package p

import (
	"bytes"
	"context"
	"encoding/binary"
	"encoding/hex"
	"fmt"
	"log"

	"cloud.google.com/go/bigtable"
	"cloud.google.com/go/pubsub"
	"github.com/certusone/wormhole/node/pkg/vaa"
	"github.com/holiman/uint256"
)

type PubSubMessage struct {
	Data []byte `json:"data"`
}

// The keys are emitterAddress hex values, so that we can quickly check a message against the index to see if it
// meets the criteria for saving payload info: if it is a token transfer, or an NFT transfer.
var NFTEmitters = map[string]string{
	// mainnet
	"0def15a24423e1edd1a5ab16f557b9060303ddbab8c803d2ee48f4b78a1cfd6b": "WnFt12ZrnzZrFZkt2xsNsaNWoQribnuQ5B5FrDbwDhD", // solana
	"0000000000000000000000006ffd7ede62328b3af38fcd61461bbfc52f5651fe": "0x6FFd7EdE62328b3Af38FCD61461Bbfc52F5651fE",  // ethereum
	"0000000000000000000000005a58505a96d1dbf8df91cb21b54419fc36e93fde": "0x5a58505a96D1dbf8dF91cB21B54419FC36e93fdE",  // bsc
	"00000000000000000000000090bbd86a6fe93d3bc3ed6335935447e75fab7fcf": "0x90bbd86a6fe93d3bc3ed6335935447e75fab7fcf",  // polygon

	// devnet
	"96ee982293251b48729804c8e8b24b553eb6b887867024948d2236fd37a577ab": "NFTWqJR8YnRVqPDvTJrYuLrQDitTG5AScqbeghi4zSA", // solana
	"00000000000000000000000026b4afb60d6c903165150c6f0aa14f8016be4aec": "0x26b4afb60d6c903165150c6f0aa14f8016be4aec",  // ethereum
}
var TokenTransferEmitters = map[string]string{
	// mainnet
	"ec7372995d5cc8732397fb0ad35c0121e0eaa90d26f828a534cab54391b3a4f5": "wormDTUJ6AWPNvk59vGQbDvGJmqbDTdgWgAqcLBCgUb",  // solana
	"0000000000000000000000003ee18b2214aff97000d974cf647e7c347e8fa585": "0x3ee18B2214AFF97000D974cf647E7C347E8fa585",   // ethereum
	"0000000000000000000000007cf7b764e38a0a5e967972c1df77d432510564e2": "terra10nmmwe8r3g99a9newtqa7a75xfgs2e8z87r2sf", // terra
	"000000000000000000000000b6f6d86a8f9879a9c87f643768d9efc38c1da6e7": "0xB6F6D86a8f9879A9c87f643768d9efc38c1Da6E7",   // bsc
	"0000000000000000000000005a58505a96d1dbf8df91cb21b54419fc36e93fde": "0x5a58505a96d1dbf8df91cb21b54419fc36e93fde",   // polygon

	// devnet
	"c69a1b1a65dd336bf1df6a77afb501fc25db7fc0938cb08595a9ef473265cb4f": "B6RHG3mfcckmrYN1UhmJzyS1XX3fZKbkeUcpJe9Sy3FE", // solana
	"0000000000000000000000000290fb167208af455bb137780163b7b7a9a10c16": "0x0290fb167208af455bb137780163b7b7a9a10c16",   // EVM chains
	"000000000000000000000000784999135aaa8a3ca5914468852fdddbddd8789d": "terra10pyejy66429refv3g35g2t7am0was7ya7kz2a4", // terra
}

type (
	TokenTransfer struct {
		PayloadId     uint8
		Amount        uint256.Int
		OriginAddress [32]byte
		OriginChain   uint16
		TargetAddress [32]byte
		TargetChain   uint16
	}
	NFTTransfer struct {
		PayloadId     uint8
		OriginAddress [32]byte
		OriginChain   uint16
		Symbol        [32]byte
		Name          [32]byte
		TokenId       uint256.Int
		URI           []byte
		TargetAddress [32]byte
		TargetChain   uint16
	}
	AssetMeta struct {
		PayloadId    uint8
		TokenAddress [32]byte
		TokenChain   uint16
		Decimals     uint8
		Symbol       [32]byte
		Name         [32]byte
	}
)

func DecodeTokenTransfer(data []byte) (*TokenTransfer, error) {
	tt := &TokenTransfer{}
	tt.PayloadId = data[0]

	reader := bytes.NewReader(data[1:])

