package service

import (
	"strings"

	"gorm.io/gorm"

	"nl-pms-api/internal/commonservice"
	"nl-pms-api/internal/model"
)

// SettingsService 用户设置与全局资源（fest_img:* / file_storage）。
type SettingsService struct {
	DB *gorm.DB
}

func isGlobalSetting(name string) bool {
	return name == "file_storage" || strings.HasPrefix(name, "fest_img:")
}

func settingOwner(userID int64, name string) int64 {
	if isGlobalSetting(name) {
		return commonservice.AdminUserID
	}
	return userID
}

// GetSetting 读取单条设置；全局键从管理员账号读。
func (s *SettingsService) GetSetting(userID int64, name string) (*model.SyncSetting, error) {
	name = strings.TrimSpace(name)
	if name == "" {
		return nil, commonservice.BadRequest("SETTING_NAME_REQUIRED")
	}
	owner := settingOwner(userID, name)
	var row model.SyncSetting
	if err := s.DB.Where("user_id = ? AND name = ?", owner, name).First(&row).Error; err != nil {
		if err == gorm.ErrRecordNotFound {
			return nil, commonservice.NotFound("NOT_FOUND")
		}
		return nil, commonservice.Internal("QUERY_FAILED")
	}
	return &row, nil
}

// ListByPrefix 按前缀批量拉取（如 fest_img:），全局前缀从管理员账号读。
func (s *SettingsService) ListByPrefix(userID int64, prefix string) ([]model.SyncSetting, error) {
	prefix = strings.TrimSpace(prefix)
	if prefix == "" {
		return nil, commonservice.BadRequest("SETTING_PREFIX_REQUIRED")
	}
	owner := userID
	if strings.HasPrefix(prefix, "fest_img:") || prefix == "fest_img:" {
		owner = commonservice.AdminUserID
	}
	var rows []model.SyncSetting
	if err := s.DB.Where("user_id = ? AND name LIKE ?", owner, prefix+"%").
		Order("name").Find(&rows).Error; err != nil {
		return nil, commonservice.Internal("QUERY_FAILED")
	}
	if rows == nil {
		rows = []model.SyncSetting{}
	}
	return rows, nil
}

// GetGlobal 读取挂在管理员名下的全局设置。
func (s *SettingsService) GetGlobal(name string) (*model.SyncSetting, error) {
	return s.GetSetting(commonservice.AdminUserID, name)
}

// PutSetting LWW 写入；全局键仅管理员可写，且落在 user_id=1。
func (s *SettingsService) PutSetting(userID int64, name, value, updatedAt string) error {
	name = strings.TrimSpace(name)
	if name == "" {
		return commonservice.BadRequest("SETTING_NAME_REQUIRED")
	}
	if updatedAt == "" {
		updatedAt = commonservice.NowRFC()
	}
	owner := userID
	if isGlobalSetting(name) {
		if userID != commonservice.AdminUserID {
			return commonservice.Forbidden("FORBIDDEN")
		}
		owner = commonservice.AdminUserID
	}
	q := `INSERT INTO sync_settings(user_id,name,value,updated_at) VALUES(?,?,?,?)
		ON DUPLICATE KEY UPDATE value=IF(VALUES(updated_at)>updated_at,VALUES(value),value),
		updated_at=IF(VALUES(updated_at)>updated_at,VALUES(updated_at),updated_at)`
	if err := s.DB.Exec(q, owner, name, value, updatedAt).Error; err != nil {
		return commonservice.Internal("SAVE_FAILED")
	}
	return nil
}