(*
    Copyright 2021 Anton Krotov

    This file is part of CEdit.

    CEdit is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    CEdit is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with CEdit. If not, see <http://www.gnu.org/licenses/>.
*)

MODULE Languages;

IMPORT Lines;


CONST

    langNone* = 0; langC* = 1; langOberon* = 2; langPascal* = 3;
    langFasm* = 4; langLua* = 5; langIni* = 6;

TYPE

    tLine = Lines.tLine;

    tKeyWords = RECORD
        words: ARRAY 200, 32 OF WCHAR; cnt: INTEGER
    END;

    procGetStr = PROCEDURE (secName, keyName: ARRAY OF CHAR; VAR s: ARRAY OF CHAR);


VAR

    oberonKW, cKW, pascalKW, luaKW, iniKW, fasmKW: ARRAY 3 OF tKeyWords;


PROCEDURE checkKW (s: ARRAY OF WCHAR; KW: tKeyWords): BOOLEAN;
VAR
    i: INTEGER;
BEGIN
    i := KW.cnt - 1;
    WHILE (i >= 0) & (s # KW.words[i]) DO
        DEC(i)
    END
    RETURN i >= 0
END checkKW;


PROCEDURE isKey* (s: ARRAY OF WCHAR; lang, kwSet: INTEGER): BOOLEAN;
VAR
    res: BOOLEAN;
BEGIN
    res := FALSE;
    CASE lang OF
    |langC:      res := checkKW(s, cKW[kwSet - 1])
    |langOberon: res := checkKW(s, oberonKW[kwSet - 1])
    |langPascal: res := checkKW(s, pascalKW[kwSet - 1])
    |langLua:    res := checkKW(s, luaKW[kwSet - 1])
    |langIni:    res := checkKW(s, iniKW[kwSet - 1])
    |langFasm:   res := checkKW(s, fasmKW[kwSet - 1])
    END
    RETURN res
END isKey;


PROCEDURE SkipString* (line: tLine; VAR pos: INTEGER; n: INTEGER);
VAR
    quot: WCHAR;
BEGIN
    quot := Lines.getChar(line, pos);
    REPEAT
        INC(pos)
    UNTIL (pos > n) OR (Lines.getChar(line, pos) = quot)
END SkipString;


PROCEDURE C (line: tLine; VAR depth, cond, pos: INTEGER; n: INTEGER);
VAR
    c: WCHAR;
BEGIN
    c := Lines.getChar(line, pos);
    IF depth = 0 THEN
        IF c = "/" THEN
            IF cond = 0 THEN
                cond := 1
            ELSE
                cond := 0;
                pos := n
            END
        ELSIF (c = "*") & (cond = 1) THEN
            depth := 1;
            cond := 0
        ELSIF (c = "'") OR (c = '"') THEN
            SkipString(line, pos, n);
            cond := 0
        ELSE
            cond := 0
        END
    ELSIF depth = 1 THEN
        IF c = "*" THEN
            cond := 1
        ELSIF (c = "/") & (cond = 1) THEN
            cond := 0;
            depth := 0
        ELSE
            cond := 0
        END
    END
END C;


PROCEDURE getChar (line: tLine; i: INTEGER): WCHAR;
VAR
    res: WCHAR;
BEGIN
    IF i >= line.length THEN
        res := 0X
    ELSE
        res := Lines.getChar(line, i)
    END
    RETURN res
END getChar;


PROCEDURE LuaLong* (line: tLine; pos: INTEGER): INTEGER;
VAR
    res: INTEGER;
BEGIN
    res := -1;
    IF getChar(line, pos) = "[" THEN
        INC(pos);
        WHILE getChar(line, pos) = "=" DO
            INC(res);
            INC(pos)
        END;
        IF getChar(line, pos) = "[" THEN
            INC(res)
        ELSE
            res := -1
        END
    END
    RETURN res
END LuaLong;


PROCEDURE Lua (line: tLine; VAR depth, cond, pos: INTEGER; n: INTEGER);
VAR
    c: WCHAR;
    k: INTEGER;
BEGIN
    c := Lines.getChar(line, pos);
    IF depth = 0 THEN
        IF c = "-" THEN
            IF cond = 0 THEN
                cond := 1
            ELSE
                cond := 0;
                k := LuaLong(line, pos + 1);
                IF k >= 0 THEN
                    depth := k*2 + 1
                ELSE
                    pos := n
                END
            END
        ELSIF c = "[" THEN
            cond := 0;
            k := LuaLong(line, pos);
            IF k >= 0 THEN
                depth := (k + 1)*2
            END
        ELSIF (c = "'") OR (c = '"') THEN
            SkipString(line, pos, n);
            cond := 0
        ELSE
            cond := 0
        END
    ELSIF depth > 0 THEN
        IF (cond = 0) & (c = "]") THEN
            cond := 1
        ELSIF (cond >= 1) & (c = "=") THEN
            INC(cond)
        ELSIF (cond >= 1) & (c = "]") & (cond*2 - depth MOD 2 = depth) THEN
            depth := 0;
            cond := 0
        ELSE
            cond := 0
        END
    END
END Lua;


