package main

import (
	"fmt"
	"runtime"
	"testing"
)

func TestPingDeviceLocalhost(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping ping test on windows")
	}
	ms, err := pingDevice("127.0.0.1", 5000)
	if err != nil {
		t.Skipf("ping not available: %v", err)
	}
	if ms <= 0 {
		t.Errorf("expected positive response time, got %v", ms)
	}
}

func TestPingDeviceInvalidIP(t *testing.T) {
	_, err := pingDevice("not-an-ip", 5000)
	if err == nil {
		t.Error("expected error for invalid IP")
	}
}

func TestPingDeviceIPv6(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("skipping ping test on windows")
	}
	ms, err := pingDevice("::1", 5000)
	if err != nil {
		t.Skipf("IPv6 not available: %v", err)
	}
	if ms <= 0 {
		t.Errorf("expected positive response time, got %v", ms)
	}
}

func TestIcmpPingLocalhost(t *testing.T) {
	ms, err := icmpPing("127.0.0.1", 5000)
	if err != nil {
		t.Skipf("ICMP not available: %v", err)
	}
	if ms <= 0 {
		t.Errorf("expected positive response time, got %v", ms)
	}
}

func TestIcmpPingIPv6(t *testing.T) {
	ms, err := icmpPing("::1", 5000)
	if err != nil {
		t.Skipf("IPv6 ICMP not available: %v", err)
	}
	if ms <= 0 {
		t.Errorf("expected positive response time, got %v", ms)
	}
}

func TestIcmpPingInvalidIP(t *testing.T) {
	_, err := icmpPing("not-an-ip", 5000)
	if err == nil {
		t.Error("expected error for invalid IP")
	}
}

func TestErrICMPUnavailableError(t *testing.T) {
	err := &errICMPUnavailable{err: fmt.Errorf("permission denied")}
	if err.Error() != "permission denied" {
		t.Errorf("got %q, want %q", err.Error(), "permission denied")
	}
}

func TestParsePingTime(t *testing.T) {
	tests := []struct {
		name    string
		output  string
		want    float64
		wantErr bool
	}{
		{
			name:   "standard linux",
			output: "64 bytes from 8.8.8.8: icmp_seq=1 ttl=118 time=12.3 ms",
			want:   12.3,
		},
		{
			name:   "localhost",
			output: "64 bytes from localhost: icmp_seq=1 ttl=64 time=0.123 ms",
			want:   0.123,
		},
		{
			name:   "multiline",
			output: "PING 8.8.8.8 (8.8.8.8): 56 data bytes\n64 bytes from 8.8.8.8: icmp_seq=0 ttl=118 time=15.7 ms\n--- 8.8.8.8 ping statistics ---",
			want:   15.7,
		},
		{
			name:    "no time field",
			output:  "Request timeout for icmp_seq 0",
			wantErr: true,
		},
		{
			name:    "empty",
			output:  "",
			wantErr: true,
		},
		{
			name:   "time= without ms suffix",
			output: "64 bytes from 10.0.0.1: icmp_seq=1 ttl=64 time=1.234\n",
			want:   1.234,
		},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := parsePingTime(tt.output)
			if tt.wantErr {
				if err == nil {
					t.Errorf("expected error, got %v", got)
				}
				return
			}
			if err != nil {
				t.Errorf("unexpected error: %v", err)
				return
			}
			if got != tt.want {
				t.Errorf("got %v, want %v", got, tt.want)
			}
		})
	}
}