// Scintilla source code edit control
/** @file LexTAL.cxx
 ** Lexer for TAL
 ** Based on LexPascal.cxx
 ** Written by Laurent le Tynevez
 ** Updated by Simon Steele <s.steele@pnotepad.org> September 2002
 ** Updated by Mathias Rauen <scite@madshi.net> May 2003 (Delphi adjustments)
 ** Updated by Rod Falck, Aug 2006 Converted to TACL
 **/

#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

inline bool isTACLoperator(char ch)
    {
    return ch == '\'' || isoperator(ch);
    }

inline bool isTACLwordchar(char ch)
    {
    return ch == '#' || ch == '^' || ch == '|' || ch == '_' || iswordchar(ch);
    }

inline bool isTACLwordstart(char ch)
    {
    return ch == '#' || ch == '|' || ch == '_' || iswordstart(ch);
    }

static void getRange(unsigned int start,
        unsigned int end,
        Accessor &styler,
        char *s,
        unsigned int len) {
    unsigned int i = 0;
    while ((i < end - start + 1) && (i < len-1)) {
        s[i] = static_cast<char>(tolower(styler[start + i]));
        i++;
    }
    s[i] = '\0';
}

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

static void ColourTo(Accessor &styler, unsigned int end, unsigned int attr, bool bInAsm) {
    if ((bInAsm) && (attr == SCE_C_OPERATOR || attr == SCE_C_NUMBER || attr == SCE_C_DEFAULT || attr == SCE_C_WORD || attr == SCE_C_IDENTIFIER)) {
        styler.ColourTo(end, SCE_C_REGEX);
    } else
        styler.ColourTo(end, attr);
}

// returns 1 if the item starts a class definition, and -1 if the word is "end", and 2 if the word is "asm"
static int classifyWordTACL(unsigned int start, unsigned int end, /*WordList &keywords*/WordList *keywordlists[], Accessor &styler, bool bInAsm) {
    int ret = 0;

    WordList& keywords = *keywordlists[0];
    WordList& builtins = *keywordlists[1];
    WordList& commands = *keywordlists[2];

    char s[100];
    getRange(start, end, styler, s, sizeof(s));

    char chAttr = SCE_C_IDENTIFIER;
    if (isdigit(s[0]) || (s[0] == '.')) {
        chAttr = SCE_C_NUMBER;
    }
    else {
        if (s[0] == '#' || keywords.InList(s)) {
            chAttr = SCE_C_WORD;

            if (strcmp(s, "asm") == 0) {
                ret = 2;
            }
            else if (strcmp(s, "end") == 0) {
                ret = -1;
            }
        }
        else if (s[0] == '|' || builtins.InList(s)) {
            chAttr = SCE_C_WORD2;
        }
        else if (commands.InList(s)) {
            chAttr = SCE_C_UUID;
        }
        else if (strcmp(s, "comment") == 0) {
            chAttr = SCE_C_COMMENTLINE;
            ret = 3;
        }
    }
    ColourTo(styler, end, chAttr, (bInAsm && ret != -1));
    return ret;
}

static int classifyFoldPointTACL(const char* s) {
    int lev = 0;
    if (s[0] == '[')
        lev=1;
    else if (s[0] == ']')
        lev=-1;
    return lev;
}

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

    styler.StartAt(startPos);

    int state = initStyle;
    if (state == SCE_C_CHARACTER)   // Does not leak onto next line
        state = SCE_C_DEFAULT;
    char chPrev = ' ';
    char chNext = styler[startPos];
    unsigned int lengthDoc = startPos + length;

    bool bInClassDefinition;

    int currentLine = styler.GetLine(startPos);
    if (currentLine > 0) {
        styler.SetLineState(currentLine, styler.GetLineState(currentLine-1));
        bInClassDefinition = (styler.GetLineState(currentLine) == 1);
    } else {
        styler.SetLineState(currentLine, 0);
        bInClassDefinition = false;
    }

    bool bInAsm = (state == SCE_C_REGEX);
    if (bInAsm)
        state = SCE_C_DEFAULT;

    styler.StartSegment(startPos);
    int visibleChars = 0;
    unsigned int i;
    for (i = startPos; i < lengthDoc; i++) {
        char ch = chNext;

