<?php
namespace ProVM\Common\Implement;

use PDO;
use PDOException;
use ProVM\Common\Exception\Database\BlankResult;
use Psr\Log\LoggerInterface;
use ProVM\Common\Define\Model as ModelInterface;

abstract class Repository
{
    public function __construct(PDO $connection, LoggerInterface $logger)
    {
        $this->setConnection($connection)
            ->setLogger($logger);
    }

    protected PDO $connection;
    protected string $table;
    protected LoggerInterface $logger;

    public function getConnection(): PDO
    {
        return $this->connection;
    }
    public function getTable(): string
    {
        return $this->table;
    }
    public function getLogger(): LoggerInterface
    {
        return $this->logger;
    }

    public function setConnection(PDO $pdo): Repository
    {
        $this->connection = $pdo;
        return $this;
    }
    public function setTable(string $table): Repository
    {
        $this->table = $table;
        return $this;
    }
    public function setLogger(LoggerInterface $logger): Repository
    {
        $this->logger = $logger;
        return $this;
    }

    abstract protected function fieldsForUpdate(): array;
    abstract protected function valuesForUpdate(ModelInterface $model): array;
    protected function idProperty(): string
    {
        return 'getId';
    }
    protected function idField(): string
    {
        return 'id';
    }
    public function update(ModelInterface $model, ModelInterface $old): void
    {
        $query = "UPDATE `{$this->getTable()}` SET ";
        $model_values = $this->valuesForUpdate($model);
        $old_values = $this->valuesForUpdate($old);
        $columns = [];
        $values = [];
        foreach ($this->fieldsForUpdate() as $i => $column) {
            if (isset($model_values[$i]) and $old_values[$i] !== $model_values[$i]) {
                $columns []= "`{$column}` = ?";
                $values []= $model_values[$i];
            }
        }
        if (count($columns) === 0) {
            return;
        }
        $query .= implode(', ', $columns) . " WHERE {$this->idField()} = ?";
        $values []= $old->{$this->idProperty()}();
        $st = $this->getConnection()->prepare($query);
        $st->execute($values);
    }
    abstract protected function fieldsForInsert(): array;
    abstract protected function valuesForInsert(ModelInterface $model): array;
    protected function insert(ModelInterface $model): void
    {
        $fields = $this->fieldsForInsert();
        $fields_string = implode(', ', array_map(function($field) {
            return "`{$field}`";
        }, $fields));
        $fields_questions = implode(', ', array_fill(0, count($fields), '?'));
        $query = "INSERT INTO `{$this->getTable()}` ({$fields_string}) VALUES ({$fields_questions})";
        $values = $this->valuesForInsert($model);
        $st = $this->getConnection()->prepare($query);
        $st->execute($values);
    }
    abstract protected function defaultFind(ModelInterface $model): ModelInterface;
    public function save(ModelInterface &$model): void
    {
        try {
            $old = $this->defaultFind($model);
            $this->update($model, $old);
        } catch (BlankResult $e) {
            $this->insert($model);
            $model->setId($this->getConnection()->lastInsertId());
        } catch(PDOException $e) {
            $this->getLogger()->error($e);
            throw $e;
        }
    }
    abstract public function load(array $row): ModelInterface;

    abstract protected function fieldsForCreate(): array;
    abstract protected function valuesForCreate(array $data): array;
    abstract protected function defaultSearch(array $data): ModelInterface;
    public function create(array $data): ModelInterface
    {
        try {
            return $this->defaultSearch($data);
        } catch (PDOException | BlankResult $e) {
            $data[$this->idField()] = 0;
            return $this->load($data);
        }
    }

    protected function getId(ModelInterface $model): int
    {
        return $model->getId();
    }
    public function resetIndex(): void
    {
        $query = "ALTER TABLE `{$this->getTable()}` AUTO_INCREMENT = 1";
        $this->getConnection()->query($query);
    }
    public function optimize(): void
    {
        $query = "OPTIMIZE TABLE `{$this->getTable()}`";
        $this->getConnection()->query($query);
    }
    public function delete(ModelInterface $model): void
    {
        $query = "DELETE FROM `{$this->getTable()}` WHERE `{$this->idField()}` = ?";
        $st = $this->getConnection()->prepare($query);
        $st->execute([$this->getId($model)]);
        $this->resetIndex();
        $this->optimize();
    }

    protected function fetchOne(string $query, ?array $values = null): ModelInterface
    {
        if ($values !== null) {
            $st = $this->getConnection()->prepare($query);
            $st->execute($values);
        } else {
            $st = $this->getConnection()->query($query);
        }
        $row = $st->fetch(PDO::FETCH_ASSOC);
        if (!$row) {
            throw new BlankResult();
        }
        return $this->load($row);
    }
    protected function fetchMany(string $query, ?array $values = null): array
    {
        if ($values !== null) {
            $st = $this->getConnection()->prepare($query);
            $st->execute($values);
        } else {
            $st = $this->getConnection()->query($query);
        }
        $rows = $st->fetchAll(PDO::FETCH_ASSOC);
        if (!$rows) {
            throw new BlankResult();
        }
        return array_map([$this, 'load'], $rows);
    }

    public function fetchAll(): array
    {
        $query = "SELECT * FROM `{$this->getTable()}`";
        return $this->fetchMany($query);
    }
    public function fetchById(int $id): ModelInterface
    {
        $query = "SELECT * FROM `{$this->getTable()}` WHERE `{$this->idField()}` = ?";
        return $this->fetchOne($query, [$id]);
    }
}