package ec

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

type categoryRequest struct {
	ParentIdentity string `json:"parent_identity"`
	Name           string `json:"name" binding:"required,max=128"`
	SortNo         int    `json:"sort_no"`
}

type ecCategoryView struct {
	Identity       string `json:"identity"`
	ParentIdentity string `json:"parent_identity,omitempty"`
	Name           string `json:"name"`
	SortNo         int    `json:"sort_no"`
	Status         int    `json:"status"`
}

func ecCategoryViews(list []models.EcCategory) ([]ecCategoryView, error) {
	parents := make(map[uint64]string)
	for _, item := range list {
		if item.ParentID != 0 {
			parents[item.ParentID] = ""
		}
	}
	if len(parents) > 0 {
		var rows []struct {
			ID       uint64
			Identity string
		}
		ids := make([]uint64, 0, len(parents))
		for id := range parents {
			ids = append(ids, id)
		}
		if err := impl.DBService.Model(&models.EcCategory{}).Select("id", "identity").Where("id IN ?", ids).Find(&rows).Error; err != nil {
			return nil, err
		}
		for _, row := range rows {
			parents[row.ID] = row.Identity
		}
	}
	views := make([]ecCategoryView, 0, len(list))
	for _, item := range list {
		views = append(views, ecCategoryView{Identity: item.Identity, ParentIdentity: parents[item.ParentID], Name: item.Name, SortNo: item.SortNo, Status: item.Status})
	}
	return views, nil
}

func ListEcCategory(ctx *gin.Context) {
	page, size := common.PageSize(ctx)
	var list []models.EcCategory
	var total int64
	query := common.ActiveRecords(impl.DBService.Model(&models.EcCategory{}))
	if err := query.Count(&total).Error; err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	if err := query.Order("sort_no asc, id asc").Offset((page - 1) * size).Limit(size).Find(&list).Error; err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	views, err := ecCategoryViews(list)
	if err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	infra.Response.Success(ctx, gin.H{"total": total, "list": views})
}

func GetEcCategory(ctx *gin.Context) {
	var category models.EcCategory
	if err := common.ActiveRecords(impl.DBService).Where("identity = ?", ctx.Param("identity")).First(&category).Error; err != nil {
		common.RespondRecordError(ctx, err)
		return
	}
	views, err := ecCategoryViews([]models.EcCategory{category})
	if err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	infra.Response.Success(ctx, views[0])
}

func CreateEcCategory(ctx *gin.Context) {
	var request categoryRequest
	if err := ctx.ShouldBindJSON(&request); err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	parentID, err := common.ResolveIdentityID(&models.EcCategory{}, request.ParentIdentity, false)
	if err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	category := models.EcCategory{Entity: common.NewEntity(common.StatusDraft), ParentID: parentID, Name: request.Name, SortNo: request.SortNo}
	if err := impl.DBService.Create(&category).Error; err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	common.RespondCreatedResource(ctx, category)
}

func UpdateEcCategory(ctx *gin.Context) {
	var request categoryRequest
	if err := ctx.ShouldBindJSON(&request); err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	var category models.EcCategory
	if err := common.ActiveRecords(impl.DBService).Where("identity = ?", ctx.Param("identity")).First(&category).Error; err != nil {
		common.RespondRecordError(ctx, err)
		return
	}
	parentID, err := common.ResolveIdentityID(&models.EcCategory{}, request.ParentIdentity, false)
	if err != nil {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	var rows []models.EcCategory
	if err := impl.DBService.Select("id", "parent_id").Find(&rows).Error; err != nil {
		infra.Response.Error(ctx, err)
		return
	}
	parents := make(map[uint64]uint64, len(rows))
	for _, row := range rows {
		parents[row.ID] = row.ParentID
	}
	if wouldCreateCategoryCycle(category.ID, parentID, parents) {
		infra.Response.Error(ctx, errcode.ErrInvalidArgument)
		return
	}
	common.UpdateAllowedByIdentity(ctx, &models.EcCategory{}, gin.H{"parent_id": parentID, "name": request.Name, "sort_no": request.SortNo}, []string{"parent_id", "name", "sort_no"})
}

func wouldCreateCategoryCycle(categoryID, parentID uint64, parents map[uint64]uint64) bool {
	seen := map[uint64]bool{}
	for parentID != 0 {
		if parentID == categoryID || seen[parentID] {
			return true
		}
		seen[parentID] = true
		parentID = parents[parentID]
	}
	return false
}