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

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

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

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

public function addToken(Token $token): void {
$this->tokens[] = $token;
}

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

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

public function next(): void {
\next($this->tokens);
$this->pos++;
}

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

public function rewind(): void {
\reset($this->tokens);
$this->pos = 0;
}

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

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

/**
* @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 Token $value
*
* @throws TokenCollectionException
*/
public function offsetSet($offset, $value): void {
if (!\is_int($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;
}

public function offsetUnset($offset): void {
unset($this->tokens[$offset]);
}
}