// Scintilla source code edit control
/** @file LexCPP.cxx
 ** Lexer for C++, C, Java, and JavaScript.
 **/
// Copyright 1998-2005 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 <ctype.h>
#include <stdio.h>
#include <stdarg.h> 

#include "Platform.h"

#include "PropSet.h"
#include "Accessor.h"
#include "StyleContext.h"
#include "KeyWords.h"
#include "Scintilla.h"
#include "SciLexer.h"
#include "CharacterSet.h"
#include "string"

#ifdef SCI_NAMESPACE
using namespace Scintilla;
#endif

#if 0
extern std::string GetCurrentFileName();
#endif

static bool IsDisabledCodeEnd(Accessor &styler, StyleContext &sc, int &depth) {
	char buf[6];
	int offset(0);
	
	char chWhite(0);
	//skip all prefix whitespaces
	do {
		offset++;
		chWhite = styler.SafeGetCharAt(sc.currentPos+offset, 0);
	} while( chWhite && (chWhite == '\t' || chWhite == ' '));
	
	buf[0] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[1] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[2] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[3] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[4] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[5] = 0;
	
	if (strcmp(buf, "endif") == 0) {
		if(depth == 0) {
			sc.Forward(5);
			return true;
		} else {
			depth--;
		}
	}
	return false;
}

#if 0
static bool IsPrepBlockStart(Accessor &styler, StyleContext &sc) {
	//check if this is a pre-preocessor block start
	//#if
	//#ifdef 
	char buf[6];
	int offset(0);
	
	char chWhite(0);
	//skip all prefix whitespaces
	do {
		offset++;
		chWhite = styler.SafeGetCharAt(sc.currentPos+offset, 0);
	} while( chWhite && (chWhite == '\t' || chWhite == ' '));
	
	buf[0] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[1] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[2] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[3] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[4] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[5] = 0;

	if (strncmp(buf, "if", 2) == 0 || strcmp(buf, "ifdef") == 0) {
		return true;
	}
	return false;
}
#endif

static bool IsDisabledCode(Accessor &styler, StyleContext &sc) {
	char buf[4];
	int offset(0);
	
	char chWhite(0);
	//skip all prefix whitespaces
	do {
		offset++;
		chWhite = styler.SafeGetCharAt(sc.currentPos+offset, 0);
	} while( chWhite && (chWhite == '\t' || chWhite == ' '));
	
	buf[0] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[1] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[2] = styler.SafeGetCharAt(sc.currentPos+offset, 0); offset++;
	buf[3] = 0;

	if (strcmp(buf, "if ") == 0 || strcmp(buf, "if\t") == 0) {
		//we found 'if ', check whether the next word is '0'
		char chNext = styler.SafeGetCharAt(sc.currentPos+offset, 0);
		while ( chNext ) {
			if (chNext == '\t' || chNext == ' ') {
				//skip whitespaces
				offset++;
				chNext = styler.SafeGetCharAt(sc.currentPos+offset, 0);
				continue;
			} else {
				//we got a valid char (which is not whitespace nor null)
				if (chNext == '0') {
					sc.SetState(SCE_C_PREPROCESSOR_DISABLED);
					return true;
				}
				break;
			}
		}
	}
	return false;
}

static bool IsSpaceEquiv(int state) {
	return (state <= SCE_C_COMMENTDOC) ||
	       // including SCE_C_DEFAULT, SCE_C_COMMENT, SCE_C_COMMENTLINE
	       (state == SCE_C_COMMENTLINEDOC) || (state == SCE_C_COMMENTDOCKEYWORD) ||
	       (state == SCE_C_COMMENTDOCKEYWORDERROR);
}

static void ColouriseCppDoc(unsigned int startPos, int length, int initStyle, WordList *keywordlists[],
                            Accessor &styler, bool caseSensitive) {

	WordList &keywords = *keywordlists[0];
	WordList &keywords2 = *keywordlists[1];
	WordList &keywords3 = *keywordlists[2];
	WordList &keywords4 = *keywordlists[3];

