// Scintilla source code edit control
// @file LexAU3.cxx
// Lexer for AutoIt3  http://www.hiddensoft.com/autoit3
// by Jos van der Zande, jvdzande@yahoo.com
//
// Changes:
// March 28, 2004 - Added the standard Folding code
// April 21, 2004 - Added Preprosessor Table + Syntax Highlighting
//                  Fixed Number highlighting
//                  Changed default isoperator to IsAOperator to have a better match to AutoIt3
//                  Fixed "#comments_start" -> "#comments-start"
//                  Fixed "#comments_end" -> "#comments-end"
//                  Fixed Sendkeys in Strings when not terminated with }
//                  Added support for Sendkey strings that have second parameter e.g. {UP 5} or {a down}
// April 26, 2004 - Fixed # pre-processor statement inside of comment block would invalidly change the color.
//                  Added logic for #include <xyz.au3> to treat the <> as string
//                  Added underscore to IsAOperator.
// May 17, 2004   - Changed the folding logic from indent to keyword folding.
//                  Added Folding logic for blocks of single-commentlines or commentblock.
//                        triggered by: fold.comment=1
//                  Added Folding logic for preprocessor blocks triggered by fold.preprocessor=1
//                  Added Special for #region - #endregion syntax highlight and folding.
// May 30, 2004   - Fixed issue with continuation lines on If statements.
// June 5, 2004   - Added comma to Operators for better readability.
//                  Added fold.compact support set with fold.compact=1
//                  Changed folding inside of #cs-#ce. Default is no keyword folding inside comment blocks when fold.comment=1
//                        it will now only happen when fold.comment=2.
// Sep 5, 2004    - Added logic to handle colourizing words on the last line.
//                        Typed Characters now show as "default" till they match any table.
// Oct 10, 2004   - Added logic to show Comments in "Special" directives.
// Nov  1, 2004   - Added better testing for Numbers supporting x and e notation.
// Nov 28, 2004   - Added logic to handle continuation lines for syntax highlighting.
// Jan 10, 2005   - Added Abbreviations Keyword used for expansion
// Mar 24, 2005   - Updated Abbreviations Keywords to fix when followed by Operator.
// Apr 18, 2005   - Updated #CE/#Comment-End logic to take a linecomment ";" into account
//                - Added folding support for With...EndWith
//                - Added support for a DOT in variable names
//                - Fixed Underscore in CommentBlock
// May 23, 2005   - Fixed the SentKey lexing in case of a missing }
// Aug 11, 2005   - Fixed possible bug with s_save length > 100.
// Aug 23, 2005   - Added Switch/endswitch support to the folding logic.
// Sep 27, 2005   - Fixed the SentKey lexing logic in case of multiple sentkeys.
// Mar 12, 2006   - Fixed issue with <> coloring as String in stead of Operator in rare occasions.
// Apr  8, 2006   - Added support for AutoIt3 Standard UDF library (SCE_AU3_UDF)
// Mar  9, 2007   - Fixed bug with + following a String getting the wrong Color.
// Jun 20, 2007   - Fixed Commentblock issue when LF's are used as EOL.
// Jul 26, 2007   - Fixed #endregion undetected bug.
//
// Copyright for Scintilla: 1998-2001 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
// Scintilla source code edit control

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include <assert.h>
#include <ctype.h>

#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"

#ifdef SCI_NAMESPACE
using namespace Scintilla;
#endif

static inline bool IsTypeCharacter(const int ch)
{
    return ch == '$';
}
static inline bool IsAWordChar(const int ch)
{
    return (ch < 0x80) && (isalnum(ch) || ch == '_');
}

static inline bool IsAWordStart(const int ch)
{
    return (ch < 0x80) && (isalnum(ch) || ch == '_' || ch == '@' || ch == '#' || ch == '$' || ch == '.');
}

static inline bool IsAOperator(char ch) {
    if (isascii(ch) && isalnum(ch))
        return false;
    if (ch == '+' || ch == '-' || ch == '*' || ch == '/' ||
        ch == '&' || ch == '^' || ch == '=' || ch == '<' || ch == '>' ||
        ch == '(' || ch == ')' || ch == '[' || ch == ']' || ch == ',' )
        return true;
    return false;
}

