// 功能描述：用户商品收藏、分类列表与条件状态更新；版本：1.0.0。
package user

import (
	"errors"
	"fmt"
	"math"

	"git.apinb.com/bsm-sdk/core/errcode"
	"git.apinb.com/bsm-sdk/core/infra"
	"git.apinb.com/heqiapp/platforms/backend/api/internal/impl"
	common "git.apinb.com/heqiapp/platforms/backend/api/internal/logic/common"
	"git.apinb.com/heqiapp/platforms/backend/api/internal/models"
	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

var errFavoriteChanged = errcode.NewError(2404, "收藏状态已变化，请刷新后重试")

// favoriteValue 只返回商品公开标识和收藏状态，版本绑定收藏关系以防旧请求复活。
func favoriteValue(item models.EcFavorite, productIdentity string) gin.H {
	revision := ""
	if item.ID != 0 {
		revision = fmt.Sprintf("%s:%d", item.Identity, item.Revision)
	}
	return gin.H{"product_identity": productIdentity, "favorite": item.ID != 0 && item.Status == common.StatusEnable, "revision": revision}
}

// FavoriteState 读取当前账户对指定商品的状态；商品下架后仍能取消收藏。
func FavoriteState(ctx *gin.Context) {
	account, ok := common.UserAccount(ctx)
	if !ok {
		return
	}
	var product models.EcProduct
	if err := impl.DBService.Unscoped().Where("identity = ?", ctx.Param("identity")).Take(&product).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			err = errcode.ErrRecordNotFound
		}
		infra.Response.Error(ctx, err)
		return
	}
	var item models.EcFavorite
	if err := impl.DBService.Where("user_account_id = ? AND ec_product_id = ?", account.ID, product.ID).Find(&item).Error; err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	infra.Response.Success(ctx, favoriteValue(item, product.Identity))
}

// SetFavorite 使用绝对收藏状态和原版本；相同目标重试无写入，不支持物理删除。
func SetFavorite(ctx *gin.Context) {
	account, ok := common.UserAccount(ctx)
	if !ok {
		return
	}
	var request struct {
		Favorite *bool  `json:"favorite" binding:"required"`
		Revision string `json:"revision" binding:"max=128"`
	}
	if ctx.ShouldBindJSON(&request) != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	var item models.EcFavorite
	err := impl.DBService.Transaction(func(tx *gorm.DB) error {
		if err := lockAddressOwner(tx, account.ID); err != nil {
			return err
		}
		var product models.EcProduct
		if err := tx.Unscoped().Where("identity = ?", ctx.Param("identity")).Take(&product).Error; err != nil {
			if errors.Is(err, gorm.ErrRecordNotFound) {
				return errcode.ErrRecordNotFound
			}
			return err
		}
		if err := tx.Where("user_account_id = ? AND ec_product_id = ?", account.ID, product.ID).Find(&item).Error; err != nil {
			return err
		}
		state := favoriteValue(item, product.Identity)
		if state["favorite"] == *request.Favorite {
			return nil
		}
		if state["revision"] != request.Revision {
			return errFavoriteChanged
		}
		if *request.Favorite && (product.Status != common.StatusEnable || product.DeletedAt.Valid) {
			return errcode.ErrRecordNotFound
		}
		if *request.Favorite {
			var count int64
			if err := tx.Model(&models.EcFavorite{}).Where("user_account_id = ? AND status = ?", account.ID, common.StatusEnable).Count(&count).Error; err != nil {
				return err
			}
			if count >= 1000 {
				return errcode.ErrOutOfRange
			}
		}
		if item.ID == 0 {
			item = models.EcFavorite{Entity: common.NewEntity(common.StatusEnable), UserAccountID: account.ID, EcProductID: product.ID, Revision: 1}
			return tx.Create(&item).Error
		}
		if item.Revision >= math.MaxInt64 {
			return errcode.ErrOutOfRange
		}
		status := common.StatusArchived
		if *request.Favorite {
			status = common.StatusEnable
		}
		return tx.Model(&item).Updates(map[string]any{"status": status, "revision": item.Revision + 1}).Error
	})
	if err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	infra.Response.Success(ctx, favoriteValue(item, ctx.Param("identity")))
}

// ListFavorites 按最后状态更新时间分页；下架/软删除商品仍展示历史条目并禁止加购。
func ListFavorites(ctx *gin.Context) {
	account, ok := common.UserAccount(ctx)
	if !ok {
		return
	}
	query, page, ok := paginateClientList(ctx, impl.DBService.Where("user_account_id = ? AND status = ?", account.ID, common.StatusEnable))
	if !ok {
		return
	}
	var items []models.EcFavorite
	if err := query.Order("updated_at desc, identity").Find(&items).Error; err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	result, err := favoriteRows(impl.DBService, items)
	if err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	respondClientPage(ctx, page, result)
}