// Scintilla source code edit control
/** @file LexTCL.cxx
 ** Lexer for TCL language.
 **/
// Copyright 1998-2001 by Andre Arpin <arpin@kingston.net>
// The License.txt file describes the conditions under which this software may be distributed.

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

#include "Platform.h"

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

// Extended to accept accented characters
static inline bool IsAWordChar(int ch) {
	return ch >= 0x80 ||
        (isalnum(ch) || ch == '_' || ch ==':'); // : name space separator
}

static inline bool IsAWordStart(int ch) {
	return ch >= 0x80 ||
	       (isalpha(ch) || ch == '_');
}

static inline bool IsANumberChar(int ch) {
	// Not exactly following number definition (several dots are seen as OK, etc.)
	// but probably enough in most cases.
	return (ch < 0x80) &&
	       (isdigit(ch) || toupper(ch) == 'E' ||
	        ch == '.' || ch == '-' || ch == '+');
}

static void ColouriseTCLDoc(unsigned int startPos, int length, int initStyle, WordList *keywordlists[], Accessor &styler) {
	bool foldComment = styler.GetPropertyInt("fold.comment") != 0;
	bool commentLevel = false;
    bool subBrace = false; // substitution begin with a brace ${.....}
	enum tLineState {LS_DEFAULT, LS_OPEN_COMMENT, LS_OPEN_DOUBLE_QUOTE, LS_MASK_STATE = 0xf, 
        LS_COMMAND_EXPECTED = 16, LS_BRACE_ONLY = 32 } lineState = LS_DEFAULT;
	bool prevSlash = false;
	int currentLevel = 0;
    bool expected = 0;
    int subParen = 0;

	int currentLine = styler.GetLine(startPos);
	length += startPos - styler.LineStart(currentLine);
	// make sure lines overlap
	startPos = styler.LineStart(currentLine);

	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];
    WordList &keywords9 = *keywordlists[8];

	if (currentLine > 0) {
        int ls = styler.GetLineState(currentLine - 1);
		lineState = tLineState(ls & LS_MASK_STATE);
		expected = LS_COMMAND_EXPECTED == tLineState(ls & LS_COMMAND_EXPECTED);
        subBrace = LS_BRACE_ONLY == tLineState(ls & LS_BRACE_ONLY);
		currentLevel = styler.LevelAt(currentLine - 1) >> 17;
		commentLevel = (styler.LevelAt(currentLine - 1) >> 16) & 1;
	} else
		styler.SetLevel(0, SC_FOLDLEVELBASE | SC_FOLDLEVELHEADERFLAG);
	bool visibleChars = false;

