#pragma once
#include <queue>
#include <stdexcept>
#include <vector>
#include "WorkItem.h"

struct WorkItemComparator {
    bool operator()(const WorkItem& a, const WorkItem& b) const {
        return a.priority < b.priority; // max-heap: higher priority first
    }
};

class PriorityQueue {
public:
    void enqueue(WorkItem item) {
        heap_.push(std::move(item));
    }

    WorkItem dequeue() {
        if (heap_.empty()) throw std::underflow_error("queue is empty");
        WorkItem top = heap_.top();
        heap_.pop();
        return top;
    }

    const WorkItem& peek() const {
        if (heap_.empty()) throw std::underflow_error("queue is empty");
        return heap_.top();
    }

    std::size_t size() const { return heap_.size(); }
    bool empty() const { return heap_.empty(); }

private:
    std::priority_queue<WorkItem, std::vector<WorkItem>, WorkItemComparator> heap_;
};