(*
    BSD 2-Clause License

    Copyright (c) 2019-2020, Anton Krotov
    All rights reserved.
*)

MODULE HOST;

IMPORT SYSTEM, API, RTL;


CONST

    slash* = "/";
    OS* = "LINUX";

    bit_depth* = RTL.bit_depth;
    maxint* = RTL.maxint;
    minint* = RTL.minint;


VAR

    argc: INTEGER;

    eol*: ARRAY 2 OF CHAR;

    maxreal*: REAL;


PROCEDURE ExitProcess* (code: INTEGER);
BEGIN
    API.exit(code)
END ExitProcess;


PROCEDURE GetArg* (n: INTEGER; VAR s: ARRAY OF CHAR);
VAR
    i, len, ptr: INTEGER;
    c: CHAR;

BEGIN
    i := 0;
    len := LEN(s) - 1;
    IF (n < argc) & (len > 0) THEN
        SYSTEM.GET(API.MainParam + (n + 1) * SYSTEM.SIZE(INTEGER), ptr);
        REPEAT
            SYSTEM.GET(ptr, c);
            s[i] := c;
            INC(i);
            INC(ptr)
        UNTIL (c = 0X) OR (i = len)
    END;
    s[i] := 0X
END GetArg;


PROCEDURE GetCurrentDirectory* (VAR path: ARRAY OF CHAR);
VAR
    n: INTEGER;

BEGIN
    GetArg(0, path);
    n := LENGTH(path) - 1;
    WHILE path[n] # slash DO
        DEC(n)
    END;
    path[n + 1] := 0X
END GetCurrentDirectory;


PROCEDURE FileRead* (F: INTEGER; VAR Buffer: ARRAY OF CHAR; bytes: INTEGER): INTEGER;
VAR
    res: INTEGER;

BEGIN
    res := API.fread(SYSTEM.ADR(Buffer[0]), 1, bytes, F);
    IF res <= 0 THEN
        res := -1
    END

    RETURN res
END FileRead;


PROCEDURE FileWrite* (F: INTEGER; Buffer: ARRAY OF BYTE; bytes: INTEGER): INTEGER;
VAR
    res: INTEGER;

BEGIN
    res := API.fwrite(SYSTEM.ADR(Buffer[0]), 1, bytes, F);
    IF res <= 0 THEN
        res := -1
    END

    RETURN res
END FileWrite;


PROCEDURE FileCreate* (FName: ARRAY OF CHAR): INTEGER;
    RETURN API.fopen(SYSTEM.ADR(FName[0]), SYSTEM.SADR("wb"))
END FileCreate;


PROCEDURE FileClose* (File: INTEGER);
BEGIN
    File := API.fclose(File)
END FileClose;


PROCEDURE FileOpen* (FName: ARRAY OF CHAR): INTEGER;
    RETURN API.fopen(SYSTEM.ADR(FName[0]), SYSTEM.SADR("rb"))
END FileOpen;


PROCEDURE OutChar* (c: CHAR);
BEGIN
    API.putc(c)
END OutChar;


PROCEDURE GetTickCount* (): INTEGER;
VAR
    tp:  API.TP;
    res: INTEGER;

BEGIN
    IF API.clock_gettime(0, tp) = 0 THEN
        res := tp[0] * 100 + tp[1] DIV 10000000
    ELSE
        res := 0
    END

    RETURN res
END GetTickCount;


PROCEDURE isRelative* (path: ARRAY OF CHAR): BOOLEAN;
    RETURN path[0] # slash
END isRelative;


PROCEDURE now* (VAR year, month, day, hour, min, sec: INTEGER);
END now;


PROCEDURE UnixTime* (): INTEGER;
    RETURN API.time(0)
END UnixTime;


PROCEDURE d2s* (x: REAL): INTEGER;
VAR
    h, l, s, e: INTEGER;

BEGIN
    SYSTEM.GET(SYSTEM.ADR(x), l);
    SYSTEM.GET(SYSTEM.ADR(x) + 4, h);

    s := ASR(h, 31) MOD 2;
    e := (h DIV 100000H) MOD 2048;
    IF e <= 896 THEN
        h := (h MOD 100000H) * 8 + (l DIV 20000000H) MOD 8 + 800000H;
        REPEAT
            h := h DIV 2;
            INC(e)
        UNTIL e = 897;
        e := 896;
        l := (h MOD 8) * 20000000H;
        h := h DIV 8
    ELSIF (1151 <= e) & (e < 2047) THEN
        e := 1151;
        h := 0;
        l := 0
    ELSIF e = 2047 THEN
        e := 1151;
        IF (h MOD 100000H # 0) OR (l # 0) THEN
            h := 80000H;
            l := 0
        END
    END;
    DEC(e, 896)

    RETURN LSL(s, 31) + LSL(e, 23) + (h MOD 100000H) * 8 + (l DIV 20000000H) MOD 8
END d2s;


PROCEDURE splitf* (x: REAL; VAR a, b: INTEGER): INTEGER;
VAR
    res: INTEGER;

BEGIN
    a := 0;
    b := 0;
    SYSTEM.MOVE(SYSTEM.ADR(x), SYSTEM.ADR(a), 4);
    SYSTEM.MOVE(SYSTEM.ADR(x) + 4, SYSTEM.ADR(b), 4);
    SYSTEM.GET(SYSTEM.ADR(x), res)
    RETURN res
END splitf;


BEGIN
    eol := 0AX;
    maxreal := 1.9;
    PACK(maxreal, 1023);
    SYSTEM.GET(API.MainParam, argc)
END HOST.