package cat

import "testing"

func TestParseYaesuFreq(t *testing.T) {
	cases := []struct {
		reply, prefix string
		want          int64
		ok            bool
	}{
		{"FA014074000;", "FA", 14074000, true},
		{"FB007100000;", "FB", 7100000, true},
		{"FA000474000;", "FA", 474000, true}, // 630 m — leading zeros must not truncate
		{"FA010368000000;", "FA", 10368000000, true},
		{"FB;", "FB", 0, false},          // query echoed back with no value
		{"FA014074000;", "FB", 0, false}, // wrong VFO — never silently accepted
		{"", "FA", 0, false},
		{"FAxxxxxxxxx;", "FA", 0, false},
	}
	for _, c := range cases {
		got, ok := parseYaesuFreq(c.reply, c.prefix)
		if got != c.want || ok != c.ok {
			t.Errorf("parseYaesuFreq(%q,%q) = %d,%v — want %d,%v", c.reply, c.prefix, got, ok, c.want, c.ok)
		}
	}
}

// The split rules. Getting these wrong writes a WRONG TX frequency into the log,
// which is why an ambiguous state resolves to "not split" rather than to a
// guess — the same principle the OmniRig backend arrived at the hard way.
func TestResolveYaesuVFOs(t *testing.T) {
	const a, b = 14074000, 14100000
	cases := []struct {
		name           string
		fa, fb         int64
		vfo            string
		split          bool
		wantTX, wantRX int64
		wantSplit      bool
	}{
		{"simplex on A", a, b, "A", false, a, 0, false},
		{"simplex on B", a, b, "B", false, b, 0, false},
		{"split, listening on A → TX on B", a, b, "A", true, b, a, true},
		{"split, listening on B → TX on A", a, b, "B", true, a, b, true},
		{"split flag but the other VFO is unread", a, 0, "A", true, a, 0, false},
		{"split flag but both VFOs identical", a, a, "A", true, a, 0, false},
	}
	for _, c := range cases {
		tx, rx, sp := resolveYaesuVFOs(c.fa, c.fb, c.vfo, c.split)
		if tx != c.wantTX || rx != c.wantRX || sp != c.wantSplit {
			t.Errorf("%s: got tx=%d rx=%d split=%v — want tx=%d rx=%d split=%v",
				c.name, tx, rx, sp, c.wantTX, c.wantRX, c.wantSplit)
		}
	}
}

// ST and FT say different things, and reading them alike inverted the split
// display on an FTDX101 (F4NBZ, 2026-07-29): the panel showed split ON with the
// radio OFF and the reverse.
//
//	ST is a split FLAG   — ST1 means split, whatever VFO is in use.
//	FT names the TX VFO  — FT0 = transmit on A, FT1 = transmit on B.
//
// Split is on when the rig transmits on a DIFFERENT VFO from the one it listens
// to, so FT has to be compared with the current VFO. That is why the same model
// behaved correctly for one operator and backwards for another: one was on MAIN,
// the other on SUB.
func TestYaesuSplitReply(t *testing.T) {
	cases := []struct {
		reply, cmd, vfo string
		want            bool
	}{
		// The flag is absolute.
		{"ST1;", "ST", "A", true},
		{"ST0;", "ST", "A", false},
		{"ST1;", "ST", "B", true},
		{"ST0;", "ST", "B", false},

		// Listening on A: transmit on B is split, transmit on A is not.
		{"FT1;", "FT", "A", true},
		{"FT0;", "FT", "A", false},
		// Listening on B: exactly the opposite — the reported inversion.
		{"FT0;", "FT", "B", true},
		{"FT1;", "FT", "B", false},
		// The pair enums the Yaesus also report start with the listening VFO.
		{"FT0;", "FT", "BA", true},
		{"FT1;", "FT", "AB", true},

		{"ST1;", "FT", "A", false}, // reply for the other command — not accepted
		{"ST", "ST", "A", false},   // truncated
		{"", "ST", "A", false},
	}
	for _, c := range cases {
		if got := yaesuSplitFromReply(c.reply, c.cmd, c.vfo); got != c.want {
			t.Errorf("yaesuSplitFromReply(%q, %q, vfo=%q) = %v, want %v",
				c.reply, c.cmd, c.vfo, got, c.want)
		}
	}
}

// The sideband follows the frequency, worldwide convention — a CAT backend that
// puts USB on 40 m makes every SSB QSO wrong.
func TestYaesuModeDigit(t *testing.T) {
	cases := []struct {
		mode string
		hz   int64
		want byte
	}{
		{"SSB", 7150000, '1'},  // LSB below 10 MHz
		{"SSB", 14250000, '2'}, // USB above
		{"LSB", 14250000, '1'}, // explicit wins over the convention
		{"USB", 7150000, '2'},
		{"CW", 7030000, '3'},
		{"RTTY", 14080000, '6'},
		{"AM", 7150000, '5'},
		{"FM", 145000000, '4'},
		{"FT8", 7074000, '8'},  // DATA-LSB
		{"FT8", 14074000, 'C'}, // DATA-USB
		{"JS8", 14078000, 'C'}, // any unknown digital rides on DATA
		{"", 14074000, 0},      // nothing to set
	}
	for _, c := range cases {
		if got := yaesuModeDigit(c.mode, c.hz); got != c.want {
			t.Errorf("yaesuModeDigit(%q, %d) = %q, want %q", c.mode, c.hz, got, c.want)
		}
	}
}

