<?php

declare(strict_types=1);

namespace App\Repository;

use PDO;

/**
 * Data access for the `todo_items` table.
 *
 * @phpstan-type TodoItemRow array{
 *     id: int, list_id: int, text: string, complete: bool, position: int,
 *     created_at: string, updated_at: string
 * }
 */
final class TodoItemRepository
{
    public function __construct(private readonly PDO $pdo)
    {
    }

    /**
     * @return TodoItemRow[]
     */
    public function allForList(int $listId): array
    {
        $stmt = $this->pdo->prepare(
            'SELECT * FROM todo_items WHERE list_id = :list ORDER BY position ASC, id ASC'
        );
        $stmt->execute(['list' => $listId]);

        return array_map($this->cast(...), $stmt->fetchAll());
    }

    /**
     * @return TodoItemRow|null
     */
    public function findInList(int $id, int $listId): ?array
    {
        $stmt = $this->pdo->prepare('SELECT * FROM todo_items WHERE id = :id AND list_id = :list');
        $stmt->execute(['id' => $id, 'list' => $listId]);

        $row = $stmt->fetch();

        return $row === false ? null : $this->cast($row);
    }

    /**
     * @return TodoItemRow
     */
    public function create(int $listId, string $text, bool $complete, ?int $position): array
    {
        $position ??= $this->nextPosition($listId);

        $stmt = $this->pdo->prepare(
            'INSERT INTO todo_items (list_id, text, complete, position)
             VALUES (:list, :text, :complete, :position)'
        );
        $stmt->execute([
            'list' => $listId,
            'text' => $text,
            'complete' => $complete ? 1 : 0,
            'position' => $position,
        ]);

        /** @var TodoItemRow $item */
        $item = $this->findInList((int) $this->pdo->lastInsertId(), $listId);

        return $item;
    }

    /**
     * @param array{text?: string, complete?: bool, position?: int} $fields
     * @return TodoItemRow
     */
    public function update(int $id, int $listId, array $fields): array
    {
        $sets = ['updated_at = ' . "strftime('%Y-%m-%dT%H:%M:%SZ', 'now')"];
        $params = ['id' => $id];

        if (array_key_exists('text', $fields)) {
            $sets[] = 'text = :text';
            $params['text'] = $fields['text'];
        }
        if (array_key_exists('complete', $fields)) {
            $sets[] = 'complete = :complete';
            $params['complete'] = $fields['complete'] ? 1 : 0;
        }
        if (array_key_exists('position', $fields)) {
            $sets[] = 'position = :position';
            $params['position'] = $fields['position'];
        }

        $stmt = $this->pdo->prepare('UPDATE todo_items SET ' . implode(', ', $sets) . ' WHERE id = :id');
        $stmt->execute($params);

        /** @var TodoItemRow $item */
        $item = $this->findInList($id, $listId);

        return $item;
    }

    public function delete(int $id): void
    {
        $this->pdo->prepare('DELETE FROM todo_items WHERE id = :id')->execute(['id' => $id]);
    }

    private function nextPosition(int $listId): int
    {
        $stmt = $this->pdo->prepare(
            'SELECT COALESCE(MAX(position), -1) + 1 FROM todo_items WHERE list_id = :list'
        );
        $stmt->execute(['list' => $listId]);

        return (int) $stmt->fetchColumn();
    }

    /**
     * @param array<string, mixed> $row
     * @return TodoItemRow
     */
    private function cast(array $row): array
    {
        $row['id'] = (int) $row['id'];
        $row['list_id'] = (int) $row['list_id'];
        $row['complete'] = (bool) $row['complete'];
        $row['position'] = (int) $row['position'];

        /** @var TodoItemRow $row */
        return $row;
    }
}