package shreder

import (
	"bytes"
	"encoding/binary"
	"fmt"

	"github.com/gagliardetto/solana-go"
	"github.com/shopspring/decimal"
)

var dbotProgramID = solana.MustPublicKeyFromBase58("DBotWvSso9oD1ZB3aHx2LiD2ZoFpF8PbKjaT4uHKLLVs")

var (
	dbotPumpFunBuyIX = []byte{0x4e, 0x13, 0x6d, 0x72, 0x3d, 0x72, 0xbe, 0x9d}
	dbotPumpAmmBuyIX = []byte{0x99, 0x76, 0xb6, 0x1e, 0xe4, 0x03, 0xdc, 0xf4}
)

func parseDbotInstruction(tx VersionedTransaction, instructionIndex int) (TxSignalBatch, error) {
	if instructionIndex >= len(tx.Instructions) {
		return nil, fmt.Errorf("instruction index out of bounds")
	}
	ix := tx.Instructions[instructionIndex]
	if len(ix.Data) < 8 {
		return nil, nil
	}

	isPumpFun := false
	isPumpAmm := false

	if len(ix.Accounts) > 11 {
		key, err := tx.GetAccount(int(ix.Accounts[11]))
		if err != nil {
			return nil, err
		}
		if key.Equals(pumpProgramID) {
			isPumpFun = true
		}
	}

	if len(ix.Accounts) > 16 {
		key, err := tx.GetAccount(int(ix.Accounts[16]))
		if err != nil {
			return nil, err
		}
		if key.Equals(pumpAmmProgramID) {
			isPumpAmm = true
		}
	}

	disc := ix.Data[:8]

	if isPumpFun {
		if !bytes.Equal(disc, dbotPumpFunBuyIX) {
			return nil, nil
		}
		if len(ix.Data) < 16 {
			return nil, fmt.Errorf("data too short for dbot pumpfun buy args, len=%d", len(ix.Data))
		}
		if len(ix.Accounts) < 3 {
			return nil, fmt.Errorf("accounts too short")
		}

		mint, err := tx.GetAccount(int(ix.Accounts[2]))
		if err != nil {
			return nil, err
		}
		solAmount := binary.LittleEndian.Uint64(ix.Data[8:16])

		return TxSignalBatch{&TxSignal{
			TxHash:             tx.Signatures[0].String(),
			Label:              "dbot",
			Maker:              tx.StaticAccountKeys[0].String(),
			Token0Address:      mint.String(),
			Token1Address:      wsolMint,
			Token0Amount:       decimal.Zero,
			Token1Amount:       formatSolAmount(solAmount),
			Program:            "Pump",
			Event:              "buy",
			ExactSOL:           true,
			IsToken2022:        false,
			IsMayhemMode:       false,
			Block:              tx.Block,
			Token0AmountUint64: 0,
			Token1AmountUint64: solAmount,
		}}, nil
	}

	if isPumpAmm {
		if !bytes.Equal(disc, dbotPumpAmmBuyIX) {
			return nil, nil
		}
		if len(ix.Data) < 16 {
			return nil, fmt.Errorf("data too short for dbot pumpamm buy args, len=%d", len(ix.Data))
		}
		if len(ix.Accounts) < 5 {
			return nil, fmt.Errorf("accounts too short")
		}

		base, err := tx.GetAccount(int(ix.Accounts[3]))
		if err != nil {
			return nil, err
		}
		quote, err := tx.GetAccount(int(ix.Accounts[4]))
		if err != nil {
			return nil, err
		}
		if !quote.Equals(solana.WrappedSol) {
			return nil, nil
		}

		solAmount := binary.LittleEndian.Uint64(ix.Data[8:16])

		return TxSignalBatch{&TxSignal{
			TxHash:             tx.Signatures[0].String(),
			Label:              "dbot",
			Maker:              tx.StaticAccountKeys[0].String(),
			Token0Address:      base.String(),
			Token1Address:      wsolMint,
			Token0Amount:       decimal.Zero,
			Token1Amount:       formatSolAmount(solAmount),
			Program:            "PumpAMM",
			Event:              "buy",
			ExactSOL:           true,
			IsToken2022:        false,
			IsMayhemMode:       false,
			Block:              tx.Block,
			Token0AmountUint64: 0,
			Token1AmountUint64: solAmount,
		}}, nil
	}

	return nil, nil
}