///////////////////////////////////////////////////////////////////////////////
// GetSendKey() filters the portion before and after a/multiple space(s)
// and return the first portion to be looked-up in the table
// also check if the second portion is valid... (up,down.on.off,toggle or a number)
///////////////////////////////////////////////////////////////////////////////

static int GetSendKey(const char *szLine, char *szKey)
{
    int     nFlag   = 0;
    int     nStartFound = 0;
    int     nKeyPos = 0;
    int     nSpecPos= 0;
    int     nSpecNum= 1;
    int     nPos    = 0;
    char    cTemp;
    char    szSpecial[100];

    // split the portion of the sendkey in the part before and after the spaces
    while ( ( (cTemp = szLine[nPos]) != '\0'))
    {
        // skip leading Ctrl/Shift/Alt state
        if (cTemp == '{') {
            nStartFound = 1;
        }
        //
        if (nStartFound == 1) {
            if ((cTemp == ' ') && (nFlag == 0) ) // get the stuff till first space
            {
                nFlag = 1;
                // Add } to the end of the first bit for table lookup later.
                szKey[nKeyPos++] = '}';
            }
            else if (cTemp == ' ')
            {
                // skip other spaces
            }
            else if (nFlag == 0)
            {
                // save first portion into var till space or } is hit
                szKey[nKeyPos++] = cTemp;
            }
            else if ((nFlag == 1) && (cTemp != '}'))
            {
                // Save second portion into var...
                szSpecial[nSpecPos++] = cTemp;
                // check if Second portion is all numbers for repeat fuction
                if (isdigit(cTemp) == false) {nSpecNum = 0;}
            }
        }
        nPos++;                                 // skip to next char

    } // End While


    // Check if the second portion is either a number or one of these keywords
    szKey[nKeyPos] = '\0';
    szSpecial[nSpecPos] = '\0';
    if (strcmp(szSpecial,"down")== 0    || strcmp(szSpecial,"up")== 0  ||
        strcmp(szSpecial,"on")== 0      || strcmp(szSpecial,"off")== 0 ||
        strcmp(szSpecial,"toggle")== 0  || nSpecNum == 1 )
    {
        nFlag = 0;
    }
    else
    {
        nFlag = 1;
    }
    return nFlag;  // 1 is bad, 0 is good

} // GetSendKey()

//
// Routine to check the last "none comment" character on a line to see if its a continuation
//
static bool IsContinuationLine(unsigned int szLine, Accessor &styler)
{
    int nsPos = styler.LineStart(szLine);
    int nePos = styler.LineStart(szLine+1) - 2;
    //int stylech = styler.StyleAt(nsPos);
    while (nsPos < nePos)
    {
        //stylech = styler.StyleAt(nePos);
        int stylech = styler.StyleAt(nsPos);
        if (!(stylech == SCE_AU3_COMMENT)) {
            char ch = styler.SafeGetCharAt(nePos);
            if (!isspacechar(ch)) {
                if (ch == '_')
                    return true;
                else
                    return false;
            }
        }
        nePos--; // skip to next char
    } // End While
    return false;
} // IsContinuationLine()

//
// syntax highlighting logic
static void ColouriseAU3Doc(unsigned int startPos,
                            int length, int initStyle,
                            WordList *keywordlists[],
                            Accessor &styler) {

    WordList &keywords = *keywordlists[0];
    WordList &keywords2 = *keywordlists[1];
    WordList &keywords3 = *keywordlists[2];
    WordList &keywords4 = *keywordlists[3];
    WordList &keywords5 = *keywordlists[4];
    WordList &keywords6 = *keywordlists[5];
    WordList &keywords7 = *keywordlists[6];
    WordList &keywords8 = *keywordlists[7];
    // find the first previous line without continuation character at the end
    int lineCurrent = styler.GetLine(startPos);
    int s_startPos = startPos;
    // When not inside a Block comment: find First line without _
    if (!(initStyle==SCE_AU3_COMMENTBLOCK)) {
        while ((lineCurrent > 0 && IsContinuationLine(lineCurrent,styler)) ||
               (lineCurrent > 1 && IsContinuationLine(lineCurrent-1,styler))) {
            lineCurrent--;
            startPos = styler.LineStart(lineCurrent); // get start position
            initStyle =  0;                           // reset the start style to 0
        }
    }
    // Set the new length to include it from the start and set the start position
    length = length + s_startPos - startPos;      // correct the total length to process
    styler.StartAt(startPos);

