package innerring

import (
	"context"
	"fmt"
	"sort"

	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/innerring/processors/governance"
	control "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/control/ir"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/sdnotify"
	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/state"
	"github.com/nspcc-dev/neo-go/pkg/util"
	"github.com/spf13/viper"
	"go.uber.org/zap"
)

const voteMethod = "vote"

var (
	persistateMainChainLastBlockKey = []byte("main_chain_last_processed_block")
	persistateSideChainLastBlockKey = []byte("side_chain_last_processed_block")
)

// EpochCounter is a getter for a global epoch counter.
func (s *Server) EpochCounter() uint64 {
	return s.epochCounter.Load()
}

// SetEpochCounter is a setter for contract processors to update global
// epoch counter.
func (s *Server) SetEpochCounter(val uint64) {
	s.epochCounter.Store(val)
	if s.irMetrics != nil {
		s.irMetrics.SetEpoch(val)
	}
}

// EpochDuration is a getter for a global epoch duration.
func (s *Server) EpochDuration() uint64 {
	return s.epochDuration.Load()
}

// SetEpochDuration is a setter for the Netmap processor to update global
// epoch duration.
func (s *Server) SetEpochDuration(val uint64) {
	s.epochDuration.Store(val)
}

// IsActive is a getter for a global active flag state.
func (s *Server) IsActive(ctx context.Context) bool {
	return s.InnerRingIndex(ctx) >= 0
}

// IsAlphabet is a getter for a global alphabet flag state.
func (s *Server) IsAlphabet(ctx context.Context) bool {
	return s.AlphabetIndex(ctx) >= 0
}

// InnerRingIndex is a getter for a global index of node in inner ring list. Negative
// index means that node is not in the inner ring list.
func (s *Server) InnerRingIndex(ctx context.Context) int {
	index, err := s.statusIndex.InnerRingIndex()
	if err != nil {
		s.log.Error(ctx, logs.InnerringCantGetInnerRingIndex, zap.Error(err))
		return -1
	}

	return int(index)
}

// InnerRingSize is a getter for a global size of inner ring list. This value
// paired with inner ring index.
func (s *Server) InnerRingSize(ctx context.Context) int {
	size, err := s.statusIndex.InnerRingSize()
	if err != nil {
		s.log.Error(ctx, logs.InnerringCantGetInnerRingSize, zap.Error(err))
		return 0
	}

	return int(size)
}

// AlphabetIndex is a getter for a global index of node in alphabet list.
// Negative index means that node is not in the alphabet list.
func (s *Server) AlphabetIndex(ctx context.Context) int {
	index, err := s.statusIndex.AlphabetIndex()
	if err != nil {
		s.log.Error(ctx, logs.InnerringCantGetAlphabetIndex, zap.Error(err))
		return -1
	}

	return int(index)
}

func (s *Server) voteForSidechainValidator(ctx context.Context, prm governance.VoteValidatorPrm) error {
	validators := prm.Validators

	index := s.InnerRingIndex(ctx)
	if s.contracts.alphabet.indexOutOfRange(index) {
		s.log.Info(ctx, logs.InnerringIgnoreValidatorVoteNodeNotInAlphabetRange)

		return nil
	}

	if len(validators) == 0 {
		s.log.Info(ctx, logs.InnerringIgnoreValidatorVoteEmptyValidatorsList)

		return nil
	}

	epoch := s.EpochCounter()

	var (
		nonce uint32 = 1
		vub   uint32
		vubP  *uint32
		err   error
	)

	if prm.Hash != nil {
		nonce, vub, err = s.morphClient.CalculateNonceAndVUB(prm.Hash)
		if err != nil {
			return fmt.Errorf("could not calculate nonce and `validUntilBlock` values: %w", err)
		}
		vubP = &vub
	}

	s.contracts.alphabet.iterate(func(letter GlagoliticLetter, contract util.Uint160) {
		_, err := s.morphClient.NotaryInvoke(ctx, contract, s.feeConfig.SideChainFee(), nonce, vubP, voteMethod, epoch, validators)
		if err != nil {
			s.log.Warn(ctx, logs.InnerringCantInvokeVoteMethodInAlphabetContract,
				zap.Int8("alphabet_index", int8(letter)),
				zap.Uint64("epoch", epoch),
				zap.Error(err))
		}
	})

	return nil
}

// VoteForSidechainValidator calls vote method on alphabet contracts with
// the provided list of keys.
func (s *Server) VoteForSidechainValidator(ctx context.Context, prm governance.VoteValidatorPrm) error {
	sort.Sort(prm.Validators)
	return s.voteForSidechainValidator(ctx, prm)
}

// ResetEpochTimer resets the block timer that produces events to update epoch
// counter in the netmap contract. It is used to synchronize this even production
// based on the block with a notification of the last epoch.
func (s *Server) ResetEpochTimer(h uint32) error {
	s.epochTimer.Tick(h)
	return s.epochTimer.Reset()
}

func (s *Server) setHealthStatus(ctx context.Context, hs control.HealthStatus) {
	s.healthStatus.Store(int32(hs))
	s.notifySystemd(ctx, hs)
	if s.irMetrics != nil {
		s.irMetrics.SetHealth(int32(hs))
	}
}

func (s *Server) CompareAndSwapHealthStatus(ctx context.Context, oldSt, newSt control.HealthStatus) (swapped bool) {
	if swapped = s.healthStatus.CompareAndSwap(int32(oldSt), int32(newSt)); swapped {
		s.notifySystemd(ctx, newSt)
		if s.irMetrics != nil {
			s.irMetrics.SetHealth(int32(newSt))
		}
	}
	return
}

// HealthStatus returns the current health status of the IR application.
func (s *Server) HealthStatus() control.HealthStatus {
	return control.HealthStatus(s.healthStatus.Load())
}

func initPersistentStateStorage(cfg *viper.Viper) (*state.PersistentStorage, error) {
	persistPath := cfg.GetString("node.persistent_state.path")
	persistStorage, err := state.NewPersistentStorage(persistPath)
	if err != nil {
		return nil, fmt.Errorf("persistent state init error: %w", err)
	}

	return persistStorage, nil
}

func (s *Server) notifySystemd(ctx context.Context, st control.HealthStatus) {
	if !s.sdNotify {
		return
	}
	var err error
	switch st {
	case control.HealthStatus_READY:
		err = sdnotify.FlagAndStatus(sdnotify.ReadyEnabled)
	case control.HealthStatus_SHUTTING_DOWN:
		err = sdnotify.FlagAndStatus(sdnotify.StoppingEnabled)
	case control.HealthStatus_RECONFIGURING:
		err = sdnotify.FlagAndStatus(sdnotify.ReloadingEnabled)
	default:
		err = sdnotify.Status(fmt.Sprintf("%v", st))
	}
	if err != nil {
		s.log.Error(ctx, logs.FailedToReportStatusToSystemd, zap.Error(err))
	}
}