	int previousLevel = currentLevel;
    StyleContext sc(startPos, length, initStyle, styler);
	for (; ; sc.Forward()) {
		bool atEnd = !sc.More();  // make sure we process last word at end of file
next:
        if (subBrace) {
            if (sc.ch == '}') {
                subBrace = false;
                sc.SetState(SCE_TCL_OPERATOR); // }
                sc.ForwardSetState(SCE_TCL_DEFAULT);
            }
            else
                sc.SetState(SCE_TCL_SUB_BRACE);
            if (!sc.atLineEnd)
                continue;
        } else if (sc.state == SCE_TCL_DEFAULT || sc.state ==SCE_TCL_OPERATOR) {
            expected &= isspacechar(static_cast<unsigned char>(sc.ch)) || IsAWordStart(sc.ch);
        } else if (sc.state == SCE_TCL_SUBSTITUTION) {
            if (sc.ch == '(')
                subParen++;
            else if (sc.ch == ')') {
                if (subParen)
                    subParen--;
                else
                    sc.SetState(SCE_TCL_DEFAULT); // lets the code below fix it
            } else if (!IsAWordChar(sc.ch)) {
                sc.SetState(SCE_TCL_DEFAULT);
                subParen = 0;
            }
        }
        else
        {
            if (!IsAWordChar(sc.ch)) {
                if (sc.state == SCE_TCL_IDENTIFIER ||  sc.state == SCE_TCL_MODIFIER || expected) {
                    char s[100];
                    sc.GetCurrent(s, sizeof(s));
                    bool quote = sc.state == SCE_TCL_IN_QUOTE;
                    if (commentLevel  || expected) {
                        if (keywords.InList(s)) {
                            sc.ChangeState(quote ? SCE_TCL_WORD_IN_QUOTE : SCE_TCL_WORD);
                        } else if (keywords2.InList(s)) {
                            sc.ChangeState(quote ? SCE_TCL_WORD_IN_QUOTE : SCE_TCL_WORD2);
                        } else if (keywords3.InList(s)) {
                            sc.ChangeState(quote ? SCE_TCL_WORD_IN_QUOTE : SCE_TCL_WORD3);
                        } else if (keywords4.InList(s)) {
                            sc.ChangeState(quote ? SCE_TCL_WORD_IN_QUOTE : SCE_TCL_WORD4);
                        } else if (sc.GetRelative(-static_cast<int>(strlen(s))-1) == '{' &&
                            keywords5.InList(s) && sc.ch == '}') { // {keyword} exactly no spaces
                                sc.ChangeState(SCE_TCL_EXPAND);
                        }
                        if (keywords6.InList(s)) {
                            sc.ChangeState(SCE_TCL_WORD5);
                        } else if (keywords7.InList(s)) {
                            sc.ChangeState(SCE_TCL_WORD6);
                        } else if (keywords8.InList(s)) {
                            sc.ChangeState(SCE_TCL_WORD7);
                        } else if (keywords9.InList(s)) {
                            sc.ChangeState(SCE_TCL_WORD8);
                        } 
                    }
                    expected = false;
                    sc.SetState(quote ? SCE_TCL_IN_QUOTE : SCE_TCL_DEFAULT);
                } else if (sc.state == SCE_TCL_MODIFIER || sc.state == SCE_TCL_SUBSTITUTION) {
                    sc.SetState(SCE_TCL_DEFAULT);
                }
            }
        }
		if (atEnd)
			break;
		if (sc.atLineEnd) {
			currentLine = styler.GetLine(sc.currentPos);
			if (foldComment && sc.state == SCE_TCL_COMMENTLINE) {
				if (currentLevel == 0) {
					++currentLevel;
					commentLevel = true;
				}
			} else {
				if (visibleChars && commentLevel) {
					--currentLevel;
					--previousLevel;
					commentLevel = false;
				}
			}
			int flag = 0;
			if (!visibleChars)
				flag = SC_FOLDLEVELWHITEFLAG;
			if (currentLevel > previousLevel)
				flag = SC_FOLDLEVELHEADERFLAG;
			styler.SetLevel(currentLine, flag + previousLevel + SC_FOLDLEVELBASE + (currentLevel << 17) + (commentLevel << 16));

			// Update the line state, so it can be seen by next line
			if (sc.state == SCE_TCL_IN_QUOTE)
				lineState = LS_OPEN_DOUBLE_QUOTE;
			else if (prevSlash) {
				if (sc.state == SCE_TCL_COMMENT || sc.state == SCE_TCL_COMMENTLINE)
					lineState = LS_OPEN_COMMENT;
			}
            styler.SetLineState(currentLine, 
                (subBrace ? LS_BRACE_ONLY : 0) |
                (expected ? LS_COMMAND_EXPECTED : 0)  | lineState);
            sc.SetState(SCE_TCL_DEFAULT);
			prevSlash = false;
			previousLevel = currentLevel;
			lineState = LS_DEFAULT;
			continue;
		}

		if (prevSlash) {
			prevSlash = (sc.state == SCE_TCL_COMMENT || sc.state == SCE_TCL_COMMENTLINE) && isspacechar(static_cast<unsigned char>(sc.ch));
			continue;
		}

