<?php

declare(strict_types=1);

namespace Infrastructure\Persistence;

// @responsibility: Persistenz für Tasks (CRUD, Suche, Pagination)

use Domain\Entity\Task;
use Domain\Repository\TaskRepositoryInterface;
use Infrastructure\Config\DatabaseFactory;

class TaskRepository implements TaskRepositoryInterface
{
    private \PDO $pdo;

    public function __construct(?\PDO $pdo = null)
    {
        $this->pdo = $pdo ?? DatabaseFactory::dev();
    }

    public function find(int $id): ?Task
    {
        $stmt = $this->pdo->prepare('SELECT * FROM tasks WHERE id = :id');
        $stmt->execute(['id' => $id]);
        $row = $stmt->fetch();

        return $row !== false ? Task::fromArray($row) : null;
    }

    public function findById(int $id): ?Task
    {
        return $this->find($id);
    }

    public function findByUuid(string $uuid): ?Task
    {
        $stmt = $this->pdo->prepare('SELECT * FROM tasks WHERE uuid = :uuid');
        $stmt->execute(['uuid' => $uuid]);
        $row = $stmt->fetch();

        return $row !== false ? Task::fromArray($row) : null;
    }

    public function findAll(array $filters = [], int $limit = 50, int $offset = 0): array
    {
        $where = [];
        $params = [];

        if (isset($filters['status']) && $filters['status'] !== '') {
            $where[] = 'status = :status';
            $params['status'] = $filters['status'];
        }
        if (isset($filters['type']) && $filters['type'] !== '') {
            $where[] = 'type = :type';
            $params['type'] = $filters['type'];
        }
        if (isset($filters['created_by']) && $filters['created_by'] !== '') {
            $where[] = 'created_by = :created_by';
            $params['created_by'] = $filters['created_by'];
        }
        if (isset($filters['search']) && $filters['search'] !== '') {
            $where[] = '(title LIKE :search OR description LIKE :search)';
            $params['search'] = '%' . $filters['search'] . '%';
        }

        $whereClause = count($where) > 0 ? 'WHERE ' . implode(' AND ', $where) : '';

        $sql = "SELECT * FROM tasks {$whereClause} ORDER BY created_at DESC LIMIT :limit OFFSET :offset";

        $stmt = $this->pdo->prepare($sql);
        foreach ($params as $key => $value) {
            $stmt->bindValue(':' . $key, $value);
        }
        $stmt->bindValue(':limit', $limit, \PDO::PARAM_INT);
        $stmt->bindValue(':offset', $offset, \PDO::PARAM_INT);
        $stmt->execute();

        $tasks = [];
        while ($row = $stmt->fetch()) {
            $tasks[] = Task::fromArray($row);
        }

        return $tasks;
    }

    public function findByStatus(string $status, int $limit = 50): array
    {
        return $this->findAll(['status' => $status], $limit);
    }

    public function findByAssignee(string $assignee, int $limit = 50): array
    {
        $sql = 'SELECT t.* FROM tasks t
                INNER JOIN task_assignments ta ON t.id = ta.task_id
                WHERE ta.assignee = :assignee
                ORDER BY t.created_at DESC
                LIMIT :limit';

        $stmt = $this->pdo->prepare($sql);
        $stmt->bindValue(':assignee', $assignee);
        $stmt->bindValue(':limit', $limit, \PDO::PARAM_INT);
        $stmt->execute();

        $tasks = [];
        while ($row = $stmt->fetch()) {
            $tasks[] = Task::fromArray($row);
        }

        return $tasks;
    }

    public function findByCreator(string $createdBy, int $limit = 50): array
    {
        return $this->findAll(['created_by' => $createdBy], $limit);
    }

    public function findSubtasks(int $parentTaskId): array
    {
        $stmt = $this->pdo->prepare(
            'SELECT * FROM tasks WHERE parent_task_id = :parent_id ORDER BY created_at ASC'
        );
        $stmt->execute(['parent_id' => $parentTaskId]);

