IMPLEMENTATION MODULE VT52;

FROM STextIO IMPORT WriteString, WriteChar, WriteLn;
FROM NumberIO IMPORT WriteCard;
FROM ASCII IMPORT esc;
FROM Strings IMPORT Concat, Length, String1;
FROM NumberIO IMPORT WriteHex;

(* CONST
    ALTKEYPAD   = "=";
    NUMKEYPAD   = ">";
    SETGR       = "F";
    RESETGR     = "G";
    CURSORUP    = "A";
    CURSORDN    = "B";
    CURSORRT    = "C";
    CURSORLF    = "D";
    CURSORHOME  = "H";
    CURSORPOS   = "Y";
    REVINDEX    = "I";
    CLEAREOL    = "K";
    CLEAREOS    = "/Z";
    IDENTRESP   = "KL";
    VT52C        = "<"; *)

VAR
    altkeypadStr    : ARRAY[0..2] OF CHAR;
    numkeypadStr    : ARRAY[0..2] OF CHAR;
    setgrStr        : ARRAY[0..2] OF CHAR;
    resetgrStr      : ARRAY[0..2] OF CHAR;
    cursorupStr     : ARRAY[0..2] OF CHAR;
    cursordnStr     : ARRAY[0..2] OF CHAR;
    cursorrtStr     : ARRAY[0..2] OF CHAR;
    cursorlfStr     : ARRAY[0..2] OF CHAR;
    cursorhomeStr   : ARRAY[0..2] OF CHAR;
    cursorposStr    : ARRAY[0..2] OF CHAR;
    revindexStr     : ARRAY[0..2] OF CHAR;
    cleareolStr     : ARRAY[0..2] OF CHAR;
    cleareosStr     : ARRAY[0..2] OF CHAR;
    identStr        : ARRAY[0..2] OF CHAR;
    identrespStr    : ARRAY[0..2] OF CHAR;
    clsStr          : ARRAY[0..5] OF CHAR; 
    vt52Str         : ARRAY[0..3] OF CHAR; 

VAR
    i : CARDINAL;

    PROCEDURE vt52;                 (* Enter/exit ANSI mode (VT52)            ^[< *)
    BEGIN
        WriteString(vt52Str)
    END vt52;

    PROCEDURE altkeypad;             (* Enter alternate keypad mode            ^[= *)
    BEGIN
        WriteString(altkeypadStr)
    END altkeypad;

    PROCEDURE numkeypad;             (* Exit alternate keypad mode             ^[> *)
    BEGIN
        WriteString(numkeypadStr)
    END numkeypad;


    PROCEDURE setgr;                 (* Use special graphics character set     ^[F *)
    BEGIN
        WriteString(setgrStr)
    END setgr;

    PROCEDURE resetgr;               (* Use normal US/UK character set         ^[G *)
    BEGIN
        WriteString(resetgrStr)
    END resetgr;


    PROCEDURE cursorup;              (* Move cursor up one line                ^[A *)
    BEGIN
        WriteString(cursorupStr)
    END cursorup;

    PROCEDURE cursordn;              (* Move cursor down one line              ^[B *)
    BEGIN
        WriteString(cursordnStr)
    END cursordn;

    PROCEDURE cursorrt;              (* Move cursor right one char             ^[C *)
    BEGIN
        WriteString(cursorrtStr)
    END cursorrt;

    PROCEDURE cursorlf;              (* Move cursor left one char              ^[D *)
    BEGIN
        WriteString(cursorlfStr)
    END cursorlf;

    PROCEDURE cursorhome;            (* Move cursor to upper left corner       ^[H *)
    BEGIN
        WriteString(cursorhomeStr)
    END cursorhome;

    PROCEDURE cursorpos(x : CARDINAL; y : CARDINAL);        (* Move cursor to v,h location            ^[<v><h> *)
        VAR
            tempString      : ARRAY[0..15] OF CHAR;
            tempString1,
            tempString2,
            tempString3     : String1;
            xPos, yPos      : CARDINAL;
    BEGIN
        tempString := "";
        (* tempString3[0] := "f"; *)
        Concat(tempString,cursorposStr, tempString);
        xPos := x + 31; 
        yPos := y + 31; 
        tempString1[0] :=  CHR(yPos);
        tempString2[0] :=  CHR(xPos);
        Concat(tempString,tempString1, tempString);
        Concat(tempString,tempString2, tempString);
        (* Concat(tempString,tempString3, tempString); *)
        WriteString(tempString);

    END cursorpos;

    PROCEDURE revindex;              (* Generate a reverse line-feed           ^[I *)
    BEGIN
        WriteString(revindexStr)
    END revindex;

    PROCEDURE cleareol;              (* Erase to end of current line           ^[K *)
    BEGIN
        WriteString(cleareolStr)
    END cleareol;

    PROCEDURE cleareos;              (* Erase to end of screen                 ^[J *)
    BEGIN
        WriteString(cleareosStr)
    END cleareos;

    PROCEDURE ident;                 (* Identify what the terminal is          ^[Z *)
    BEGIN
        WriteString(identStr)
    END ident;

    PROCEDURE identresp;             (* Correct response to ident              ^[/Z *)
    BEGIN
        WriteString(identrespStr)
    END identresp;

    PROCEDURE cls;
    BEGIN
        WriteString(clsStr)
    END cls;

BEGIN
    (**** VT52 *****)
    Concat(esc,"[<",vt52Str);

    (**** altkeypad *****)
    Concat(esc,"[=", altkeypadStr);

    (**** numkeypad *****)
    Concat(esc,"[=>",numkeypadStr);

    (**** setgr *****)
    Concat(esc,"[F",setgrStr);

    (**** resetgr *****)
    Concat(esc,"[G",resetgrStr);

    (**** cursorup *****)
    Concat(esc,"[A",cursorupStr);

    (**** cursordn *****)
    Concat(esc,"[B",cursordnStr);

    (**** cursorrt *****)
    Concat(esc,"[C",cursorrtStr);

    (**** cursorlf *****)
    Concat(esc,"[D",cursorlfStr);

    (**** cursorhome *****)
    Concat(esc,"[H",cursorhomeStr);

    (**** cursorpos *****)
    Concat(esc,"[Y",cursorposStr);

    (**** revindex *****)
    Concat(esc,"[I",revindexStr);

    (**** cleareol *****)
    Concat(esc,"[K",cleareolStr);

    (**** cleareos *****)
    Concat(esc,"[J",cleareosStr);

    (**** ident *****)
    Concat(esc,"[Z",identStr);

    (**** identresp *****)
    Concat(esc,"[/Z",identrespStr);
 
    (**** cls *****)
    clsStr := "";
    Concat(esc,"[H",clsStr);
    Concat(clsStr,esc,clsStr);
    Concat(clsStr,"[J",clsStr);
    (****)
END VT52.