package keeper

import (
	"context"

	sdk "github.com/cosmos/cosmos-sdk/types"
	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
	"github.com/tharsis/ethermint/x/nameservice/types"
)

// BondIDAttributeName denotes the record bond ID.
const BondIDAttributeName = "bondId"

// ExpiryTimeAttributeName denotes the record expiry time.
const ExpiryTimeAttributeName = "expiryTime"

type Querier struct {
	Keeper
}

var _ types.QueryServer = Querier{}

func (q Querier) Params(c context.Context, _ *types.QueryParamsRequest) (*types.QueryParamsResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	params := q.Keeper.GetParams(ctx)
	return &types.QueryParamsResponse{Params: &params}, nil
}

func (q Querier) ListRecords(c context.Context, req *types.QueryListRecordsRequest) (*types.QueryListRecordsResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	attributes := req.GetAttributes()
	all := req.GetAll()
	records := []types.Record{}

	if len(attributes) > 0 {
		records = q.Keeper.MatchRecords(ctx, func(record *types.RecordType) bool {
			return MatchOnAttributes(record, attributes, all)
		})
	} else {
		records = q.Keeper.ListRecords(ctx)
	}

	return &types.QueryListRecordsResponse{Records: records}, nil
}

func (q Querier) GetRecord(c context.Context, req *types.QueryRecordByIdRequest) (*types.QueryRecordByIdResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	id := req.GetId()
	if !q.Keeper.HasRecord(ctx, id) {
		return nil, sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "Record not found.")
	}
	record := q.Keeper.GetRecord(ctx, id)
	return &types.QueryRecordByIdResponse{Record: record}, nil
}

func (q Querier) GetRecordByBondId(c context.Context, req *types.QueryRecordByBondIdRequest) (*types.QueryRecordByBondIdResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	records := q.recordKeeper.QueryRecordsByBond(ctx, req.GetId())
	return &types.QueryRecordByBondIdResponse{Records: records}, nil
}

func (q Querier) GetNameServiceModuleBalance(c context.Context, _ *types.GetNameServiceModuleBalanceRequest) (*types.GetNameServiceModuleBalanceResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	balances := q.Keeper.GetModuleBalances(ctx)
	return &types.GetNameServiceModuleBalanceResponse{
		Balances: balances,
	}, nil
}

func (q Querier) ListNameRecords(c context.Context, _ *types.QueryListNameRecordsRequest) (*types.QueryListNameRecordsResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	nameRecords := q.Keeper.ListNameRecords(ctx)
	return &types.QueryListNameRecordsResponse{Names: nameRecords}, nil
}

func (q Querier) Whois(c context.Context, request *types.QueryWhoisRequest) (*types.QueryWhoisResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	nameAuthority := q.Keeper.GetNameAuthority(ctx, request.GetName())
	return &types.QueryWhoisResponse{NameAuthority: nameAuthority}, nil
}

func (q Querier) LookupWrn(c context.Context, req *types.QueryLookupWrn) (*types.QueryLookupWrnResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	wrn := req.GetWrn()
	if !q.Keeper.HasNameRecord(ctx, wrn) {
		return nil, sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "WRN not found.")
	}
	nameRecord := q.Keeper.GetNameRecord(ctx, wrn)
	if nameRecord == nil {
		return nil, sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "name record not found.")
	}
	return &types.QueryLookupWrnResponse{Name: nameRecord}, nil
}

func (q Querier) ResolveWrn(c context.Context, req *types.QueryResolveWrn) (*types.QueryResolveWrnResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	wrn := req.GetWrn()
	record := q.Keeper.ResolveWRN(ctx, wrn)
	if record == nil {
		return nil, sdkerrors.Wrap(sdkerrors.ErrUnknownRequest, "record not found.")
	}
	return &types.QueryResolveWrnResponse{Record: record}, nil
}

func (q Querier) GetRecordExpiryQueue(c context.Context, _ *types.QueryGetRecordExpiryQueue) (*types.QueryGetRecordExpiryQueueResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	records := q.Keeper.GetRecordExpiryQueue(ctx)
	return &types.QueryGetRecordExpiryQueueResponse{Records: records}, nil
}

func (q Querier) GetAuthorityExpiryQueue(c context.Context, _ *types.QueryGetAuthorityExpiryQueue) (*types.QueryGetAuthorityExpiryQueueResponse, error) {
	ctx := sdk.UnwrapSDKContext(c)
	authorities := q.Keeper.GetAuthorityExpiryQueue(ctx)
	return &types.QueryGetAuthorityExpiryQueueResponse{Authorities: authorities}, nil
}

func matchOnRecordField(record *types.RecordType, attr *types.QueryListRecordsRequest_KeyValueInput) (fieldFound bool, matched bool) {
	fieldFound = false
	matched = true

	switch attr.Key {
	case BondIDAttributeName:
		{
			fieldFound = true
			if record.BondId != attr.Value.GetString_() {
				matched = false
				return
			}
		}
	case ExpiryTimeAttributeName:
		{
			fieldFound = true
			if record.ExpiryTime != attr.Value.GetString_() {
				matched = false
				return
			}
		}
	}

	return
}

func MatchOnAttributes(record *types.RecordType, attributes []*types.QueryListRecordsRequest_KeyValueInput, all bool) bool {
	// Filter deleted records.
	if record.Deleted {
		return false
	}

	// If ONLY named records are requested, check for that condition first.
	if !all && len(record.Names) == 0 {
		return false
	}

	recAttrs := record.Attributes

	for _, attr := range attributes {
		// First try matching on record struct fields.
		fieldFound, matched := matchOnRecordField(record, attr)

		if fieldFound {
			if !matched {
				return false
			}

			continue
		}

		recAttrVal, recAttrFound := recAttrs[attr.Key]
		if !recAttrFound {
			return false
		}

		if attr.Value.Int != 0 {
			recAttrValInt, ok := recAttrVal.(int)
			if !ok || int(attr.Value.GetInt()) != recAttrValInt {
				return false
			}
		}

		if attr.Value.String_ != "" {
			recAttrValString, ok := recAttrVal.(string)
			if !ok {
				return false
			}

			if attr.Value.GetString_() != recAttrValString {
				return false
			}
		}

		// TODO: Handle other attribute value types.
	}

	return true
}