<?php

class Habit
{
    public static function allForUser(int $userId, array $filters = []): array
    {
        $where = ['h.user_id = :user_id'];
        $params = ['user_id' => $userId];

        if (!empty($filters['category_id'])) {
            $where[] = 'h.category_id = :category_id';
            $params['category_id'] = (int) $filters['category_id'];
        }

        if (($filters['status'] ?? '') === 'done') {
            $where[] = 'hl.id IS NOT NULL';
        } elseif (($filters['status'] ?? '') === 'open') {
            $where[] = 'hl.id IS NULL';
        }

        $sql = 'SELECT h.*, c.name AS category_name, c.color AS category_color,
                    CASE WHEN hl.id IS NULL THEN 0 ELSE 1 END AS done_today
                FROM habits h
                LEFT JOIN categories c ON c.id = h.category_id
                LEFT JOIN habit_logs hl
                    ON hl.habit_id = h.id
                    AND hl.completed_on = CURRENT_DATE
                WHERE ' . implode(' AND ', $where) . '
                ORDER BY h.created_at DESC';

        $statement = Database::connection()->prepare($sql);
        $statement->execute($params);

        return $statement->fetchAll();
    }

    public static function findForUser(int $id, int $userId): ?array
    {
        $statement = Database::connection()->prepare(
            'SELECT * FROM habits WHERE id = :id AND user_id = :user_id LIMIT 1'
        );
        $statement->execute(['id' => $id, 'user_id' => $userId]);

        $habit = $statement->fetch();
        return $habit ?: null;
    }

    public static function create(int $userId, array $data): bool
    {
        $sql = 'INSERT INTO habits (user_id, category_id, title, description, target_per_week)
                VALUES (:user_id, :category_id, :title, :description, :target_per_week)';

        return Database::connection()->prepare($sql)->execute([
            'user_id' => $userId,
            'category_id' => $data['category_id'] ?: null,
            'title' => $data['title'],
            'description' => $data['description'],
            'target_per_week' => (int) $data['target_per_week'],
        ]);
    }

    public static function update(int $id, int $userId, array $data): bool
    {
        $sql = 'UPDATE habits
                SET category_id = :category_id,
                    title = :title,
                    description = :description,
                    target_per_week = :target_per_week
                WHERE id = :id AND user_id = :user_id';

        return Database::connection()->prepare($sql)->execute([
            'id' => $id,
            'user_id' => $userId,
            'category_id' => $data['category_id'] ?: null,
            'title' => $data['title'],
            'description' => $data['description'],
            'target_per_week' => (int) $data['target_per_week'],
        ]);
    }

    public static function delete(int $id, int $userId): bool
    {
        $statement = Database::connection()->prepare('DELETE FROM habits WHERE id = :id AND user_id = :user_id');

        return $statement->execute(['id' => $id, 'user_id' => $userId]);
    }

    public static function toggleToday(int $id, int $userId): bool
    {
        $habit = self::findForUser($id, $userId);

        if (!$habit) {
            return false;
        }

        $db = Database::connection();
        $check = $db->prepare(
            'SELECT id FROM habit_logs WHERE habit_id = :habit_id AND completed_on = CURRENT_DATE LIMIT 1'
        );
        $check->execute(['habit_id' => $id]);
        $log = $check->fetch();

        if ($log) {
            return $db->prepare('DELETE FROM habit_logs WHERE id = :id')->execute(['id' => $log['id']]);
        }

        $insert = $db->prepare('INSERT INTO habit_logs (habit_id, completed_on) VALUES (:habit_id, CURRENT_DATE)');
        return $insert->execute(['habit_id' => $id]);
    }
}