package tciserver

import (
	"fmt"
	"strings"
	"testing"
)

// fakeRig is a radio that remembers what it was told. Everything here is about
// what OpsLog does with a client's command, so the rig only has to answer and
// record.
type fakeRig struct {
	freq, rxFreq int64
	mode         string
	split        bool
	txHz         int64
	ptt          bool
	splitErr     error
	calls        []string
}

func (r *fakeRig) Freq() int64          { return r.freq }
func (r *fakeRig) RxFreq() int64        { return r.rxFreq }
func (r *fakeRig) Mode() string         { return r.mode }
func (r *fakeRig) Split() (bool, int64) { return r.split, r.txHz }
func (r *fakeRig) SetFreq(hz int64) error {
	r.calls = append(r.calls, fmt.Sprintf("freq=%d", hz))
	r.freq, r.rxFreq = hz, hz
	return nil
}
func (r *fakeRig) SetMode(m string) error {
	r.calls = append(r.calls, "mode="+m)
	r.mode = m
	return nil
}
func (r *fakeRig) SetPTT(on bool) error {
	r.calls = append(r.calls, fmt.Sprintf("ptt=%v", on))
	r.ptt = on
	return nil
}
func (r *fakeRig) SetSplit(on bool, txHz int64) error {
	if r.splitErr != nil {
		return r.splitErr
	}
	r.calls = append(r.calls, fmt.Sprintf("split=%v,%d", on, txHz))
	r.split, r.txHz = on, txHz
	return nil
}

// srv builds a server with no listener — handle() and publish() are the whole
// protocol, and neither needs a socket.
func srv(r *fakeRig) *Server { return New(0, r, nil) }

// A client with no connection: send() would need one, so reads are checked
// through the returned line instead. This is why handle returns what it sent.
func ask(t *testing.T, s *Server, cmd string) string {
	t.Helper()
	return s.handle(&client{}, cmd)
}

// The initialisation block is what a client needs before it will believe there
// is a radio at all. Its contents come from §4.1 of the protocol document, and
// a client that does not see ready; simply waits for ever.
func TestInitBlockCarriesTheDocumentedInitialisationSet(t *testing.T) {
	s := srv(&fakeRig{freq: 14074000, rxFreq: 14074000, mode: "USB"})
	block := strings.Join(s.initBlock(), "")
	for _, want := range []string{
		"protocol:ExpertSDR3,", "device:", "receive_only:false;", "trx_count:1;",
		"channel_count:2;", "vfo_limits:", "if_limits:", "modulations_list:",
		"ready;", "start;",
	} {
		if !strings.Contains(block, want) {
			t.Errorf("the initialisation block is missing %q — a client would not proceed past connect", want)
		}
	}
	// And the current state, so a client that connects mid-session shows the
	// right frequency instead of waiting for the operator to touch something.
	if !strings.Contains(block, "vfo:0,0,14074000;") {
		t.Errorf("no current frequency in the block:\n%s", block)
	}
	if !strings.Contains(block, "modulation:0,usb;") {
		t.Errorf("no current mode in the block:\n%s", block)
	}
}

// Channel A is where we LISTEN, channel B where we transmit. Handing these to a
// client the wrong way round is the one mistake here that puts a station on the
// DX's own frequency, so it is pinned in both directions.
func TestSplitPutsTheListeningFrequencyOnChannelA(t *testing.T) {
	// OpsLog's RigState is ADIF: Freq is the TRANSMIT frequency, RxFreq where we
	// listen. A DX transmitting on 14025 and listening up 2.
	r := &fakeRig{freq: 14027000, rxFreq: 14025000, mode: "CW", split: true, txHz: 14027000}
	s := srv(r)
	block := strings.Join(s.initBlock(), "")
	if !strings.Contains(block, "vfo:0,0,14025000;") {
		t.Errorf("channel A is not the receive frequency:\n%s", block)
	}
	if !strings.Contains(block, "vfo:0,1,14027000;") {
		t.Errorf("channel B is not the transmit frequency:\n%s", block)
	}
	if !strings.Contains(block, "split_enable:0,true;") {
		t.Errorf("split was not announced:\n%s", block)
	}
}

// Simplex: both channels report the one frequency, so a client reading either
// gets the right answer.
func TestSimplexReportsTheSameFrequencyOnBothChannels(t *testing.T) {
	s := srv(&fakeRig{freq: 7100000, rxFreq: 7100000, mode: "SSB"})
	if got := ask(t, s, "vfo:0,0"); got != "vfo:0,0,7100000;" {
		t.Errorf("read of channel A = %q", got)
	}
	if got := ask(t, s, "vfo:0,1"); got != "vfo:0,1,7100000;" {
		t.Errorf("read of channel B = %q", got)
	}
	// 7 MHz is below 10, so SSB is lower sideband — a client told "ssb" would
	// not recognise it at all, the modulation list is the vocabulary.
	if got := ask(t, s, "modulation:0"); got != "modulation:0,lsb;" {
		t.Errorf("read of the mode = %q, want lsb below 10 MHz", got)
	}
}

