// Scintilla source code edit control
/** @file LexDMAP.cxx
 ** Lexer for MSC Nastran DMAP.
 ** Written by Mark Robinson, based on the Fortran lexer by Chuan-jian Shen, Last changed Aug. 2013
 **/
// Copyright 1998-2001 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
/***************************************/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
#include <ctype.h>

#include <string>
#include <string_view>
/***************************************/
#include "ILexer.h"
#include "Scintilla.h"
#include "SciLexer.h"

#include "WordList.h"
#include "LexAccessor.h"
#include "Accessor.h"
#include "StyleContext.h"
#include "CharacterSet.h"
#include "LexerModule.h"
/***************************************/

using namespace Lexilla;

/***********************************************/
static inline bool IsAWordChar(const int ch) {
    return (ch < 0x80) && (isalnum(ch) || ch == '_' || ch == '%');
}
/**********************************************/
static inline bool IsAWordStart(const int ch) {
    return (ch < 0x80) && (isalnum(ch));
}
/***************************************/
static void ColouriseDMAPDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
            WordList *keywordlists[], Accessor &styler) {
    WordList &keywords = *keywordlists[0];
    WordList &keywords2 = *keywordlists[1];
    WordList &keywords3 = *keywordlists[2];
    /***************************************/
    Sci_Position posLineStart = 0, numNonBlank = 0;
    Sci_Position endPos = startPos + length;
    /***************************************/
    // backtrack to the nearest keyword
    while ((startPos > 1) && (styler.StyleAt(startPos) != SCE_DMAP_WORD)) {
        startPos--;
    }
    startPos = styler.LineStart(styler.GetLine(startPos));
    initStyle = styler.StyleAt(startPos - 1);
    StyleContext sc(startPos, endPos-startPos, initStyle, styler);
    /***************************************/
    for (; sc.More(); sc.Forward()) {
        // remember the start position of the line
        if (sc.atLineStart) {
            posLineStart = sc.currentPos;
            numNonBlank = 0;
            sc.SetState(SCE_DMAP_DEFAULT);
        }
        if (!IsASpaceOrTab(sc.ch)) numNonBlank ++;
        /***********************************************/
        // Handle data appearing after column 72; it is ignored
        Sci_Position toLineStart = sc.currentPos - posLineStart;
        if (toLineStart >= 72 || sc.ch == '$') {
            sc.SetState(SCE_DMAP_COMMENT);
            while (!sc.atLineEnd && sc.More()) sc.Forward(); // Until line end
            continue;
        }
        /***************************************/
        // Determine if the current state should terminate.
        if (sc.state == SCE_DMAP_OPERATOR) {
            sc.SetState(SCE_DMAP_DEFAULT);
        } else if (sc.state == SCE_DMAP_NUMBER) {
            if (!(IsAWordChar(sc.ch) || sc.ch=='\'' || sc.ch=='\"' || sc.ch=='.')) {
                sc.SetState(SCE_DMAP_DEFAULT);
            }
        } else if (sc.state == SCE_DMAP_IDENTIFIER) {
            if (!IsAWordChar(sc.ch) || (sc.ch == '%')) {
                char s[100];
                sc.GetCurrentLowered(s, sizeof(s));
                if (keywords.InList(s)) {
                    sc.ChangeState(SCE_DMAP_WORD);
                } else if (keywords2.InList(s)) {
                    sc.ChangeState(SCE_DMAP_WORD2);
                } else if (keywords3.InList(s)) {
                    sc.ChangeState(SCE_DMAP_WORD3);
                }
                sc.SetState(SCE_DMAP_DEFAULT);
            }
        } else if (sc.state == SCE_DMAP_COMMENT) {
            if (sc.ch == '\r' || sc.ch == '\n') {
                sc.SetState(SCE_DMAP_DEFAULT);
            }
        } else if (sc.state == SCE_DMAP_STRING1) {
            if (sc.ch == '\'') {
                if (sc.chNext == '\'') {
                    sc.Forward();
                } else {
                    sc.ForwardSetState(SCE_DMAP_DEFAULT);
                }
            } else if (sc.atLineEnd) {
                sc.ChangeState(SCE_DMAP_STRINGEOL);
                sc.ForwardSetState(SCE_DMAP_DEFAULT);
            }
        } else if (sc.state == SCE_DMAP_STRING2) {
            if (sc.atLineEnd) {
                sc.ChangeState(SCE_DMAP_STRINGEOL);
                sc.ForwardSetState(SCE_DMAP_DEFAULT);
            } else if (sc.ch == '\"') {
                if (sc.chNext == '\"') {
                    sc.Forward();
                } else {
                    sc.ForwardSetState(SCE_DMAP_DEFAULT);