#if 0	
	static std::string file_name;
	static int depth(0);
	
	if (file_name != GetCurrentFileName()) {
		file_name = GetCurrentFileName();
		depth = 0;
	}
#endif

	bool stylingWithinPreprocessor = styler.GetPropertyInt("styling.within.preprocessor") != 0;

	CharacterSet setOKBeforeRE(CharacterSet::setNone, "(=,");

	CharacterSet setDoxygen(CharacterSet::setLower, "$@\\&<>#{}[]");

	CharacterSet setWordStart(CharacterSet::setAlpha, "_", 0x80, true);
	CharacterSet setWord(CharacterSet::setAlphaNum, "._", 0x80, true);
	if (styler.GetPropertyInt("lexer.cpp.allow.dollars", 1) != 0) {
		setWordStart.Add('$');
		setWord.Add('$');
	}

	int chPrevNonWhite = ' ';
	int visibleChars = 0;
	bool lastWordWasUUID = false;
	int styleBeforeDCKeyword = SCE_C_DEFAULT;
	bool continuationLine = false;

	if (initStyle == SCE_C_PREPROCESSOR) {
		// Set continuationLine if last character of previous line is '\'
		int lineCurrent = styler.GetLine(startPos);
		if (lineCurrent > 0) {
			int chBack = styler.SafeGetCharAt(startPos-1, 0);
			int chBack2 = styler.SafeGetCharAt(startPos-2, 0);
			int lineEndChar = '!';
			if (chBack2 == '\r' && chBack == '\n') {
				lineEndChar = styler.SafeGetCharAt(startPos-3, 0);
			} else if (chBack == '\n' || chBack == '\r') {
				lineEndChar = chBack2;
			}
			continuationLine = lineEndChar == '\\';
		}
	}

	// look back to set chPrevNonWhite properly for better regex colouring
	if (startPos > 0) {
		int back = startPos;
		while (--back && IsSpaceEquiv(styler.StyleAt(back)))
			;
		if (styler.StyleAt(back) == SCE_C_OPERATOR) {
			chPrevNonWhite = styler.SafeGetCharAt(back);
		}
	}

	StyleContext sc(startPos, length, initStyle, styler);

	for (; sc.More(); sc.Forward()) {

		if (sc.atLineStart) {
			if (sc.state == SCE_C_STRING) {
				// Prevent SCE_C_STRINGEOL from leaking back to previous line which
				// ends with a line continuation by locking in the state upto this position.
				sc.SetState(SCE_C_STRING);
			}
			// Reset states to begining of colourise so no surprises
			// if different sets of lines lexed.
			visibleChars = 0;
			lastWordWasUUID = false;
		}

		// Handle line continuation generically.
		if (sc.ch == '\\') {
			if (sc.chNext == '\n' || sc.chNext == '\r') {
				sc.Forward();
				if (sc.ch == '\r' && sc.chNext == '\n') {
					sc.Forward();
				}
				continuationLine = true;
				continue;
			}
		}

