<?php declare(strict_types = 1);
namespace TheSeer\Tokenizer;

class TokenCollection implements \ArrayAccess, \Iterator, \Countable {

/**
* @var Token[]
*/
private $tokens = [];

/**
* @var int
*/
private $pos;

/**
* @param Token $token
*/
public function addToken(Token $token) {
$this->tokens[] = $token;
}

/**
* @return Token
*/
public function current(): Token {
return current($this->tokens);
}

/**
* @return int
*/
public function key(): int {
return key($this->tokens);
}

/**
* @return void
*/
public function next() {
next($this->tokens);
$this->pos++;
}

/**
* @return bool
*/
public function valid(): bool {
return $this->count() > $this->pos;
}

/**
* @return void
*/
public function rewind() {
reset($this->tokens);
$this->pos = 0;
}

/**
* @return int
*/
public function count(): int {
return count($this->tokens);
}

/**
* @param mixed $offset
*
* @return bool
*/
public function offsetExists($offset): bool {
return isset($this->tokens[$offset]);
}

/**
* @param mixed $offset
*
* @return Token
* @throws TokenCollectionException
*/
public function offsetGet($offset): Token {
if (!$this->offsetExists($offset)) {
throw new TokenCollectionException(
sprintf('No Token at offest %s', $offset)
);
}

return $this->tokens[$offset];
}

/**
* @param mixed $offset
* @param Token $value
*
* @throws TokenCollectionException
*/
public function offsetSet($offset, $value) {
if (!is_int($offset)) {
$type = gettype($offset);
throw new TokenCollectionException(
sprintf(
'Offset must be of type integer, %s given',
$type === 'object' ? get_class($value) : $type
)
);
}
if (!$value instanceof Token) {
$type = gettype($value);
throw new TokenCollectionException(
sprintf(
'Value must be of type %s, %s given',
Token::class,
$type === 'object' ? get_class($value) : $type
)
);
}
$this->tokens[$offset] = $value;
}

/**
* @param mixed $offset
*/
public function offsetUnset($offset) {
unset($this->tokens[$offset]);
}

}