# Common Interfaces for Exchange Modules

## Overview

This document defines the common interfaces that all exchange-specific modules should implement to ensure consistency across the MEV bot.

## Core Interface

```go
type Exchange interface {
    // Swap operations
    Swap(fromToken, toToken string, amount *big.Int) (*SwapResult, error)
    SwapExactIn(fromToken, toToken string, amountIn *big.Int) (*SwapResult, error)
    SwapExactOut(fromToken, toToken string, amountOut *big.Int) (*SwapResult, error)
    
    // Liquidity operations
    AddLiquidity(tokenA, tokenB string, amountADesired, amountBDesired *big.Int) (*LiquidityResult, error)
    RemoveLiquidity(tokenA, tokenB string, liquidity *big.Int) (*LiquidityResult, error)
    
    // Pricing functions
    GetPrice(fromToken, toToken string, amount *big.Int) (*big.Int, error)
    GetAmountsOut(amountIn *big.Int, path []string) ([]*big.Int, error)
    GetAmountsIn(amountOut *big.Int, path []string) ([]*big.Int, error)
    
    // Pool information
    GetPoolReserves(tokenA, tokenB string) (*big.Int, *big.Int, error)
    GetPair(tokenA, tokenB string) (common.Address, error)
    
    // Pool management
    GetAllPools() []Pool
    GetPoolByAddress(address common.Address) (Pool, error)
    
    // Fee calculations
    GetSwapFee() (*big.Int, error)
    CalculateSlippage(amount *big.Int, slippagePercent float64) (*big.Int, error)
}
```

## Swap Result Structure

```go
type SwapResult struct {
    FromToken      string
    ToToken        string
    AmountIn       *big.Int
    AmountOut      *big.Int
    ExpectedAmount *big.Int
    GasEstimate    *big.Int
    Route          []string
}
```

## Liquidity Result Structure

```go
type LiquidityResult struct {
    TokenA         string
    TokenB         string
    AmountA        *big.Int
    AmountB        *big.Int
    Liquidity      *big.Int
    GasEstimate    *big.Int
}
```

## Pool Structure

```go
type Pool struct {
    Address   common.Address
    Token0    string
    Token1    string
    Reserve0  *big.Int
    Reserve1  *big.Int
    Fee       *big.Int
}
```

## Error Handling

- All functions should return standardized errors
- Network-related errors should be distinguishable
- Invalid input errors should be clearly identified
- Slippage tolerance exceeded errors should be handled

## Implementation Guidelines

1. All external calls should be properly validated
2. Input parameters should be sanitized before use
3. Gas estimation should be performed where possible
4. Proper timeout handling for external calls
5. Fallback mechanisms for critical operations