		// Determine if the current state should terminate.
		switch (sc.state) {
		case SCE_C_OPERATOR:
			sc.SetState(SCE_C_DEFAULT);
			break;
		case SCE_C_NUMBER:
			// We accept almost anything because of hex. and number suffixes
			if (!setWord.Contains(sc.ch)) {
				sc.SetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_IDENTIFIER:
			if (!setWord.Contains(sc.ch) || (sc.ch == '.')) {
				char s[1000];
				if (caseSensitive) {
					sc.GetCurrent(s, sizeof(s));
				} else {
					sc.GetCurrentLowered(s, sizeof(s));
				}
				if (keywords.InList(s)) {
					lastWordWasUUID = strcmp(s, "uuid") == 0;
					sc.ChangeState(SCE_C_WORD);
				} else if (keywords2.InList(s)) {
					sc.ChangeState(SCE_C_WORD2);
				} else if (keywords4.InList(s)) {
					sc.ChangeState(SCE_C_GLOBALCLASS);
				}
				sc.SetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_PREPROCESSOR:
			if (sc.atLineStart && !continuationLine) {
				sc.SetState(SCE_C_DEFAULT);
			} else if (stylingWithinPreprocessor) {
				if (IsASpace(sc.ch)) {
					sc.SetState(SCE_C_DEFAULT);
				}
			} else {
				if (sc.Match('/', '*') || sc.Match('/', '/')) {
					sc.SetState(SCE_C_DEFAULT);
				}
			}
			break;
		case SCE_C_PREPROCESSOR_DISABLED:
			if (visibleChars == 0 && sc.ch == '#') {
#if 0				
				if(IsPrepBlockStart(styler, sc)){
					//nested block, increase the depth
					depth++;
				} else 
#endif			
				int dummy(0);
				if(IsDisabledCodeEnd(styler, sc, dummy)){
					sc.ForwardSetState(SCE_C_DEFAULT);
				}
			}
			break;
		case SCE_C_COMMENT:
			if (sc.Match('*', '/')) {
				sc.Forward();
				sc.ForwardSetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_COMMENTDOC:
			if (sc.Match('*', '/')) {
				sc.Forward();
				sc.ForwardSetState(SCE_C_DEFAULT);
			} else if (sc.ch == '@' || sc.ch == '\\') { // JavaDoc and Doxygen support
				// Verify that we have the conditions to mark a comment-doc-keyword
				if ((IsASpace(sc.chPrev) || sc.chPrev == '*') && (!IsASpace(sc.chNext))) {
					styleBeforeDCKeyword = SCE_C_COMMENTDOC;
					sc.SetState(SCE_C_COMMENTDOCKEYWORD);
				}
			}
			break;
		case SCE_C_COMMENTLINE:
			if (sc.atLineStart) {
				sc.SetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_COMMENTLINEDOC:
			if (sc.atLineStart) {
				sc.SetState(SCE_C_DEFAULT);
			} else if (sc.ch == '@' || sc.ch == '\\') { // JavaDoc and Doxygen support
				// Verify that we have the conditions to mark a comment-doc-keyword
				if ((IsASpace(sc.chPrev) || sc.chPrev == '/' || sc.chPrev == '!') && (!IsASpace(sc.chNext))) {
					styleBeforeDCKeyword = SCE_C_COMMENTLINEDOC;
					sc.SetState(SCE_C_COMMENTDOCKEYWORD);
				}
			}
			break;
		case SCE_C_COMMENTDOCKEYWORD:
			if ((styleBeforeDCKeyword == SCE_C_COMMENTDOC) && sc.Match('*', '/')) {
				sc.ChangeState(SCE_C_COMMENTDOCKEYWORDERROR);
				sc.Forward();
				sc.ForwardSetState(SCE_C_DEFAULT);
			} else if (!setDoxygen.Contains(sc.ch)) {
				char s[100];
				if (caseSensitive) {
					sc.GetCurrent(s, sizeof(s));
				} else {
					sc.GetCurrentLowered(s, sizeof(s));
				}
				if (!IsASpace(sc.ch) || !keywords3.InList(s + 1)) {
					sc.ChangeState(SCE_C_COMMENTDOCKEYWORDERROR);
				}
				sc.SetState(styleBeforeDCKeyword);
			}
			break;
		case SCE_C_STRING:
			if (sc.atLineEnd) {
				sc.ChangeState(SCE_C_STRINGEOL);
			} else if (sc.ch == '\\') {
				if (sc.chNext == '\"' || sc.chNext == '\'' || sc.chNext == '\\') {
					sc.Forward();
				}
			} else if (sc.ch == '\"') {
				sc.ForwardSetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_CHARACTER:
			if (sc.atLineEnd) {
				sc.ChangeState(SCE_C_STRINGEOL);
			} else if (sc.ch == '\\') {
				if (sc.chNext == '\"' || sc.chNext == '\'' || sc.chNext == '\\') {
					sc.Forward();
				}
			} else if (sc.ch == '\'') {
				sc.ForwardSetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_REGEX:
			if (sc.atLineStart) {
				sc.SetState(SCE_C_DEFAULT);
			} else if (sc.ch == '/') {
				sc.Forward();
				while ((sc.ch < 0x80) && islower(sc.ch))
					sc.Forward();    // gobble regex flags
				sc.SetState(SCE_C_DEFAULT);
			} else if (sc.ch == '\\') {
				// Gobble up the quoted character
				if (sc.chNext == '\\' || sc.chNext == '/') {
					sc.Forward();
				}
			}
			break;
		case SCE_C_STRINGEOL:
			if (sc.atLineStart) {
				sc.SetState(SCE_C_DEFAULT);
			}
			break;
		case SCE_C_VERBATIM:
			if (sc.ch == '\"') {
				if (sc.chNext == '\"') {
					sc.Forward();
				} else {
					sc.ForwardSetState(SCE_C_DEFAULT);
				}
			}
			break;
		case SCE_C_UUID:
			if (sc.ch == '\r' || sc.ch == '\n' || sc.ch == ')') {
				sc.SetState(SCE_C_DEFAULT);
			}
		}

