<?php

namespace App\Services;

use RuntimeException;
use App\Forms\CommonForm;
use App\Models\CommonModel;
use App\Entities\CommonEntity;
use App\Libraries\AuthContext;
use App\Exceptions\FormValidationException;
use CodeIgniter\Database\Exceptions\DatabaseException;

abstract class CommonService
{
    private ?AuthContext $_authContext = null;
    private array $_classPaths = [];
    protected $title = null;

    protected ?object $_form = null;
    protected ?object $_helper = null;

    protected string $formClass = '';
    protected string $helperClass = '';

    protected function __construct(protected CommonModel $model)
    {
    }

    abstract public function getEntityClass(): string;

    /**
     * 공통 트랜잭션 래퍼
     */
    final protected function dbTransaction(callable $callback, string $functionName = ''): mixed
    {
        $db = \Config\Database::connect();

        try {
            $db->transException(true)->transStart();
            $result = $callback($db);
            $db->transComplete();
            return $result;

        } catch (FormValidationException $e) {
            // 검증 에러는 감싸지 말고 그대로 던져야 Ajax가 422 + errors 받음
            $db->transRollback();
            throw $e;

        } catch (DatabaseException $e) {
            $db->transRollback();
            $errorMessage = sprintf(
                "\n----[%s]에서 트랜잭션 실패: DB 오류----\n%s\n%s\n------------------------------\n",
                static::class . '->' . ($functionName ?: 'dbTransaction'),
                $this->model->getLastQuery() ?? 'No Query Available',
                $e->getMessage()
            );
            log_message('error', $errorMessage);
            throw new RuntimeException($errorMessage, $e->getCode(), $e);

        } catch (\Throwable $e) {
            $db->transRollback();
            throw new RuntimeException($e->getMessage(), $e->getCode(), $e);
        }
    }

    final public function getActionForm(): mixed
    {
        if ($this->_form === null && $this->formClass) {
            $this->_form = new $this->formClass();
            if (method_exists($this->_form, 'setAttributes')) {
                $this->_form->setAttributes([
                    'pk_field' => $this->getPKField(),
                    'title_field' => $this->getTitleField(),
                    'table' => $this->model->getTable(),
                    'useAutoIncrement' => $this->model->useAutoIncrement(),
                    'class_path' => $this->getClassPaths(false),
                ]);
            }
        }
        return $this->_form;
    }

    public function getHelper(): mixed
    {
        if ($this->_helper === null && $this->helperClass) {
            $this->_helper = new $this->helperClass();
            if (method_exists($this->_helper, 'setAttributes')) {
                $this->_helper->setAttributes([
                    'pk_field' => $this->getPKField(),
                    'title_field' => $this->getTitleField(),
                    'table' => $this->model->getTable(),
                    'useAutoIncrement' => $this->model->useAutoIncrement(),
                    'class_path' => $this->getClassPaths(false),
                ]);
            }
        }
        return $this->_helper;
    }

    final public function getAuthContext(): AuthContext
    {
        if ($this->_authContext === null) {
            $this->_authContext = new AuthContext();
        }
        return $this->_authContext;
    }

    final protected function addClassPaths(string $path): void
    {
        $this->_classPaths[] = $path;
    }

    final public function getPKField(): string
    {
        return $this->model->getPKField();
    }

    final public function getTitleField(): string
    {
        return $this->model->getTitleField();
    }

    final public function getClassPaths($isArray = true, $delimeter = DIRECTORY_SEPARATOR): array|string
    {
        return $isArray ? $this->_classPaths : implode($delimeter, $this->_classPaths);
    }

    final public function getNextPK(): int
    {
        $pkField = $this->getPKField();
        $row = $this->model->selectMax($pkField)->get()->getRow();
        return isset($row->{$pkField}) ? ((int) $row->{$pkField} + 1) : 1;
    }