    StyleContext sc(startPos, length, initStyle, styler);
    char si;     // string indicator "=1 '=2
    char ni;     // Numeric indicator error=9 normal=0 normal+dec=1 hex=2 Enot=3
    char ci;     // comment indicator 0=not linecomment(;)
    char s_save[100];
    si=0;
    ni=0;
    ci=0;
    //$$$
    for (; sc.More(); sc.Forward()) {
        char s[100];
        sc.GetCurrentLowered(s, sizeof(s));
        // **********************************************
        // save the total current word for eof processing
        if (IsAWordChar(sc.ch) || sc.ch == '}')
        {
            strcpy(s_save,s);
            int tp = static_cast<int>(strlen(s_save));
            if (tp < 99) {
                s_save[tp] = static_cast<char>(tolower(sc.ch));
                s_save[tp+1] = '\0';
            }
        }
        // **********************************************
        //
        switch (sc.state)
        {
            case SCE_AU3_COMMENTBLOCK:
            {
                //Reset at line end
                if (sc.atLineEnd) {
                    ci=0;
                    if (strcmp(s, "#ce")== 0 || strcmp(s, "#comments-end")== 0) {
                        if (sc.atLineEnd)
                            sc.SetState(SCE_AU3_DEFAULT);
                        else
                            sc.SetState(SCE_AU3_COMMENTBLOCK);
                    }
                    break;
                }
                //skip rest of line when a ; is encountered
                if (sc.chPrev == ';') {
                    ci=2;
                    sc.SetState(SCE_AU3_COMMENTBLOCK);
                }
                // skip rest of the line
                if (ci==2)
                    break;
                // check when first character is detected on the line
                if (ci==0) {
                    if (IsAWordStart(static_cast<char>(sc.ch)) || IsAOperator(static_cast<char>(sc.ch))) {
                        ci=1;
                        sc.SetState(SCE_AU3_COMMENTBLOCK);
                    }
                    break;
                }
                if (!(IsAWordChar(sc.ch) || (sc.ch == '-' && strcmp(s, "#comments") == 0))) {
                    if ((strcmp(s, "#ce")== 0 || strcmp(s, "#comments-end")== 0))
                            sc.SetState(SCE_AU3_COMMENT);  // set to comment line for the rest of the line
                    else
                        ci=2;  // line doesn't begin with #CE so skip the rest of the line
                }
                break;
            }
            case SCE_AU3_COMMENT:
            {
                if (sc.atLineEnd) {sc.SetState(SCE_AU3_DEFAULT);}
                break;
            }
            case SCE_AU3_OPERATOR:
            {
                // check if its a COMobject
                if (sc.chPrev == '.' && IsAWordChar(sc.ch)) {
                    sc.SetState(SCE_AU3_COMOBJ);
                }
                else {
                    sc.SetState(SCE_AU3_DEFAULT);
                }
                break;
            }
            case SCE_AU3_SPECIAL:
            {
                if (sc.ch == ';') {sc.SetState(SCE_AU3_COMMENT);}
                if (sc.atLineEnd) {sc.SetState(SCE_AU3_DEFAULT);}
                break;
            }
            case SCE_AU3_KEYWORD:
            {
                if (!(IsAWordChar(sc.ch) || (sc.ch == '-' && (strcmp(s, "#comments") == 0 || strcmp(s, "#include") == 0))))
                {
                    if (!IsTypeCharacter(sc.ch))
                    {
                        if (strcmp(s, "#cs")== 0 || strcmp(s, "#comments-start")== 0 )
                        {
                            sc.ChangeState(SCE_AU3_COMMENTBLOCK);
                            sc.SetState(SCE_AU3_COMMENTBLOCK);
                            break;
                        }
                        else if (keywords.InList(s)) {
                            sc.ChangeState(SCE_AU3_KEYWORD);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                        else if (keywords2.InList(s)) {
                            sc.ChangeState(SCE_AU3_FUNCTION);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                        else if (keywords3.InList(s)) {
                            sc.ChangeState(SCE_AU3_MACRO);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                        else if (keywords5.InList(s)) {
                            sc.ChangeState(SCE_AU3_PREPROCESSOR);
                            sc.SetState(SCE_AU3_DEFAULT);
                            if (strcmp(s, "#include")== 0)
                            {
                                si = 3;   // use to determine string start for #inlude <>
                            }
                        }
                        else if (keywords6.InList(s)) {
                            sc.ChangeState(SCE_AU3_SPECIAL);
                            sc.SetState(SCE_AU3_SPECIAL);
                        }
                        else if ((keywords7.InList(s)) && (!IsAOperator(static_cast<char>(sc.ch)))) {
                            sc.ChangeState(SCE_AU3_EXPAND);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                        else if (keywords8.InList(s)) {
                            sc.ChangeState(SCE_AU3_UDF);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                        else if (strcmp(s, "_") == 0) {
                            sc.ChangeState(SCE_AU3_OPERATOR);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                        else if (!IsAWordChar(sc.ch)) {
                            sc.ChangeState(SCE_AU3_DEFAULT);
                            sc.SetState(SCE_AU3_DEFAULT);
                        }
                    }
                }
                if (sc.atLineEnd) {
                    sc.SetState(SCE_AU3_DEFAULT);}
                break;
            }
            case SCE_AU3_NUMBER:
            {
                // Numeric indicator error=9 normal=0 normal+dec=1 hex=2 E-not=3
                //
                // test for Hex notation
                if (strcmp(s, "0") == 0 && (sc.ch == 'x' || sc.ch == 'X') && ni == 0)
                {
                    ni = 2;
                    break;
                }
                // test for E notation
                if (IsADigit(sc.chPrev) && (sc.ch == 'e' || sc.ch == 'E') && ni <= 1)
                {
                    ni = 3;
                    break;
                }
                //  Allow Hex characters inside hex numeric strings
                if ((ni == 2) &&
                    (sc.ch == 'a' || sc.ch == 'b' || sc.ch == 'c' || sc.ch == 'd' || sc.ch == 'e' || sc.ch == 'f' ||
                     sc.ch == 'A' || sc.ch == 'B' || sc.ch == 'C' || sc.ch == 'D' || sc.ch == 'E' || sc.ch == 'F' ))
                {
                    break;
                }
                // test for 1 dec point only
                if (sc.ch == '.')
                {
                    if (ni==0)
                    {
                        ni=1;
                    }
                    else
                    {
                        ni=9;
                    }
                    break;
                }
                // end of numeric string ?
                if (!(IsADigit(sc.ch)))
                {
                    if (ni==9)
                    {
                        sc.ChangeState(SCE_AU3_DEFAULT);
                    }
                    sc.SetState(SCE_AU3_DEFAULT);
                }
                break;
            }
            case SCE_AU3_VARIABLE:
            {
                // Check if its a COMObject
                if (sc.ch == '.' && !IsADigit(sc.chNext)) {
                    sc.SetState(SCE_AU3_OPERATOR);
                }
                else if (!IsAWordChar(sc.ch)) {
                    sc.SetState(SCE_AU3_DEFAULT);
                }
                break;
            }
            case SCE_AU3_COMOBJ:
            {
                if (!(IsAWordChar(sc.ch))) {
                    sc.SetState(SCE_AU3_DEFAULT);
                }
                break;
            }
            case SCE_AU3_STRING:
            {
                // check for " to end a double qouted string or
                // check for ' to end a single qouted string
                if ((si == 1 && sc.ch == '\"') || (si == 2 && sc.ch == '\'') || (si == 3 && sc.ch == '>'))
                {
                    sc.ForwardSetState(SCE_AU3_DEFAULT);
                    si=0;
                    break;
                }
                if (sc.atLineEnd)
                {
                    si=0;
                    // at line end and not found a continuation char then reset to default
                    int lineCurrent = styler.GetLine(sc.currentPos);
                    if (!IsContinuationLine(lineCurrent,styler))
                    {
                        sc.SetState(SCE_AU3_DEFAULT);
                        break;
                    }
                }
                // find Sendkeys in a STRING
                if (sc.ch == '{' || sc.ch == '+' || sc.ch == '!' || sc.ch == '^' || sc.ch == '#' ) {
                    sc.SetState(SCE_AU3_SENT);}
                break;
            }