	if err := binary.Read(reader, binary.BigEndian, &tt.Amount); err != nil {
		return nil, fmt.Errorf("failed to read Amount: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &tt.OriginAddress); err != nil {
		return nil, fmt.Errorf("failed to read OriginAddress: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &tt.OriginChain); err != nil {
		return nil, fmt.Errorf("failed to read OriginChain: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &tt.TargetAddress); err != nil {
		return nil, fmt.Errorf("failed to read TargetAddress: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &tt.TargetChain); err != nil {
		return nil, fmt.Errorf("failed to read TargetChain: %w", err)
	}

	return tt, nil
}
func DecodeNFTTransfer(data []byte) (*NFTTransfer, error) {
	nt := &NFTTransfer{}
	nt.PayloadId = data[0]

	reader := bytes.NewReader(data[1:])

	if err := binary.Read(reader, binary.BigEndian, &nt.OriginAddress); err != nil {
		return nil, fmt.Errorf("failed to read OriginAddress: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &nt.OriginChain); err != nil {
		return nil, fmt.Errorf("failed to read OriginChain: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &nt.Symbol); err != nil {
		return nil, fmt.Errorf("failed to read Symbol: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &nt.Name); err != nil {
		return nil, fmt.Errorf("failed to read Name: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &nt.TokenId); err != nil {
		return nil, fmt.Errorf("failed to read TokenId: %w", err)
	}

	// uri len
	uriLen, er := reader.ReadByte()
	if er != nil {
		return nil, fmt.Errorf("failed to read URI length")
	}

	// uri
	uri := make([]byte, int(uriLen))
	n, err := reader.Read(uri)
	if err != nil || n == 0 {
		return nil, fmt.Errorf("failed to read uri [%d]: %w", n, err)
	}
	nt.URI = uri[:n]

	if err := binary.Read(reader, binary.BigEndian, &nt.TargetAddress); err != nil {
		return nil, fmt.Errorf("failed to read : %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &nt.TargetChain); err != nil {
		return nil, fmt.Errorf("failed to read : %w", err)
	}

	return nt, nil
}

func DecodeAssetMeta(data []byte) (*AssetMeta, error) {
	am := &AssetMeta{}
	am.PayloadId = data[0]

	reader := bytes.NewReader(data[1:])

	tokenAddress := [32]byte{}
	if n, err := reader.Read(tokenAddress[:]); err != nil || n != 32 {
		return nil, fmt.Errorf("failed to read TokenAddress [%d]: %w", n, err)
	}
	am.TokenAddress = tokenAddress

	if err := binary.Read(reader, binary.BigEndian, &am.TokenChain); err != nil {
		return nil, fmt.Errorf("failed to read TokenChain: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &am.Decimals); err != nil {
		return nil, fmt.Errorf("failed to read Decimals: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &am.Symbol); err != nil {
		return nil, fmt.Errorf("failed to read Symbol: %w", err)
	}

	if err := binary.Read(reader, binary.BigEndian, &am.Name); err != nil {
		return nil, fmt.Errorf("failed to read Name: %w", err)
	}

	return am, nil
}

// TEMP: until this https://forge.certus.one/c/wormhole/+/1850 lands
func makeRowKey(emitterChain vaa.ChainID, emitterAddress vaa.Address, sequence uint64) string {
	// left-pad the sequence with zeros to 16 characters, because bigtable keys are stored lexicographically
	return fmt.Sprintf("%d:%s:%016d", emitterChain, emitterAddress, sequence)
}
func writePayloadToBigTable(ctx context.Context, rowKey string, colFam string, mutation *bigtable.Mutation) error {

	filter := bigtable.ChainFilters(
		bigtable.FamilyFilter(colFam),
		bigtable.ColumnFilter("PayloadId"))
	conditionalMutation := bigtable.NewCondMutation(filter, nil, mutation)

	err := tbl.Apply(ctx, rowKey, conditionalMutation)
	if err != nil {
		log.Printf("Failed to write payload for %v to BigTable. err: %v", rowKey, err)
		return err
	}
	return nil
}

// ProcessVAA is triggered by a PubSub message, emitted after row is saved to BigTable by guardiand
func ProcessVAA(ctx context.Context, m PubSubMessage) error {
	data := string(m.Data)
	if data == "" {
		return fmt.Errorf("no data to process in message")
	}

	signedVaa, err := vaa.Unmarshal(m.Data)
	if err != nil {
		log.Println("failed Unmarshaling VAA")
		return err
	}