        chNext = styler.SafeGetCharAt(i + 1);

        if ((ch == '\r' && chNext != '\n') || (ch == '\n')) {
            // Trigger on CR only (Mac style) or either on LF from CR+LF (Dos/Win) or on LF alone (Unix)
            // Avoid triggering two times on Dos/Win
            // End of line
            if (state == SCE_C_CHARACTER) {
                ColourTo(styler, i, state, bInAsm);
                state = SCE_C_DEFAULT;
            }
            visibleChars = 0;
            currentLine++;
            styler.SetLineState(currentLine, (bInClassDefinition ? 1 : 0));
        }

        if (styler.IsLeadByte(ch)) {
            chNext = styler.SafeGetCharAt(i + 2);
            chPrev = ' ';
            i += 1;
            continue;
        }

        if (state == SCE_C_DEFAULT) {
            if (isTACLwordstart(ch)) {
                ColourTo(styler, i-1, state, bInAsm);
                state = SCE_C_IDENTIFIER;
            } else if (ch == '{') {
                ColourTo(styler, i-1, state, bInAsm);
                state = SCE_C_COMMENT;
            } else if (ch == '{' && chNext == '*') {
                ColourTo(styler, i-1, state, bInAsm);
                state = SCE_C_COMMENTDOC;
            } else if (ch == '=' && chNext == '=') {
                ColourTo(styler, i-1, state, bInAsm);
                state = SCE_C_COMMENTLINE;
            } else if (ch == '"') {
                ColourTo(styler, i-1, state, bInAsm);
                state = SCE_C_STRING;
            } else if (ch == '?' && visibleChars == 0) {
                ColourTo(styler, i-1, state, bInAsm);
                state = SCE_C_PREPROCESSOR;
            } else if (isTACLoperator(ch)) {
                ColourTo(styler, i-1, state, bInAsm);
                ColourTo(styler, i, SCE_C_OPERATOR, bInAsm);
            }
        } else if (state == SCE_C_IDENTIFIER) {
            if (!isTACLwordchar(ch)) {
                int lStateChange = classifyWordTACL(styler.GetStartSegment(), i - 1, keywordlists, styler, bInAsm);

                if(lStateChange == 1) {
                    styler.SetLineState(currentLine, 1);
                    bInClassDefinition = true;
                } else if(lStateChange == 2) {
                    bInAsm = true;
                } else if(lStateChange == -1) {
                    styler.SetLineState(currentLine, 0);
                    bInClassDefinition = false;
                    bInAsm = false;
                }

                if (lStateChange == 3) {
                     state = SCE_C_COMMENTLINE;
                }
                else {
                    state = SCE_C_DEFAULT;
                    chNext = styler.SafeGetCharAt(i + 1);
                    if (ch == '{') {
                        state = SCE_C_COMMENT;
                    } else if (ch == '{' && chNext == '*') {
                        ColourTo(styler, i-1, state, bInAsm);
                        state = SCE_C_COMMENTDOC;
                    } else if (ch == '=' && chNext == '=') {
                        state = SCE_C_COMMENTLINE;
                    } else if (ch == '"') {
                        state = SCE_C_STRING;
                    } else if (isTACLoperator(ch)) {
                        ColourTo(styler, i, SCE_C_OPERATOR, bInAsm);
                    }
                }
            }
        } else {
            if (state == SCE_C_PREPROCESSOR) {
                if ((ch == '\r' || ch == '\n') && !(chPrev == '\\' || chPrev == '\r')) {
                    ColourTo(styler, i-1, state, bInAsm);
                    state = SCE_C_DEFAULT;
                }
            } else if (state == SCE_C_COMMENT) {
                if (ch == '}' || (ch == '\r' || ch == '\n') ) {
                    ColourTo(styler, i, state, bInAsm);
                    state = SCE_C_DEFAULT;
                }
            } else if (state == SCE_C_COMMENTDOC) {
                if (ch == '}' || (ch == '\r' || ch == '\n')) {
                    if (((i > styler.GetStartSegment() + 2) || (
                        (initStyle == SCE_C_COMMENTDOC) &&
                        (styler.GetStartSegment() == static_cast<unsigned int>(startPos))))) {
                            ColourTo(styler, i, state, bInAsm);
                            state = SCE_C_DEFAULT;
                    }
                }
            } else if (state == SCE_C_COMMENTLINE) {
                if (ch == '\r' || ch == '\n') {
                    ColourTo(styler, i-1, state, bInAsm);
                    state = SCE_C_DEFAULT;
                }
            } else if (state == SCE_C_STRING) {
                if (ch == '"' || ch == '\r' || ch == '\n') {
                    ColourTo(styler, i, state, bInAsm);
                    state = SCE_C_DEFAULT;
                }
            }
        }
        if (!isspacechar(ch))
            visibleChars++;
        chPrev = ch;
    }

