// Scintilla source code edit control
/** @file LexPowerShell.cxx
 ** Lexer for PowerShell scripts.
 **/
// Copyright 2008 by Tim Gerundt <tim@gerundt.de>
// 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 "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

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

static void ColourisePowerShellDoc(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];

    styler.StartAt(startPos);

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

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

        if (sc.state == SCE_POWERSHELL_COMMENT) {
            if (sc.atLineEnd) {
                sc.SetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_COMMENTSTREAM) {
            if (sc.ch == '>' && sc.chPrev == '#') {
                sc.ForwardSetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_STRING) {
            // This is a doubles quotes string
            if (sc.ch == '\"') {
                sc.ForwardSetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_CHARACTER) {
            // This is a single quote string
            if (sc.ch == '\'') {
                sc.ForwardSetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_NUMBER) {
            if (!IsADigit(sc.ch)) {
                sc.SetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_VARIABLE) {
            if (!IsAWordChar(sc.ch)) {
                sc.SetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_OPERATOR) {
            if (!isoperator(static_cast<char>(sc.ch))) {
                sc.SetState(SCE_POWERSHELL_DEFAULT);
            }
        } else if (sc.state == SCE_POWERSHELL_IDENTIFIER) {
            if (!IsAWordChar(sc.ch)) {
                char s[100];
                sc.GetCurrentLowered(s, sizeof(s));

                if (keywords.InList(s)) {
                    sc.ChangeState(SCE_POWERSHELL_KEYWORD);
                } else if (keywords2.InList(s)) {
                    sc.ChangeState(SCE_POWERSHELL_CMDLET);
                } else if (keywords3.InList(s)) {
                    sc.ChangeState(SCE_POWERSHELL_ALIAS);
                } else if (keywords4.InList(s)) {
                    sc.ChangeState(SCE_POWERSHELL_FUNCTION);
                } else if (keywords5.InList(s)) {
                    sc.ChangeState(SCE_POWERSHELL_USER1);
                }
                sc.SetState(SCE_POWERSHELL_DEFAULT);
            }
        }

        // Determine if a new state should be entered.
        if (sc.state == SCE_POWERSHELL_DEFAULT) {
            if (sc.ch == '#') {
                sc.SetState(SCE_POWERSHELL_COMMENT);
            } else if (sc.ch == '<' && sc.chNext == '#') {
                sc.SetState(SCE_POWERSHELL_COMMENTSTREAM);
            } else if (sc.ch == '\"') {
                sc.SetState(SCE_POWERSHELL_STRING);
            } else if (sc.ch == '\'') {
                sc.SetState(SCE_POWERSHELL_CHARACTER);
            } else if (sc.ch == '$') {
                sc.SetState(SCE_POWERSHELL_VARIABLE);
            } else if (IsADigit(sc.ch) || (sc.ch == '.' && IsADigit(sc.chNext))) {
                sc.SetState(SCE_POWERSHELL_NUMBER);
            } else if (isoperator(static_cast<char>(sc.ch))) {
                sc.SetState(SCE_POWERSHELL_OPERATOR);
            } else if (IsAWordChar(sc.ch)) {
                sc.SetState(SCE_POWERSHELL_IDENTIFIER);
            }
        }
    }
    sc.Complete();
}

// 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 FoldPowerShellDoc(unsigned int startPos, int length, int initStyle,
                           WordList *[], Accessor &styler) {
    bool foldComment = styler.GetPropertyInt("fold.comment") != 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 (style == SCE_POWERSHELL_OPERATOR) {
            if (ch == '{') {
                // Measure the minimum before a '{' to allow
                // folding on "} else {"
                if (levelMinCurrent > levelNext) {
                    levelMinCurrent = levelNext;
                }
                levelNext++;
            } else if (ch == '}') {
                levelNext--;
            }
        } else if (foldComment && style == SCE_POWERSHELL_COMMENTSTREAM) {
            if (stylePrev != SCE_POWERSHELL_COMMENTSTREAM) {
                levelNext++;
            } else if (styleNext != SCE_POWERSHELL_COMMENTSTREAM) {
                levelNext--;
            }
        }
        if (!IsASpace(ch))
            visibleChars++;
        if (atEOL || (i == endPos-1)) {
            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;
        }
    }
}

static const char * const powershellWordLists[] = {
    "Commands",
    "Cmdlets",
    "Aliases",
    "Functions",
    "User1",
    0
};

LexerModule lmPowerShell(SCLEX_POWERSHELL, ColourisePowerShellDoc, "powershell", FoldPowerShellDoc, powershellWordLists);

