package governance

import (
	"errors"
	"strconv"

	"gno.land/p/gnoswap/store"
	bptree "gno.land/p/nt/bptree/v0"
	ufmt "gno.land/p/nt/ufmt/v0"
)

type StoreKey string

func (s StoreKey) String() string {
	return string(s)
}

const (
	StoreKeyConfigCounter   StoreKey = "configCounter"   // Config version counter
	StoreKeyProposalCounter StoreKey = "proposalCounter" // Proposal ID counter

	StoreKeyConfigs StoreKey = "configs" // Configurations BPTree

	StoreKeyProposals StoreKey = "proposals" // Proposals BPTree

	StoreKeyProposalUserVotingInfos StoreKey = "proposalUserVotingInfos" // Proposal voting infos BPTree

	StoreKeyUserProposals StoreKey = "userProposals" // User proposals mapping BPTree
)

type governanceStore struct {
	kvStore store.KVStore
}

// Counter methods
func (s *governanceStore) HasConfigCounterStoreKey() bool {
	return s.kvStore.Has(StoreKeyConfigCounter.String())
}

func (s *governanceStore) GetConfigCounter() *Counter {
	result, err := s.kvStore.Get(StoreKeyConfigCounter.String())
	if err != nil {
		panic(err)
	}

	counter, ok := result.(*Counter)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to *Counter: %T", result))
	}

	return counter
}

func (s *governanceStore) SetConfigCounter(_ int, rlm realm, counter *Counter) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	return s.kvStore.Set(0, rlm, StoreKeyConfigCounter.String(), counter)
}

func (s *governanceStore) HasProposalCounterStoreKey() bool {
	return s.kvStore.Has(StoreKeyProposalCounter.String())
}

func (s *governanceStore) GetProposalCounter() *Counter {
	result, err := s.kvStore.Get(StoreKeyProposalCounter.String())
	if err != nil {
		panic(err)
	}

	counter, ok := result.(*Counter)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to int64: %T", result))
	}

	return counter
}

func (s *governanceStore) SetProposalCounter(_ int, rlm realm, counter *Counter) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	return s.kvStore.Set(0, rlm, StoreKeyProposalCounter.String(), counter)
}

// Configs methods
func (s *governanceStore) HasConfigsStoreKey() bool {
	return s.kvStore.Has(StoreKeyConfigs.String())
}

func (s *governanceStore) GetConfigs() *bptree.BPTree {
	result, err := s.kvStore.Get(StoreKeyConfigs.String())
	if err != nil {
		panic(err)
	}

	configs, ok := result.(*bptree.BPTree)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to *bptree.BPTree: %T", result))
	}

	return configs
}

func (s *governanceStore) SetConfigs(_ int, rlm realm, configs *bptree.BPTree) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	return s.kvStore.Set(0, rlm, StoreKeyConfigs.String(), configs)
}

func (s *governanceStore) GetConfig(version int64) (Config, bool) {
	configs := s.GetConfigs()
	result, ok := configs.Get(formatInt64Key(version))
	if !ok {
		return Config{}, false
	}

	config, ok := result.(Config)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to Config: %T", result))
	}

	return config, true
}

func (s *governanceStore) SetConfig(_ int, rlm realm, version int64, config Config) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	if !s.HasConfigsStoreKey() {
		return errors.New("configs store key not found")
	}

	configs := s.GetConfigs()
	configs.Set(formatInt64Key(version), config)

	return s.kvStore.Set(0, rlm, StoreKeyConfigs.String(), configs)
}

// Proposals methods
func (s *governanceStore) HasProposalsStoreKey() bool {
	return s.kvStore.Has(StoreKeyProposals.String())
}

func (s *governanceStore) GetProposals() *bptree.BPTree {
	result, err := s.kvStore.Get(StoreKeyProposals.String())
	if err != nil {
		panic(err)
	}

	proposals, ok := result.(*bptree.BPTree)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to *bptree.BPTree: %T", result))
	}

	return proposals
}

func (s *governanceStore) SetProposals(_ int, rlm realm, proposals *bptree.BPTree) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	return s.kvStore.Set(0, rlm, StoreKeyProposals.String(), proposals)
}

func (s *governanceStore) GetProposal(proposalID int64) (*Proposal, bool) {
	proposals := s.GetProposals()
	result, ok := proposals.Get(formatInt64Key(proposalID))
	if !ok {
		return nil, false
	}

	proposal, ok := result.(*Proposal)
	if !ok {
		return nil, false
	}
	return proposal, true
}

func (s *governanceStore) SetProposal(_ int, rlm realm, proposalID int64, proposal *Proposal) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	if !s.HasProposalsStoreKey() {
		return errors.New("proposals store key not found")
	}

	proposals := s.GetProposals()
	proposals.Set(formatInt64Key(proposalID), proposal)

	return s.kvStore.Set(0, rlm, StoreKeyProposals.String(), proposals)
}

// Proposal User Voting Infos methods
func (s *governanceStore) HasProposalUserVotingInfosStoreKey() bool {
	return s.kvStore.Has(StoreKeyProposalUserVotingInfos.String())
}