            case SCE_AU3_SENT:
            {
                // Send key string ended
                if (sc.chPrev == '}' && sc.ch != '}')
                {
                    // set color to SENDKEY when valid sendkey .. else set back to regular string
                    char sk[100];
                    // split {111 222} and return {111} and check if 222 is valid.
                    // if return code = 1 then invalid 222 so must be string
                    if (GetSendKey(s,sk))
                    {
                        sc.ChangeState(SCE_AU3_STRING);
                    }
                    // if single char between {?} then its ok as sendkey for a single character
                    else if (strlen(sk) == 3)
                    {
                        sc.ChangeState(SCE_AU3_SENT);
                    }
                    // if sendkey {111} is in table then ok as sendkey
                    else if (keywords4.InList(sk))
                    {
                        sc.ChangeState(SCE_AU3_SENT);
                    }
                    else
                    {
                        sc.ChangeState(SCE_AU3_STRING);
                    }
                    sc.SetState(SCE_AU3_STRING);
                }
                else
                {
                    // check if the start is a valid SendKey start
                    int     nPos    = 0;
                    int     nState  = 1;
                    char    cTemp;
                    while (!(nState == 2) && ((cTemp = s[nPos]) != '\0'))
                    {
                        if (cTemp == '{' && nState == 1)
                        {
                            nState = 2;
                        }
                        if (nState == 1 && !(cTemp == '+' || cTemp == '!' || cTemp == '^' || cTemp == '#' ))
                        {
                            nState = 0;
                        }
                        nPos++;
                    }
                    //Verify characters infront of { ... if not assume  regular string
                    if (nState == 1 && (!(sc.ch == '{' || sc.ch == '+' || sc.ch == '!' || sc.ch == '^' || sc.ch == '#' ))) {
                        sc.ChangeState(SCE_AU3_STRING);
                        sc.SetState(SCE_AU3_STRING);
                    }
                    // If invalid character found then assume its a regular string
                    if (nState == 0) {
                        sc.ChangeState(SCE_AU3_STRING);
                        sc.SetState(SCE_AU3_STRING);
                    }
                }
                // check if next portion is again a sendkey
                if (sc.atLineEnd)
                {
                    sc.ChangeState(SCE_AU3_STRING);
                    sc.SetState(SCE_AU3_DEFAULT);
                    si = 0;  // reset string indicator
                }
                //* check in next characters following a sentkey are again a sent key
                // Need this test incase of 2 sentkeys like {F1}{ENTER} but not detect {{}
                if (sc.state == SCE_AU3_STRING && (sc.ch == '{' || sc.ch == '+' || sc.ch == '!' || sc.ch == '^' || sc.ch == '#' )) {
                    sc.SetState(SCE_AU3_SENT);}
                // check to see if the string ended...
                // Sendkey string isn't complete but the string ended....
                if ((si == 1 && sc.ch == '\"') || (si == 2 && sc.ch == '\''))
                {
                    sc.ChangeState(SCE_AU3_STRING);
                    sc.ForwardSetState(SCE_AU3_DEFAULT);
                }
                break;
            }
        }  //switch (sc.state)

