package asset

import (
	"context"
	kratoserrors "github.com/go-kratos/kratos/v3/errors"
	"strings"
	"time"
)

var (
	ErrNotFound          = kratoserrors.NotFound("ASSET_USER_NOT_FOUND", "user asset not found")
	ErrInsufficient      = kratoserrors.BadRequest("ASSET_INSUFFICIENT", "insufficient diamond balance")
	ErrInvalidAdjustment = kratoserrors.BadRequest("ASSET_ADJUSTMENT_INVALID", "invalid balance adjustment")
	ErrSelfDisable       = kratoserrors.BadRequest("ASSET_SELF_DISABLE", "current administrator cannot be disabled")
)

type User struct {
	UserID                                                 uint
	Username, Nickname, Avatar                             string
	Enabled                                                bool
	DiamondBalance, TotalRechargeCents, TotalSpentDiamonds int64
	CreatedAt                                              time.Time
	LastLoginAt                                            *time.Time
	RecentOrders                                           []OrderRecord
	RecentSends                                            []SendRecord
}
type OrderRecord struct {
	OrderNo               string
	Diamonds, AmountCents int64
	Status                string
	CreatedAt             time.Time
}
type SendRecord struct {
	SerialNo, RoomName, GiftName, GiftIcon string
	DiamondTotal                           int64
	CreatedAt                              time.Time
}
type Filter struct {
	Keyword   string
	UserID    uint
	Enabled   *bool
	CreatedAt []time.Time
}
type ListOptions struct {
	Offset, Limit int
	OrderBy       string
}
type Adjustment struct {
	UserID, OperatorUserID uint
	Type                   string
	Amount                 int64
	Reason                 string
}
type Repo interface {
	List(context.Context, Filter, ListOptions) ([]*User, int64, error)
	Get(context.Context, uint) (*User, error)
	SetEnabled(context.Context, uint, bool) error
	Adjust(context.Context, *Adjustment) (*User, error)
}
type Usecase struct{ repo Repo }

func NewUsecase(repo Repo) *Usecase { return &Usecase{repo: repo} }
func (uc *Usecase) List(ctx context.Context, f Filter, o ListOptions) ([]*User, int64, error) {
	if o.Limit < 1 || o.Limit > 100 {
		o.Limit = 10
	}
	return uc.repo.List(ctx, f, o)
}
func (uc *Usecase) Get(ctx context.Context, id uint) (*User, error) {
	if id == 0 {
		return nil, ErrNotFound
	}
	return uc.repo.Get(ctx, id)
}
func (uc *Usecase) SetEnabled(ctx context.Context, actor, id uint, enabled bool) error {
	if actor == id && !enabled {
		return ErrSelfDisable
	}
	return uc.repo.SetEnabled(ctx, id, enabled)
}
func (uc *Usecase) Adjust(ctx context.Context, v *Adjustment) (*User, error) {
	if v == nil || v.UserID == 0 || v.OperatorUserID == 0 || v.Amount < 1 || v.Amount > 99999 || (v.Type != "increase" && v.Type != "decrease") {
		return nil, ErrInvalidAdjustment
	}
	v.Reason = strings.TrimSpace(v.Reason)
	if n := len([]rune(v.Reason)); n < 5 || n > 50 {
		return nil, ErrInvalidAdjustment
	}
	return uc.repo.Adjust(ctx, v)
}