// 内置系统定时任务注册表 — 告警引擎 / 数据清理等 // Logan.Li
package systask

import (
	"fmt"
	"sync"
	"time"

	"ezops/model"
	"ezops/pkg/auditcleaner"
	"ezops/pkg/billingsync"
	"ezops/pkg/database"
	snmppkg "ezops/pkg/snmp"

	"gorm.io/gorm"
)

// Def 系统任务元数据 // Logan.Li
type Def struct {
	Code        string `json:"code"`
	Name        string `json:"name"`
	Description string `json:"description"`
	Schedule    string `json:"schedule"`
	Category    string `json:"category"` // monitor / cleanup
	Runnable    bool   `json:"runnable"`
	Enabled     bool   `json:"enabled"`
}

// Item API 列表项（元数据 + 运行状态） // Logan.Li
type Item struct {
	Def
	LastRunAt      *time.Time `json:"last_run_at,omitempty"`
	LastStatus     string     `json:"last_status,omitempty"`
	LastMessage    string     `json:"last_message,omitempty"`
	RunCount       int64      `json:"run_count"`
	LastDurationMs int        `json:"last_duration_ms"`
	Extra          any        `json:"extra,omitempty"`
}

var (
	mu sync.RWMutex
	db *gorm.DB

	catalog = []Def{
		{
			Code: "alert_engine", Name: "告警引擎扫描",
			Description: "扫描 Agent 指标阈值、主机离线、端口策略与日志告警规则，触发通知与自动恢复",
			Schedule: "每 30 秒", Category: "monitor", Runnable: false, Enabled: true,
		},
		{
			Code: "middleware_monitor", Name: "中间件监控采集",
			Description: "直连 Redis/MySQL 等中间件目标采集指标并写入监控库",
			Schedule: "每 30 秒", Category: "monitor", Runnable: false, Enabled: true,
		},
		{
			Code: "agent_report_cleanup", Name: "Agent 上报清理",
			Description: "清理 7 天前的 Agent 指标上报原始数据，防止表膨胀",
			Schedule: "每 24 小时", Category: "cleanup", Runnable: true, Enabled: true,
		},
		{
			Code: "audit_log_cleanup", Name: "审计日志清理",
			Description: "按系统设置中的保留天数清理操作审计、登录日志、终端会话与命令记录",
			Schedule: "每 24 小时", Category: "cleanup", Runnable: true, Enabled: true,
		},
		{
			Code: "snmp_metrics_cleanup", Name: "SNMP 指标清理",
			Description: "清理 7 天前的 SNMP 采集指标历史，防止表膨胀",
			Schedule: "每 24 小时", Category: "cleanup", Runnable: true, Enabled: true,
		},
		{
			Code: "cloud_billing_sync", Name: "云账单同步",
			Description: "从云账号 AK 拉取昨日账单（按产品+地域），写入云账单管理；当前支持阿里云",
			Schedule: "每天 10:30", Category: "finops", Runnable: true, Enabled: true,
		},
	}
)

// Init 注入数据库连接，并确保状态行存在 // Logan.Li
func Init(gdb *gorm.DB) {
	mu.Lock()
	db = gdb
	mu.Unlock()
	ensureStatusRows(gdb)
}

func ensureStatusRows(gdb *gorm.DB) {
	for _, d := range catalog {
		var row model.SystemTaskStatus
		if gdb.Where("code = ?", d.Code).First(&row).Error == gorm.ErrRecordNotFound {
			gdb.Create(&model.SystemTaskStatus{Code: d.Code, LastStatus: "pending"})
		}
	}
}

// Catalog 返回任务定义列表 // Logan.Li
func Catalog() []Def {
	out := make([]Def, len(catalog))
	copy(out, catalog)
	return out
}

// Record 记录任务执行结果 // Logan.Li
func Record(code, status, message string, duration time.Duration) {
	mu.RLock()
	gdb := db
	mu.RUnlock()
	if gdb == nil {
		return
	}
	now := time.Now()
	updates := map[string]interface{}{
		"last_run_at":      now,
		"last_status":      status,
		"last_message":     truncate(message, 480),
		"last_duration_ms": int(duration.Milliseconds()),
		"run_count":        gorm.Expr("run_count + 1"),
	}
	gdb.Model(&model.SystemTaskStatus{}).Where("code = ?", code).Updates(updates)
}

func truncate(s string, max int) string {
	if len(s) <= max {
		return s
	}
	return s[:max]
}