        // Determine if a new state should be entered:

        if (sc.state == SCE_AU3_DEFAULT)
        {
            if (sc.ch == ';') {sc.SetState(SCE_AU3_COMMENT);}
            else if (sc.ch == '#') {sc.SetState(SCE_AU3_KEYWORD);}
            else if (sc.ch == '$') {sc.SetState(SCE_AU3_VARIABLE);}
            else if (sc.ch == '.' && !IsADigit(sc.chNext)) {sc.SetState(SCE_AU3_OPERATOR);}
            else if (sc.ch == '@') {sc.SetState(SCE_AU3_KEYWORD);}
            //else if (sc.ch == '_') {sc.SetState(SCE_AU3_KEYWORD);}
            else if (sc.ch == '<' && si==3) {sc.SetState(SCE_AU3_STRING);}  // string after #include
            else if (sc.ch == '\"') {
                sc.SetState(SCE_AU3_STRING);
                si = 1; }
            else if (sc.ch == '\'') {
                sc.SetState(SCE_AU3_STRING);
                si = 2; }
            else if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext)))
            {
                sc.SetState(SCE_AU3_NUMBER);
                ni = 0;
            }
            else if (IsAWordStart(sc.ch)) {sc.SetState(SCE_AU3_KEYWORD);}
            else if (IsAOperator(static_cast<char>(sc.ch))) {sc.SetState(SCE_AU3_OPERATOR);}
            else if (sc.atLineEnd) {sc.SetState(SCE_AU3_DEFAULT);}
        }
    }      //for (; sc.More(); sc.Forward())