// A reply belongs to the command that asked for it.
//
// Without this, a CW macro knocked the CAT link over: KY produces no reply, so
// the poll loop's next FA; collected a leftover frame, failed to parse it as a
// frequency, and the Manager treated that as "lost the rig" and reconnected —
// the CAT dropping for a few seconds on every macro click.
func TestYaesuCmdPrefix(t *testing.T) {
	cases := []struct{ cmd, want string }{
		{"FA;", "FA"},
		{"FB;", "FB"},
		{"MD0;", "MD"},
		{"KY;", "KY"},
		{"KY CQ TEST;", "KY"},
		{"SM0;", "SM"},
		{"RM4;", "RM"},
		{"AG0;", "AG"},
		{"TX;", "TX"},
		{"", ""},
		{";", ""},
	}
	for _, c := range cases {
		if got := cmdPrefix(c.cmd); got != c.want {
			t.Errorf("cmdPrefix(%q) = %q, want %q", c.cmd, got, c.want)
		}
	}
}

// Writing split is as asymmetric as reading it.
//
// ST takes the state directly. FT sets which VFO TRANSMITS, so "split on" means
// transmit on the OTHER VFO from the one being listened to. Sending FT1 for "on"
// regardless is right only on VFO A — on SUB it would CLEAR the split it was
// asked to set, which is the same inversion that showed on the FTDX101 panel.
func TestYaesuSplitCommand(t *testing.T) {
	cases := []struct {
		cmd, vfo string
		on       bool
		want     string
	}{
		{"ST", "A", true, "ST1;"},
		{"ST", "B", true, "ST1;"}, // the flag does not care which VFO
		{"ST", "B", false, "ST0;"},

		// Listening on A: split means transmit on B.
		{"FT", "A", true, "FT1;"},
		{"FT", "A", false, "FT0;"},
		// Listening on B: split means transmit on A — the reverse.
		{"FT", "B", true, "FT0;"},
		{"FT", "B", false, "FT1;"},
		// Pair enums start with the listening VFO.
		{"FT", "BA", true, "FT0;"},
		{"FT", "AB", true, "FT1;"},
	}
	for _, c := range cases {
		if got := yaesuSplitCommand(c.cmd, c.vfo, c.on); got != c.want {
			t.Errorf("yaesuSplitCommand(%q, vfo=%q, on=%v) = %q, want %q",
				c.cmd, c.vfo, c.on, got, c.want)
		}
	}
}

// Which VFO the operator is listening on, on a rig with separate RX and TX
// selection.
//
// Reported on an FTDX101 (2026-07-29): moving RX alone to SUB displayed VFO B
// correctly, but moving BOTH RX and TX to SUB displayed VFO A — the operator was
// entirely on B and OpsLog showed the other one. FR reports the receive VFO; VS
// does not answer that question on this rig.
//
// With FR read correctly the split follows too, since split is "transmit VFO
// differs from receive VFO".
func TestYaesuReceiveVFOAndSplit(t *testing.T) {
	cases := []struct {
		name      string
		fr, ft    string // replies
		wantVFO   string
		wantSplit bool
	}{
		{"everything on main", "FR0;", "FT0;", "A", false},
		{"RX on sub, TX still on main — split", "FR1;", "FT0;", "B", true},
		{"RX and TX both on sub — NOT split", "FR1;", "FT1;", "B", false},
		{"RX on main, TX on sub — split", "FR0;", "FT1;", "A", true},
	}
	for _, c := range cases {
		vfo := "A"
		if len(c.fr) >= 3 && c.fr[2] == '1' {
			vfo = "B"
		}
		if vfo != c.wantVFO {
			t.Errorf("%s: receive VFO = %s, want %s", c.name, vfo, c.wantVFO)
		}
		if got := yaesuSplitFromReply(c.ft, "FT", vfo); got != c.wantSplit {
			t.Errorf("%s: split = %v, want %v", c.name, got, c.wantSplit)
		}
	}
}

