package events

import (
	"fmt"
	"math/big"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/holiman/uint256"
)

// EventType represents the type of DEX event
type EventType int

const (
	Unknown EventType = iota
	Swap
	AddLiquidity
	RemoveLiquidity
	NewPool
)

// String returns a string representation of the event type
func (et EventType) String() string {
	switch et {
	case Unknown:
		return "Unknown"
	case Swap:
		return "Swap"
	case AddLiquidity:
		return "AddLiquidity"
	case RemoveLiquidity:
		return "RemoveLiquidity"
	case NewPool:
		return "NewPool"
	default:
		return "Unknown"
	}
}

type Event struct {
	Type            EventType
	Protocol        string // UniswapV2, UniswapV3, SushiSwap, etc.
	PoolAddress     common.Address
	Token0          common.Address
	Token1          common.Address
	Amount0         *big.Int
	Amount1         *big.Int
	SqrtPriceX96    *uint256.Int
	Liquidity       *uint256.Int
	Tick            int
	Timestamp       uint64
	TransactionHash common.Hash
	BlockNumber     uint64
}

// EventParser parses DEX events from Ethereum transactions
type EventParser struct {
	// Known DEX contract addresses
	UniswapV2Factory common.Address
	UniswapV3Factory common.Address
	SushiSwapFactory common.Address

	// Router addresses
	UniswapV2Router01 common.Address
	UniswapV2Router02 common.Address
	UniswapV3Router   common.Address
	SushiSwapRouter   common.Address

	// Known pool addresses (for quick lookup)
	knownPools map[common.Address]string

	// Event signatures for parsing logs
	swapEventV2Sig common.Hash
	swapEventV3Sig common.Hash
	mintEventV2Sig common.Hash
	mintEventV3Sig common.Hash
	burnEventV2Sig common.Hash
	burnEventV3Sig common.Hash
}

// NewEventParser creates a new event parser with official Arbitrum deployment addresses
func NewEventParser() *EventParser {
	parser := &EventParser{
		// Official Arbitrum DEX Factory Addresses
		UniswapV2Factory:  common.HexToAddress("0xf1D7CC64Fb4452F05c498126312eBE29f30Fbcf9"), // Official Uniswap V2 Factory on Arbitrum
		UniswapV3Factory:  common.HexToAddress("0x1F98431c8aD98523631AE4a59f267346ea31F984"), // Official Uniswap V3 Factory on Arbitrum  
		SushiSwapFactory:  common.HexToAddress("0xc35DADB65012eC5796536bD9864eD8773aBc74C4"), // Official SushiSwap V2 Factory on Arbitrum
		
		// Official Arbitrum DEX Router Addresses  
		UniswapV2Router01: common.HexToAddress("0x0000000000000000000000000000000000000000"), // V2Router01 not deployed on Arbitrum
		UniswapV2Router02: common.HexToAddress("0x4752ba5dbc23f44d87826276bf6fd6b1c372ad24"), // Official Uniswap V2 Router02 on Arbitrum
		UniswapV3Router:   common.HexToAddress("0xE592427A0AEce92De3Edee1F18E0157C05861564"), // Official Uniswap V3 SwapRouter on Arbitrum
		SushiSwapRouter:   common.HexToAddress("0x1b02dA8Cb0d097eB8D57A175b88c7D8b47997506"), // Official SushiSwap Router on Arbitrum
		knownPools:        make(map[common.Address]string),
	}

	// Initialize event signatures
	parser.swapEventV2Sig = crypto.Keccak256Hash([]byte("Swap(address,uint256,uint256,uint256,uint256,address)"))
	parser.swapEventV3Sig = crypto.Keccak256Hash([]byte("Swap(address,address,int256,int256,uint160,uint128,int24)"))
	parser.mintEventV2Sig = crypto.Keccak256Hash([]byte("Mint(address,uint256,uint256)"))
	parser.mintEventV3Sig = crypto.Keccak256Hash([]byte("Mint(address,address,int24,int24,uint128,uint256,uint256)"))
	parser.burnEventV2Sig = crypto.Keccak256Hash([]byte("Burn(address,uint256,uint256)"))
	parser.burnEventV3Sig = crypto.Keccak256Hash([]byte("Burn(address,int24,int24,uint128,uint256,uint256)"))

