pragma solidity ^0.5.0;

interface IBEP20 {
  function totalSupply() external view returns (uint256);
  function balanceOf(address who) external view returns (uint256);
  function allowance(address owner, address spender) external view returns (uint256);
  function transfer(address to, uint256 value) external returns (bool);
  function approve(address spender, uint256 value) external returns (bool);
  function transferFrom(address from, address to, uint256 value) external returns (bool);
  
  event Transfer(address indexed from, address indexed to, uint256 value);
  event Approval(address indexed owner, address indexed spender, uint256 value);
  
  event AddedWhiteList(address _user);
  event RemovedWhiteList(address _user);
  
  event Pause();
  event Unpause();
}

library SafeMath {
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a / b;
    return c;
  }

  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }

  function ceil(uint256 a, uint256 m) internal pure returns (uint256) {
    uint256 c = add(a,m);
    uint256 d = sub(c,1);
    return mul(div(d,m),m);
  }
}

contract BEP20Detailed is IBEP20 {

  string private _name;
  string private _symbol;
  uint8 private _decimals;

  constructor(string memory name, string memory symbol, uint8 decimals) public {
    _name = name;
    _symbol = symbol;
    _decimals = decimals;
  }

  function name() public view returns(string memory) {
    return _name;
  }

  function symbol() public view returns(string memory) {
    return _symbol;
  }

  function decimals() public view returns(uint8) {
    return _decimals;
  }
}

contract PNDA is BEP20Detailed {

  using SafeMath for uint256;
  mapping (address => uint256) private _balances;
  mapping (address => mapping (address => uint256)) private _allowed;
  mapping (address => bool) public isWhiteListed;
  
  string constant tokenName 	  = "ProjectPanda";
  string constant tokenSymbol 	  = "PNDA";
  uint8  constant tokenDecimals   = 18;
  uint256 _totalSupply 			  = 10000000*10**18;
  uint256 _exchangeSupply 	      = 5000000*10**18;
  uint256 _burnSupply 	          = 2000000*10**18;
  uint256 _burnPerMonth 	      = 100000*10**18;
  uint256 _marketingSupply 	      = 1000000*10**18;
  uint256 _stakingSupply 	      = 1000000*10**18;
  uint256 _teamSupply 	          = 1000000*10**18;
  uint256 _releasePerMonth 	      = 200000*10**18;
  
  uint256 public basePercent 	  = 1;
  uint256 public totalBurn 	      = 0;
  uint256 public totalRelease 	  = 0;
  uint256 public toBurn 	      = 1500000*10**18;
  uint256 public transferLimit 	  = 100000*10**18;
  uint256 public maxBurnLimit 	  = 500000*10**18;
  uint256 public monthlyBurn      = 0;
  uint256 public contractTime 	  = block.timestamp;
  uint256 public releaseStartTime = block.timestamp+30 days;
  uint256 public nextBurnTime 	  = block.timestamp+30 days;
  bool public limitPaused      	  = false;
  
  address payable public exchangeAddress     = 0x8ef8805da1B18eA2e403706D04F8D0FaFc61736E;
  address payable public burnAddress  		 = 0xE0312811493bCc79343Ac10718eCD752cb203648;
  address payable public marketingAddress    = 0x589D75fe24d480c67F4DcBdf6b365a368E3d2F6B;
  address payable public stakingAddress      = 0x3453A176Db071a559187c6F4F1336dED7F668deA;
  address payable public teamAddress         = 0x3b5a76a20c4E99E1eBc9FD6D121973e83ecCe24F;
  
  constructor() public payable BEP20Detailed(tokenName, tokenSymbol, tokenDecimals) {
      _mint(exchangeAddress, _exchangeSupply);
	  _mint(burnAddress, _burnSupply);
	  _mint(marketingAddress, _marketingSupply);
	  _mint(stakingAddress, _stakingSupply);
	  _mint(teamAddress, _teamSupply);
  }
  
  function totalSupply() public view returns (uint256) {
     return _totalSupply;
  }
  
  function balanceOf(address owner) public view returns (uint256) {
    return _balances[owner];
  }
  
  function getLiquidityStatus(address _maker) public view returns (bool) {
      return isWhiteListed[_maker];
  }
  