// The state digit of a reply, when the parameter is not one character.
//
// An FTDX101 answers "FR01;" where an FTDX10 answers "FR0;". The state is the
// FIRST digit on both — the second is a separate parameter.
//
// This test asserted the opposite for one evening. Reading the LAST digit turned
// "FR01" into SUB, so an operator with RX and TX on MAIN saw the main frequency
// freeze and a spot click tune VFO B (F4NBZ, 2026-07-29). The fault it was meant
// to fix — "SUB shows MAIN" — came from reading VS, not from this digit, and the
// FR probe alone had already fixed it.
func TestYaesuStateDigit(t *testing.T) {
	cases := []struct {
		reply, cmd string
		want       byte
	}{
		{"FR0;", "FR", '0'}, // FTDX10 form
		{"FR1;", "FR", '1'},
		{"FR01;", "FR", '0'}, // FTDX101 form: MAIN — the reported bug read this as SUB
		{"FR11;", "FR", '1'}, // …and this is SUB
		{"ST1;", "ST", '1'},
		{"FT0;", "FT", '0'},
		{"VS1;", "VS", '1'},
		{"FR1", "FR", '1'}, // terminator already stripped

		{"ST1;", "FR", 0}, // another command's reply is never accepted
		{"FR;", "FR", 0},  // query echoed with no value
		{"FRx;", "FR", 0}, // not a digit
		{"", "FR", 0},
	}
	for _, c := range cases {
		if got := yaesuStateDigit(c.reply, c.cmd); got != c.want {
			t.Errorf("yaesuStateDigit(%q, %q) = %q, want %q", c.reply, c.cmd, got, c.want)
		}
	}

	// End to end, both directions of the reported fault:
	if d := yaesuStateDigit("FR01;", "FR"); d != '0' {
		t.Fatalf("FR01 read as %q — the operator is on MAIN and must be seen there", d)
	}
	if d := yaesuStateDigit("FR11;", "FR"); d != '1' {
		t.Fatalf("FR11 read as %q — the operator is on SUB", d)
	}
}

// A spot click tunes the VFO the operator is ON, and the display reads that same
// VFO. Both follow from the receive-VFO digit, which is why it is pinned here in
// the operator's terms rather than only as a byte.
//
// Reported both ways round on an FTDX101 (F4NBZ, 2026-07-29): with RX and TX on
// SUB everything worked, and with them on MAIN the frequency froze and a spot
// clicked tuned the sub VFO.
func TestYaesuActiveVFOFollowsReceiveVFO(t *testing.T) {
	// Mirrors ReadState's choice of VFO and SetFrequency's choice of command.
	activeVFO := func(frReply string) string {
		if yaesuStateDigit(frReply, "FR") == '1' {
			return "B"
		}
		return "A"
	}
	tuneCmd := func(vfo string) string {
		if vfo == "B" {
			return "FB" // sub
		}
		return "FA" // main
	}

	cases := []struct {
		name, fr, wantVFO, wantCmd string
	}{
		{"RX and TX on MAIN (FTDX101 two-digit reply)", "FR01;", "A", "FA"},
		{"RX and TX on SUB (FTDX101)", "FR11;", "B", "FB"},
		{"MAIN on a one-digit rig", "FR0;", "A", "FA"},
		{"SUB on a one-digit rig", "FR1;", "B", "FB"},
	}
	for _, c := range cases {
		vfo := activeVFO(c.fr)
		if vfo != c.wantVFO {
			t.Errorf("%s: active VFO = %s, want %s", c.name, vfo, c.wantVFO)
		}
		if cmd := tuneCmd(vfo); cmd != c.wantCmd {
			t.Errorf("%s: a spot click would write %s, want %s", c.name, cmd, c.wantCmd)
		}
	}
}

// Which split command to ASK, given what else the rig answers.
//
// ST is a bare flag and its meaning varies: an FTDX101 with RX and TX both on
// SUB reports ST1, which is plain simplex on the sub VFO, and OpsLog showed
// split with the main frequency as the transmit one (F4NBZ, 2026-07-29).
//
// FT names the transmit VFO. Where the receive VFO is known too (FR), split is
// derived from the pair — they differ or they do not — which is a fact about the
// rig rather than a flag to be interpreted. So FT is preferred when FR answered.
func TestYaesuSplitProbeOrder(t *testing.T) {
	order := func(rxVFOCmd string) []string {
		if rxVFOCmd != "" {
			return []string{"FT", "ST"}
		}
		return []string{"ST", "FT"}
	}

	if got := order("FR")[0]; got != "FT" {
		t.Errorf("with FR available the first split probe is %q, want FT", got)
	}
	if got := order("")[0]; got != "ST" {
		t.Errorf("without FR the first split probe is %q, want ST", got)
	}
	// Both remain available: a rig answering only one must still be handled.
	for _, rx := range []string{"FR", ""} {
		if len(order(rx)) != 2 {
			t.Errorf("rxVFOCmd=%q: both probes must remain, got %v", rx, order(rx))
		}
	}

	// The case that was reported, end to end: RX and TX both on sub is NOT split.
	if yaesuSplitFromReply("FT1;", "FT", "B") {
		t.Error("RX and TX both on SUB reported as split")
	}
	// And the flag alone would have got it wrong, which is why the order changed.
	if !yaesuSplitFromReply("ST1;", "ST", "B") {
		t.Error("ST1 is a flag and reads as split whatever the VFO — that is the trap")
	}
}