		// Determine if a new state should be entered.
		if (sc.state == SCE_C_DEFAULT) {
			if (sc.Match('@', '\"')) {
				sc.SetState(SCE_C_VERBATIM);
				sc.Forward();
			} else if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
				if (lastWordWasUUID) {
					sc.SetState(SCE_C_UUID);
					lastWordWasUUID = false;
				} else {
					sc.SetState(SCE_C_NUMBER);
				}
			} else if (setWordStart.Contains(sc.ch) || (sc.ch == '@')) {
				if (lastWordWasUUID) {
					sc.SetState(SCE_C_UUID);
					lastWordWasUUID = false;
				} else {
					sc.SetState(SCE_C_IDENTIFIER);
				}
			} else if (sc.Match('/', '*')) {
				if (sc.Match("/**") || sc.Match("/*!")) {	// Support of Qt/Doxygen doc. style
					sc.SetState(SCE_C_COMMENTDOC);
				} else {
					sc.SetState(SCE_C_COMMENT);
				}
				sc.Forward();	// Eat the * so it isn't used for the end of the comment
			} else if (sc.Match('/', '/')) {
				if ((sc.Match("///") && !sc.Match("////")) || sc.Match("//!"))
					// Support of Qt/Doxygen doc. style
					sc.SetState(SCE_C_COMMENTLINEDOC);
				else
					sc.SetState(SCE_C_COMMENTLINE);
			} else if (sc.ch == '/' && setOKBeforeRE.Contains(chPrevNonWhite)) {
				sc.SetState(SCE_C_REGEX);	// JavaScript's RegEx
			} else if (sc.ch == '\"') {
				sc.SetState(SCE_C_STRING);
			} else if (sc.ch == '\'') {
				sc.SetState(SCE_C_CHARACTER);
			} else if (sc.ch == '#' && visibleChars == 0) {
				if ( !IsDisabledCode(styler, sc)) {
					// Preprocessor commands are alone on their line
					sc.SetState(SCE_C_PREPROCESSOR);

					// Skip whitespace between # and preprocessor word
					do {
						sc.Forward();
					} while ((sc.ch == ' ' || sc.ch == '\t') && sc.More());
					if (sc.atLineEnd) {
						sc.SetState(SCE_C_DEFAULT);
					}
				}
			} else if (isoperator(static_cast<char>(sc.ch))) {
				sc.SetState(SCE_C_OPERATOR);
			}
		}

		if (!IsASpace(sc.ch) && !IsSpaceEquiv(sc.state)) {
			chPrevNonWhite = sc.ch;
			visibleChars++;
		}
		continuationLine = false;
	}
	sc.Complete();
}

static bool IsStreamCommentStyle(int style) {
	return style == SCE_C_COMMENT ||
	       style == SCE_C_COMMENTDOC ||
	       style == SCE_C_COMMENTDOCKEYWORD ||
	       style == SCE_C_COMMENTDOCKEYWORDERROR;
}