// List 合并元数据与库中状态 // Logan.Li
func List(gdb *gorm.DB, extras map[string]any) []Item {
	ensureStatusRows(gdb)
	var rows []model.SystemTaskStatus
	gdb.Find(&rows)
	statusMap := make(map[string]model.SystemTaskStatus, len(rows))
	for _, r := range rows {
		statusMap[r.Code] = r
	}

	items := make([]Item, 0, len(catalog))
	for _, d := range catalog {
		item := Item{Def: d}
		if st, ok := statusMap[d.Code]; ok {
			item.LastRunAt = st.LastRunAt
			item.LastStatus = st.LastStatus
			item.LastMessage = st.LastMessage
			item.RunCount = st.RunCount
			item.LastDurationMs = st.LastDurationMs
		}
		if extras != nil {
			if ex, ok := extras[d.Code]; ok {
				item.Extra = ex
			}
		}
		// 审计清理任务补充保留天数 // Logan.Li
		if d.Code == "audit_log_cleanup" {
			days := auditcleaner.GetRetentionDays(gdb)
			if item.Extra == nil {
				item.Extra = map[string]any{"retention_days": days}
			}
		}
		if d.Code == "snmp_metrics_cleanup" && item.Extra == nil {
			item.Extra = map[string]any{"retention_days": snmppkg.MetricsRetentionDays}
		}
		items = append(items, item)
	}
	return items
}

// RunManual 手动触发可运行的系统任务 // Logan.Li
func RunManual(gdb *gorm.DB, driver, code string) (Item, error) {
	def, ok := findDef(code)
	if !ok {
		return Item{}, fmt.Errorf("未知系统任务: %s", code)
	}
	if !def.Runnable {
		return Item{}, fmt.Errorf("任务 %s 不支持手动执行", def.Name)
	}

	start := time.Now()
	var msg string
	var err error

	switch code {
	case "agent_report_cleanup":
		sql := database.CleanupAgentReportsSQL(driver)
		r := gdb.Exec(sql)
		err = r.Error
		msg = fmt.Sprintf("清理 %d 条 Agent 上报记录", r.RowsAffected)
	case "audit_log_cleanup":
		var result auditcleaner.Result
		result, err = auditcleaner.RunFromSettings(gdb)
		if err == nil {
			msg = fmt.Sprintf("清理 %d 条超期记录（保留 %d 天）", result.Total, result.RetentionDays)
			now := time.Now()
			gdb.Model(&model.AuditSettings{}).Where("id > 0").Updates(map[string]interface{}{
				"last_cleanup_at":      now,
				"last_cleanup_summary": result.SummaryJSON(),
			})
		}
	case "snmp_metrics_cleanup":
		sql := database.CleanupSNMPMetricsSQL(driver, snmppkg.MetricsRetentionDays)
		r := gdb.Exec(sql)
		err = r.Error
		msg = fmt.Sprintf("清理 %d 条 SNMP 指标（保留 %d 天）", r.RowsAffected, snmppkg.MetricsRetentionDays)
	case "cloud_billing_sync":
		result := billingsync.SyncDate(gdb, billingsync.Yesterday(), nil)
		msg = billingsync.SummaryMessage(result)
		if result.Accounts == 0 {
			err = fmt.Errorf("没有可同步的活跃云账号")
		} else if result.Created == 0 && result.Updated == 0 && len(result.Errors) > 0 {
			err = fmt.Errorf("%s", result.Errors[0])
		}
	default:
		return Item{}, fmt.Errorf("任务 %s 未实现手动执行", code)
	}

	duration := time.Since(start)
	status := "success"
	if err != nil {
		status = "failed"
		msg = err.Error()
	}
	Record(code, status, msg, duration)

	items := List(gdb, nil)
	for _, it := range items {
		if it.Code == code {
			return it, err
		}
	}
	return Item{Def: def}, err
}

func findDef(code string) (Def, bool) {
	for _, d := range catalog {
		if d.Code == code {
			return d, true
		}
	}
	return Def{}, false
}