#!/usr/bin/env python3
"""
先来先服务调度算法 (FCFS)
First Come First Served
"""

from typing import List, Dict

from base import (
    Process,
    ProcessScheduler,
    generate_random_processes,
    print_processes
)


class FCFSScheduler(ProcessScheduler):
    """先来先服务调度 (First Come First Served)"""
    
    def schedule(self) -> Dict:
        """FCFS 调度算法"""
        # 按到达时间排序
        ready_queue = sorted(self.processes, key=lambda p: (p.arrival_time, p.pid))
        
        current_time = 0
        for p in ready_queue:
            if p.arrival_time > current_time:
                current_time = p.arrival_time
            
            p.start_time = current_time
            current_time += p.burst_time
            self.calculate_metrics(p, current_time)
            self.results.append(p)
        
        return self.print_results("FCFS (先来先服务)")


if __name__ == "__main__":
    processes = generate_random_processes(n=5, seed=42)
    print_processes(processes, "测试数据")
    
    scheduler = FCFSScheduler(processes)
    scheduler.schedule()