        $tasks = [];
        while ($row = $stmt->fetch()) {
            $tasks[] = Task::fromArray($row);
        }

        return $tasks;
    }

    public function save(Task $task): int
    {
        $sql = 'INSERT INTO tasks (
            uuid, title, description, type, status,
            created_by, created_by_type, parent_task_id, due_date,
            created_at, updated_at, completed_at, metadata
        ) VALUES (
            :uuid, :title, :description, :type, :status,
            :created_by, :created_by_type, :parent_task_id, :due_date,
            :created_at, :updated_at, :completed_at, :metadata
        )';

        $stmt = $this->pdo->prepare($sql);
        $data = $task->toArray();

        $stmt->execute([
            'uuid' => $data['uuid'],
            'title' => $data['title'],
            'description' => $data['description'],
            'type' => $data['type'],
            'status' => $data['status'],
            'created_by' => $data['created_by'],
            'created_by_type' => $data['created_by_type'],
            'parent_task_id' => $data['parent_task_id'],
            'due_date' => $data['due_date'],
            'created_at' => $data['created_at'],
            'updated_at' => $data['updated_at'],
            'completed_at' => $data['completed_at'],
            'metadata' => json_encode($data['metadata']),
        ]);

        return (int) $this->pdo->lastInsertId();
    }

    public function update(Task $task): bool
    {
        $sql = 'UPDATE tasks SET
            title = :title,
            description = :description,
            type = :type,
            status = :status,
            parent_task_id = :parent_task_id,
            due_date = :due_date,
            updated_at = :updated_at,
            completed_at = :completed_at,
            metadata = :metadata
        WHERE id = :id';

        $stmt = $this->pdo->prepare($sql);
        $data = $task->toArray();

        return $stmt->execute([
            'id' => $data['id'],
            'title' => $data['title'],
            'description' => $data['description'],
            'type' => $data['type'],
            'status' => $data['status'],
            'parent_task_id' => $data['parent_task_id'],
            'due_date' => $data['due_date'],
            'updated_at' => $data['updated_at'],
            'completed_at' => $data['completed_at'],
            'metadata' => json_encode($data['metadata']),
        ]);
    }

    public function delete(int $id): bool
    {
        $stmt = $this->pdo->prepare('DELETE FROM tasks WHERE id = :id');

        return $stmt->execute(['id' => $id]);
    }

    public function count(array $filters = []): int
    {
        $where = [];
        $params = [];

        if (isset($filters['status']) && $filters['status'] !== '') {
            $where[] = 'status = :status';
            $params['status'] = $filters['status'];
        }
        if (isset($filters['type']) && $filters['type'] !== '') {
            $where[] = 'type = :type';
            $params['type'] = $filters['type'];
        }

        $whereClause = count($where) > 0 ? 'WHERE ' . implode(' AND ', $where) : '';

        $stmt = $this->pdo->prepare("SELECT COUNT(*) FROM tasks {$whereClause}");
        $stmt->execute($params);

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

    public function getStatistics(): array
    {
        $sql = "SELECT
            COUNT(*) as total,
            SUM(CASE WHEN status = 'pending' THEN 1 ELSE 0 END) as pending,
            SUM(CASE WHEN status = 'in_progress' THEN 1 ELSE 0 END) as in_progress,
            SUM(CASE WHEN status = 'completed' THEN 1 ELSE 0 END) as completed,
            SUM(CASE WHEN status = 'failed' THEN 1 ELSE 0 END) as failed,
            SUM(CASE WHEN status = 'cancelled' THEN 1 ELSE 0 END) as cancelled,
            SUM(CASE WHEN type = 'human_task' THEN 1 ELSE 0 END) as human_tasks,
            SUM(CASE WHEN type = 'ai_task' THEN 1 ELSE 0 END) as ai_tasks,
            SUM(CASE WHEN type = 'mixed' THEN 1 ELSE 0 END) as mixed_tasks
        FROM tasks";

        $stmt = $this->pdo->query($sql);

        return $stmt->fetch();
    }
}