    /**
     * 단일 엔티티를 조회합니다.
     */
    abstract protected function getEntity_process($entity): CommonEntity;

    final public function getEntity($where = null, ?string $message = null): ?CommonEntity
    {
        try {
            $entity = null;
            if ($where !== null) {
                $entity = is_array($where) ? $this->model->where($where)->first() : $this->model->find($where);
            }

            if ($entity === null) {
                return null;
            }

            $entityClass = $this->getEntityClass();
            if (!$entity instanceof $entityClass) {
                throw new RuntimeException(
                    static::class . '->' . __FUNCTION__ . "에서 오류발생:Return Type은 {$entityClass}만 가능:" . get_class($entity)
                );
            }

            return $this->getEntity_process($entity);

        } catch (DatabaseException $e) {
            $errorMessage = sprintf(
                "\n------DB Query 오류 (%s)-----\nQuery: %s\nError: %s\n------------------------------\n",
                static::class . '->' . __FUNCTION__,
                $this->model->getLastQuery() ?? 'No Query Available',
                $e->getMessage()
            );
            log_message('error', $errorMessage);
            throw new RuntimeException($errorMessage, $e->getCode(), $e);

        } catch (\Throwable $e) {
            $errorMessage = sprintf(
                "\n------일반 오류 (%s)-----\nError: %s\n------------------------------\n",
                static::class . '->' . __FUNCTION__,
                $e->getMessage()
            );
            throw new RuntimeException($errorMessage, $e->getCode(), $e);
        }
    }

    /**
     * 엔티티 배열 조회합니다.
     * @return CommonEntity[] CommonEntity 인스턴스 배열
     */
    protected function getEntities_process(mixed $where = null, array $columns = ['*'], array $entities = []): array
    {
        if ($where) {
            $this->model->where($where);
        }

        // 기본 Order By 이용
        $this->setOrderBy();

        if (!empty($columns) && $columns !== ['*']) {
            $this->model->select(implode(',', $columns));
        }

        /** @var array<\App\Entities\CommonEntity> $results */
        $results = $this->model->findAll();
        log_message('debug', (string) $this->model->getLastQuery());

        foreach ($results as $entity) {
            $entities[] = $entity;
        }

        return $entities;
    }

    public function getEntities(?array $where = null, array $columns = ['*'], array $entities = []): array
    {
        try {
            /** @var array<\App\Entities\CommonEntity> $entities */
            $entities = $this->getEntities_process($where, $columns, $entities);
            return $entities;

        } catch (DatabaseException $e) {
            $errorMessage = sprintf(
                "\n------DB Query 오류 (%s)-----\nQuery: %s\nError: %s\n------------------------------\n",
                static::class . '->' . __FUNCTION__,
                $this->model->getLastQuery() ?? 'No Query Available',
                $e->getMessage()
            );
            log_message('error', $errorMessage);
            throw new RuntimeException($errorMessage, $e->getCode(), $e);

        } catch (\Throwable $e) {
            $errorMessage = sprintf(
                "\n------일반 오류 (%s)-----\nError: %s\n------------------------------\n",
                static::class . '->' . __FUNCTION__,
                $e->getMessage()
            );
            throw new RuntimeException($errorMessage, $e->getCode(), $e);
        }
    }

    // CURD 결과처리용
    protected function save_process($entity): CommonEntity
    {
        try {
            if (!$this->model->save($entity)) {
                $errors = $this->model->errors();
                $errorMsg = is_array($errors) ? implode(', ', $errors) : 'DB 저장 작업이 실패했습니다.';
                throw new RuntimeException(static::class . '->' . __FUNCTION__ . '에서 오류발생: ' . $errorMsg);
            }
            return $entity;

        } catch (\Throwable $e) {
            log_message('debug', __FUNCTION__ . ':' . var_export($entity, true));
            log_message('debug', __FUNCTION__ . ':' . (string) $this->model->getLastQuery());
            throw new RuntimeException(static::class . '->' . __FUNCTION__ . '에서 오류발생:' . $e->getMessage());
        }
    }

    // Action 작업시 field에따른 Hook처리(각 Service에서 override)
    protected function fieldhook_process(string $field, $value, array $formDatas): array
    {
        return $formDatas;
    }