    //*************************************
    // Colourize the last word correctly
    //*************************************
    if (sc.state == SCE_AU3_KEYWORD)
        {
        if (strcmp(s_save, "#cs")== 0 || strcmp(s_save, "#comments-start")== 0 )
        {
            sc.ChangeState(SCE_AU3_COMMENTBLOCK);
            sc.SetState(SCE_AU3_COMMENTBLOCK);
        }
        else if (keywords.InList(s_save)) {
            sc.ChangeState(SCE_AU3_KEYWORD);
            sc.SetState(SCE_AU3_KEYWORD);
        }
        else if (keywords2.InList(s_save)) {
            sc.ChangeState(SCE_AU3_FUNCTION);
            sc.SetState(SCE_AU3_FUNCTION);
        }
        else if (keywords3.InList(s_save)) {
            sc.ChangeState(SCE_AU3_MACRO);
            sc.SetState(SCE_AU3_MACRO);
        }
        else if (keywords5.InList(s_save)) {
            sc.ChangeState(SCE_AU3_PREPROCESSOR);
            sc.SetState(SCE_AU3_PREPROCESSOR);
        }
        else if (keywords6.InList(s_save)) {
            sc.ChangeState(SCE_AU3_SPECIAL);
            sc.SetState(SCE_AU3_SPECIAL);
        }
        else if (keywords7.InList(s_save) && sc.atLineEnd) {
            sc.ChangeState(SCE_AU3_EXPAND);
            sc.SetState(SCE_AU3_EXPAND);
        }
        else if (keywords8.InList(s_save)) {
            sc.ChangeState(SCE_AU3_UDF);
            sc.SetState(SCE_AU3_UDF);
        }
        else {
            sc.ChangeState(SCE_AU3_DEFAULT);
            sc.SetState(SCE_AU3_DEFAULT);
        }
    }
    if (sc.state == SCE_AU3_SENT)
    {
        // Send key string ended
        if (sc.chPrev == '}' && sc.ch != '}')
        {
            // set color to SENDKEY when valid sendkey .. else set back to regular string
            char sk[100];
            // split {111 222} and return {111} and check if 222 is valid.
            // if return code = 1 then invalid 222 so must be string
            if (GetSendKey(s_save,sk))
            {
                sc.ChangeState(SCE_AU3_STRING);
            }
            // if single char between {?} then its ok as sendkey for a single character
            else if (strlen(sk) == 3)
            {
                sc.ChangeState(SCE_AU3_SENT);
            }
            // if sendkey {111} is in table then ok as sendkey
            else if (keywords4.InList(sk))
            {
                sc.ChangeState(SCE_AU3_SENT);
            }
            else
            {
                sc.ChangeState(SCE_AU3_STRING);
            }
            sc.SetState(SCE_AU3_STRING);
        }
        // check if next portion is again a sendkey
        if (sc.atLineEnd)
        {
            sc.ChangeState(SCE_AU3_STRING);
            sc.SetState(SCE_AU3_DEFAULT);
        }
    }
    //*************************************
    sc.Complete();
}

//
static bool IsStreamCommentStyle(int style) {
    return style == SCE_AU3_COMMENT || style == SCE_AU3_COMMENTBLOCK;
}

//
// Routine to find first none space on the current line and return its Style
// needed for comment lines not starting on pos 1
static int GetStyleFirstWord(unsigned int szLine, Accessor &styler)
{
    int nsPos = styler.LineStart(szLine);
    int nePos = styler.LineStart(szLine+1) - 1;
    while (isspacechar(styler.SafeGetCharAt(nsPos)) && nsPos < nePos)
    {
        nsPos++; // skip to next char

    } // End While
    return styler.StyleAt(nsPos);

} // GetStyleFirstWord()