    // Process to end of document
    if (state == SCE_C_IDENTIFIER) {
        classifyWordTACL(styler.GetStartSegment(), i - 1, keywordlists, styler, bInAsm);
        }
    else
        ColourTo(styler, lengthDoc - 1, state, bInAsm);
}

static void FoldTACLDoc(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;
    unsigned int endPos = startPos + length;
    int visibleChars = 0;
    int 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;
    bool section = false;

    int lastStart = 0;

    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 (stylePrev == SCE_C_DEFAULT && (style == SCE_C_WORD || style == SCE_C_PREPROCESSOR))
        {
            // Store last word start point.
            lastStart = i;
        }

        if (stylePrev == SCE_C_WORD || stylePrev == SCE_C_PREPROCESSOR) {
            if(isTACLwordchar(ch) && !isTACLwordchar(chNext)) {
                char s[100];
                getRange(lastStart, i, styler, s, sizeof(s));
                if (stylePrev == SCE_C_PREPROCESSOR && strcmp(s, "?section") == 0)
                    {
                    section = true;
                    levelCurrent = 1;
                    levelPrev = 0;
                    }
                else if (stylePrev == SCE_C_WORD)
                    levelCurrent += classifyFoldPointTACL(s);
            }
        }

        if (style == SCE_C_OPERATOR) {
            if (ch == '[') {
                levelCurrent++;
            } else if (ch == ']') {
                levelCurrent--;
            }
        }
        if (foldComment && (style == SCE_C_COMMENTLINE)) {
            if ((ch == '/') && (chNext == '/')) {
                char chNext2 = styler.SafeGetCharAt(i + 2);
                if (chNext2 == '{') {
                    levelCurrent++;
                } else if (chNext2 == '}') {
                    levelCurrent--;
                }
            }
        }

        if (foldPreprocessor && (style == SCE_C_PREPROCESSOR)) {
            if (ch == '{' && chNext == '$') {
                unsigned int j=i+2; // skip {$
                while ((j<endPos) && IsASpaceOrTab(styler.SafeGetCharAt(j))) {
                    j++;
                }
                if (styler.Match(j, "region") || styler.Match(j, "if")) {
                    levelCurrent++;
                } else if (styler.Match(j, "end")) {
                    levelCurrent--;
                }
            }
        }

        if (foldComment && IsStreamCommentStyle(style)) {
            if (!IsStreamCommentStyle(stylePrev)) {
                levelCurrent++;
            } else if (!IsStreamCommentStyle(styleNext) && !atEOL) {
                // Comments don't end at end of line and the next character may be unstyled.
                levelCurrent--;
            }
        }
        if (atEOL) {
            int lev = levelPrev | SC_FOLDLEVELBASE;
            if (visibleChars == 0 && foldCompact)
                lev |= SC_FOLDLEVELWHITEFLAG;
            if ((levelCurrent > levelPrev || section) && (visibleChars > 0))
                lev |= SC_FOLDLEVELHEADERFLAG;
            if (lev != styler.LevelAt(lineCurrent)) {
                styler.SetLevel(lineCurrent, lev);
            }
            lineCurrent++;
            levelPrev = levelCurrent;
            visibleChars = 0;
            section = false;
        }

        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 TACLWordListDesc[] = {
    "Builtins",
    "Labels",
    "Commands",
    0
};

LexerModule lmTACL(SCLEX_TACL, ColouriseTACLDoc, "TACL", FoldTACLDoc, TACLWordListDesc);