    // 생성용
    protected function create_process(array $formDatas): CommonEntity
    {
        try {
            $actionForm = $this->getActionForm();
            if (!$actionForm instanceof CommonForm) {
                throw new RuntimeException(static::class . '->' . __FUNCTION__ . '에서 오류발생: actionForm이 정의되지 않았습니다.');
            }

            // create 폼 초기화
            $actionForm->form_init_process('create', $formDatas);

            // 검증
            $actionForm->validate($formDatas);

            // 후처리
            $processedDatas = $formDatas;
            foreach (array_keys($processedDatas) as $field) {
                $value = $processedDatas[$field] ?? null;
                $processedDatas = $this->fieldhook_process($field, $value, $processedDatas);
            }

            $entityClass = $this->getEntityClass();
            $entity = new $entityClass($processedDatas);

            if (!$entity instanceof CommonEntity) {
                throw new RuntimeException('Return Type은 CommonEntity만 가능');
            }
            if (!$entity instanceof $entityClass) {
                throw new RuntimeException("Return Type은 {$entityClass}만 가능");
            }
            $entity = $this->save_process($entity);

            // 생성 PK 설정
            if ($this->model->useAutoIncrement()) {
                $entity->{$this->getPKField()} = $this->model->getInsertID();
            }

            return $entity;

        } catch (FormValidationException $e) {
            throw $e;
        } catch (\Throwable $e) {
            throw new RuntimeException(static::class . '->' . __FUNCTION__ . '에서 오류발생:' . $e->getMessage());
        }
    }

    final public function create(array $formDatas): CommonEntity
    {
        return $this->dbTransaction(function () use ($formDatas) {
            $formDatas['user_uid'] = (int) $this->getAuthContext()->getUID();
            return $this->create_process($formDatas);
        }, __FUNCTION__);
    }

    // 수정용
    protected function modify_process($entity, array $formDatas): CommonEntity
    {
        try {
            $actionForm = $this->getActionForm();
            if (!$actionForm instanceof CommonForm) {
                throw new RuntimeException(
                    static::class . '->' . __FUNCTION__ . '에서 오류발생: actionForm이 정의되지 않았습니다.'
                );
            }

            // 기존 엔티티 데이터 + 수정 데이터 병합
            $validateFormDatas = $entity->toArray();
            foreach ($formDatas as $key => $value) {
                $validateFormDatas[$key] = $value;
            }

            // 병합 데이터 기준으로 modify 폼 초기화
            $actionForm->form_init_process('modify', $validateFormDatas);

            // 검증
            $actionForm->validate($validateFormDatas);

            // 후처리
            $processedDatas = $validateFormDatas;
            foreach (array_keys($processedDatas) as $field) {
                $value = $processedDatas[$field] ?? null;
                $processedDatas = $this->fieldhook_process($field, $value, $processedDatas);
            }

            $entity->fill($processedDatas);
            if ($entity->hasChanged()) {
                $entity = $this->save_process($entity);
            }
            return $entity;
        } catch (FormValidationException $e) {
            throw $e;
        } catch (\Throwable $e) {
            throw new RuntimeException(
                static::class . '->' . __FUNCTION__ . '에서 오류발생:' . $e->getMessage()
            );
        }
    }

    final public function modify(string|int $uid, array $formDatas): CommonEntity
    {
        return $this->dbTransaction(function () use ($uid, $formDatas) {
            $entity = $this->getEntity($uid);
            if (!$entity) {
                throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생: {$uid}에 해당하는 정보을 찾을수 없습니다.");
            }

            $formDatas['user_uid'] = (int) $this->getAuthContext()->getUID();
            return $this->modify_process($entity, $formDatas);
        }, __FUNCTION__);
    }

    // 배치 작업용 수정
    protected function batchjob_process($entity, array $formDatas): CommonEntity
    {
        $entity = $this->modify_process($entity, $formDatas);
        return $entity;
    }

    final public function batchjob(array $uids, array $formDatas): array
    {
        return $this->dbTransaction(function () use ($uids, $formDatas) {
            $entities = [];

            foreach ($uids as $uid) {
                $entity = $this->getEntity($uid);
                if (!$entity) {
                    throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생: {$uid}에 해당하는 정보을 찾을수 없습니다.");
                }

