class Profile

final class Profile implements \IteratorAggregate, \Serializable {
    public const ROOT = 'ROOT';
    public const BLOCK = 'block';
    public const TEMPLATE = 'template';
    public const MACRO = 'macro';
    private $starts = [];
    private $ends = [];
    private $profiles = [];
    public function __construct(string $template = 'main', string $type = self::ROOT, string $name = 'main') {
        $this->name = str_starts_with($name, '__internal_') ? 'INTERNAL' : $name;
        $this->enter();
    }
    public function getTemplate() : string {
        return $this->template;
    }
    public function getType() : string {
        return $this->type;
    }
    public function getName() : string {
        return $this->name;
    }
    public function isRoot() : bool {
        return self::ROOT === $this->type;
    }
    public function isTemplate() : bool {
        return self::TEMPLATE === $this->type;
    }
    public function isBlock() : bool {
        return self::BLOCK === $this->type;
    }
    public function isMacro() : bool {
        return self::MACRO === $this->type;
    }
    
    /**
     * @return Profile[]
     */
    public function getProfiles() : array {
        return $this->profiles;
    }
    public function addProfile(self $profile) : void {
        $this->profiles[] = $profile;
    }
    
    /**
     * Returns the duration in microseconds.
     */
    public function getDuration() : float {
        if ($this->isRoot() && $this->profiles) {
            // for the root node with children, duration is the sum of all child durations
            $duration = 0;
            foreach ($this->profiles as $profile) {
                $duration += $profile->getDuration();
            }
            return $duration;
        }
        return isset($this->ends['wt']) && isset($this->starts['wt']) ? $this->ends['wt'] - $this->starts['wt'] : 0;
    }
    
    /**
     * Returns the start time in microseconds.
     */
    public function getStartTime() : float {
        return $this->starts['wt'] ?? 0.0;
    }
    
    /**
     * Returns the end time in microseconds.
     */
    public function getEndTime() : float {
        return $this->ends['wt'] ?? 0.0;
    }
    
    /**
     * Returns the memory usage in bytes.
     */
    public function getMemoryUsage() : int {
        return isset($this->ends['mu']) && isset($this->starts['mu']) ? $this->ends['mu'] - $this->starts['mu'] : 0;
    }
    
    /**
     * Returns the peak memory usage in bytes.
     */
    public function getPeakMemoryUsage() : int {
        return isset($this->ends['pmu']) && isset($this->starts['pmu']) ? $this->ends['pmu'] - $this->starts['pmu'] : 0;
    }
    
    /**
     * Starts the profiling.
     */
    public function enter() : void {
        $this->starts = [
            'wt' => microtime(true),
            'mu' => memory_get_usage(),
            'pmu' => memory_get_peak_usage(),
        ];
    }
    
    /**
     * Stops the profiling.
     */
    public function leave() : void {
        $this->ends = [
            'wt' => microtime(true),
            'mu' => memory_get_usage(),
            'pmu' => memory_get_peak_usage(),
        ];
    }
    public function reset() : void {
        $this->starts = $this->ends = $this->profiles = [];
        $this->enter();
    }
    public function getIterator() : \Traversable {
        return new \ArrayIterator($this->profiles);
    }
    public function serialize() : string {
        return serialize($this->__serialize());
    }
    public function unserialize($data) : void {
        $this->__unserialize(unserialize($data));
    }
    
    /**
     * @internal
     */
    public function __serialize() : array {
        return [
            $this->template,
            $this->name,
            $this->type,
            $this->starts,
            $this->ends,
            $this->profiles,
        ];
    }
    
    /**
     * @internal
     */
    public function __unserialize(array $data) : void {
        [
            $this->template,
            $this->name,
            $this->type,
            $this->starts,
            $this->ends,
            $this->profiles,
        ] = $data;
    }

}