package model

import (
	"context"
	"fmt"

	"github.com/QuantumNous/new-api/common"

	"github.com/gin-gonic/gin"
)

// OperationLog 记录用户对数据的增删改操作，用于审计。
type OperationLog struct {
	Id          int    `json:"id" gorm:"index:idx_oplog_created_at_id,priority:1"`
	UserId      int    `json:"user_id" gorm:"index;index:idx_oplog_user_id_id,priority:1"`
	Username    string `json:"username" gorm:"index;default:''"`
	CreatedAt   int64  `json:"created_at" gorm:"bigint;index:idx_oplog_created_at_id,priority:2;index:idx_oplog_created_at_action"`
	Action      string `json:"action" gorm:"type:varchar(32);index;index:idx_oplog_created_at_action"` // create / update / delete
	TargetType  string `json:"target_type" gorm:"type:varchar(64);index;default:''"`                    // 资源类型: channel, token, user, redemption, model, setting …
	TargetId    int    `json:"target_id" gorm:"index;default:0"`                                       // 资源 ID
	TargetName  string `json:"target_name" gorm:"type:varchar(255);default:''"`                        // 资源名称（便于检索）
	Content     string `json:"content"`                                                                // 操作描述
	Ip          string `json:"ip" gorm:"index;default:''"`                                             // 操作者 IP
	RequestBody string `json:"request_body" gorm:"type:text"`                                          // 请求体快照（脱敏后）
	UserRole    int    `json:"user_role" gorm:"default:0"`                                             // 操作者角色
}

// 操作类型常量
const (
	OperationActionCreate = "create"
	OperationActionUpdate = "update"
	OperationActionDelete = "delete"
)

// RecordOperationLog 记录一条操作日志。
func RecordOperationLog(c *gin.Context, userId int, action string, targetType string, targetId int, targetName string, content string, requestBody string) {
	username := c.GetString("username")
	userRole := c.GetInt("role")
	ip := c.ClientIP()

	log := &OperationLog{
		UserId:      userId,
		Username:    username,
		CreatedAt:   common.GetTimestamp(),
		Action:      action,
		TargetType:  targetType,
		TargetId:    targetId,
		TargetName:  targetName,
		Content:     content,
		Ip:          ip,
		RequestBody: requestBody,
		UserRole:    userRole,
	}
	err := DB.Create(log).Error
	if err != nil {
		common.SysError("failed to record operation log: " + err.Error())
	}
}

// GetOperationLogs 管理员分页查询操作日志。
func GetOperationLogs(action string, targetType string, targetId int, username string, startTimestamp int64, endTimestamp int64, startIdx int, num int) (logs []*OperationLog, total int64, err error) {
	tx := DB.Model(&OperationLog{})

	if action != "" {
		tx = tx.Where("action = ?", action)
	}
	if targetType != "" {
		tx = tx.Where("target_type = ?", targetType)
	}
	if targetId != 0 {
		tx = tx.Where("target_id = ?", targetId)
	}
	if username != "" {
		tx = tx.Where("username = ?", username)
	}
	if startTimestamp != 0 {
		tx = tx.Where("created_at >= ?", startTimestamp)
	}
	if endTimestamp != 0 {
		tx = tx.Where("created_at <= ?", endTimestamp)
	}

	err = tx.Count(&total).Error
	if err != nil {
		return nil, 0, err
	}
	err = tx.Order("id desc").Limit(num).Offset(startIdx).Find(&logs).Error
	return logs, total, err
}

// GetUserOperationLogs 普通用户查询自己的操作日志。
func GetUserOperationLogs(userId int, action string, targetType string, startTimestamp int64, endTimestamp int64, startIdx int, num int) (logs []*OperationLog, total int64, err error) {
	tx := DB.Model(&OperationLog{}).Where("user_id = ?", userId)

	if action != "" {
		tx = tx.Where("action = ?", action)
	}
	if targetType != "" {
		tx = tx.Where("target_type = ?", targetType)
	}
	if startTimestamp != 0 {
		tx = tx.Where("created_at >= ?", startTimestamp)
	}
	if endTimestamp != 0 {
		tx = tx.Where("created_at <= ?", endTimestamp)
	}

	err = tx.Count(&total).Error
	if err != nil {
		return nil, 0, err
	}
	err = tx.Order("id desc").Limit(num).Offset(startIdx).Find(&logs).Error
	return logs, total, err
}

// DeleteOldOperationLogs 清理指定时间之前的操作日志。
func DeleteOldOperationLogs(ctx context.Context, targetTimestamp int64, limit int) (int64, error) {
	var total int64 = 0
	for {
		if ctx.Err() != nil {
			return total, ctx.Err()
		}
		result := DB.Where("created_at < ?", targetTimestamp).Limit(limit).Delete(&OperationLog{})
		if result.Error != nil {
			return total, result.Error
		}
		total += result.RowsAffected
		if result.RowsAffected < int64(limit) {
			break
		}
	}
	return total, nil
}

// GetOperationLogStats 按操作类型统计数量。
func GetOperationLogStats(startTimestamp int64, endTimestamp int64) (map[string]int64, error) {
	type result struct {
		Action string
		Count  int64
	}
	var results []result
	tx := DB.Model(&OperationLog{}).Select("action, count(*) as count")
	if startTimestamp != 0 {
		tx = tx.Where("created_at >= ?", startTimestamp)
	}
	if endTimestamp != 0 {
		tx = tx.Where("created_at <= ?", endTimestamp)
	}
	tx = tx.Group("action")
	if err := tx.Scan(&results).Error; err != nil {
		return nil, fmt.Errorf("查询操作日志统计失败: %w", err)
	}
	stats := make(map[string]int64, len(results))
	for _, r := range results {
		stats[r.Action] = r.Count
	}
	return stats, nil
}

// SanitizeRequestBody 脱敏请求体中的敏感字段。
func SanitizeRequestBody(body string) string {
	if body == "" {
		return ""
	}
	var m map[string]interface{}
	if err := common.Unmarshal([]byte(body), &m); err != nil {
		// 无法解析为 JSON，直接返回截断后的原始内容
		if len(body) > 2000 {
			return body[:2000] + "...(truncated)"
		}
		return body
	}
	// 脱敏敏感字段
	sensitiveKeys := []string{"password", "key", "secret", "token", "access_token", "refresh_token", "api_key", "credential"}
	for _, k := range sensitiveKeys {
		if _, ok := m[k]; ok {
			m[k] = "******"
		}
	}
	sanitized, err := common.Marshal(m)
	if err != nil {
		return body
	}
	result := string(sanitized)
	if len(result) > 4000 {
		result = result[:4000] + "...(truncated)"
	}
	return result
}