package shreder

import (
	"fmt"

	"github.com/gagliardetto/solana-go"
	"github.com/near/borsh-go"
)

// only buy function with pump program
var fjszProgramID = solana.MustPublicKeyFromBase58("FJsZbftBqRLfF7uqUKpm4s2goDr6xsQ5Q3mN7AFJB6hK")
var (
	fjszBuyTokensIX = []byte{0xe7, 0x3f, 0x99, 0x83, 0xf3, 0xed, 0xe3, 0x3c}
)

type fjszBuyArgs struct {
	SolAmount   uint64
	TokenAmount uint64
}

func parseFjszInstruction(tx VersionedTransaction, instructionIndex int) (TxSignalBatch, error) {
	if instructionIndex >= len(tx.Instructions) {
		return nil, fmt.Errorf("instruction index out of bounds")
	}

	instruction := tx.Instructions[instructionIndex]
	if len(instruction.Data) == 0 {
		return nil, fmt.Errorf("data is empty")
	}

	if !matchMethod(instruction.Data, fjszBuyTokensIX) {
		return nil, nil
	}
	if len(instruction.Accounts) < 7 {
		return nil, fmt.Errorf("accounts too short")
	}
	if len(instruction.Data) < 16 {
		return nil, fmt.Errorf("data too short for fjzs buy args, len=%d", len(instruction.Data))
	}

	mint, err := tx.GetAccount(int(instruction.Accounts[2]))
	if err != nil {
		return nil, err
	}
	user, err := tx.GetAccount(int(instruction.Accounts[6]))
	if err != nil {
		return nil, err
	}

	var args fjszBuyArgs
	if err := borsh.Deserialize(&args, instruction.Data[8:]); err != nil {
		return nil, fmt.Errorf("failed to parse buy tokens args: %w", err)
	}

	return TxSignalBatch{&TxSignal{
		TxHash:             tx.Signatures[0].String(),
		Label:              "fjsz",
		Maker:              user.String(),
		Token0Address:      mint.String(),
		Token1Address:      wsolMint,
		Token0Amount:       formatTokenAmount(args.TokenAmount),
		Token1Amount:       formatSolAmount(args.SolAmount),
		Program:            "Pump",
		Event:              "buy",
		IsToken2022:        false,
		IsMayhemMode:       false,
		Block:              tx.Block,
		Token0AmountUint64: args.TokenAmount,
		Token1AmountUint64: args.SolAmount,
	}}, nil
}