	// Pre-populate known Arbitrum pools (high volume pools)
	parser.knownPools[common.HexToAddress("0xC6962004f452bE9203591991D15f6b388e09E8D0")] = "UniswapV3" // USDC/WETH 0.05%
	parser.knownPools[common.HexToAddress("0x17c14D2c404D167802b16C450d3c99F88F2c4F4d")] = "UniswapV3" // USDC/WETH 0.3%
	parser.knownPools[common.HexToAddress("0x2f5e87C9312fa29aed5c179E456625D79015299c")] = "UniswapV3" // WBTC/WETH 0.05%
	parser.knownPools[common.HexToAddress("0x149e36E72726e0BceA5c59d40df2c43F60f5A22D")] = "UniswapV3" // WBTC/WETH 0.3%
	parser.knownPools[common.HexToAddress("0x641C00A822e8b671738d32a431a4Fb6074E5c79d")] = "UniswapV3" // USDT/WETH 0.05%
	parser.knownPools[common.HexToAddress("0xFe7D6a84287235C7b4b57C4fEb9a44d4C6Ed3BB8")] = "UniswapV3" // ARB/WETH 0.05%
	parser.knownPools[common.HexToAddress("0x80A9ae39310abf666A87C743d6ebBD0E8C42158E")] = "UniswapV3" // WETH/USDT 0.3%
	parser.knownPools[common.HexToAddress("0xC82819F72A9e77E2c0c3A69B3196478f44303cf4")] = "UniswapV3" // WETH/USDC 1%

	// Add SushiSwap pools
	parser.knownPools[common.HexToAddress("0x905dfCD5649217c42684f23958568e533C711Aa3")] = "SushiSwap" // WETH/USDC
	parser.knownPools[common.HexToAddress("0x3221022e37029923aCe4235D812273C5A42C322d")] = "SushiSwap" // WETH/USDT

	// Add GMX pools
	parser.knownPools[common.HexToAddress("0x70d95587d40A2caf56bd97485aB3Eec10Bee6336")] = "GMX" // GLP Pool
	parser.knownPools[common.HexToAddress("0x489ee077994B6658eAfA855C308275EAd8097C4A")] = "GMX" // GMX/WETH

	return parser
}

// ParseTransactionReceipt parses events from a transaction receipt
func (ep *EventParser) ParseTransactionReceipt(receipt *types.Receipt, blockNumber uint64, timestamp uint64) ([]*Event, error) {
	events := make([]*Event, 0)

	// Parse logs for DEX events
	for _, log := range receipt.Logs {
		// Skip anonymous logs
		if len(log.Topics) == 0 {
			continue
		}

		// Check if this is a DEX event based on the topic signature
		eventSig := log.Topics[0]

		var event *Event
		var err error

		switch eventSig {
		case ep.swapEventV2Sig:
			event, err = ep.parseUniswapV2Swap(log, blockNumber, timestamp, receipt.TxHash)
		case ep.swapEventV3Sig:
			event, err = ep.parseUniswapV3Swap(log, blockNumber, timestamp, receipt.TxHash)
		case ep.mintEventV2Sig:
			event, err = ep.parseUniswapV2Mint(log, blockNumber, timestamp, receipt.TxHash)
		case ep.mintEventV3Sig:
			event, err = ep.parseUniswapV3Mint(log, blockNumber, timestamp, receipt.TxHash)
		case ep.burnEventV2Sig:
			event, err = ep.parseUniswapV2Burn(log, blockNumber, timestamp, receipt.TxHash)
		case ep.burnEventV3Sig:
			event, err = ep.parseUniswapV3Burn(log, blockNumber, timestamp, receipt.TxHash)
		}

		if err != nil {
			// Log error but continue parsing other logs
			continue
		}

		if event != nil {
			events = append(events, event)
		}
	}

	return events, nil
}

// IsDEXInteraction checks if a transaction interacts with a known DEX contract
func (ep *EventParser) IsDEXInteraction(tx *types.Transaction) bool {
	if tx.To() == nil {
		return false
	}

	to := *tx.To()

	// Check factory contracts
	if to == ep.UniswapV2Factory ||
		to == ep.UniswapV3Factory ||
		to == ep.SushiSwapFactory {
		return true
	}

	// Check router contracts
	if to == ep.UniswapV2Router01 ||
		to == ep.UniswapV2Router02 ||
		to == ep.UniswapV3Router ||
		to == ep.SushiSwapRouter {
		return true
	}

	// Check known pools
	if _, exists := ep.knownPools[to]; exists {
		return true
	}

	return false
}

// identifyProtocol identifies which DEX protocol a transaction is interacting with
func (ep *EventParser) identifyProtocol(tx *types.Transaction) string {
	if tx.To() == nil {
		return "Unknown"
	}

	to := *tx.To()