//
static void FoldAU3Doc(unsigned int startPos, int length, int, WordList *[], Accessor &styler)
{
    int endPos = startPos + length;
    // get settings from the config files for folding comments and preprocessor lines
    bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
    bool foldInComment = styler.GetPropertyInt("fold.comment") == 2;
    bool foldCompact = styler.GetPropertyInt("fold.compact", 1) != 0;
    bool foldpreprocessor = styler.GetPropertyInt("fold.preprocessor") != 0;
    // Backtrack to previous line in case need to fix its fold status
    int lineCurrent = styler.GetLine(startPos);
    if (startPos > 0) {
        if (lineCurrent > 0) {
            lineCurrent--;
            startPos = styler.LineStart(lineCurrent);
        }
    }
    // vars for style of previous/current/next lines
    int style = GetStyleFirstWord(lineCurrent,styler);
    int stylePrev = 0;
    // find the first previous line without continuation character at the end
    while ((lineCurrent > 0 && IsContinuationLine(lineCurrent,styler)) ||
           (lineCurrent > 1 && IsContinuationLine(lineCurrent-1,styler))) {
        lineCurrent--;
        startPos = styler.LineStart(lineCurrent);
    }
    if (lineCurrent > 0) {
        stylePrev = GetStyleFirstWord(lineCurrent-1,styler);
    }
    // vars for getting first word to check for keywords
    bool FirstWordStart = false;
    bool FirstWordEnd = false;
    char szKeyword[11]="";
    int  szKeywordlen = 0;
    char szThen[5]="";
    int  szThenlen = 0;
    bool ThenFoundLast = false;
    // var for indentlevel
    int levelCurrent = SC_FOLDLEVELBASE;
    if (lineCurrent > 0)
        levelCurrent = styler.LevelAt(lineCurrent-1) >> 16;
    int levelNext = levelCurrent;
    //
    int visibleChars = 0;
    char chNext = styler.SafeGetCharAt(startPos);
    char chPrev = ' ';
    //
    for (int i = startPos; i < endPos; i++) {
        char ch = chNext;
        chNext = styler.SafeGetCharAt(i + 1);
        if (IsAWordChar(ch)) {
            visibleChars++;
        }
        // get the syle for the current character neede to check in comment
        int stylech = styler.StyleAt(i);
        // get first word for the line for indent check max 9 characters
        if (FirstWordStart && (!(FirstWordEnd))) {
            if (!IsAWordChar(ch)) {
                FirstWordEnd = true;
                szKeyword[szKeywordlen] = '\0';
            }
            else {
                if (szKeywordlen < 10) {
                szKeyword[szKeywordlen++] = static_cast<char>(tolower(ch));
                }
            }
        }
        // start the capture of the first word
        if (!(FirstWordStart)) {
            if (IsAWordChar(ch) || IsAWordStart(ch) || ch == ';') {
                FirstWordStart = true;
                szKeyword[szKeywordlen++] = static_cast<char>(tolower(ch));
            }
        }
        // only process this logic when not in comment section
        if (!(stylech == SCE_AU3_COMMENT)) {
            if (ThenFoundLast) {
                if (IsAWordChar(ch)) {
                    ThenFoundLast = false;
                }
            }
            // find out if the word "then" is the last on a "if" line
            if (FirstWordEnd && strcmp(szKeyword,"if") == 0) {
                if (szThenlen == 4) {
                    szThen[0] = szThen[1];
                    szThen[1] = szThen[2];
                    szThen[2] = szThen[3];
                    szThen[3] = static_cast<char>(tolower(ch));
                    if (strcmp(szThen,"then") == 0 ) {
                        ThenFoundLast = true;
                    }
                }
                else {
                    szThen[szThenlen++] = static_cast<char>(tolower(ch));
                    if (szThenlen == 5) {
                        szThen[4] = '\0';
                    }
                }
            }
        }
        // End of Line found so process the information
        if ((ch == '\r' && chNext != '\n') || (ch == '\n') || (i == endPos)) {
            // **************************
            // Folding logic for Keywords
            // **************************
            // if a keyword is found on the current line and the line doesn't end with _ (continuation)
            //    and we are not inside a commentblock.
            if (szKeywordlen > 0 && (!(chPrev == '_')) &&
                ((!(IsStreamCommentStyle(style)) || foldInComment)) ) {
                szKeyword[szKeywordlen] = '\0';
                // only fold "if" last keyword is "then"  (else its a one line if)
                if (strcmp(szKeyword,"if") == 0  && ThenFoundLast) {
                        levelNext++;
                }
                // create new fold for these words
                if (strcmp(szKeyword,"do") == 0   || strcmp(szKeyword,"for") == 0 ||
                    strcmp(szKeyword,"func") == 0 || strcmp(szKeyword,"while") == 0||
                    strcmp(szKeyword,"with") == 0 || strcmp(szKeyword,"#region") == 0 ) {