func (s *governanceStore) GetProposalUserVotingInfos() *bptree.BPTree {
	result, err := s.kvStore.Get(StoreKeyProposalUserVotingInfos.String())
	if err != nil {
		panic(err)
	}

	votingInfos, ok := result.(*bptree.BPTree)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to *bptree.BPTree: %T", result))
	}

	return votingInfos
}

func (s *governanceStore) SetProposalUserVotingInfos(_ int, rlm realm, votingInfos *bptree.BPTree) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	return s.kvStore.Set(0, rlm, StoreKeyProposalUserVotingInfos.String(), votingInfos)
}

func (s *governanceStore) GetProposalVotingInfos(proposalID int64) (*bptree.BPTree, bool) {
	votingInfos := s.GetProposalUserVotingInfos()
	votingInfo, ok := votingInfos.Get(formatInt64Key(proposalID))
	if !ok {
		return nil, false
	}

	votingInfoTree, ok := votingInfo.(*bptree.BPTree)
	if !ok {
		return nil, false
	}

	return votingInfoTree, true
}

func (s *governanceStore) SetProposalVotingInfos(_ int, rlm realm, proposalID int64, votingInfos *bptree.BPTree) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	if !s.HasProposalUserVotingInfosStoreKey() {
		return errors.New("proposal user voting infos store key not found")
	}

	allVotingInfos := s.GetProposalUserVotingInfos()
	allVotingInfos.Set(formatInt64Key(proposalID), votingInfos)

	return s.kvStore.Set(0, rlm, StoreKeyProposalUserVotingInfos.String(), allVotingInfos)
}

// User Proposals methods
func (s *governanceStore) HasUserProposalsStoreKey() bool {
	return s.kvStore.Has(StoreKeyUserProposals.String())
}

func (s *governanceStore) GetUserProposals() *bptree.BPTree {
	result, err := s.kvStore.Get(StoreKeyUserProposals.String())
	if err != nil {
		panic(err)
	}

	userProposals, ok := result.(*bptree.BPTree)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to *bptree.BPTree: %T", result))
	}

	return userProposals
}

func (s *governanceStore) SetUserProposals(_ int, rlm realm, userProposals *bptree.BPTree) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	return s.kvStore.Set(0, rlm, StoreKeyUserProposals.String(), userProposals)
}

func (s *governanceStore) GetUserProposalsTree() *bptree.BPTree {
	return s.GetUserProposals()
}

func (s *governanceStore) GetUserProposalIDs(user string) ([]int64, bool) {
	userProposals := s.GetUserProposals()
	result, ok := userProposals.Get(user)
	if !ok {
		return nil, false
	}

	proposalIDs, ok := result.([]int64)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to []int64: %T", result))
	}

	return proposalIDs, true
}

func (s *governanceStore) AddUserProposal(_ int, rlm realm, user string, proposalID int64) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	if !s.HasUserProposalsStoreKey() {
		return errors.New("user proposals store key not found")
	}

	userProposals := s.GetUserProposals()

	// Get existing proposals for user
	var proposalIDs []int64
	if existing, ok := userProposals.Get(user); ok {
		proposalIDs, ok = existing.([]int64)
		if !ok {
			panic(ufmt.Sprintf("failed to cast result to []int64: %T", existing))
		}
	}

	// Add new proposal ID
	proposalIDs = append(proposalIDs, proposalID)
	userProposals.Set(user, proposalIDs)

	return s.kvStore.Set(0, rlm, StoreKeyUserProposals.String(), userProposals)
}

func (s *governanceStore) RemoveUserProposal(_ int, rlm realm, user string, proposalID int64) error {
	if !rlm.IsCurrent() {
		return ErrSpoofedRealm
	}

	if !s.HasUserProposalsStoreKey() {
		return errors.New("user proposals store key not found")
	}

	userProposals := s.GetUserProposals()
	proposalIDsRaw, ok := userProposals.Get(user)
	// proposal already removed
	if !ok {
		return nil
	}

	proposalIDs, ok := proposalIDsRaw.([]int64)
	if !ok {
		panic(ufmt.Sprintf("failed to cast result to []int64: %T", proposalIDs))
	}

	newProposalIDs := make([]int64, 0)

	for _, id := range proposalIDs {
		if id != proposalID {
			newProposalIDs = append(newProposalIDs, id)
		}
	}

	if len(newProposalIDs) == 0 {
		userProposals.Remove(user)
	} else {
		userProposals.Set(user, newProposalIDs)
	}

	return s.kvStore.Set(0, rlm, StoreKeyUserProposals.String(), userProposals)
}

// NewGovernanceStore creates a new governance store instance with the provided KV store.
// This function is used by the upgrade system to create storage instances for each implementation.
func NewGovernanceStore(kvStore store.KVStore) IGovernanceStore {
	return &governanceStore{
		kvStore: kvStore,
	}
}

// formatInt64Key formats int64 identifiers for storage keys.
func formatInt64Key(id int64) string {
	return strconv.FormatInt(id, 10)
}