# Smart Contract

## Contract Overview

The SHIM token is an ERC-20 token with additional features like fee mechanisms, trading limits, and liquidity functions. It's designed to work with Uniswap V2 and includes anti-whale measures.

## Core Functions

### 1. Constructor

```solidity
constructor () ERC20("ShimaNest", "SHIM")
```

* Initializes the token with name "ShimaNest" and symbol "SHIM"
* Sets up router addresses for different chains (BSC mainnet/testnet, ETH mainnet/testnet)
* Transfers ownership to `0x4F69F9cEDC6Cf0db1AF4DdCE364DcD9EEB1408dF`
* Creates Uniswap V2 pair
* Sets initial fees (3% liquidity, 2% marketing on both buy/sell)
* Configures wallet/transaction limits
* Mints 20 billion tokens to owner
* Disables trading initially

### 2. Fee Management Functions

**`updateBuyFees()`**

```solidity
function updateBuyFees(uint256 _liquidityFeeOnBuy, uint256 _marketingFeeOnBuy)
```

* Allows owner to update buy fees
* Ensures total fees don't exceed 10%
* Emits `UpdateBuyFees` event

**`updateSellFees()`**

```solidity
function updateSellFees(uint256 _liquidityFeeOnSell, uint256 _marketingFeeOnSell)
```

* Similar to `updateBuyFees` but for sell transactions
* Also caps total fees at 10%

**`updateWalletToWalletTransferFee()`**

```solidity
function updateWalletToWalletTransferFee(uint256 _walletToWalletTransferFee)
```

* Sets fee for wallet-to-wallet transfers (non-dex transactions)
* Maximum fee capped at 5%

### 3. Wallet Management Functions

**`changeMarketingWallet()`**

```solidity
function changeMarketingWallet(address _marketingWallet)
```

* Allows owner to change marketing wallet address
* Prevents setting to zero address
* Emits `MarketingWalletChanged` event

**`excludeFromFees()`**

```solidity
function excludeFromFees(address account, bool excluded)
```

* Excludes/includes account from fees
* Only callable by owner
* Emits `ExcludeFromFees` event

### 4. Trading Functions

**`enableTrading()`**

```solidity
function enableTrading()
```

* Activates trading (initially disabled)
* Also enables swapping functionality
* Can only be called once

**`_transfer()` (Internal)**

```solidity
function _transfer(address from, address to, uint256 amount)
```

* Main transfer function with all fee logic
* Checks trading status and limits
* Handles fee collection and redistribution
* Implements anti-whale measures
* Processes swaps when thresholds are met

### 5. Liquidity Functions

**`swapAndLiquify()`**

```solidity
function swapAndLiquify(uint256 tokens)
```

* Internal function that:
  1. Swaps half of tokens for ETH
  2. Adds liquidity with other half of tokens and received ETH
  3. Sends LP tokens to dead address
* Emits `SwapAndLiquify` event

**`swapAndSendMarketing()`**

```solidity
function swapAndSendMarketing(uint256 tokenAmount)
```

* Swaps tokens for ETH
* Sends ETH to marketing wallet
* Emits `SwapAndSendMarketing` event

### 6. Limit Management Functions

**Max Wallet Limits:**

```solidity
function setEnableMaxWalletLimit(bool enable)
function setMaxWalletAmount(uint256 _maxWalletAmount)
function excludeFromMaxWallet(address account, bool exclude)
```

* Enable/disable wallet limit
* Set max wallet amount (min 1% of supply)
* Exclude addresses from limit

### **Max Transaction Limits:**

```solidity
function setEnableMaxTransactionLimit(bool enable)
function setMaxTransactionAmounts(uint256 _maxTransactionAmountBuy, uint256 _maxTransactionAmountSell)
function excludeFromMaxTransactionLimit(address account, bool exclude)
```

* Similar to wallet limits but for transactions
* Minimum 0.1% of supply for both buy/sell limits

### 7. Utility Functions

**`claimStuckTokens()`**

```solidity
function claimStuckTokens(address token)
```

* Allows owner to recover accidentally sent tokens
* Cannot recover the token itself

**`setSwapTokensAtAmount()`**

```solidity
function setSwapTokensAtAmount(uint256 newAmount)
```

* Sets threshold for auto-swapping accumulated fees
* Must be > 0.0001% of total supply

**`setSwapEnabled()`**

```solidity
function setSwapEnabled(bool _enabled)
```

* Toggles whether fee auto-swapping is active

## Key Features

1. **Fee Mechanism**:
   * Different fees for buying/selling (default 5% total)
   * Separate wallet-to-wallet transfer fee
   * Fees are split between liquidity and marketing
2. **Anti-Whale Protection**:
   * Max wallet limit (default 2%)
   * Max transaction limits (default 1% buy/sell)
3. **Liquidity Management**:
   * Automatic LP creation from fees
   * Marketing fees converted to ETH
4. **Security Measures**:
   * Trading initially disabled
   * Owner can exclude addresses from limits/fees
   * Prevents setting dangerous limits (<0.1%)
5. **Multi-Chain Support**:
   * Detects chain ID to use correct router addresses
   * Supports BSC and Ethereum mainnets/testnets

## Events

The contract emits several events for important state changes:

* Fee updates
* Wallet/limit changes
* Swap activities
* Exclusions from limits/fees
* Ownership transfers (from Ownable)

This comprehensive token contract includes robust features for DeFi trading while implementing protections against common issues like whale manipulation and providing flexibility for fee adjustments.