<?php

declare(strict_types=1);

namespace app\admin\library\traits;

use Throwable;
use support\Response;

/**
 * 后台控制器 trait（Webman 迁移版）
 * 提供 CRUD 方法：index、add、edit、del、sortable
 * 方法需返回 Response，供 Webman 路由直接返回
 */
trait Backend
{
    /**
     * 排除入库字段
     * 时间戳字段（create_time/update_time）由模型自动维护，禁止前端传入非法值（如 'now'）
     */
    protected function excludeFields(array $params): array
    {
        if (!is_array($this->preExcludeFields)) {
            $this->preExcludeFields = explode(',', (string) $this->preExcludeFields);
        }

        $exclude = array_merge(
            $this->preExcludeFields,
            ['create_time', 'update_time', 'createtime', 'updatetime']
        );
        foreach ($exclude as $field) {
            $field = trim($field);
            if ($field !== '' && array_key_exists($field, $params)) {
                unset($params[$field]);
            }
        }
        return $params;
    }

    /**
     * 查看（内部实现，由 Backend::index(Request) 调用）
     */
    protected function _index(): Response
    {
        if ($this->request && $this->request->get('select')) {
            return $this->select($this->request);
        }

        list($where, $alias, $limit, $order) = $this->queryBuilder();
        $res = $this->model
            ->field($this->indexField)
            ->withJoin($this->withJoinTable, $this->withJoinType)
            ->alias($alias)
            ->where($where)
            ->order($order)
            ->paginate($limit);

        return $this->success('', [
            'list'   => $res->items(),
            'total'  => $res->total(),
            'remark' => get_route_remark(),
        ]);
    }

    /**
     * 递归应用输入过滤（如 clean_xss）
     */
    protected function applyInputFilter(array $data): array
    {
        if (!$this->inputFilter || !function_exists($this->inputFilter)) {
            return $data;
        }
        $filter = $this->inputFilter;
        foreach ($data as $k => $v) {
            if (is_string($v)) {
                $data[$k] = call_user_func($filter, $v);
            } elseif (is_array($v)) {
                $data[$k] = $this->applyInputFilter($v);
            }
        }
        return $data;
    }

    /**
     * 添加（内部实现）
     */
    protected function _add(): Response
    {
        if ($this->request && $this->request->method() === 'POST') {
            $data = $this->request->post();
            if (!$data) {
                return $this->error(__('Parameter %s can not be empty', ['']));
            }

            $data = $this->applyInputFilter($data);
            $data = $this->excludeFields($data);
            if ($this->dataLimit && $this->dataLimitFieldAutoFill) {
                $data[$this->dataLimitField] = $this->auth->id;
            }

            $result = false;
            $this->model->startTrans();
            try {
                if ($this->modelValidate) {
                    $validate = str_replace("\\model\\", "\\validate\\", get_class($this->model));
                    if (class_exists($validate)) {
                        $validate = new $validate();
                        if ($this->modelSceneValidate) {
                            $validate->scene('add');
                        }
                        $validate->check($data);
                    }
                }
                $result = $this->model->save($data);
                $this->model->commit();
            } catch (Throwable $e) {
                $this->model->rollback();
                return $this->error($e->getMessage());
            }
            if ($result !== false) {
                return $this->success(__('Added successfully'));
            }
            return $this->error(__('No rows were added'));
        }

        return $this->error(__('Parameter error'));
    }

    /**
     * 编辑（内部实现）
     */
    protected function _edit(): Response
    {
        $pk = $this->model->getPk();
        $id = $this->request ? ($this->request->post($pk) ?? $this->request->get($pk)) : null;
        $row = $this->model->find($id);
        if (!$row) {
            return $this->error(__('Record not found'));
        }

        $dataLimitAdminIds = $this->getDataLimitAdminIds();
        if ($dataLimitAdminIds && !in_array($row[$this->dataLimitField], $dataLimitAdminIds)) {
            return $this->error(__('You have no permission'));
        }

        if ($this->request && $this->request->method() === 'POST') {
            $data = $this->request->post();
            if (!$data) {
                return $this->error(__('Parameter %s can not be empty', ['']));
            }

            $data = $this->applyInputFilter($data);
            $data = $this->excludeFields($data);
            $result = false;
            $this->model->startTrans();
            try {
                if ($this->modelValidate) {
                    $validate = str_replace("\\model\\", "\\validate\\", get_class($this->model));
                    if (class_exists($validate)) {
                        $validate = new $validate();
                        if ($this->modelSceneValidate) {
                            $validate->scene('edit');
                        }
                        $data[$pk] = $row[$pk];
                        $validate->check($data);
                    }
                }
                $result = $row->save($data);
                $this->model->commit();
            } catch (Throwable $e) {
                $this->model->rollback();
                return $this->error($e->getMessage());
            }
            if ($result !== false) {
                return $this->success(__('Update successful'));
            }
            return $this->error(__('No rows updated'));
        }

        return $this->success('', [
            'row' => $row
        ]);
    }

    /**
     * 删除（内部实现）
     */
    protected function _del(): Response
    {
        $where = [];
        $dataLimitAdminIds = $this->getDataLimitAdminIds();
        if ($dataLimitAdminIds) {
            $where[] = [$this->dataLimitField, 'in', $dataLimitAdminIds];
        }