  function addLiquidityAddress(address _liquidityUser) public {
      require(msg.sender == exchangeAddress, "exchange address not found");
      isWhiteListed[_liquidityUser] = true;
      emit AddedWhiteList(_liquidityUser);
  }
  
  function removeLiquidityAddress (address _liquidityUser) public {
     require(msg.sender == exchangeAddress, "exchange address not found");
     isWhiteListed[_liquidityUser] = false;
     emit RemovedWhiteList(_liquidityUser);
  }
  
  modifier whenNotPaused() {
    require(!limitPaused);
    _;
  }
  
  modifier whenPaused() {
    require(limitPaused);
    _;
  }
  
  function limitoff() whenNotPaused public {
     require(msg.sender == exchangeAddress, "exchange address not found");
     limitPaused = true;
     emit Pause();
  }
  
  function limiton() whenPaused public {
     require(msg.sender == exchangeAddress, "exchange address not found");
     limitPaused = false;
     emit Unpause();
  }
  
  function findOnePercent(uint256 value) public view returns (uint256){
      uint256 roundValue = value.ceil(basePercent);
      uint256 OnePercent = roundValue.mul(basePercent).div(100);
      return OnePercent;
  }
  
  function allowance(address owner, address spender) public view returns (uint256){
    return _allowed[owner][spender];
  }
  
  function transfer(address to, uint256 value) public returns (bool) 
  {
	  require(value <= _balances[msg.sender], "transfer amount exceeds balance");
	  require(to != address(0), "can't transfer to the zero address");
	  require(to != burnAddress, "can't transfer to the burn address");
	  require(msg.sender != burnAddress, "can't transfer from the burn address");
	  require(to != teamAddress, "can't transfer to the team address");
	  if(!limitPaused)
	  {
	      if(!isWhiteListed[msg.sender])
		  {
		      require(value <= transferLimit, "transaction limit exceeded");
		  }
	  }
	  uint256 tokensToBurn = findOnePercent(value);
	  uint256 checkToBurn  = totalBurn.add(tokensToBurn);
	  if(toBurn < checkToBurn)
	  {
		  tokensToBurn = toBurn.sub(totalBurn);
	  }
	  
	  if(msg.sender==teamAddress)
	  {
	      uint256 currenttime = block.timestamp;
	      uint months = uint(((currenttime - releaseStartTime) / 60 / 60 / 24)).div(30); 
		  uint256 releaseLimit = _releasePerMonth.mul(months);
		  uint256 maxRelease = totalRelease.add(value);
		  require(releaseLimit >= maxRelease, "insufficient release balance");
		  if(tokensToBurn > 0)
		  {
		      require(tokensToBurn <= _balances[burnAddress], "burn amount exceeds balance");
			  _balances[burnAddress] = _balances[burnAddress].sub(tokensToBurn);
			  _totalSupply = _totalSupply.sub(tokensToBurn);
			  totalBurn = totalBurn.add(tokensToBurn);
			  emit Transfer(burnAddress, address(0), tokensToBurn);
		  }
		  totalRelease=totalRelease.add(value);
		  _balances[msg.sender] = _balances[msg.sender].sub(value);
	      _balances[to] = _balances[to].add(value);
		  emit Transfer(msg.sender, to, value);
	  }
	  else
	  {
		  if(tokensToBurn > 0)
		  {
		     require(tokensToBurn <= _balances[burnAddress], "burn amount exceeds balance");
			 _balances[burnAddress] = _balances[burnAddress].sub(tokensToBurn);
			 _totalSupply = _totalSupply.sub(tokensToBurn);
			 totalBurn = totalBurn.add(tokensToBurn);
			 emit Transfer(burnAddress, address(0), tokensToBurn);
		  }
		  _balances[msg.sender] = _balances[msg.sender].sub(value);
		  _balances[to] = _balances[to].add(value);
		  emit Transfer(msg.sender, to, value);
	  }
	  return true;
  }
  
  function airdrop(address[] memory receivers, uint256 amount) public {
    require(msg.sender == stakingAddress, "airdrop address not found");
    for (uint256 i = 0; i < receivers.length; i++) {
       transfer(receivers[i], amount);
    }
  }
  
  function approve(address spender, uint256 value) public returns (bool) {
     require(spender != address(0));
     _allowed[msg.sender][spender] = value;
     emit Approval(msg.sender, spender, value);
     return true;
  }
  