		if (sc.atLineStart) {
			visibleChars = false;
			if (lineState == LS_OPEN_COMMENT) {
				sc.SetState(SCE_TCL_COMMENT);
				lineState = LS_DEFAULT;
				continue;
			}
			if (lineState == LS_OPEN_DOUBLE_QUOTE)
				sc.SetState(SCE_TCL_IN_QUOTE);
			else
            {
				sc.SetState(SCE_TCL_DEFAULT);
                expected = IsAWordStart(sc.ch)|| isspacechar(static_cast<unsigned char>(sc.ch));
            }
		}

		switch (sc.state) {
		case SCE_TCL_NUMBER:
			if (!IsANumberChar(sc.ch))
				sc.SetState(SCE_TCL_DEFAULT);
			break;
		case SCE_TCL_IN_QUOTE:
			if (sc.ch == '"') {
				sc.ForwardSetState(SCE_TCL_DEFAULT);
				visibleChars = true; // necessary for a " as the first and only character on a line
				goto next;
			} else if (sc.ch == '[' || sc.ch == ']' || sc.ch == '$') {
				sc.SetState(SCE_TCL_OPERATOR);
                expected = sc.ch == '[';
                sc.ForwardSetState(SCE_TCL_IN_QUOTE);
				goto next;
			} 
			prevSlash = sc.ch == '\\';
			continue;
		case SCE_TCL_OPERATOR:
			sc.SetState(SCE_TCL_DEFAULT);
			break;
		}

		if (sc.ch == '#') {
			if (visibleChars) {
                if (sc.state != SCE_TCL_IN_QUOTE && expected) {
					sc.SetState(SCE_TCL_COMMENT);
                    expected = false;
                }
			} else
				sc.SetState(SCE_TCL_COMMENTLINE);
		}

		if (!isspacechar(static_cast<unsigned char>(sc.ch))) {
			visibleChars = true;
		}

		if (sc.ch == '\\') {
			prevSlash = true;
			continue;
		}

		// Determine if a new state should be entered.
		if (sc.state == SCE_TCL_DEFAULT) {
			if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
				sc.SetState(SCE_TCL_NUMBER);
			} else if (IsAWordStart(sc.ch) & expected) {
				sc.SetState(SCE_TCL_IDENTIFIER);
			} else {
				switch (sc.ch) {
				case '\"':
					sc.SetState(SCE_TCL_IN_QUOTE);
					break;
				case '{':
					sc.SetState(SCE_TCL_OPERATOR);
					expected = true;
					++currentLevel;
					break;
				case '}':
					sc.SetState(SCE_TCL_OPERATOR);
					--currentLevel;
					break;
				case '[':
				case ']':
					sc.SetState(SCE_TCL_OPERATOR);
					expected = true;
					break;
				case '(':
				case ')':
					sc.SetState(SCE_TCL_OPERATOR);
					break;
				case ';':
                    expected = true;
					break;
                case '$':
                    subParen = 0;
                    if (sc.chNext != '{') {
                        sc.SetState(SCE_TCL_SUBSTITUTION);
                    } 
                    else {
                        sc.ForwardSetState(SCE_TCL_OPERATOR);  // {
                        sc.ForwardSetState(SCE_TCL_SUB_BRACE);     
                        subBrace = true;
                    }
                    break;
                case '-':
                    if (!IsADigit(sc.chNext))
                        sc.SetState(SCE_TCL_MODIFIER);
                    break;
				}
			}
		}
	}
	sc.Complete();
}

static const char * const tclWordListDesc[] = {
            "TCL Keywords",
            "TK Keywords",
            "iTCL Keywords",
            "tkCommands",
            "expand"
            "user1",
            "user2",
            "user3",
            "user4",
            0
        };

// this code supports folding in the colourizer
LexerModule lmTCL(SCLEX_TCL, ColouriseTCLDoc, "tcl", 0, tclWordListDesc);