	// create the bigtable identifier from the VAA data
	rowKey := makeRowKey(signedVaa.EmitterChain, signedVaa.EmitterAddress, signedVaa.Sequence)
	emitterHex := signedVaa.EmitterAddress.String()
	payloadId := int(signedVaa.Payload[0])

	if _, ok := TokenTransferEmitters[emitterHex]; ok {
		// figure out if it's a transfer or asset metadata

		if payloadId == 1 {
			// token transfer
			payload, decodeErr := DecodeTokenTransfer(signedVaa.Payload)
			if decodeErr != nil {
				log.Println("failed decoding payload for row ", rowKey)
				return decodeErr
			}
			// save payload to bigtable, then publish a new PubSub message for further processing
			colFam := columnFamilies[2]
			mutation := bigtable.NewMutation()
			ts := bigtable.Now()
			mutation.Set(colFam, "PayloadId", ts, []byte(fmt.Sprint(payload.PayloadId)))
			// TODO: find a better way of representing amount as a string
			mutation.Set(colFam, "Amount", ts, []byte(fmt.Sprint(payload.Amount[3])))
			mutation.Set(colFam, "OriginAddress", ts, []byte(hex.EncodeToString(payload.OriginAddress[:])))
			mutation.Set(colFam, "OriginChain", ts, []byte(fmt.Sprint(payload.OriginChain)))
			mutation.Set(colFam, "TargetAddress", ts, []byte(hex.EncodeToString(payload.TargetAddress[:])))
			mutation.Set(colFam, "TargetChain", ts, []byte(fmt.Sprint(payload.TargetChain)))

			writeErr := writePayloadToBigTable(ctx, rowKey, colFam, mutation)
			if writeErr != nil {
				return writeErr
			}

			// now that the payload is saved to BigTable,
			// pass along the message to the topic that will calculate TokenTransferDetails
			pubSubTokenTransferDetailsTopic.Publish(ctx, &pubsub.Message{Data: m.Data})
		} else if payloadId == 2 {
			// asset meta
			payload, decodeErr := DecodeAssetMeta(signedVaa.Payload)
			if decodeErr != nil {
				log.Println("failed decoding payload for row ", rowKey)
				return decodeErr
			}

			// save payload to bigtable
			colFam := columnFamilies[3]
			mutation := bigtable.NewMutation()
			ts := bigtable.Now()

			mutation.Set(colFam, "PayloadId", ts, []byte(fmt.Sprint(payload.PayloadId)))
			mutation.Set(colFam, "TokenAddress", ts, []byte(hex.EncodeToString(payload.TokenAddress[:])))
			mutation.Set(colFam, "TokenChain", ts, []byte(fmt.Sprint(payload.TokenChain)))
			mutation.Set(colFam, "Decimals", ts, []byte(fmt.Sprint(payload.Decimals)))
			mutation.Set(colFam, "Name", ts, []byte(payload.Name[:]))
			mutation.Set(colFam, "Symbol", ts, []byte(payload.Symbol[:]))
			writeErr := writePayloadToBigTable(ctx, rowKey, colFam, mutation)
			if writeErr != nil {
				log.Println("wrote TokenTransferPayload to bigtable!", rowKey)
			}
			return writeErr
		} else {
			// unknown payload type
			log.Println("encountered unknown payload type for row ", rowKey)
			return nil
		}
	} else if _, ok := NFTEmitters[emitterHex]; ok {
		if payloadId == 1 {
			// NFT transfer
			payload, decodeErr := DecodeNFTTransfer(signedVaa.Payload)
			if decodeErr != nil {
				log.Println("failed decoding payload for row ", rowKey)
				return decodeErr
			}
			// save payload to bigtable
			colFam := columnFamilies[4]
			mutation := bigtable.NewMutation()
			ts := bigtable.Now()

			mutation.Set(colFam, "PayloadId", ts, []byte(fmt.Sprint(payload.PayloadId)))
			mutation.Set(colFam, "OriginAddress", ts, []byte(hex.EncodeToString(payload.OriginAddress[:])))
			mutation.Set(colFam, "OriginChain", ts, []byte(fmt.Sprint(payload.OriginChain)))
			mutation.Set(colFam, "Symbol", ts, []byte(payload.Symbol[:]))
			mutation.Set(colFam, "Name", ts, []byte(payload.Name[:]))
			// TODO: find a better way of representing tokenId as a string
			mutation.Set(colFam, "TokenId", ts, []byte(fmt.Sprint(payload.TokenId[3])))
			mutation.Set(colFam, "URI", ts, []byte(payload.URI))
			mutation.Set(colFam, "TargetAddress", ts, []byte(hex.EncodeToString(payload.TargetAddress[:])))
			mutation.Set(colFam, "TargetChain", ts, []byte(fmt.Sprint(payload.TargetChain)))

			writeErr := writePayloadToBigTable(ctx, rowKey, colFam, mutation)
			if writeErr == nil {
				log.Println("wrote NFTTransferPayload to bigtable!", rowKey)
			}
			return writeErr
		} else {
			// unknown payload type
			log.Println("encountered unknown payload type for row ", rowKey)
			return nil
		}
	}

	// this is not a payload we are ready to decode & save. return success
	return nil
}