package importer

import (
	"os"
	"os/exec"
	"strings"
	"testing"

	"housecarl/internal/model"
	"housecarl/internal/render"
	"housecarl/internal/validate"
)

// The maintainer's router ruleset (testdata/router.nft), as nft 1.1.3
// lists it in JSON (router.json) and text (router.txt).
func importRouter(t *testing.T) *Result {
	t.Helper()
	js, _ := os.ReadFile("testdata/router.json")
	txt, _ := os.ReadFile("testdata/router.txt")
	defs, _ := os.ReadFile("testdata/router.nft")
	res, err := Import(Input{JSON: js, Text: string(txt), Defines: string(defs)})
	if err != nil {
		t.Fatal(err)
	}
	return res
}

func TestImportRouter(t *testing.T) {
	res := importRouter(t)
	st := res.State
	for _, n := range res.Notes {
		t.Log("note:", n)
	}
	for _, r := range res.Raw {
		t.Log("raw:", r)
	}
	// Zones, named by the defines; wan is external.
	wan := st.Zone("wan")
	if wan == nil || !wan.External || wan.Interfaces[0] != "wan" {
		t.Errorf("zone wan: %+v", wan)
	}
	if z := st.Zone("dhcp"); z == nil || z.Interfaces[0] != "enp2s0" {
		t.Errorf("zone dhcp: %+v (zones %+v)", z, st.Zones)
	}
	// Sets named by the defines.
	if s := st.Set("trusted_ips"); s == nil || len(s.Entries) != 7 {
		t.Errorf("set trusted_ips: %+v", s)
	}
	if s := st.Set("masq_to_internet"); s == nil {
		t.Errorf("no set masq_to_internet (sets %v)", setNames(st))
	}
	// Built-ins: the ones at the head of their chains.
	b := st.Settings.Builtins
	if !b.Loopback || !b.Established || !b.ICMPv6 || !b.PingInternal || !b.DHCPv6Client || !b.MSSClamp || !b.Antispoof {
		t.Errorf("built-ins %+v", b)
	}
	// The forward chain's asymmetric-routing rule sits between the
	// established and invalid rules: invalid stays rules, in order.
	if b.DropInvalid {
		t.Error("drop_invalid became a built-in, which would put it before the asymmetric-routing rule")
	}
	var fwd []string
	for _, r := range st.Rules {
		if r.Chain == model.ChainForward {
			fwd = append(fwd, r.Comment+"|"+strings.Join(r.CtState, ","))
		}
	}
	if len(fwd) < 2 || fwd[0] != "Needed due to asymmetric routing (internal only)|invalid" || fwd[1] != "|invalid" {
		t.Errorf("forward rules start %q", fwd)
	}
	if st.Settings.OwnPrefixes[0] != "2a02:8013:7f3d::/48" || len(st.Settings.AntispoofV4) != 6 {
		t.Errorf("antispoof %+v %+v", st.Settings.OwnPrefixes, st.Settings.AntispoofV4)
	}
	// Port forwards with their hairpin; the forward-chain accepts are
	// folded in.
	if len(st.Forwards) != 5 {
		t.Fatalf("forwards %+v", st.Forwards)
	}
	jf := st.Forwards[0]
	if jf.Name != "jellyfin" || jf.Ports != "8096" || jf.To != "10.0.10.57" || jf.ToPort != "443" || jf.PublicAddresses[0] != "217.155.8.194" ||
		!jf.Hairpin || jf.HairpinSources[0] != "internal_net" {
		t.Errorf("jellyfin %+v", jf)
	}
	for _, r := range st.Rules {
		if r.Chain == model.ChainForward && strings.Contains(r.Comment, "Forward") && len(r.CtStatus) > 0 {
			t.Errorf("forward accept not folded in: %+v", r)
		}
	}
	// Source NAT: the masquerades.
	if len(st.SNATs) != 2 || st.SNATs[0].OutZones[0] != "wan" || st.SNATs[0].Sources[0] != "masq_to_internet" ||
		!st.SNATs[1].NotOut || st.SNATs[1].OutZones[0] != "wg0" {
		t.Errorf("snats %+v %+v", st.SNATs[0], st.SNATs[1])
	}
	// The jump to wg0_input is inlined: its rules carry the source.
	var wgDNS bool
	for _, r := range st.Rules {
		if r.Chain == model.ChainInput && len(r.Sources) == 1 && r.Sources[0] == "wg0_net" && strings.Join(r.Services, ",") == "udp/53" {
			wgDNS = true
		}
	}
	if !wgDNS {
		t.Errorf("wg0_input not inlined")
	}
	// The jump's and the rule's sources both: the rule's are kept, noted.
	if !strings.Contains(strings.Join(res.Notes, "\n"), "the rule's own (10.50.50.3, 10.50.50.6) are kept") {
		t.Errorf("no note on the overlapping sources: %q", res.Notes)
	}
	// The imported configuration is valid, and renders.
	if ps := validate.Check(st, nil); validate.HasErrors(ps) {
		t.Errorf("problems: %+v", validate.Errors(ps))
	}
	text := render.Render(st, render.Options{}).Text
	for _, want := range []string{
		`ip daddr 217.155.8.194 tcp dport 8096 counter dnat ip to 10.0.10.57:443`,
		`ip saddr @internal_net_v4 ip daddr 10.0.10.57 tcp dport 443 ct status dnat counter masquerade`,
		`oifname "wan" ip saddr @masq_to_internet_v4 counter masquerade`,
		`oifname "wan" tcp flags syn tcp option maxseg size set rt mtu`,
		`ip saddr @trusted_ips_v4 tcp dport 8053 counter accept comment "hc:r`,
	} {
		if !strings.Contains(text, want) {
			t.Errorf("render: missing %q", want)
		}
	}
	if t.Failed() {
		t.Log(text)
	}
}

