import sys
import re
import math

from PyQt5.Qt import *  # noqa

from PyQt5.Qsci import QsciScintilla
from PyQt5 import Qsci
from PyQt5.Qsci import QsciLexerCPP


class Foo(QsciScintilla):

    def __init__(self, parent=None):
        super().__init__(parent)

        # http://www.scintilla.org/ScintillaDoc.html#Folding
        self.setFolding(QsciScintilla.BoxedTreeFoldStyle)

        # Indentation
        self.setIndentationsUseTabs(False)
        self.setIndentationWidth(4)
        self.setBackspaceUnindents(True)
        self.setIndentationGuides(True)

        # Set the default font
        self.font = QFont()
        self.font.setFamily('Consolas')
        self.font.setFixedPitch(True)
        self.font.setPointSize(10)
        self.setFont(self.font)
        self.setMarginsFont(self.font)

        # Margin 0 is used for line numbers
        fontmetrics = QFontMetrics(self.font)
        self.setMarginsFont(self.font)
        self.setMarginWidth(0, fontmetrics.width("000") + 6)
        self.setMarginLineNumbers(0, True)
        self.setMarginsBackgroundColor(QColor("#cccccc"))

        # Indentation
        self.setIndentationsUseTabs(False)
        self.setIndentationWidth(4)
        self.setBackspaceUnindents(True)

        lexer = QsciLexerCPP()
        lexer.setFoldAtElse(True)
        lexer.setFoldComments(True)
        lexer.setFoldCompact(False)
        lexer.setFoldPreprocessor(True)
        self.setLexer(lexer)

        # Use raw messages to Scintilla here
        # (all messages are documented here: http://www.scintilla.org/ScintillaDoc.html)
        # Ensure the width of the currently visible lines can be scrolled
        self.SendScintilla(QsciScintilla.SCI_SETSCROLLWIDTHTRACKING, 1)
        # Multiple cursor support
        self.SendScintilla(QsciScintilla.SCI_SETMULTIPLESELECTION, True)
        self.SendScintilla(QsciScintilla.SCI_SETMULTIPASTE, 1)
        self.SendScintilla(
            QsciScintilla.SCI_SETADDITIONALSELECTIONTYPING, True)

        # Comment feature goes here
        # self.commenter = Commenter(self, "//")
        QShortcut(QKeySequence("Ctrl+7"), self, self.comment_blocks)


    def init_test_selections(self):
        # initialize multiple selections
        offset1 = self.positionFromLineIndex(21, 0)
        offset2 = self.positionFromLineIndex(29, 5)
        self.SendScintilla(self.SCI_SETSELECTION, offset1, offset2)

        offset1 = self.positionFromLineIndex(31, 0)
        offset2 = self.positionFromLineIndex(33, 20)
        self.SendScintilla(self.SCI_ADDSELECTION, offset1, offset2)

        offset1 = self.positionFromLineIndex(37, 0)
        offset2 = self.positionFromLineIndex(39, 5)
        self.SendScintilla(self.SCI_ADDSELECTION, offset1, offset2)

    def comment_blocks(self):
        comment_chars = '// '
        selections = [(self.SendScintilla(QsciScintilla.SCI_GETSELECTIONNSTART, i), self.SendScintilla(QsciScintilla.SCI_GETSELECTIONNEND, i)) for i in range(self.SendScintilla(QsciScintilla.SCI_GETSELECTIONS))]
        def block_indentation(lineFrom, lineTo):
            """Get the minimum indentation for the line range"""
            indent = min(self.indentation(line) for line in range(lineFrom, lineTo))
            return indent

        def comment(selFrom, selTo):
            lineFrom = selFrom[0]
            lineTo = selTo[0] + 1
            indent = block_indentation(lineFrom, lineTo)
            # for line in range(lineTo-1, lineFrom-1, -1):
            for line in range(lineFrom, lineTo):
                text = self.text(line).lstrip()
                if not text:
                    self.insertAt(' ' * indent + comment_chars, line, 0)  # Make sure blank lines are preserved
                else:
                    self.insertAt(comment_chars, line, indent)
            self.setSelection(lineFrom, selFrom[1], lineTo, selTo[1])  # Restore selection TODO: for muliple selections see init_test_selections()
        for sel in reversed(selections):  # Positions will change due to inserted comment chars..so run loop in reverse
            sel_from = self.lineIndexFromPosition(sel[0])
            sel_to = self.lineIndexFromPosition(sel[1])
            comment(sel_from, sel_to)


def main():
    app = QApplication(sys.argv)
    ex = Foo()
    ex.setText("""\
#include <iostream>
using namespace std;

void Function0() {
    cout << "Function0";
}

void Function1() {
    cout << "Function1";
}

void Function2() {
    cout << "Function2";
}

void Function3() {
    cout << "Function3";
}


int main(void) {
    if (1) {
        if (1) {
            if (1) {
                if (1) {
                    int yay;
                }
            }
        }
    }

    if (1) {
        if (1) {
            if (1) {
                if (1) {
                    int yay2;
                }
            }
        }
    }

    return 0;
}\
    """)
    ex.init_test_selections()
    ex.comment_blocks()
    ex.resize(800, 600)
    ex.show()
    sys.exit(app.exec_())


if __name__ == "__main__":
    main()