package main

import (
	"encoding/json"
	"io"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"
)

func TestReadHostPubLine(t *testing.T) {
	dir := t.TempDir()
	p := dir + "/k.pub"
	if err := writeFileAtomic(p, []byte("ecdsa-sha2-nistp256 AAAAB3Nz root@fleet\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	line, err := readHostPubLine(p)
	if err != nil {
		t.Fatal(err)
	}
	if line != "ecdsa-sha2-nistp256 AAAAB3Nz root@fleet" {
		t.Errorf("got %q", line)
	}
	if err := writeFileAtomic(p, []byte("garbage\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if _, err := readHostPubLine(p); err == nil {
		t.Error("expected error on malformed key")
	}
}

func TestSplitPrincipals(t *testing.T) {
	got := splitPrincipals(" a, b ,,c ")
	if len(got) != 3 || got[0] != "a" || got[1] != "b" || got[2] != "c" {
		t.Errorf("got %v", got)
	}
	if len(splitPrincipals("")) != 0 {
		t.Error("empty string should yield no principals")
	}
}

func TestDhcpDomain(t *testing.T) {
	dir := t.TempDir()
	rc := dir + "/resolv.conf"
	old := resolvConf
	resolvConf = rc
	defer func() { resolvConf = old }()

	if err := os.WriteFile(rc, []byte("domain corp.example\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if d := dhcpDomain(); d != "corp.example" {
		t.Errorf("domain line: got %q", d)
	}
	if err := os.WriteFile(rc, []byte("nameserver 1.1.1.1\nsearch a.lab b.lab\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if d := dhcpDomain(); d != "a.lab" {
		t.Errorf("search line: got %q", d)
	}
	os.Remove(rc)
	if d := dhcpDomain(); d != "" {
		t.Errorf("missing file: got %q", d)
	}
}

func TestDefaultPrincipalsFQDN(t *testing.T) {
	h, _ := os.Hostname()
	if h == "" || strings.Contains(h, ".") {
		t.Skip("host name unsuitable for this test")
	}
	dir := t.TempDir()
	rc := dir + "/resolv.conf"
	if err := os.WriteFile(rc, []byte("nameserver 10.0.0.1\nsearch fleet.lab example.org\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	old := resolvConf
	resolvConf = rc
	defer func() { resolvConf = old }()

	got := defaultPrincipals()
	if len(got) != 2 || got[0] != h || got[1] != h+".fleet.lab" {
		t.Errorf("defaultPrincipals = %v, want [%s %s.fleet.lab]", got, h, h)
	}
}

func TestAppendUnique(t *testing.T) {
	got := appendUnique([]string{"a", "b"}, "b", "c", "", "a", "d")
	want := []string{"a", "b", "c", "d"}
	if len(got) != len(want) {
		t.Fatalf("got %v want %v", got, want)
	}
	for i := range want {
		if got[i] != want[i] {
			t.Fatalf("got %v want %v", got, want)
		}
	}
}

func TestParseHandle(t *testing.T) {
	h, err := parseHandle("0x81000100")
	if err != nil || uint32(h) != 0x81000100 {
		t.Fatalf("h=%#x err=%v", uint32(h), err)
	}
	if _, err := parseHandle("nothex"); err == nil {
		t.Error("expected error")
	}
}

func TestRequestHostCert(t *testing.T) {
	const certLine = "ecdsa-sha2-nistp256-cert-v01@openssh.com AAAAcert host.fleet.lab"
	var gotReq hostCertRequest
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		defer r.Body.Close()
		raw, _ := io.ReadAll(r.Body)
		_ = json.Unmarshal(raw, &gotReq)
		writeJSON(w, http.StatusOK, hostCertResponse{Cert: certLine})
	}))
	defer srv.Close()

	got, err := requestHostCert(srv.Client(), srv.URL, "ecdsa-sha2-nistp256 AAAA host", []string{"host", "host.fleet.lab"}, "host.fleet.lab")
	if err != nil {
		t.Fatalf("requestHostCert: %v", err)
	}
	if got != certLine {
		t.Errorf("cert = %q", got)
	}
	if gotReq.PublicKey != "ecdsa-sha2-nistp256 AAAA host" || gotReq.KeyID != "host.fleet.lab" || len(gotReq.Principals) != 2 {
		t.Errorf("broker received unexpected request: %+v", gotReq)
	}
}

func TestRequestHostCertErrorBody(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		writeJSON(w, http.StatusForbidden, hostCertResponse{Error: "not enrolled"})
	}))
	defer srv.Close()
	if _, err := requestHostCert(srv.Client(), srv.URL, "ecdsa-sha2-nistp256 AAAA host", []string{"host"}, "host"); err == nil || !strings.Contains(err.Error(), "not enrolled") {
		t.Errorf("want error carrying broker message, got %v", err)
	}
}

// writeJSON mirrors the broker's small JSON helper for the test server.
func writeJSON(w http.ResponseWriter, code int, v any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(code)
	_ = json.NewEncoder(w).Encode(v)
}