	// Check factory contracts
	if to == ep.UniswapV2Factory {
		return "UniswapV2"
	}
	if to == ep.UniswapV3Factory {
		return "UniswapV3"
	}
	if to == ep.SushiSwapFactory {
		return "SushiSwap"
	}

	// Check router contracts
	if to == ep.UniswapV2Router01 || to == ep.UniswapV2Router02 {
		return "UniswapV2"
	}
	if to == ep.UniswapV3Router {
		return "UniswapV3"
	}
	if to == ep.SushiSwapRouter {
		return "SushiSwap"
	}

	// Check known pools
	if protocol, exists := ep.knownPools[to]; exists {
		return protocol
	}

	// Try to identify from function signature in transaction data
	if len(tx.Data()) >= 4 {
		sig := common.Bytes2Hex(tx.Data()[:4])
		switch sig {
		case "0xac9650d8": // multicall (Uniswap V3)
			return "UniswapV3"
		case "0x88316456": // swap (Uniswap V2)
			return "UniswapV2"
		case "0x128acb08": // swap (SushiSwap)
			return "SushiSwap"
		case "0x38ed1739": // swapExactTokensForTokens (Uniswap V2)
			return "UniswapV2"
		case "0x8803dbee": // swapTokensForExactTokens (Uniswap V2)
			return "UniswapV2"
		case "0x7ff36ab5": // swapExactETHForTokens (Uniswap V2)
			return "UniswapV2"
		case "0xb6f9de95": // swapExactTokensForETH (Uniswap V2)
			return "UniswapV2"
		case "0x414bf389": // exactInputSingle (Uniswap V3)
			return "UniswapV3"
		case "0xdb3e2198": // exactInput (Uniswap V3)
			return "UniswapV3"
		case "0xf305d719": // exactOutputSingle (Uniswap V3)
			return "UniswapV3"
		case "0x04e45aaf": // exactOutput (Uniswap V3)
			return "UniswapV3"
		case "0x18cbafe5": // swapExactTokensForTokensSupportingFeeOnTransferTokens (Uniswap V2)
			return "UniswapV2"
		case "0x18cffa1c": // swapExactETHForTokensSupportingFeeOnTransferTokens (Uniswap V2)
			return "UniswapV2"
		case "0x791ac947": // swapExactTokensForETHSupportingFeeOnTransferTokens (Uniswap V2)
			return "UniswapV2"
		case "0x5ae401dc": // multicall (Uniswap V3)
			return "UniswapV3"
		}
	}

	return "Unknown"
}

// parseUniswapV2Swap parses a Uniswap V2 Swap event
func (ep *EventParser) parseUniswapV2Swap(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
	if len(log.Topics) != 2 || len(log.Data) != 32*4 {
		return nil, fmt.Errorf("invalid Uniswap V2 Swap event log")
	}

	// Parse the data fields
	amount0In := new(big.Int).SetBytes(log.Data[0:32])
	amount1In := new(big.Int).SetBytes(log.Data[32:64])
	amount0Out := new(big.Int).SetBytes(log.Data[64:96])
	amount1Out := new(big.Int).SetBytes(log.Data[96:128])

	// Determine which token is being swapped in/out
	var amount0, amount1 *big.Int
	if amount0In.Cmp(big.NewInt(0)) > 0 {
		amount0 = amount0In
	} else {
		amount0 = new(big.Int).Neg(amount0Out)
	}

	if amount1In.Cmp(big.NewInt(0)) > 0 {
		amount1 = amount1In
	} else {
		amount1 = new(big.Int).Neg(amount1Out)
	}

	event := &Event{
		Type:            Swap,
		Protocol:        "UniswapV2",
		PoolAddress:     log.Address,
		Amount0:         amount0,
		Amount1:         amount1,
		Timestamp:       timestamp,
		TransactionHash: txHash,
		BlockNumber:     blockNumber,
	}

	return event, nil
}

// parseUniswapV3Swap parses a Uniswap V3 Swap event
func (ep *EventParser) parseUniswapV3Swap(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
	if len(log.Topics) != 3 || len(log.Data) != 32*5 {
		return nil, fmt.Errorf("invalid Uniswap V3 Swap event log")
	}

	// Parse the data fields
	amount0 := new(big.Int).SetBytes(log.Data[0:32])
	amount1 := new(big.Int).SetBytes(log.Data[32:64])
	sqrtPriceX96 := new(big.Int).SetBytes(log.Data[64:96])
	liquidity := new(big.Int).SetBytes(log.Data[96:128])
	tick := new(big.Int).SetBytes(log.Data[128:160])

