package infrastructure

import (
	"context"
	"encoding/json"
	"fmt"
	"sync"
	"time"

	"oc-datacenter/infrastructure/minio"
	"oc-datacenter/infrastructure/storage"

	oclib "cloud.o-forge.io/core/oc-lib"
	"cloud.o-forge.io/core/oc-lib/dbs"
	bookingmodel "cloud.o-forge.io/core/oc-lib/models/booking"
	"cloud.o-forge.io/core/oc-lib/models/common/enum"
	"cloud.o-forge.io/core/oc-lib/models/workflow_execution"
	"cloud.o-forge.io/core/oc-lib/tools"
	"go.mongodb.org/mongo-driver/bson/primitive"
)

// processedBookings tracks booking IDs already handled this process lifetime.
var processedBookings sync.Map

// closingStates is the set of terminal booking states.
var closingStates = map[enum.BookingStatus]bool{
	enum.FAILURE:   true,
	enum.SUCCESS:   true,
	enum.FORGOTTEN: true,
	enum.CANCELLED: true,
}

// WatchBookings is a safety-net fallback for when oc-monitord fails to launch.
// It detects bookings that are past expected_start_date by at least 1 minute and
// are still in a non-terminal state. Instead of writing to the database directly,
// it emits WORKFLOW_STEP_DONE_EVENT with State=FAILURE on NATS so that oc-scheduler
// handles the state transition — keeping a single source of truth for booking state.
//
// Must be launched in a goroutine from main.
func WatchBookings() {
	logger := oclib.GetLogger()
	logger.Info().Msg("BookingWatchdog: started")
	ticker := time.NewTicker(time.Minute)
	defer ticker.Stop()
	for range ticker.C {
		if err := scanStaleBookings(); err != nil {
			logger.Error().Msg("BookingWatchdog: " + err.Error())
		}
	}
}

// scanStaleBookings queries all bookings whose ExpectedStartDate passed more than
// 1 minute ago. Non-terminal ones get a WORKFLOW_STEP_DONE_EVENT FAILURE emitted
// on NATS so oc-scheduler closes them.
func scanStaleBookings() error {
	myself, err := oclib.GetMySelf()
	if err != nil {
		return fmt.Errorf("could not resolve local peer: %w", err)
	}
	peerID := myself.GetID()

	deadline := time.Now().UTC().Add(-time.Minute)
	res := oclib.NewRequest(oclib.LibDataEnum(oclib.BOOKING), "", peerID, []string{}, nil).
		Search(&dbs.Filters{
			And: map[string][]dbs.Filter{
				"expected_start_date": {{
					Operator: dbs.LTE.String(),
					Value:    primitive.NewDateTimeFromTime(deadline),
				}},
			},
		}, "", false)

	if res.Err != "" {
		return fmt.Errorf("stale booking search failed: %s", res.Err)
	}

	for _, dbo := range res.Data {
		b, ok := dbo.(*bookingmodel.Booking)
		if !ok {
			continue
		}
		go emitWatchdogFailure(b)
	}
	return nil
}

// emitWatchdogFailure publishes a WORKFLOW_STEP_DONE_EVENT FAILURE for a stale
// booking. oc-scheduler is the single authority for booking state transitions.
func emitWatchdogFailure(b *bookingmodel.Booking) {
	logger := oclib.GetLogger()

	if _, done := processedBookings.Load(b.GetID()); done {
		return
	}
	if closingStates[b.State] {
		processedBookings.Store(b.GetID(), struct{}{})
		return
	}

	now := time.Now().UTC()
	payload, err := json.Marshal(tools.WorkflowLifecycleEvent{
		BookingID: b.GetID(),
		State:     enum.FAILURE.EnumIndex(),
		RealEnd:   &now,
	})
	if err != nil {
		return
	}
	tools.NewNATSCaller().SetNATSPub(tools.WORKFLOW_STEP_DONE_EVENT, tools.NATSResponse{
		FromApp: "oc-datacenter",
		Method:  int(tools.WORKFLOW_STEP_DONE_EVENT),
		Payload: payload,
	})

	logger.Info().Msgf("BookingWatchdog: booking %s stale → emitting FAILURE", b.GetID())
	processedBookings.Store(b.GetID(), struct{}{})
}

// ── Infra teardown helpers (called from nats.go on WORKFLOW_DONE_EVENT) ────────

