package main

import (
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"strconv"
)

type SimRequest struct {
	Algorithm string      `json:"algorithm"`
	TimeSlice int         `json:"timeSlice"`
	Processes []ProcInput `json:"processes"`
}

type ProcInput struct {
	Name        string `json:"name"`
	Priority    int    `json:"priority"`
	ArrivalTime int    `json:"arrivalTime"`
	NeedTime    int    `json:"needTime"`
}

func main() {
	port := "8080"
	if len(os.Args) > 1 {
		p, err := strconv.Atoi(os.Args[1])
		if err == nil && p > 0 && p < 65536 {
			port = os.Args[1]
		}
	}

	fs := http.FileServer(http.Dir("./static"))
	http.Handle("/", fs)

	http.HandleFunc("/api/simulate", handleSimulate)

	fmt.Printf("进程调度模拟器已启动: http://localhost:%s\n", port)
	if err := http.ListenAndServe(":"+port, nil); err != nil {
		fmt.Fprintf(os.Stderr, "服务器启动失败: %v\n", err)
		os.Exit(1)
	}
}

func handleSimulate(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}

	var req SimRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request: "+err.Error(), http.StatusBadRequest)
		return
	}

	procs := make([]*PCB, len(req.Processes))
	for i, p := range req.Processes {
		procs[i] = NewPCB(p.Name, p.Priority, p.ArrivalTime, p.NeedTime)
	}

	var result SimResult
	if req.Algorithm == "mlfq" {
		ts := [3]int{1, 2, 4}
		if req.TimeSlice > 0 {
			ts[0] = req.TimeSlice
			ts[1] = req.TimeSlice * 2
			ts[2] = req.TimeSlice * 4
		}
		result = SimulateMLFQ(procs, ts)
	} else {
		ts := 2
		if req.TimeSlice > 0 {
			ts = req.TimeSlice
		}
		result = SimulatePriorityRR(procs, ts)
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(result)
}