	// Convert to signed values if needed
	if amount0.Cmp(big.NewInt(0)) > 0x7fffffffffffffff {
		amount0 = amount0.Sub(amount0, new(big.Int).Lsh(big.NewInt(1), 256))
	}
	if amount1.Cmp(big.NewInt(0)) > 0x7fffffffffffffff {
		amount1 = amount1.Sub(amount1, new(big.Int).Lsh(big.NewInt(1), 256))
	}

	event := &Event{
		Type:            Swap,
		Protocol:        "UniswapV3",
		PoolAddress:     log.Address,
		Amount0:         amount0,
		Amount1:         amount1,
		SqrtPriceX96:    uint256.MustFromBig(sqrtPriceX96),
		Liquidity:       uint256.MustFromBig(liquidity),
		Tick:            int(tick.Int64()),
		Timestamp:       timestamp,
		TransactionHash: txHash,
		BlockNumber:     blockNumber,
	}

	return event, nil
}

// parseUniswapV2Mint parses a Uniswap V2 Mint event
func (ep *EventParser) parseUniswapV2Mint(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
	if len(log.Topics) != 2 || len(log.Data) != 32*2 {
		return nil, fmt.Errorf("invalid Uniswap V2 Mint event log")
	}

	// Parse the data fields
	amount0 := new(big.Int).SetBytes(log.Data[0:32])
	amount1 := new(big.Int).SetBytes(log.Data[32:64])

	event := &Event{
		Type:            AddLiquidity,
		Protocol:        "UniswapV2",
		PoolAddress:     log.Address,
		Amount0:         amount0,
		Amount1:         amount1,
		Timestamp:       timestamp,
		TransactionHash: txHash,
		BlockNumber:     blockNumber,
	}

	return event, nil
}

// parseUniswapV3Mint parses a Uniswap V3 Mint event
func (ep *EventParser) parseUniswapV3Mint(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
	if len(log.Topics) != 3 || len(log.Data) != 32*4 {
		return nil, fmt.Errorf("invalid Uniswap V3 Mint event log")
	}

	// Parse the data fields
	amount0 := new(big.Int).SetBytes(log.Data[0:32])
	amount1 := new(big.Int).SetBytes(log.Data[32:64])

	event := &Event{
		Type:            AddLiquidity,
		Protocol:        "UniswapV3",
		PoolAddress:     log.Address,
		Amount0:         amount0,
		Amount1:         amount1,
		Timestamp:       timestamp,
		TransactionHash: txHash,
		BlockNumber:     blockNumber,
	}

	return event, nil
}

// parseUniswapV2Burn parses a Uniswap V2 Burn event
func (ep *EventParser) parseUniswapV2Burn(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
	if len(log.Topics) != 2 || len(log.Data) != 32*2 {
		return nil, fmt.Errorf("invalid Uniswap V2 Burn event log")
	}

	// Parse the data fields
	amount0 := new(big.Int).SetBytes(log.Data[0:32])
	amount1 := new(big.Int).SetBytes(log.Data[32:64])

	event := &Event{
		Type:            RemoveLiquidity,
		Protocol:        "UniswapV2",
		PoolAddress:     log.Address,
		Amount0:         amount0,
		Amount1:         amount1,
		Timestamp:       timestamp,
		TransactionHash: txHash,
		BlockNumber:     blockNumber,
	}

	return event, nil
}

// parseUniswapV3Burn parses a Uniswap V3 Burn event
func (ep *EventParser) parseUniswapV3Burn(log *types.Log, blockNumber uint64, timestamp uint64, txHash common.Hash) (*Event, error) {
	if len(log.Topics) != 3 || len(log.Data) != 32*4 {
		return nil, fmt.Errorf("invalid Uniswap V3 Burn event log")
	}

	// Parse the data fields
	amount0 := new(big.Int).SetBytes(log.Data[0:32])
	amount1 := new(big.Int).SetBytes(log.Data[32:64])

	event := &Event{
		Type:            RemoveLiquidity,
		Protocol:        "UniswapV3",
		PoolAddress:     log.Address,
		Amount0:         amount0,
		Amount1:         amount1,
		Timestamp:       timestamp,
		TransactionHash: txHash,
		BlockNumber:     blockNumber,
	}

	return event, nil
}

// AddKnownPool adds a pool address to the known pools map
func (ep *EventParser) AddKnownPool(address common.Address, protocol string) {
	ep.knownPools[address] = protocol
}

// GetKnownPools returns all known pools
func (ep *EventParser) GetKnownPools() map[common.Address]string {
	return ep.knownPools
}