                        levelNext++;
                }
                // create double Fold for select&switch because Case will subtract one of the current level
                if (strcmp(szKeyword,"select") == 0 || strcmp(szKeyword,"switch") == 0) {
                        levelNext++;
                        levelNext++;
                }
                // end the fold for these words before the current line
                if (strcmp(szKeyword,"endfunc") == 0 || strcmp(szKeyword,"endif") == 0 ||
                    strcmp(szKeyword,"next") == 0    || strcmp(szKeyword,"until") == 0 ||
                    strcmp(szKeyword,"endwith") == 0 ||strcmp(szKeyword,"wend") == 0){
                        levelNext--;
                        levelCurrent--;
                }
                // end the fold for these words before the current line and Start new fold
                if (strcmp(szKeyword,"case") == 0      || strcmp(szKeyword,"else") == 0 ||
                    strcmp(szKeyword,"elseif") == 0 ) {
                        levelCurrent--;
                }
                // end the double fold for this word before the current line
                if (strcmp(szKeyword,"endselect") == 0 || strcmp(szKeyword,"endswitch") == 0 ) {
                        levelNext--;
                        levelNext--;
                        levelCurrent--;
                        levelCurrent--;
                }
                // end the fold for these words on the current line
                if (strcmp(szKeyword,"#endregion") == 0 ) {
                        levelNext--;
                }
            }
            // Preprocessor and Comment folding
            int styleNext = GetStyleFirstWord(lineCurrent + 1,styler);
            // *************************************
            // Folding logic for preprocessor blocks
            // *************************************
            // process preprosessor line
            if (foldpreprocessor && style == SCE_AU3_PREPROCESSOR) {
                if (!(stylePrev == SCE_AU3_PREPROCESSOR) && (styleNext == SCE_AU3_PREPROCESSOR)) {
                    levelNext++;
                }
                // fold till the last line for normal comment lines
                else if (stylePrev == SCE_AU3_PREPROCESSOR && !(styleNext == SCE_AU3_PREPROCESSOR)) {
                    levelNext--;
                }
            }
            // *********************************
            // Folding logic for Comment blocks
            // *********************************
            if (foldComment && IsStreamCommentStyle(style)) {
                // Start of a comment block
                if (!(stylePrev==style) && IsStreamCommentStyle(styleNext) && styleNext==style) {
                    levelNext++;
                }
                // fold till the last line for normal comment lines
                else if (IsStreamCommentStyle(stylePrev)
                        && !(styleNext == SCE_AU3_COMMENT)
                        && stylePrev == SCE_AU3_COMMENT
                        && style == SCE_AU3_COMMENT) {
                    levelNext--;
                }
                // fold till the one but last line for Blockcomment lines
                else if (IsStreamCommentStyle(stylePrev)
                        && !(styleNext == SCE_AU3_COMMENTBLOCK)
                        && style == SCE_AU3_COMMENTBLOCK) {
                    levelNext--;
                    levelCurrent--;
                }
            }
            int levelUse = levelCurrent;
            int lev = levelUse | levelNext << 16;
            if (visibleChars == 0 && foldCompact)
                lev |= SC_FOLDLEVELWHITEFLAG;
            if (levelUse < levelNext) {
                lev |= SC_FOLDLEVELHEADERFLAG;
            }
            if (lev != styler.LevelAt(lineCurrent)) {
                styler.SetLevel(lineCurrent, lev);
            }
            // reset values for the next line
            lineCurrent++;
            stylePrev = style;
            style = styleNext;
            levelCurrent = levelNext;
            visibleChars = 0;
            // if the last character is an Underscore then don't reset since the line continues on the next line.
            if (!(chPrev == '_')) {
                szKeywordlen = 0;
                szThenlen = 0;
                FirstWordStart = false;
                FirstWordEnd = false;
                ThenFoundLast = false;
            }
        }
        // save the last processed character
        if (!isspacechar(ch)) {
            chPrev = ch;
            visibleChars++;
        }
    }
}


//

static const char * const AU3WordLists[] = {
    "#autoit keywords",
    "#autoit functions",
    "#autoit macros",
    "#autoit Sent keys",
    "#autoit Pre-processors",
    "#autoit Special",
    "#autoit Expand",
    "#autoit UDF",
    0
};
LexerModule lmAU3(SCLEX_AU3, ColouriseAU3Doc, "au3", FoldAU3Doc , AU3WordLists);
