MODULE ttysize;

(* Quick check of the tvtty libc binding: raw mode, terminal size, timed read. *)

FROM SYSTEM IMPORT ADDRESS, ADR, ADDADR, CAST, BYTE;
FROM tvtty IMPORT tcgetattr, tcsetattr, ioctl, read, write;
FROM InOut IMPORT WriteString, WriteLn, WriteInt;
FROM Delay IMPORT Delay;

TYPE BytePtr = POINTER TO BYTE;

CONST
    ICANON = 2; ECHO = 8; ISIG = 1; IEXTEN = 32768;
    ICRNL = 256; IXON = 1024;
    TCSAFLUSH = 2; TIOCGWINSZ = 5413H;

VAR
    t  : ARRAY [0..63] OF BYTE;
    ws : ARRAY [0..7] OF BYTE;
    rc : INTEGER;

PROCEDURE GetDWord(p : ADDRESS; off : INTEGER) : CARDINAL;
    VAR q : BytePtr; v : CARDINAL;
BEGIN
    q := CAST(BytePtr, ADDADR(p, off));
    v := VAL(CARDINAL, q^);
    q := CAST(BytePtr, ADDADR(q, 1)); v := v + VAL(CARDINAL, q^) * 256;
    q := CAST(BytePtr, ADDADR(q, 1)); v := v + VAL(CARDINAL, q^) * 65536;
    q := CAST(BytePtr, ADDADR(q, 1)); v := v + VAL(CARDINAL, q^) * 16777216;
    RETURN v
END GetDWord;

PROCEDURE PutDWord(p : ADDRESS; off : INTEGER; v : CARDINAL);
    VAR q : BytePtr; x : CARDINAL;
BEGIN
    x := v;
    q := CAST(BytePtr, ADDADR(p, off)); q^ := VAL(BYTE, x MOD 256); x := x DIV 256;
    q := CAST(BytePtr, ADDADR(q, 1));  q^ := VAL(BYTE, x MOD 256); x := x DIV 256;
    q := CAST(BytePtr, ADDADR(q, 1));  q^ := VAL(BYTE, x MOD 256); x := x DIV 256;
    q := CAST(BytePtr, ADDADR(q, 1));  q^ := VAL(BYTE, x MOD 256)
END PutDWord;

PROCEDURE Raw;
    VAR lf, iff : CARDINAL;
BEGIN
    rc := tcgetattr(0, ADR(t));
    lf := GetDWord(ADR(t), 12);
    lf := VAL(CARDINAL, CAST(BITSET, lf) * CAST(BITSET, MAX(CARDINAL) - (ICANON + ECHO + ISIG + IEXTEN)));
    PutDWord(ADR(t), 12, lf);
    iff := GetDWord(ADR(t), 0);
    iff := VAL(CARDINAL, CAST(BITSET, iff) * CAST(BITSET, MAX(CARDINAL) - (ICRNL + IXON)));
    PutDWord(ADR(t), 0, iff);
    t[17 + 6] := 0;   (* VMIN = 0 *)
    t[17 + 5] := 1;   (* VTIME = 1 (0.1 s) *)
    rc := tcsetattr(0, TCSAFLUSH, ADR(t))
END Raw;

PROCEDURE Restore;
BEGIN
    rc := tcsetattr(0, TCSAFLUSH, ADR(t))
END Restore;

VAR
    rows, cols, tries : INTEGER;
    buf : ARRAY [0..31] OF CHAR;
    b   : CARDINAL;
    found : BOOLEAN;

BEGIN
    WriteString("tcgetattr rc="); WriteInt(rc, 0); WriteLn;
    Raw;
    IF ioctl(1, TIOCGWINSZ, ADR(ws)) = 0 THEN
        rows := VAL(INTEGER, ws[0]) + VAL(INTEGER, ws[1]) * 256;
        cols := VAL(INTEGER, ws[2]) + VAL(INTEGER, ws[3]) * 256
    ELSE
        rows := 24; cols := 80
    END;
    WriteString("size="); WriteInt(rows, 0); WriteString("x"); WriteInt(cols, 0); WriteLn;
    WriteString("waiting 2s for a key (press one): ");
    found := FALSE;
    tries := 0;
    WHILE (NOT found) AND (tries < 20) DO
        rc := read(0, ADR(buf), 1);
        IF rc > 0 THEN
            b := VAL(CARDINAL, ORD(buf[0]));
            WriteString("got byte "); WriteInt(VAL(INTEGER, b), 0); WriteLn;
            found := TRUE
        ELSE
            tries := tries + 1;
            Delay(1)
        END
    END;
    IF NOT found THEN WriteString("no key"); WriteLn END;
    Restore;
    WriteString("restored"); WriteLn
END ttysize.