                }
            }
        }
        /***************************************/
        // Determine if a new state should be entered.
        if (sc.state == SCE_DMAP_DEFAULT) {
            if (sc.ch == '$') {
                sc.SetState(SCE_DMAP_COMMENT);
            } else if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext)) || (sc.ch == '-' && IsADigit(sc.chNext))) {
                sc.SetState(SCE_F_NUMBER);
            } else if (IsAWordStart(sc.ch)) {
                sc.SetState(SCE_DMAP_IDENTIFIER);
            } else if (sc.ch == '\"') {
                sc.SetState(SCE_DMAP_STRING2);
            } else if (sc.ch == '\'') {
                sc.SetState(SCE_DMAP_STRING1);
            } else if (isoperator(static_cast<char>(sc.ch))) {
                sc.SetState(SCE_DMAP_OPERATOR);
            }
        }
    }
    sc.Complete();
}
/***************************************/
// To determine the folding level depending on keywords
static int classifyFoldPointDMAP(const char* s, const char* prevWord) {
    int lev = 0;
    if ((strcmp(prevWord, "else") == 0 && strcmp(s, "if") == 0) || strcmp(s, "enddo") == 0 || strcmp(s, "endif") == 0) {
        lev = -1;
    } else if ((strcmp(prevWord, "do") == 0 && strcmp(s, "while") == 0) || strcmp(s, "then") == 0) {
        lev = 1;
    }
    return lev;
}
// Folding the code
static void FoldDMAPDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
                           WordList *[], Accessor &styler) {
    //
    // bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
    // Do not know how to fold the comment at the moment.
    //
    bool foldCompact = styler.GetPropertyInt("fold.compact", 1) != 0;
    Sci_PositionU endPos = startPos + length;
    int visibleChars = 0;
    Sci_Position lineCurrent = styler.GetLine(startPos);
    int levelPrev = styler.LevelAt(lineCurrent) & SC_FOLDLEVELNUMBERMASK;
    int levelCurrent = levelPrev;
    char chNext = styler[startPos];
    int styleNext = styler.StyleAt(startPos);
    int style = initStyle;
    /***************************************/
    Sci_Position lastStart = 0;
    char prevWord[32] = "";
    /***************************************/
    for (Sci_PositionU i = startPos; i < endPos; i++) {
        char ch = chNext;
        chNext = styler.SafeGetCharAt(i + 1);
        int stylePrev = style;
        style = styleNext;
        styleNext = styler.StyleAt(i + 1);
        bool atEOL = (ch == '\r' && chNext != '\n') || (ch == '\n');
        //
        if ((stylePrev == SCE_DMAP_DEFAULT || stylePrev == SCE_DMAP_OPERATOR || stylePrev == SCE_DMAP_COMMENT) && (style == SCE_DMAP_WORD)) {
            // Store last word and label start point.
            lastStart = i;
        }
        /***************************************/
        if (style == SCE_DMAP_WORD) {
            if(iswordchar(ch) && !iswordchar(chNext)) {
                char s[32];
                Sci_PositionU k;
                for(k=0; (k<31 ) && (k<i-lastStart+1 ); k++) {
                    s[k] = static_cast<char>(tolower(styler[lastStart+k]));
                }
                s[k] = '\0';
                levelCurrent += classifyFoldPointDMAP(s, prevWord);
                strcpy(prevWord, s);
            }
        }
        if (atEOL) {
            int lev = levelPrev;
            if (visibleChars == 0 && foldCompact)
                lev |= SC_FOLDLEVELWHITEFLAG;
            if ((levelCurrent > levelPrev) && (visibleChars > 0))
                lev |= SC_FOLDLEVELHEADERFLAG;
            if (lev != styler.LevelAt(lineCurrent)) {
                styler.SetLevel(lineCurrent, lev);
            }
            lineCurrent++;
            levelPrev = levelCurrent;
            visibleChars = 0;
            strcpy(prevWord, "");
        }
        /***************************************/
        if (!isspacechar(ch)) visibleChars++;
    }
    /***************************************/
    // Fill in the real level of the next line, keeping the current flags as they will be filled in later
    int flagsNext = styler.LevelAt(lineCurrent) & ~SC_FOLDLEVELNUMBERMASK;
    styler.SetLevel(lineCurrent, levelPrev | flagsNext);
}
/***************************************/
static const char * const DMAPWordLists[] = {
    "Primary keywords and identifiers",
    "Intrinsic functions",
    "Extended and user defined functions",
    0,
};
/***************************************/
LexerModule lmDMAP(SCLEX_DMAP, ColouriseDMAPDoc, "DMAP", FoldDMAPDoc, DMAPWordLists);