// Package employeecollection 提供员工代收款账单与线下收款方式字典的只读投影。
// Query 只做权限范围、筛选、分页与 DTO 投影，不修改任何状态。
package employeecollection

import (
	"context"
	"strings"

	"gorm.io/gorm"

	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/internal/model/dto"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
	"github.com/break/junhong_cmp_fiber/pkg/middleware"
)

// PaymentMethodQuery 查询线下收款方式字典。
type PaymentMethodQuery struct {
	db *gorm.DB
}

// NewPaymentMethodQuery 创建线下收款方式字典查询。
func NewPaymentMethodQuery(db *gorm.DB) *PaymentMethodQuery {
	return &PaymentMethodQuery{db: db}
}

// List 分页查询线下收款方式。
// 超级管理员可查询全部字典项；其他后台账号仅返回启用项，保证停用方式不可用于新申请。
func (q *PaymentMethodQuery) List(
	ctx context.Context,
	request dto.EmployeeCollectionPaymentMethodListRequest,
) (*dto.EmployeeCollectionPaymentMethodListResponse, error) {
	if q == nil || q.db == nil {
		return nil, errors.New(errors.CodeServiceUnavailable, "线下收款方式查询尚未配置")
	}
	isSuperAdmin := middleware.GetUserTypeFromContext(ctx) == constants.UserTypeSuperAdmin
	if !isSuperAdmin && middleware.GetUserIDFromContext(ctx) == 0 {
		return nil, errors.New(errors.CodeUnauthorized)
	}
	page, pageSize := normalizePage(request.Page, request.PageSize)

	query := q.db.WithContext(ctx).Model(&model.EmployeeCollectionPaymentMethod{})
	if !isSuperAdmin {
		query = query.Where("status = ?", constants.EmployeeCollectionPaymentMethodStatusEnabled)
	} else if request.Enabled != nil {
		status := constants.EmployeeCollectionPaymentMethodStatusDisabled
		if *request.Enabled {
			status = constants.EmployeeCollectionPaymentMethodStatusEnabled
		}
		query = query.Where("status = ?", status)
	}
	if keyword := strings.TrimSpace(request.Keyword); keyword != "" {
		pattern := "%" + keyword + "%"
		query = query.Where("code LIKE ? OR name LIKE ?", pattern, pattern)
	}

	var total int64
	if err := query.Count(&total).Error; err != nil {
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询线下收款方式总数失败")
	}
	var items []model.EmployeeCollectionPaymentMethod
	if err := query.Order("sort_order ASC, id ASC").
		Offset((page - 1) * pageSize).Limit(pageSize).
		Find(&items).Error; err != nil {
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询线下收款方式列表失败")
	}
	list := make([]*dto.EmployeeCollectionPaymentMethodResponse, 0, len(items))
	for index := range items {
		list = append(list, toPaymentMethodResponse(&items[index]))
	}
	return &dto.EmployeeCollectionPaymentMethodListResponse{
		List: list, Total: total, Page: page, PageSize: pageSize,
	}, nil
}

// toPaymentMethodResponse 将字典项投影为对外响应，只暴露既有对象键与稳定字段。
func toPaymentMethodResponse(paymentMethod *model.EmployeeCollectionPaymentMethod) *dto.EmployeeCollectionPaymentMethodResponse {
	return &dto.EmployeeCollectionPaymentMethodResponse{
		ID: paymentMethod.ID, Code: paymentMethod.Code, Name: paymentMethod.Name,
		Enabled: paymentMethod.Status == constants.EmployeeCollectionPaymentMethodStatusEnabled,
		Sort:    paymentMethod.SortOrder, Remark: paymentMethod.Remark,
		CreatedAt: paymentMethod.CreatedAt, UpdatedAt: paymentMethod.UpdatedAt,
	}
}

// normalizePage 归一化分页参数，执行 DefaultPageSize 与 MaxPageSize 上限。
func normalizePage(page, pageSize int) (int, int) {
	if page <= 0 {
		page = constants.DefaultPage
	}
	if pageSize <= 0 {
		pageSize = constants.DefaultPageSize
	}
	if pageSize > constants.MaxPageSize {
		pageSize = constants.MaxPageSize
	}
	return page, pageSize
}