func setNames(st *model.State) []string {
	var out []string
	for _, s := range st.Sets {
		out = append(out, s.Name)
	}
	return out
}

func TestImportNeedsATable(t *testing.T) {
	js := []byte(`{"nftables":[{"table":{"family":"inet","name":"main"}},{"table":{"family":"ip","name":"nat"}}]}`)
	if _, err := Import(Input{JSON: js}); err == nil || !strings.Contains(err.Error(), "several tables") {
		t.Errorf("several tables: %v", err)
	}
	if _, err := Import(Input{JSON: js, Table: "ip nat"}); err != nil {
		t.Errorf("--table: %v", err)
	}
}

func TestForwardNames(t *testing.T) {
	im := &importer{st: &model.State{}}
	for _, c := range []string{"Port forward: Jellyfin", "8096 to media", "web", "web", "-"} {
		im.st.Forwards = append(im.st.Forwards, &model.PortForward{Name: forwardName(c)})
	}
	im.nameForwards()
	var got []string
	for _, f := range im.st.Forwards {
		got = append(got, f.Name)
	}
	if want := "jellyfin fwd-8096-to-media web web-2 "; strings.Join(got, " ") != want {
		t.Errorf("names %q, want %q", strings.Join(got, " "), want)
	}
}

// TestImportedRulesetPassesNft: the ruleset rendered from the import is
// accepted by the real nft (HOUSECARL_NFT, as in internal/render).
func TestImportedRulesetPassesNft(t *testing.T) {
	cmd := strings.Fields(os.Getenv("HOUSECARL_NFT"))
	if len(cmd) == 0 {
		t.Skip("HOUSECARL_NFT not set")
	}
	rs := render.Render(importRouter(t).State, render.Options{})
	c := exec.Command(cmd[0], append(cmd[1:], "-c", "-f", "/dev/stdin")...)
	c.Stdin = strings.NewReader(rs.Text)
	if out, err := c.CombinedOutput(); err != nil {
		t.Errorf("nft -c: %v\n%s", err, out)
	}
}