# -*- coding: utf-8 -*-

# Copyright (c) 2015 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a syntax highlighter for diff outputs.
"""


from PyQt5.QtGui import QColor

from E5Gui.E5GenericDiffHighlighter import TERMINAL, E5GenericDiffHighlighter


class GitDiffHighlighter(E5GenericDiffHighlighter):
    """
    Class implementing a diff highlighter for Git.
    """
    def __init__(self, doc, whitespace=True):
        """
        Constructor
        
        @param doc reference to the text document (QTextDocument)
        @param whitespace flag indicating to highlight whitespace
            at the end of a line (boolean)
        """
        self.whitespace = whitespace
        
        super(GitDiffHighlighter, self).__init__(doc)

    def generateRules(self):
        """
        Public method to generate the rule set.
        """
        diffHeader = self.makeFormat(fg=self.textColor,
                                     bg=self.headerColor)
        diffHeaderBold = self.makeFormat(fg=self.textColor,
                                         bg=self.headerColor,
                                         bold=True)
        diffContext = self.makeFormat(fg=self.textColor,
                                      bg=self.contextColor)

        diffAdded = self.makeFormat(fg=self.textColor,
                                    bg=self.addedColor)
        diffRemoved = self.makeFormat(fg=self.textColor,
                                      bg=self.removedColor)

        if self.whitespace:
            try:
                badWhitespace = self.makeFormat(fg=self.textColor,
                                                bg=self.whitespaceColor)
            except AttributeError:
                badWhitespace = self.makeFormat(fg=self.textColor,
                                                bg=QColor(255, 0, 0, 192))

        # We specify the whitespace rule last so that it is
        # applied after the diff addition/removal rules.
        diffOldRegex = TERMINAL(r'^--- ')
        diffNewRegex = TERMINAL(r'^\+\+\+ ')
        diffContextRegex = TERMINAL(r'^@@ ')

        diffHeader1Regex = TERMINAL(r'^diff --git a/.*b/.*')
        diffHeader2Regex = TERMINAL(r'^index \S+\.\.\S+')
        diffHeader3Regex = TERMINAL(r'^new file mode')
        diffHeader4Regex = TERMINAL(r'^deleted file mode')
        
        diffAddedRegex = TERMINAL(r'^\+')
        diffRemovedRegex = TERMINAL(r'^-')
        diffBarRegex = TERMINAL(r'^([ ]+.*)(\|[ ]+\d+[ ]+[+-]+)$')
        diffStsRegex = (r'(.+\|.+?)(\d+)(.+?)([\+]*?)([-]*?)$')
        diffSummaryRegex = (r'(\s+\d+ files changed[^\d]*)'
                            r'(:?\d+ insertions[^\d]*)'
                            r'(:?\d+ deletions.*)$')

        if self.whitespace:
            self.createRules((r'(..*?)(\s+)$', (None, badWhitespace)))
        self.createRules((diffOldRegex, diffRemoved),
                         (diffNewRegex, diffAdded),
                         (diffContextRegex, diffContext),
                         (diffBarRegex, (diffHeaderBold, diffHeader)),
                         (diffHeader1Regex, diffHeader),
                         (diffHeader2Regex, diffHeader),
                         (diffHeader3Regex, diffHeader),
                         (diffHeader4Regex, diffHeader),
                         (diffAddedRegex, diffAdded),
                         (diffRemovedRegex, diffRemoved),
                         (diffStsRegex, (None, diffHeader,
                                         None, diffHeader,
                                         diffHeader)),
                         (diffSummaryRegex, (diffHeader,
                                             diffHeader,
                                             diffHeader))
                         )