// Store both the current line's fold level and the next lines in the
// level store to make it easy to pick up with each increment
// and to make it possible to fiddle the current level for "} else {".
static void FoldCppDoc(unsigned int startPos, int length, int initStyle,
                       WordList *[], Accessor &styler) {
	bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
	bool foldPreprocessor = styler.GetPropertyInt("fold.preprocessor") != 0;
	bool foldCompact = styler.GetPropertyInt("fold.compact", 1) != 0;
	bool foldAtElse = styler.GetPropertyInt("fold.at.else", 0) != 0;
	unsigned int endPos = startPos + length;
	int visibleChars = 0;
	int lineCurrent = styler.GetLine(startPos);
	int levelCurrent = SC_FOLDLEVELBASE;
	if (lineCurrent > 0)
		levelCurrent = styler.LevelAt(lineCurrent-1) >> 16;
	int levelMinCurrent = levelCurrent;
	int levelNext = levelCurrent;
	char chNext = styler[startPos];
	int styleNext = styler.StyleAt(startPos);
	int style = initStyle;
	for (unsigned int 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 (foldComment && IsStreamCommentStyle(style)) {
			if (!IsStreamCommentStyle(stylePrev) && (stylePrev != SCE_C_COMMENTLINEDOC)) {
				levelNext++;
			} else if (!IsStreamCommentStyle(styleNext) && (styleNext != SCE_C_COMMENTLINEDOC) && !atEOL) {
				// Comments don't end at end of line and the next character may be unstyled.
				levelNext--;
			}
		}
		if (foldComment && (style == SCE_C_COMMENTLINE)) {
			if ((ch == '/') && (chNext == '/')) {
				char chNext2 = styler.SafeGetCharAt(i + 2);
				if (chNext2 == '{') {
					levelNext++;
				} else if (chNext2 == '}') {
					levelNext--;
				}
			}
		}
		if (foldPreprocessor && (style == SCE_C_PREPROCESSOR)) {
			if (ch == '#') {
				unsigned int j = i + 1;
				while ((j < endPos) && IsASpaceOrTab(styler.SafeGetCharAt(j))) {
					j++;
				}
				if (styler.Match(j, "region") || styler.Match(j, "if")) {
					levelNext++;
				} else if (styler.Match(j, "end")) {
					levelNext--;
				}
			}
		}
		if (style == SCE_C_OPERATOR) {
			if (ch == '{') {
				// Measure the minimum before a '{' to allow
				// folding on "} else {"
				if (levelMinCurrent > levelNext) {
					levelMinCurrent = levelNext;
				}
				levelNext++;
			} else if (ch == '}') {
				levelNext--;
			}
		}
		if (atEOL) {
			int levelUse = levelCurrent;
			if (foldAtElse) {
				levelUse = levelMinCurrent;
			}
			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);
			}
			lineCurrent++;
			levelCurrent = levelNext;
			levelMinCurrent = levelCurrent;
			visibleChars = 0;
		}
		if (!IsASpace(ch))
			visibleChars++;
	}
}

static const char * const cppWordLists[] = {
	"Primary keywords and identifiers",
	"Secondary keywords and identifiers",
	"Documentation comment keywords",
	"Unused",
	"Global classes and typedefs",
	0,
};

static void ColouriseCppDocSensitive(unsigned int startPos, int length, int initStyle, WordList *keywordlists[],
                                     Accessor &styler) {
	ColouriseCppDoc(startPos, length, initStyle, keywordlists, styler, true);
}

static void ColouriseCppDocInsensitive(unsigned int startPos, int length, int initStyle, WordList *keywordlists[],
                                       Accessor &styler) {
	ColouriseCppDoc(startPos, length, initStyle, keywordlists, styler, false);
}

LexerModule lmCPP(SCLEX_CPP, ColouriseCppDocSensitive, "cpp", FoldCppDoc, cppWordLists);
LexerModule lmCPPNoCase(SCLEX_CPPNOCASE, ColouriseCppDocInsensitive, "cppnocase", FoldCppDoc, cppWordLists);
