Migrate accessories to user data

- Add user_accessory as the per-user accessory inventory table.
- Migrate old accessory wear records to user-owned accessory ids, including legacy common_accessory_m lookups for old installs.
- Allocate default accessories for newly created users and update accessory reads to use user_accessory at runtime.
- Validate accessory ownership when wearing accessories and keep existing accessory-based responses working.

Signed-off-by: Sean Du <do4suki@gmail.com>

internal/model/user/useraccessory.go

@@ -0,0 +1,123 @@
+package usermodel
+
+import (
+	"fmt"
+	"sort"
+
+	"xorm.io/xorm"
+)
+
+type UserAccessory struct {
+	AccessoryOwningUserID int `xorm:"accessory_owning_user_id pk autoincr"`
+	UserID                int `xorm:"user_id index"`
+	AccessoryID           int `xorm:"accessory_id index"`
+	Exp                   int `xorm:"exp"`
+}
+
+func (UserAccessory) TableName() string {
+	return "user_accessory"
+}
+
+type accessoryTemplateRow struct {
+	AccessoryID int `xorm:"accessory_id"`
+}
+
+type userAccessoryCountRow struct {
+	AccessoryID int `xorm:"accessory_id"`
+	Count       int `xorm:"cnt"`
+}
+
+func LoadAccessoryTemplateIDs(mainSession xorm.Interface) ([]int, error) {
+	rows := []accessoryTemplateRow{}
+	err := mainSession.Table("accessory_m").
+		Where("is_material = ? AND rarity = ?", 0, 4).
+		Cols("accessory_id").
+		OrderBy("accessory_id ASC").
+		Find(&rows)
+	if err != nil {
+		return nil, err
+	}
+
+	ids := make([]int, 0, len(rows))
+	for _, row := range rows {
+		ids = append(ids, row.AccessoryID)
+	}
+	return ids, nil
+}
+
+func EnsureUserAccessories(userSession *xorm.Session, mainSession xorm.Interface, userID int, minCount map[int]int) error {
+	accessoryIDs, err := LoadAccessoryTemplateIDs(mainSession)
+	if err != nil {
+		return err
+	}
+
+	existingRows := []userAccessoryCountRow{}
+	err = userSession.Table(new(UserAccessory)).
+		Select("accessory_id, COUNT(*) AS cnt").
+		Where("user_id = ?", userID).
+		GroupBy("accessory_id").
+		Find(&existingRows)
+	if err != nil {
+		return err
+	}
+
+	existingCount := make(map[int]int, len(existingRows))
+	for _, row := range existingRows {
+		existingCount[row.AccessoryID] = row.Count
+	}
+
+	for _, accessoryID := range accessoryIDs {
+		targetCount := 1
+		if count, ok := minCount[accessoryID]; ok && count > targetCount {
+			targetCount = count
+		}
+
+		for existingCount[accessoryID] < targetCount {
+			_, err = userSession.Insert(&UserAccessory{
+				UserID:      userID,
+				AccessoryID: accessoryID,
+				Exp:         0,
+			})
+			if err != nil {
+				return err
+			}
+			existingCount[accessoryID]++
+		}
+	}
+
+	return nil
+}
+
+func BuildAccessoryOwningUserIDMap(userSession *xorm.Session, userID int) (map[int][]int, error) {
+	rows := []UserAccessory{}
+	err := userSession.Table(new(UserAccessory)).
+		Where("user_id = ?", userID).
+		OrderBy("accessory_id ASC, accessory_owning_user_id ASC").
+		Find(&rows)
+	if err != nil {
+		return nil, err
+	}
+
+	result := make(map[int][]int)
+	for _, row := range rows {
+		result[row.AccessoryID] = append(result[row.AccessoryID], row.AccessoryOwningUserID)
+	}
+	return result, nil
+}
+
+func ResolveAccessoryOwningUserIDsByAccessoryID(owningIDs map[int][]int, requiredCounts map[int]int) (map[int][]int, error) {
+	result := make(map[int][]int, len(requiredCounts))
+	for accessoryID, count := range requiredCounts {
+		ids := owningIDs[accessoryID]
+		if len(ids) < count {
+			return nil, fmt.Errorf("insufficient user accessories for accessory_id=%d need=%d have=%d", accessoryID, count, len(ids))
+		}
+		result[accessoryID] = append([]int(nil), ids[:count]...)
+	}
+
+	for accessoryID := range result {
+		sort.Ints(result[accessoryID])
+	}
+
+	return result, nil
+}