// The client tunes the radio.
func TestAClientCanTuneAndSetModeAndKey(t *testing.T) {
	r := &fakeRig{freq: 14074000, rxFreq: 14074000, mode: "USB"}
	s := srv(r)
	ask(t, s, "vfo:0,0,14200000")
	ask(t, s, "modulation:0,cw")
	ask(t, s, "trx:0,true")
	ask(t, s, "trx:0,false")
	want := []string{"freq=14200000", "mode=CW", "ptt=true", "ptt=false"}
	if strings.Join(r.calls, " ") != strings.Join(want, " ") {
		t.Errorf("the radio was told %v, want %v", r.calls, want)
	}
}

// Channel B is the SPLIT transmit frequency. Writing it while the rig is
// simplex must not move the only VFO there is: the client asked to prepare a
// transmit frequency, not to QSY — and a logger that did this on every spot
// click would drag the operator off the station they were listening to.
func TestWritingChannelBWhileSimplexLeavesTheRigAlone(t *testing.T) {
	r := &fakeRig{freq: 14074000, rxFreq: 14074000, mode: "USB"}
	s := srv(r)
	ask(t, s, "vfo:0,1,14080000")
	if len(r.calls) != 0 {
		t.Errorf("the radio was told %v — a split TX frequency moved a simplex rig", r.calls)
	}
	// With split armed it means what it says.
	r.split, r.txHz = true, 14074000
	ask(t, s, "vfo:0,1,14080000")
	if len(r.calls) != 1 || r.calls[0] != "split=true,14080000" {
		t.Errorf("with split on the radio was told %v, want the new transmit frequency", r.calls)
	}
}

// A backend that cannot split says so, and the refusal must not be dressed up
// as success: the client can then tell the operator to use Fake It, where
// before it would transmit on the receive frequency believing all was well.
func TestARefusedSplitIsNotAnnouncedAsDone(t *testing.T) {
	r := &fakeRig{freq: 14025000, rxFreq: 14025000, mode: "CW", splitErr: fmt.Errorf("this backend cannot split")}
	s := srv(r)
	if got := ask(t, s, "split_enable:0,true"); got != "" {
		t.Errorf("a refused split answered %q", got)
	}
	if r.split {
		t.Error("the rig was recorded as split after the backend refused")
	}
}

// Only what moved is sent. TCI clients redraw on every command they receive, so
// re-sending an unchanged frequency four times a second makes a VFO readout
// flicker and, in some clients, fights the operator's own tuning.
func TestOnlyChangesAreSent(t *testing.T) {
	r := &fakeRig{freq: 14074000, rxFreq: 14074000, mode: "USB"}
	s := srv(r)

	first := s.publish()
	if len(first) == 0 {
		t.Fatal("the first pass sent nothing — a client would never learn the state")
	}
	if got := s.publish(); len(got) != 0 {
		t.Errorf("an unchanged radio produced %v", got)
	}

	r.freq, r.rxFreq = 14200000, 14200000
	got := s.publish()
	if len(got) != 2 || !strings.Contains(strings.Join(got, ""), "14200000") {
		// Both channels move together on a simplex rig, and both are reported.
		t.Errorf("after a QSY: %v", got)
	}
	if got := s.publish(); len(got) != 0 {
		t.Errorf("the QSY was re-sent: %v", got)
	}
}

// Modes travel both ways, and the data family is the interesting half: a client
// switching to "digital" must not overwrite the mode the operator chose in
// OpsLog with a guess at which data mode it was.
func TestModeMapping(t *testing.T) {
	up := []struct {
		adif string
		hz   int64
		want string
	}{
		{"CW", 14025000, "cw"},
		{"SSB", 14200000, "usb"},
		{"SSB", 7100000, "lsb"},
		{"USB", 7100000, "usb"}, // an explicit sideband is never second-guessed
		{"FT8", 14074000, "digu"},
		{"RTTY", 14080000, "digl"},
		{"AM", 3700000, "am"},
		{"FM", 145500000, "nfm"},
		{"", 14074000, ""},
	}
	for _, c := range up {
		if got := adifToTCIMode(c.adif, c.hz); got != c.want {
			t.Errorf("adifToTCIMode(%q, %d) = %q, want %q", c.adif, c.hz, got, c.want)
		}
	}
	down := map[string]string{
		"cw": "CW", "usb": "USB", "lsb": "LSB", "am": "AM", "sam": "AM",
		"nfm": "FM", "digu": "DATA", "digl": "DATA", "": "",
	}
	for in, want := range down {
		if got := tciModeToADIF(in); got != want {
			t.Errorf("tciModeToADIF(%q) = %q, want %q", in, got, want)
		}
	}
}

// A command for something OpsLog is not — audio streams, CW macros, the
// panorama's settings — is met with silence rather than an error. A client
// sends these hopefully at connect, and a refusal it did not ask for reads as a
// fault with the rig.
func TestUnknownCommandsAreQuiet(t *testing.T) {
	s := srv(&fakeRig{freq: 14074000, rxFreq: 14074000, mode: "USB"})
	for _, cmd := range []string{"audio_start:0", "cw_macros_speed:25", "rx_filter_band:0,-2700,-100", "iq_start:0"} {
		if got := ask(t, s, cmd); got != "" {
			t.Errorf("%q answered %q", cmd, got)
		}
	}
}