#include "PythonSyntaxHighlighter.h"

PythonSyntaxHighlighter::PythonSyntaxHighlighter(QTextDocument *parent)
 : QSyntaxHighlighter(parent)
{
 keywords = QStringList() << "and" << "assert" << "break" << "class" << "continue" << "def" <<
        "del" << "elif" << "else" << "except" << "exec" << "finally" <<
        "for" << "from" << "global" << "if" << "import" << "in" <<
        "is" << "lambda" << "not" << "or" << "pass" << "print" <<
        "raise" << "return" << "try" << "while" << "yield" <<
        "None" << "True" << "False";

 operators = QStringList() << "=" <<
        // Comparison
        "==" << "!=" << "<" << "<=" << ">" << ">=" <<
        // Arithmetic
        "\\+" << "-" << "\\*" << "/" << "//" << "%" << "\\*\\*" <<
        // In-place
        "\\+=" << "-=" << "\\*=" << "/=" << "%=" <<
        // Bitwise
        "\\^" << "\\|" << "&" << "~" << ">>" << "<<";

 braces = QStringList() << "{" << "}" << "\\(" << "\\)" << "\\[" << "]";

 basicStyles.insert("keyword", getTextCharFormat("blue"));
 basicStyles.insert("operator", getTextCharFormat("red"));
 basicStyles.insert("brace", getTextCharFormat("darkGray"));
    basicStyles.insert("defclass", getTextCharFormat("black", "bold"));
 basicStyles.insert("brace", getTextCharFormat("darkGray"));
 basicStyles.insert("string", getTextCharFormat("magenta"));
 basicStyles.insert("string2", getTextCharFormat("darkMagenta"));
 basicStyles.insert("comment", getTextCharFormat("darkGreen", "italic"));
 basicStyles.insert("self", getTextCharFormat("black", "italic"));
 basicStyles.insert("numbers", getTextCharFormat("brown"));

 triSingleQuote.setPattern("'''");
 triDoubleQuote.setPattern("\"\"\"");

 initializeRules();
}

void PythonSyntaxHighlighter::initializeRules()
{
 foreach (QString currKeyword, keywords)
 {
  rules.append(HighlightingRule(QString("\\b%1\\b").arg(currKeyword), 0, basicStyles.value("keyword")));
 }
 foreach (QString currOperator, operators)
 {
  rules.append(HighlightingRule(QString("%1").arg(currOperator), 0, basicStyles.value("operator")));
 }
 foreach (QString currBrace, braces)
 {
  rules.append(HighlightingRule(QString("%1").arg(currBrace), 0, basicStyles.value("brace")));
 }
 // 'self'
    rules.append(HighlightingRule("\\bself\\b", 0, basicStyles.value("self")));

    // Double-quoted string, possibly containing escape sequences
 // FF: originally in python : r'"[^"\\]*(\\.[^"\\]*)*"'
    rules.append(HighlightingRule("\"[^\"\\\\]*(\\\\.[^\"\\\\]*)*\"", 0, basicStyles.value("string")));
    // Single-quoted string, possibly containing escape sequences
 // FF: originally in python : r"'[^'\\]*(\\.[^'\\]*)*'"
 rules.append(HighlightingRule("'[^'\\\\]*(\\\\.[^'\\\\]*)*'", 0, basicStyles.value("string")));

    // 'def' followed by an identifier
 // FF: originally: r'\bdef\b\s*(\w+)'
    rules.append(HighlightingRule("\\bdef\\b\\s*(\\w+)", 1, basicStyles.value("defclass")));
    //  'class' followed by an identifier
 // FF: originally: r'\bclass\b\s*(\w+)'
 rules.append(HighlightingRule("\\bclass\\b\\s*(\\w+)", 1, basicStyles.value("defclass")));

    // From '#' until a newline
 // FF: originally: r'#[^\\n]*'
    rules.append(HighlightingRule("#[^\\n]*", 0, basicStyles.value("comment")));

    // Numeric literals
    rules.append(HighlightingRule("\\b[+-]?[0-9]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+[lL]?\b'
    rules.append(HighlightingRule("\\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?0[xX][0-9A-Fa-f]+[lL]?\b'
    rules.append(HighlightingRule("\\b[+-]?[0-9]+(?:\\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\\b", 0, basicStyles.value("numbers"))); // r'\b[+-]?[0-9]+(?:\.[0-9]+)?(?:[eE][+-]?[0-9]+)?\b'
}

void PythonSyntaxHighlighter::highlightBlock(const QString &text)
{
 foreach (HighlightingRule currRule, rules)
 {
  int idx = currRule.pattern.indexIn(text, 0);
  while (idx >= 0)
  {
   // Get index of Nth match
   idx = currRule.pattern.pos(currRule.nth);
   int length = currRule.pattern.cap(currRule.nth).length();
   setFormat(idx, length, currRule.format);
   idx = currRule.pattern.indexIn(text, idx + length);
  }
 }

 setCurrentBlockState(0);

    // Do multi-line strings
    bool isInMultilne = matchMultiline(text, triSingleQuote, 1, basicStyles.value("string2"));
    if (!isInMultilne)
  isInMultilne = matchMultiline(text, triDoubleQuote, 2, basicStyles.value("string2"));
}

bool PythonSyntaxHighlighter::matchMultiline(const QString &text, const QRegExp &delimiter, const int inState, const QTextCharFormat &style)
{
    int start = -1;
 int add = -1;
 int end = -1;
 int length = 0;

 // If inside triple-single quotes, start at 0
 if (previousBlockState() == inState) {
        start = 0;
        add = 0;
 }
 // Otherwise, look for the delimiter on this line
 else {
        start = delimiter.indexIn(text);
        // Move past this match
        add = delimiter.matchedLength();
 }

    // As long as there's a delimiter match on this line...
    while (start >= 0) {
        // Look for the ending delimiter
        end = delimiter.indexIn(text, start + add);
        // Ending delimiter on this line?
        if (end >= add) {
            length = end - start + add + delimiter.matchedLength();
            setCurrentBlockState(0);
  }
        // No; multi-line string
        else {
            setCurrentBlockState(inState);
            length = text.length() - start + add;
  }
        // Apply formatting and look for next
        setFormat(start, length, style);
        start = delimiter.indexIn(text, start + length);
 }
    // Return True if still inside a multi-line string, False otherwise
    if (currentBlockState() == inState)
        return true;
    else
        return false;
}

const QTextCharFormat PythonSyntaxHighlighter::getTextCharFormat(const QString &colorName, const QString &style)
{
 QTextCharFormat charFormat;
 QColor color(colorName);
 charFormat.setForeground(color);
 if (style.contains("bold", Qt::CaseInsensitive))
  charFormat.setFontWeight(QFont::Bold);
 if (style.contains("italic", Qt::CaseInsensitive))
  charFormat.setFontItalic(true);
 return charFormat;
}