// teardownAdmiraltyIfRemote triggers Admiralty TeardownAsTarget only when at
// least one compute booking for the execution is on a remote peer.
// Local executions do not involve Admiralty.
func teardownAdmiraltyIfRemote(exec *workflow_execution.WorkflowExecution, selfPeerID string) {
	logger := oclib.GetLogger()

	res := oclib.NewRequest(oclib.LibDataEnum(oclib.BOOKING), "", selfPeerID, []string{}, nil).
		Search(&dbs.Filters{
			And: map[string][]dbs.Filter{
				"executions_id": {{Operator: dbs.EQUAL.String(), Value: exec.ExecutionsID}},
				"resource_type": {{Operator: dbs.EQUAL.String(), Value: tools.COMPUTE_RESOURCE.EnumIndex()}},
			},
		}, "", false)

	if res.Err != "" || len(res.Data) == 0 {
		return
	}

	for _, dbo := range res.Data {
		b, ok := dbo.(*bookingmodel.Booking)
		if !ok {
			continue
		}
		if b.DestPeerID != selfPeerID {
			logger.Info().Msgf("InfraTeardown: Admiralty teardown exec=%s (remote peer=%s)",
				exec.ExecutionsID, b.DestPeerID)
			NewAdmiraltySetter(exec.ExecutionsID).TeardownAsTarget(context.Background(), selfPeerID)
			return // one teardown per execution is enough
		}
	}
}

// teardownMinioForExecution tears down all Minio configuration for the execution:
// - storage bookings where this peer is the compute target → TeardownAsTarget
// - storage bookings where this peer is the Minio source → TeardownAsSource
func teardownMinioForExecution(ctx context.Context, executionsID string, localPeerID string) {
	logger := oclib.GetLogger()

	res := oclib.NewRequest(oclib.LibDataEnum(oclib.BOOKING), "", localPeerID, []string{}, nil).
		Search(&dbs.Filters{
			And: map[string][]dbs.Filter{
				"executions_id": {{Operator: dbs.EQUAL.String(), Value: executionsID}},
				"resource_type": {{Operator: dbs.EQUAL.String(), Value: tools.LIVE_STORAGE.EnumIndex()}},
			},
		}, "", false)

	if res.Err != "" || len(res.Data) == 0 {
		return
	}

	for _, dbo := range res.Data {
		b, ok := dbo.(*bookingmodel.Booking)
		if !ok {
			continue
		}
		if b.DestPeerID == localPeerID {
			// This peer is the compute target: tear down K8s secret + configmap.
			logger.Info().Msgf("InfraTeardown: Minio target teardown exec=%s storage=%s", executionsID, b.ResourceID)
			event := minio.MinioDeleteEvent{
				ExecutionsID: executionsID,
				MinioID:      b.ResourceID,
				SourcePeerID: b.DestPeerID,
				DestPeerID:   localPeerID,
				OriginID:     "",
			}
			minio.NewMinioSetter(executionsID, b.ResourceID).TeardownAsTarget(ctx, event)
		} else {
			// This peer is the Minio source: revoke SA + remove execution bucket.
			logger.Info().Msgf("InfraTeardown: Minio source teardown exec=%s storage=%s", executionsID, b.ResourceID)
			event := minio.MinioDeleteEvent{
				ExecutionsID: executionsID,
				MinioID:      b.ResourceID,
				SourcePeerID: localPeerID,
				DestPeerID:   b.DestPeerID,
				OriginID:     "",
			}
			minio.NewMinioSetter(executionsID, b.ResourceID).TeardownAsSource(ctx, event)
		}
	}
}

// teardownPVCForExecution deletes all local PVCs provisioned for the execution.
// It searches LIVE_STORAGE bookings and resolves the storage name via the live storage.
func teardownPVCForExecution(ctx context.Context, executionsID string, localPeerID string) {
	logger := oclib.GetLogger()

	res := oclib.NewRequest(oclib.LibDataEnum(oclib.BOOKING), "", localPeerID, []string{}, nil).
		Search(&dbs.Filters{
			And: map[string][]dbs.Filter{
				"executions_id": {{Operator: dbs.EQUAL.String(), Value: executionsID}},
				"resource_type": {{Operator: dbs.EQUAL.String(), Value: tools.LIVE_STORAGE.EnumIndex()}},
			},
		}, "", false)

	if res.Err != "" || len(res.Data) == 0 {
		return
	}

	for _, dbo := range res.Data {
		b, ok := dbo.(*bookingmodel.Booking)
		if !ok {
			continue
		}
		// Resolve storage name from live storage to compute the claim name.
		storageName := storage.ResolveStorageName(b.ResourceID, localPeerID)
		if storageName == "" {
			continue
		}
		logger.Info().Msgf("InfraTeardown: PVC teardown exec=%s storage=%s", executionsID, b.ResourceID)
		event := storage.PVCDeleteEvent{
			ExecutionsID: executionsID,
			StorageID:    b.ResourceID,
			StorageName:  storageName,
			SourcePeerID: localPeerID,
			DestPeerID:   b.DestPeerID,
			OriginID:     "",
		}
		storage.NewPVCSetter(executionsID, b.ResourceID).TeardownAsSource(ctx, event)
	}
}