->downloads = $row['downloads'];

        if ($model->downloads > 6) {
            header('Location: /book/exceeded.html');
            sendToCow(sprintf(
                " [book] \x02Warning:\x02 %s <%s> exceeded their download limit.",
                $model->name,
                $model->mail
            ));
            exit();
        }

        $updateStatement = $database->prepare(
            'UPDATE book
            SET downloads = :downloads, changed = :changed
            WHERE mail = :mail'
        );

        $updateStatement->bindValue(':mail', $model->mail);
        $updateStatement->bindValue(':downloads', $model->downloads + 1);
        $updateStatement->bindValue(':changed', $model->changed);
        $updateStatement->execute();

        if ($_REQUEST['type'] === 'epub') {
            header('Content-Type: application/epub+zip');
            header('Content-Disposition: attachment; filename=crafting_quality_software.epub');
            readfile(__DIR__ . '/../content/book-download.epub');
        } else {
            header('Content-Type: application/pdf');
            header('Content-Disposition: attachment; filename=crafting_quality_software.pdf');
            readfile(__DIR__ . '/../content/book-download.pdf');
        }

        sendToCow(sprintf(
            " \x0314[book] %s <%s> downloaded the {$_REQUEST['type']} version of the book.\x03",
            $model->name,
            $model->mail
        ));
        exit();
}

failure:
header('Location: /book/register.html');