import math

from PyQt6.QtCore import *
from PyQt6.QtGui import *
from PyQt6.QtWidgets import *

from line import Line
from logFileModel import LogFileModel


class BigText(QWidget):
    _byte_offset = 0
    _left_offset = 0
    _selection_start_byte = 0
    _selection_end_byte = 0


    def __init__(self, model: LogFileModel):
        super(BigText, self).__init__()
        self.model = model
        self.font = QFont("monospace", 20)
        self.update_font_metrics(QPainter(self))
        self.lines = []

    def paintEvent(self, event: QPaintEvent) -> None:
        self.draw()

    def mousePressEvent(self, e: QMouseEvent) -> None:
        if e.buttons() == Qt.MouseButton.LeftButton:
            self._selection_start_byte = self.to_byte_offset(e)
            self._selection_end_byte = self._selection_start_byte
            self.update()

    def mouseMoveEvent(self, e: QMouseEvent):
        current_byte = self.to_byte_offset(e)

        if self._selection_end_byte != current_byte:
            self._selection_end_byte = current_byte
            self.update()
            #print("-> %s,%s" %(self._selection_start_byte, self._selection_end_byte))

    def to_byte_offset(self, e: QMouseEvent) -> int:
        line_number = int(e.pos().y() / self.char_height)

        if line_number < len(self.lines):
            line = self.lines[line_number]
            char_in_line = round(e.pos().x() / self.char_width) + self._left_offset
            char_in_line = min(char_in_line, line.length())
            #print("%s in line %s" % (char_in_line, line_number))

            current_byte = line.byte_offset() + char_in_line
            #print("%s + %s = %s" % (line.byte_offset(), char_in_line, current_byte))
        else:
            current_byte = self.model.byte_count()
        return current_byte

    def draw(self):
        painter = QPainter()
        painter.begin(self)
        painter.setFont(self.font)
        painter.setPen(QColor(0, 0, 0))
        self.update_font_metrics(painter)

        lines_to_show = self.height() / (self.fontMetrics().height())
        self.lines = self.model.data(self._byte_offset, lines_to_show)

        # draw hightlights first - some characters may overlap to the next line
        # by drawing the background hightlights first we prevent that the hightlight
        # draws over a character
        y_line_offset = self.char_height;
        for l in self.lines:
            if l.intersects(self._selection_start_byte, self._selection_end_byte):
                self.draw_selection(painter, l, y_line_offset)
            y_line_offset = y_line_offset + self.char_height

        y_line_offset = self.char_height;
        for l in self.lines:
            painter.drawText(0, y_line_offset, l.line())
            y_line_offset = y_line_offset + self.char_height

        painter.end()

    def draw_selection(self, painter: QPainter, line: Line, y_line_offset: int):
        hightlight_color = QColor(255, 255, 0)

        if line.includes_byte(self._selection_start_byte):
            x1 = (self._selection_start_byte - line.byte_offset() - self._left_offset) * self.char_width
        else:
            x1 = 0

        if line.includes_byte(self._selection_end_byte):
            width = (self._selection_end_byte - line.byte_offset() - self._left_offset) * self.char_width - x1
            #print("char in line: %d -> width: %d" % (self._selection_end_byte - line.byte_offset() - self._left_offset, width))
        else:
            width = len(line.line().rstrip()) * self.char_width -x1

        y1 = y_line_offset- self.char_height + self.char_height / 7
        height = self.char_height
        rect = QRect(x1,y1,width,height)
        #print(rect)
        self.hightlight(painter,rect , hightlight_color)

    def hightlight(self, painter: QPainter,rect: QRect, color: QColor):
        old_brush = painter.brush()
        old_pen = painter.pen()
        painter.setBrush(color)
        painter.setPen(Qt.PenStyle.NoPen)
        painter.drawRoundedRect(rect, 3.0, 3.0)
        painter.setBrush(old_brush)
        painter.setPen(old_pen)

    def update_font_metrics(self, painter: QPainter):
        fm: QFontMetrics = painter.fontMetrics()
        self.char_height = fm.height()
        self.char_width = fm.averageCharWidth()# all chars have same with for monospace font
        text = "012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789"
        self.char_width = fm.horizontalAdvance(text)/float(len(text))
        #print("bounding rect: %s"%(boundingRect))
        #print("font width=%s height=%s" % (self.char_width, self.char_height))