package ingest

import (
	"encoding/json"
	"fmt"
	"strconv"
	"strings"
	"time"

	"git.apinb.com/ops/logs/internal/impl"
	"git.apinb.com/ops/logs/internal/models"
	"gorm.io/gorm"
)

func BuildReplayRawEventPayload(ev models.LogEvent) (RawEventIngestBody, error) {
	sourceType := replaySourceType(ev.SourceKind)
	if sourceType == "" {
		return RawEventIngestBody{}, fmt.Errorf("unsupported source kind %q", ev.SourceKind)
	}
	now := time.Now().UTC()
	rawObj := map[string]interface{}{
		"source":       sourceType,
		"replayed_at":  now.Format(time.RFC3339Nano),
		"log_entry_id": ev.ID,
		"source_ip":    ev.SourceIP,
		"remote_addr":  ev.RemoteAddr,
		"raw_packet":   ev.RawPayload,
	}
	if ev.TrapOID != "" {
		rawObj["trap_oid"] = ev.TrapOID
	}
	if ev.NormalizedDetail != "" {
		var detail interface{}
		if err := json.Unmarshal([]byte(ev.NormalizedDetail), &detail); err == nil {
			rawObj["parsed"] = detail
		}
	}
	rawBytes, err := json.Marshal(rawObj)
	if err != nil {
		return RawEventIngestBody{}, err
	}
	labels := map[string]string{
		"source_type":            "log",
		"source_subtype":         replaySubtype(ev.SourceKind),
		"replay_of_log_event_id": strconv.FormatUint(uint64(ev.ID), 10),
		"ip":                     ev.SourceIP,
		"remote_addr":            ev.RemoteAddr,
		"device":                 ev.DeviceName,
		"job":                    "logs-replay",
	}
	resourceUID := replayResourceUID(ev)
	category, identity := splitResourceUID(resourceUID)
	labels["resource_uid"] = resourceUID
	labels["resource_category"] = category
	labels["service_identity"] = identity
	return RawEventIngestBody{
		SourceType:     sourceType,
		SourceEventKey: fmt.Sprintf("logs:replay:%d:%d", ev.ID, now.UnixNano()),
		State:          "firing",
		ResourceUID:    resourceUID,
		EventTime:      now,
		Severity:       firstNonEmpty(ev.SeverityCode, "warning"),
		Title:          replayTitle(ev),
		Message:        firstNonEmpty(ev.NormalizedSummary, ev.RawPayload),
		Labels:         labels,
		Annotations: map[string]string{
			"replay":          "true",
			"dispatch_status": ev.DispatchStatus,
		},
		ParseStatus: "parsed",
		RawPayload:  rawBytes,
	}, nil
}

func EnqueueReplayLogEvent(ev models.LogEvent) (uint, error) {
	body, err := BuildReplayRawEventPayload(ev)
	if err != nil {
		return 0, err
	}
	payload, err := json.Marshal(body)
	if err != nil {
		return 0, err
	}
	row := models.AlertOutbox{
		LogEventID:  ev.ID,
		PayloadJSON: string(payload),
		Status:      outboxStatusPending,
		RetryCount:  0,
	}
	if impl.DBService == nil {
		return 0, fmt.Errorf("database is not initialized")
	}
	if err := impl.DBService.Transaction(func(tx *gorm.DB) error {
		now, err := databaseNow(tx)
		if err != nil {
			return err
		}
		row.NextRetryAt = now
		if err := enqueueOutboxRowWithDB(tx, &row); err != nil {
			return err
		}
		result := tx.Model(&models.LogEvent{}).Where("id = ?", ev.ID).Updates(map[string]interface{}{
			"dispatch_status":    "pending",
			"dispatch_outbox_id": row.ID,
			"alert_sent":         false,
		})
		if result.Error != nil {
			return result.Error
		}
		if result.RowsAffected == 0 {
			return fmt.Errorf("log event %d does not exist", ev.ID)
		}
		return nil
	}); err != nil {
		return 0, err
	}
	return row.ID, nil
}

func enqueueOutboxRowWithDB(db *gorm.DB, row *models.AlertOutbox) error {
	if db == nil {
		return fmt.Errorf("database is not initialized")
	}
	return db.Create(row).Error
}

func replaySourceType(kind string) string {
	switch strings.TrimSpace(kind) {
	case "syslog":
		return "syslog"
	case "snmp_trap", "trap":
		return "trap"
	default:
		return ""
	}
}

func replaySubtype(kind string) string {
	if kind == "snmp_trap" {
		return "snmp_trap"
	}
	return replaySourceType(kind)
}

func replayResourceUID(ev models.LogEvent) string {
	if uid := strings.TrimSpace(ev.ResourceUID); uid != "" {
		if category, identity, ok := splitKnownResourceUID(uid); ok {
			return category + ":" + identity
		}
		return canonicalLogResourceCategory(ev.ResourceType, replaySubtype(ev.SourceKind)) + ":" + uid
	}
	if category, identity, ok := splitKnownResourceUID(ev.ResourceID); ok {
		return category + ":" + identity
	}
	if ev.ResourceType != "" && ev.ResourceID != "" {
		return canonicalLogResourceCategory(ev.ResourceType, replaySubtype(ev.SourceKind)) + ":" + ev.ResourceID
	}
	category := canonicalLogResourceCategory("", replaySubtype(ev.SourceKind))
	identity := firstNonEmpty(strings.TrimSpace(ev.SourceIP), strings.TrimSpace(ev.DeviceName))
	if identity == "" {
		identity = fmt.Sprintf("log-event-%d", ev.ID)
	}
	return category + ":" + identity
}

func splitResourceUID(uid string) (string, string) {
	parts := strings.SplitN(strings.TrimSpace(uid), ":", 2)
	if len(parts) != 2 {
		return "log_source", strings.TrimSpace(uid)
	}
	return parts[0], parts[1]
}

func replayTitle(ev models.LogEvent) string {
	if ev.SourceKind == "snmp_trap" && ev.TrapOID != "" {
		return "重放 SNMP Trap " + ev.TrapOID
	}
	if ev.SourceKind == "syslog" {
		return "重放 Syslog"
	}
	return "重放日志事件"
}