PROCEDURE Pascal (line: tLine; VAR depth, cond, pos: INTEGER; n: INTEGER);
VAR
    c: WCHAR;
BEGIN
    c := Lines.getChar(line, pos);
    IF depth = 0 THEN
        IF c = "(" THEN
            cond := 1
        ELSIF c = "/" THEN
            IF cond = 2 THEN
                cond := 0;
                pos := n
            ELSE
                cond := 2
            END
        ELSIF (c = "*") & (cond = 1) THEN
            depth := 2;
            cond := 0
        ELSIF c = "'" THEN
            SkipString(line, pos, n);
            cond := 0
        ELSIF c = "{" THEN
            IF Lines.getChar(line, pos + 1) = "$" THEN
                depth := 3
            ELSE
                depth := 1
            END;
            cond := 0
        ELSE
            cond := 0
        END
    ELSIF depth IN {1, 3} THEN
        IF c = "}" THEN
            depth := 0
        END
    ELSIF depth = 2 THEN
        IF c = "*" THEN
            cond := 1
        ELSIF (c = ")") & (cond = 1) THEN
            depth := 0;
            cond := 0
        ELSE
            cond := 0
        END
    END
END Pascal;


PROCEDURE Oberon (line: tLine; VAR depth, cond, pos: INTEGER; n: INTEGER);
VAR
    c: WCHAR;
BEGIN
    c := Lines.getChar(line, pos);
    IF (depth = 0) & (c = "/") THEN
        IF cond = 3 THEN
            cond := 0;
            pos := n
        ELSE
            cond := 3
        END
    ELSIF (depth = 0) & ((c = "'") OR (c = '"')) THEN
        SkipString(line, pos, n);
        cond := 0
    ELSIF c = "(" THEN
        cond := 1
    ELSIF c = "*" THEN
        IF cond = 1 THEN
            INC(depth);
            cond := 0
        ELSE
            cond := 2
        END
    ELSIF c = ")" THEN
        IF cond = 2 THEN
            IF depth > 0 THEN
                DEC(depth)
            END
        END;
        cond := 0
    ELSE
        cond := 0
    END;
END Oberon;


PROCEDURE Ini (line: tLine; VAR depth, cond, pos: INTEGER; n: INTEGER);
VAR
    c: WCHAR;
BEGIN
    cond := 0;
    c := Lines.getChar(line, pos);
    IF depth = 0 THEN
        IF c = ";" THEN
            pos := n
        ELSIF c = '"' THEN
            SkipString(line, pos, n)
        ELSIF c = "[" THEN
            depth := 1
        END
    ELSIF depth = 1 THEN
        IF c = "]" THEN
            depth := 0
        END
    END
END Ini;


PROCEDURE comments* (line: tLine; VAR depth, cond, pos: INTEGER; n: INTEGER; lang: INTEGER);
BEGIN
    CASE lang OF
    |langNone:
    |langFasm:
    |langC:       C(line, depth, cond, pos, n)
    |langOberon:  Oberon(line, depth, cond, pos, n)
    |langPascal:  Pascal(line, depth, cond, pos, n)
    |langLua:     Lua(line, depth, cond, pos, n)
    |langIni:     Ini(line, depth, cond, pos, n)
    END
END comments;


PROCEDURE EnterKW (s: ARRAY OF CHAR; VAR KW: tKeyWords; CPrep: BOOLEAN);
CONST
    SPACE = 20X; CR = 0DX; LF = 0AX; TAB = 9X; COMMA = ",";
VAR
    i, j, k: INTEGER;

    PROCEDURE delim (c: CHAR): BOOLEAN;
        RETURN (c = COMMA) OR (c = SPACE) OR (c = CR) OR (c = LF) OR (c = TAB)
    END delim;

BEGIN
    k := KW.cnt;
    i := 0;
    REPEAT
        KW.words[k, 0] := "#";
        j := ORD(CPrep);
        WHILE (s[i] # 0X) & ~delim(s[i]) DO
            KW.words[k, j] := WCHR(ORD(s[i]));
            INC(i);
            INC(j)
        END;
        KW.words[k, j] := 0X;
        INC(k);
        WHILE delim(s[i]) DO
            INC(i)
        END
    UNTIL s[i] = 0X;
    KW.cnt := k
END EnterKW;


PROCEDURE loadKW (VAR KW: ARRAY OF tKeyWords; getStr: procGetStr; lang: ARRAY OF CHAR);
VAR
    s: ARRAY 16*1024 OF CHAR;
    key: ARRAY 4 OF CHAR;
    i: INTEGER;
BEGIN
    key := "KW1";
    FOR i := 0 TO 2 DO
        KW[i].cnt := 0;
        key[2] := CHR(ORD("1") + i);
        getStr(lang, key, s);
        EnterKW(s, KW[i], (lang = "lang_C") & (i = 1))
    END
END loadKW;


PROCEDURE init* (getStr: procGetStr);
BEGIN
    loadKW(oberonKW, getStr, "lang_Oberon");
    loadKW(cKW,      getStr, "lang_C");
    loadKW(pascalKW, getStr, "lang_Pascal");
    loadKW(luaKW,    getStr, "lang_Lua");
    loadKW(iniKW,    getStr, "lang_Ini");
    loadKW(fasmKW,   getStr, "lang_Fasm");
END init;


END Languages.