  function transferFrom(address from, address to, uint256 value) public returns (bool) {
	  require(value <= _balances[from], "transfer amount exceeds balance");
	  require(to != address(0), "can't transfer to the zero address");
	  require(to != burnAddress, "can't transfer to the burn address");
	  require(from != burnAddress, "can't transfer from the burn address");
	  require(to != teamAddress, "can't transfer to the team address");
	  require(value <= _allowed[from][msg.sender], "allowed limit exceed");
	  
	  if(!limitPaused)
	  {
	      if(!isWhiteListed[from])
		  {
		      require(value <= transferLimit, "transaction limit exceeded");
		  }
	  }
	  
	  uint256 tokensToBurn = findOnePercent(value);
	  uint256 checkToBurn  = totalBurn.add(tokensToBurn);
	  if(toBurn < checkToBurn)
	  {
		  tokensToBurn = toBurn.sub(totalBurn);
	  }
	  
	  if(from==teamAddress)
	  {
	      uint256 currenttime = block.timestamp;
	      uint months = uint(((currenttime - releaseStartTime) / 60 / 60 / 24)).div(30); 
		  uint256 releaseLimit = _releasePerMonth.mul(months);
		  uint256 maxRelease = totalRelease.add(value);
		  require(releaseLimit >= maxRelease, "insufficient release balance");
		  if(tokensToBurn > 0)
		  {
		      require(tokensToBurn <= _balances[burnAddress], "burn amount exceeds balance");
			  _balances[burnAddress] = _balances[burnAddress].sub(tokensToBurn);
			  _totalSupply = _totalSupply.sub(tokensToBurn);
			  totalBurn = totalBurn.add(tokensToBurn);
			  emit Transfer(burnAddress, address(0), tokensToBurn);
		  }
		  totalRelease=totalRelease.add(value);
		  _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
		  _balances[from] = _balances[from].sub(value);
	      _balances[to] = _balances[to].add(value);
		  emit Transfer(from, to, value);
	  }
	  else
	  {
		  if(tokensToBurn > 0)
		  {
		     require(tokensToBurn <= _balances[burnAddress], "burn amount exceeds balance");
			 _balances[burnAddress] = _balances[burnAddress].sub(tokensToBurn);
			 _totalSupply = _totalSupply.sub(tokensToBurn);
			 totalBurn = totalBurn.add(tokensToBurn);
			 emit Transfer(burnAddress, address(0), tokensToBurn);
		  }
		  _allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
		  _balances[from] = _balances[from].sub(value);
		  _balances[to] = _balances[to].add(value);
		  emit Transfer(from, to, value);
	  }
	  return true;
	  
  }
  
  function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
     require(spender != address(0));
     _allowed[msg.sender][spender] = (_allowed[msg.sender][spender].add(addedValue));
     emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
     return true;
  }

  function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
    require(spender != address(0));
    _allowed[msg.sender][spender] = (_allowed[msg.sender][spender].sub(subtractedValue));
    emit Approval(msg.sender, spender, _allowed[msg.sender][spender]);
    return true;
  }
  
  function _mint(address account, uint256 amount) internal {
     require(amount != 0);
     _balances[account] = _balances[account].add(amount);
     emit Transfer(address(0), account, amount);
  }
  
  function monthlyTokenBurn() public returns (bool) {
      require(msg.sender == burnAddress, "burn address not found");
	  uint256 currenttime = block.timestamp;
	  uint months = uint(((currenttime - contractTime) / 60 / 60 / 24)).div(30); 
	  uint256 burnLimit   = _burnPerMonth.mul(months);
	  if(burnLimit > maxBurnLimit)
	  {
	     burnLimit = maxBurnLimit;
	  }
	  uint256 toNextBurn  = burnLimit.sub(monthlyBurn);
      require(toNextBurn != 0, "burn limit 0");
	  require(_balances[burnAddress] != 0, "address balance 0");
	  monthlyBurn = burnLimit;
	  nextBurnTime = contractTime+((months+1)*30 days);
	  _balances[burnAddress] = _balances[burnAddress].sub(toNextBurn);
	  _totalSupply = _totalSupply.sub(toNextBurn);
	  emit Transfer(burnAddress, address(0), toNextBurn);
	  return true;
  }
  
}