package main

import (
    "fmt"
    "net/http"
    "os"
    "strconv"
    //"math"
    "time"
    "github.com/gorilla/mux"
)

func Async(url string, count int) <-chan int {
    c := make(chan int)
    go func() {
        cnt := 0
        for i := 0; i < count; i++ {
            GetPage(url)
            cnt = cnt + 1
            if (cnt == 50) {
                c <- i
                cnt = 0
            }
        }
    }()
    return c
}

func CallSync(w http.ResponseWriter, r *http.Request) {
    t0 := time.Now()
    c1 := Async("http://localhost:8080/", 2000)
    c2 := Async("http://localhost:8080/", 2000)
    c3 := Async("http://localhost:8080/", 2000)
    c4 := Async("http://localhost:8080/", 2000)
    c5 := Async("http://localhost:8080/", 2000)
    c6 := Async("http://localhost:8080/", 2000)
    c7 := Async("http://localhost:8080/", 2000)
    c8 := Async("http://localhost:8080/", 2000)
    c9 := Async("http://localhost:8080/", 2000)
    c10 := Async("http://localhost:8080/", 2000)
    c11 := Async("http://localhost:8080/", 2000)
    c12 := Async("http://localhost:8080/", 2000)
    c13 := Async("http://localhost:8080/", 2000)
    c14 := Async("http://localhost:8080/", 2000)
    c15 := Async("http://localhost:8080/", 2000)
    c16 := Async("http://localhost:8080/", 2000)
    c17 := Async("http://localhost:8080/", 2000)
    c18 := Async("http://localhost:8080/", 2000)
    c19 := Async("http://localhost:8080/", 2000)
    c20 := Async("http://localhost:8080/", 2000)
    count := 0
    for count < 4000 {
        select {
            case v1 := <-c1:
                count = count + 50
                fmt.Printf("%v c1\n", v1)
            case v2 := <-c2:
                count = count + 50
                fmt.Printf("%v c2\n", v2)
            case v3 := <-c3:
                count = count + 50
                fmt.Printf("%v c3\n", v3)
            case v4 := <-c4:
                count = count + 50
                fmt.Printf("%v c4\n", v4)
            case v5 := <-c5:
                count = count + 50
                fmt.Printf("%v c5\n", v5)
            case v6 := <-c6:
                count = count + 50
                fmt.Printf("%v c6\n", v6)
            case v7 := <-c7:
                count = count + 50
                fmt.Printf("%v c7\n", v7)
            case v8 := <-c8:
                count = count + 50
                fmt.Printf("%v c8\n", v8)
            case v9 := <-c9:
                count = count + 50
                fmt.Printf("%v c9\n", v9)
            case v10 := <-c10:
                count = count + 50
                fmt.Printf("%v c10\n", v10)
            case v11 := <-c11:
                count = count + 50
                fmt.Printf("%v c11\n", v11)
            case v12 := <-c12:
                count = count + 50
                fmt.Printf("%v c12\n", v12)
            case v13 := <-c13:
                count = count + 50
                fmt.Printf("%v c13\n", v13)
            case v14 := <-c14:
                count = count + 50
                fmt.Printf("%v c14\n", v14)
            case v15 := <-c15:
                count = count + 50
                fmt.Printf("%v c15\n", v15)
            case v16 := <-c16:
                count = count + 50
                fmt.Printf("%v c16\n", v16)
            case v17 := <-c17:
                count = count + 50
                fmt.Printf("%v c17\n", v17)
            case v18 := <-c18:
                count = count + 50
                fmt.Printf("%v c18\n", v18)
            case v19 := <-c19:
                count = count + 50
                fmt.Printf("%v c19\n", v19)
            case v20 := <-c20:
                count = count + 50
                fmt.Printf("%v c20\n", v20)
            default:
        }
    }
    t1 := time.Now()
    diff := t1.Sub(t0)
    num := diff.Nanoseconds() / int64(time.Millisecond)
    msec := float64(num) / 1000
    reqsec := float64(count) / msec
    fmt.Fprintf(w, "%v requests\n", count)
    fmt.Fprintf(w, "Performed in %v\n", diff)
    fmt.Fprintf(w, "At a rate of %v (requests/sec)\n", reqsec)
}

func GetPage(page string) {
    resp, err := http.Get(page)
    if err != nil {
    }
    defer resp.Body.Close()
}

func main() {
    addr := ":81"
    pid := os.Getpid()
    fmt.Println("Starting Server....")
    fmt.Println("addr= " + addr)
    fmt.Println("pid= " + strconv.Itoa(pid))
    r := mux.NewRouter()
    r.HandleFunc("/", CallSync)
    http.Handle("/", r)
    fmt.Println(http.ListenAndServe(addr, nil))
    fmt.Println("Bye")
}