package nftables

import (
	"strings"
	"testing"
)

func TestNewManager_DefaultPath(t *testing.T) {
	m := NewManager("")
	if m.GetRulesPath() != defaultRulesPath {
		t.Errorf("got %q, want %q", m.GetRulesPath(), defaultRulesPath)
	}
}

func TestNewManager_CustomPath(t *testing.T) {
	m := NewManager("/tmp/wild-central.nft")
	if m.GetRulesPath() != "/tmp/wild-central.nft" {
		t.Errorf("got %q, want /tmp/wild-central.nft", m.GetRulesPath())
	}
}

func TestPortsToStr(t *testing.T) {
	cases := []struct {
		ports []int
		want  string
	}{
		{[]int{80, 443, 8404}, "80, 443, 8404"},
		{[]int{443}, "443"},
		{[]int{}, ""},
	}
	for _, c := range cases {
		if got := portsToStr(c.ports); got != c.want {
			t.Errorf("portsToStr(%v) = %q, want %q", c.ports, got, c.want)
		}
	}
}

func TestGenerate_AlwaysIncludesStructure(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{80, 443}, nil, nil, "")

	for _, want := range []string{
		"table inet wild-central",
		"set allowed_tcp_ports",
		"chain input",
		"type filter hook input priority filter; policy accept;",
		"iif \"lo\" accept",
		"ct state { established, related } accept",
	} {
		if !strings.Contains(out, want) {
			t.Errorf("expected %q in output, got:\n%s", want, out)
		}
	}
}

func TestGenerate_WithPorts_IncludesElements(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{80, 443, 8404}, nil, nil, "")

	if !strings.Contains(out, "elements = { 80, 443, 8404 }") {
		t.Errorf("expected elements line with ports, got:\n%s", out)
	}
}

func TestGenerate_NoPorts_TCPSetHasNoElements(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{}, nil, nil, "")

	// TCP set should have no elements when no ports given
	if strings.Contains(out, "allowed_tcp_ports") && strings.Contains(out, "elements") {
		// Check that the elements line is not inside the TCP block
		tcpBlock := out[strings.Index(out, "set allowed_tcp_ports"):]
		tcpBlock = tcpBlock[:strings.Index(tcpBlock, "}")+1]
		if strings.Contains(tcpBlock, "elements") {
			t.Errorf("expected no elements in allowed_tcp_ports block when no ports, got:\n%s", tcpBlock)
		}
	}
	// UDP set always has DNS/DHCP elements
	if !strings.Contains(out, "53, 67, 68") {
		t.Errorf("expected DNS/DHCP elements in allowed_udp_ports even with no TCP ports, got:\n%s", out)
	}
}

func TestGenerate_ExtraPortsMerged(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{80, 443}, []int{22, 443}, nil, "") // 443 deduplicated

	if !strings.Contains(out, "22") {
		t.Errorf("expected extra port 22 in output, got:\n%s", out)
	}
	// 443 should appear only once
	count := strings.Count(out, "443")
	if count != 1 {
		t.Errorf("expected 443 exactly once, got %d times in:\n%s", count, out)
	}
}

func TestGenerate_NoWANInterface_NoDropRules(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{80, 443}, nil, nil, "")

	if strings.Contains(out, "drop") {
		t.Errorf("expected no drop rules without WAN interface, got:\n%s", out)
	}
}

func TestGenerate_WithWANInterface_IncludesDropRules(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{80, 443}, nil, nil, "eth0")

	if !strings.Contains(out, `iif "eth0"`) {
		t.Errorf("expected WAN interface in rules, got:\n%s", out)
	}
	if !strings.Contains(out, "drop") {
		t.Errorf("expected drop rule with WAN interface, got:\n%s", out)
	}
	if !strings.Contains(out, "@allowed_tcp_ports") {
		t.Errorf("expected reference to allowed_tcp_ports set, got:\n%s", out)
	}
	if !strings.Contains(out, "@allowed_udp_ports") {
		t.Errorf("expected reference to allowed_udp_ports set, got:\n%s", out)
	}
	// DNS and DHCP UDP ports should be in the allowed_udp_ports set
	if !strings.Contains(out, "53, 67, 68") {
		t.Errorf("expected DNS/DHCP UDP ports in allowed_udp_ports set, got:\n%s", out)
	}
}

func TestGenerate_AlwaysIncludesUDPSet(t *testing.T) {
	m := NewManager("")
	// No WAN interface — permissive mode, but UDP set should still be visible
	out := m.Generate([]int{80, 443}, nil, []int{51820}, "")

	if !strings.Contains(out, "set allowed_udp_ports") {
		t.Errorf("expected allowed_udp_ports set even without WAN interface, got:\n%s", out)
	}
	if !strings.Contains(out, "51820") {
		t.Errorf("expected extra UDP port 51820 in allowed_udp_ports set, got:\n%s", out)
	}
	// No drop rules without WAN interface
	if strings.Contains(out, "drop") {
		t.Errorf("expected no drop rules without WAN interface, got:\n%s", out)
	}
}

func TestGenerate_ExtraUDPPorts(t *testing.T) {
	m := NewManager("")
	out := m.Generate([]int{80, 443}, nil, []int{5353}, "eth0")

	// User UDP port should appear in the UDP exception list
	if !strings.Contains(out, "5353") {
		t.Errorf("expected extra UDP port 5353 in output, got:\n%s", out)
	}
	// Hardcoded DNS/DHCP should still be there
	if !strings.Contains(out, "53, 67, 68") {
		t.Errorf("expected DNS/DHCP UDP ports still present, got:\n%s", out)
	}
}