        $ids = $this->request ? ($this->request->post('ids') ?? $this->request->get('ids') ?? []) : [];
        $ids = is_array($ids) ? $ids : [];
        $where[] = [$this->model->getPk(), 'in', $ids];
        $data = $this->model->where($where)->select();

        $count = 0;
        $this->model->startTrans();
        try {
            foreach ($data as $v) {
                $count += $v->delete();
            }
            $this->model->commit();
        } catch (Throwable $e) {
            $this->model->rollback();
            return $this->error($e->getMessage());
        }
        if ($count) {
            return $this->success(__('Deleted successfully'));
        }
        return $this->error(__('No rows were deleted'));
    }

    /**
     * 排序 - 增量重排法（内部实现）
     */
    protected function _sortable(): Response
    {
        $pk = $this->model->getPk();
        $move = $this->request ? $this->request->post('move') ?? $this->request->get('move') : null;
        $target = $this->request ? $this->request->post('target') ?? $this->request->get('target') : null;
        $order = $this->request ? ($this->request->post('order') ?? $this->request->get('order')) : null;
        $order = $order ?: $this->defaultSortField;
        $direction = $this->request ? ($this->request->post('direction') ?? $this->request->get('direction')) : null;

        $dataLimitWhere = [];
        $dataLimitAdminIds = $this->getDataLimitAdminIds();
        if ($dataLimitAdminIds) {
            $dataLimitWhere[] = [$this->dataLimitField, 'in', $dataLimitAdminIds];
        }

        $moveRow = $this->model->where($dataLimitWhere)->find($move);
        $targetRow = $this->model->where($dataLimitWhere)->find($target);

        if ($move == $target || !$moveRow || !$targetRow || !$direction) {
            return $this->error(__('Record not found'));
        }

        if ($order && is_string($order)) {
            $order = explode(',', $order);
            $order = [$order[0] => $order[1] ?? 'asc'];
        }
        if (!is_array($order) || !array_key_exists($this->weighField, $order)) {
            return $this->error(__('Please use the %s field to sort before operating', [$this->weighField]));
        }

        $order = $this->queryOrderBuilder();
        $weigh = $targetRow[$this->weighField];

        $updateMethod = $order[$this->weighField] == 'desc' ? ($direction == 'up' ? 'dec' : 'inc') : ($direction == 'up' ? 'inc' : 'dec');

        $weighRowIds = $this->model
            ->where($dataLimitWhere)
            ->where($this->weighField, $weigh)
            ->order($order)
            ->column($pk);
        $weighRowsCount = count($weighRowIds);

        $this->model->where($dataLimitWhere)
            ->where($this->weighField, $updateMethod == 'dec' ? '<' : '>', $weigh)
            ->whereNotIn($pk, [$moveRow->$pk])
            ->$updateMethod($this->weighField, $weighRowsCount)
            ->save();

        if ($direction == 'down') {
            $weighRowIds = array_reverse($weighRowIds);
        }

        $moveComplete = 0;
        $weighRowIdsStr = implode(',', $weighRowIds);
        $weighRows = $this->model->where($dataLimitWhere)
            ->where($pk, 'in', $weighRowIdsStr)
            ->orderRaw("field($pk,$weighRowIdsStr)")
            ->select();

        foreach ($weighRows as $key => $weighRow) {
            if ($moveRow[$pk] == $weighRow[$pk]) {
                continue;
            }

            $rowWeighVal = $updateMethod == 'dec' ? $weighRow[$this->weighField] - $key : $weighRow[$this->weighField] + $key;

            if ($weighRow[$pk] == $targetRow[$pk]) {
                $moveComplete = 1;
                $moveRow[$this->weighField] = $rowWeighVal;
                $moveRow->save();
            }

            $rowWeighVal = $updateMethod == 'dec' ? $rowWeighVal - $moveComplete : $rowWeighVal + $moveComplete;
            $weighRow[$this->weighField] = $rowWeighVal;
            $weighRow->save();
        }

        return $this->success();
    }

    /**
     * 加载为 select(远程下拉选择框)数据，子类可覆盖
     */
    protected function _select(): Response
    {
        if (empty($this->model)) {
            return $this->success('', [
                'list'  => [],
                'total' => 0,
            ]);
        }

        $pk = $this->model->getPk();

        // 远程下拉只要求包含主键与可显示字段；这里尽量返回主键 + quickSearch 字段，避免全量字段带来性能问题
        $fields = [$pk];
        $quickSearchArr = is_array($this->quickSearchField) ? $this->quickSearchField : explode(',', (string) $this->quickSearchField);
        foreach ($quickSearchArr as $f) {
            $f = trim((string) $f);
            if ($f === '') continue;
            $f = str_contains($f, '.') ? substr($f, strrpos($f, '.') + 1) : $f;
            if ($f !== '' && !in_array($f, $fields, true)) {
                $fields[] = $f;
            }
        }

        list($where, $alias, $limit, $order) = $this->queryBuilder();
        $res = $this->model
            ->field($fields)
            ->alias($alias)
            ->where($where)
            ->order($order)
            ->paginate($limit);

        return $this->success('', [
            'list'  => $res->items(),
            'total' => $res->total(),
        ]);
    }
}