                $entityClass = $this->getEntityClass();
                if (!$entity instanceof $entityClass) {
                    throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생:Return Type은 {$entityClass}만 가능");
                }

                $formDatas['user_uid'] = (int) $this->getAuthContext()->getUID();
                $entities[] = $this->batchjob_process($entity, $formDatas);
            }

            return $entities;
        }, __FUNCTION__);
    }

    // 삭제용 (일반)
    protected function delete_process($entity): CommonEntity
    {
        $result = $this->model->delete($entity->getPK());
        if ($result === false) {
            $errors = $this->model->errors();
            $errorMsg = is_array($errors) ? implode(', ', $errors) : '삭제 작업이 실패했습니다.';
            throw new RuntimeException(static::class . '->' . __FUNCTION__ . '에서 오류발생: ' . $errorMsg);
        }

        return $entity;
    }

    final public function delete(string|int $uid): CommonEntity
    {
        return $this->dbTransaction(function () use ($uid) {
            if (!$uid) {
                throw new RuntimeException(static::class . '->' . __FUNCTION__ . '에서 삭제에 필요한 PrimaryKey 가 정의 되지 않았습니다.');
            }

            $entity = $this->getEntity($uid);
            if (!$entity) {
                throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생: {$uid}에 해당하는 정보을 찾을수 없습니다.");
            }

            $entityClass = $this->getEntityClass();
            if (!$entity instanceof $entityClass) {
                throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생:Return Type은 {$entityClass}만 가능");
            }

            return $this->delete_process($entity);
        }, __FUNCTION__);
    }

    // 삭제용 (배치 작업)
    protected function batchjob_delete_process($entity): CommonEntity
    {
        $entity = $this->delete_process($entity);
        return $entity;
    }

    final public function batchjob_delete(array $uids): array
    {
        return $this->dbTransaction(function () use ($uids) {
            $entities = [];

            foreach ($uids as $uid) {
                $entity = $this->getEntity($uid);
                if (!$entity) {
                    throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생: {$uid}에 해당하는 정보을 찾을수 없습니다.");
                }

                $entityClass = $this->getEntityClass();
                if (!$entity instanceof $entityClass) {
                    throw new RuntimeException(static::class . '->' . __FUNCTION__ . "에서 오류발생:Return Type은 {$entityClass}만 가능");
                }

                $entities[] = $this->batchjob_delete_process($entity);
            }

            return $entities;
        }, __FUNCTION__);
    }

    // Index용
    final public function getTotalCount(): int
    {
        return $this->model->countAllResults();
    }

    // Limit처리
    final public function setLimit(int $perpage): void
    {
        $this->model->limit($perpage);
    }

    // Offset처리
    final public function setOffset(int $offset): void
    {
        $this->model->offset($offset);
    }

    public function setFilter(string $field, mixed $filter_value): void
    {
        switch ($field) {
            default:
                $this->model->where("{$this->model->getTable()}.{$field}", $filter_value);
                break;
        }
    }

    // 검색어조건절처리
    public function setSearchWord(string $word): void
    {
        $this->model->orLike($this->model->getTable() . '.' . $this->getTitleField(), $word, 'both');
    }

    // 날짜검색
    public function setDateFilter(string $start, string $end): void
    {
        $this->model->where("{$this->model->getTable()}.created_at >=", $start . ' 00:00:00');
        $this->model->where("{$this->model->getTable()}.created_at <=", $end . ' 23:59:59');
    }

    // OrderBy 처리
    public function setOrderBy(mixed $field = null, mixed $value = null): void
    {
        if ($field !== null && $value !== null) {
            $this->model->orderBy($this->model->getTable() . '.' . $field, (string) $value);
        } else {
            $this->model->orderBy($this->model->getTable() . '.' . $this->getPKField(), 'DESC');
        }
    }
}