package service

import (
	"fmt"
	"os"
	"path/filepath"
	"sort"
	"strings"
	"time"

	"gorm.io/gorm"

	"filestoragesystem/internal/config"
	"filestoragesystem/internal/model"
	"filestoragesystem/internal/repository"
	"filestoragesystem/internal/utils"
	"filestoragesystem/pkg/apperr"
)

// AdminService 系统管理服务(设置/日志/备份)
type AdminService struct {
	cfg         *config.Config
	db          *gorm.DB
	settingRepo *repository.SettingRepo
	opLogRepo   *repository.OpLogRepo
	sysLogRepo  *repository.SysLogRepo
}

// ---- 系统设置 ----

// GetSettings 获取全部设置(按分组组织)
func (s *AdminService) GetSettings() (map[string][]model.SystemSetting, error) {
	settings, err := s.settingRepo.GetAll()
	if err != nil {
		return nil, err
	}
	groups := make(map[string][]model.SystemSetting)
	for _, st := range settings {
		groups[st.GroupName] = append(groups[st.GroupName], st)
	}
	return groups, nil
}

// GetSettingsByGroup 按分组获取设置
func (s *AdminService) GetSettingsByGroup(group string) ([]model.SystemSetting, error) {
	return s.settingRepo.GetByGroup(group)
}

// UpdateSettings 批量更新设置(仅更新已存在的键)
func (s *AdminService) UpdateSettings(values map[string]string) error {
	if len(values) == 0 {
		return nil
	}
	existing := make(map[string]bool)
	all, err := s.settingRepo.GetAll()
	if err != nil {
		return err
	}
	for _, st := range all {
		existing[st.Key] = true
	}
	valid := make(map[string]string)
	for k, v := range values {
		if existing[k] {
			valid[k] = v
		}
	}
	if len(valid) == 0 {
		return fmt.Errorf("没有可更新的有效设置项")
	}
	return s.settingRepo.UpdateValues(valid)
}

// ---- 日志 ----

// ListOperationLogs 操作日志列表
func (s *AdminService) ListOperationLogs(f repository.OpLogFilter) ([]model.OperationLog, int64, error) {
	if f.Page <= 0 {
		f.Page = 1
	}
	if f.PageSize <= 0 {
		f.PageSize = 20
	}
	return s.opLogRepo.List(f)
}

// GetOperationLog 操作日志详情
func (s *AdminService) GetOperationLog(id uint) (*model.OperationLog, error) {
	l, err := s.opLogRepo.FindByID(id)
	if err != nil {
		return nil, apperr.ErrNotFound
	}
	return l, nil
}

// ListSystemLogs 系统日志列表
func (s *AdminService) ListSystemLogs(f repository.SysLogFilter) ([]model.SystemLog, int64, error) {
	if f.Page <= 0 {
		f.Page = 1
	}
	if f.PageSize <= 0 {
		f.PageSize = 20
	}
	return s.sysLogRepo.List(f)
}

// GetSystemLog 系统日志详情
func (s *AdminService) GetSystemLog(id uint) (*model.SystemLog, error) {
	l, err := s.sysLogRepo.FindByID(id)
	if err != nil {
		return nil, apperr.ErrNotFound
	}
	return l, nil
}

// CleanupLogs 清理days天前的日志
func (s *AdminService) CleanupLogs(days int) (opDeleted, sysDeleted int64, err error) {
	if days <= 0 {
		days = 30
	}
	opDeleted, err = s.opLogRepo.DeleteBefore(days)
	if err != nil {
		return
	}
	sysDeleted, err = s.sysLogRepo.DeleteBefore(days)
	utils.Info("system", "清理%d天前日志：操作日志%d条，系统日志%d条", days, opDeleted, sysDeleted)
	return
}

// ---- 备份 ----

// BackupDatabase 使用VACUUM INTO备份数据库
func (s *AdminService) BackupDatabase() (string, error) {
	if err := os.MkdirAll(s.cfg.Storage.Backups, 0o755); err != nil {
		return "", err
	}
	name := fmt.Sprintf("backup-%s.db", time.Now().Format("20060102-150405"))
	target := filepath.Join(s.cfg.Storage.Backups, name)
	// SQLite安全备份：VACUUM INTO
	quoted := strings.ReplaceAll(target, "'", "''")
	if err := s.db.Exec(fmt.Sprintf("VACUUM INTO '%s'", quoted)).Error; err != nil {
		utils.Error("system", "数据库备份失败: %v", err)
		return "", fmt.Errorf("备份失败: %w", err)
	}
	utils.Info("system", "数据库备份完成: %s", name)
	return name, nil
}

// ListBackups 备份列表
func (s *AdminService) ListBackups() ([]map[string]interface{}, error) {
	entries, err := os.ReadDir(s.cfg.Storage.Backups)
	if err != nil {
		return []map[string]interface{}{}, nil
	}
	var list []map[string]interface{}
	for _, e := range entries {
		if e.IsDir() || !strings.HasSuffix(e.Name(), ".db") {
			continue
		}
		info, _ := e.Info()
		list = append(list, map[string]interface{}{
			"name": e.Name(),
			"size": info.Size(),
			"time": info.ModTime().Format(time.RFC3339),
		})
	}
	sort.Slice(list, func(i, j int) bool {
		return list[i]["name"].(string) > list[j]["name"].(string)
	})
	return list, nil
}

// BackupPath 校验备份文件名并返回其物理路径(供下载)
func (s *AdminService) BackupPath(name string) (string, error) {
	// 只允许 backup-*.db 格式，防止路径穿越
	if strings.ContainsAny(name, "/\\") || strings.Contains(name, "..") || !strings.HasPrefix(name, "backup-") || !strings.HasSuffix(name, ".db") {
		return "", fmt.Errorf("非法的备份文件名")
	}
	p := filepath.Join(s.cfg.Storage.Backups, name)
	if _, err := os.Stat(p); err != nil {
		return "", fmt.Errorf("备份文件不存在")
	}
	return p, nil
}

// ---- 站点状态 ----

// SiteStatus 公开的站点状态信息
func (s *AdminService) SiteStatus() map[string]interface{} {
	get := func(k, def string) string {
		if v, err := s.settingRepo.GetValue(k); err == nil {
			return v
		}
		return def
	}
	return map[string]interface{}{
		"site_name":        get("site_name", "云泽文件存储云平台"),
		"site_description": get("site_description", ""),
		"site_logo":        get("site_logo", ""),
		"site_icp":         get("site_icp", ""),
		"site_copyright":   get("site_copyright", ""),
		"site_enabled":     get("site_enabled", "true") == "true",
		"register_enabled": get("register_enabled", "true") == "true",
		"maintenance_msg":  get("site_maintenance_msg", ""),
	}
}

// IsSiteEnabled 站点是否开启
func (s *AdminService) IsSiteEnabled() bool {
	if v, err := s.settingRepo.GetValue("site_enabled"); err == nil {
		return v == "true" || v == "1"
	}
	return true
}