"""
Very simple SVG library.

Author: Sergey Vartanov (me@enzet.ru)
"""

import math


class SVG:
    def __init__(self, file_):
        self.file = file_
        self.index = 0

    def begin(self, width, height):
        self.file.write(
            '<?xml version="1.0" encoding="UTF-8" standalone="no"?>\n\n')
        self.file.write(
            f'''<svg version="1.1" baseProfile="full"
            xmlns="http://www.w3.org/2000/svg"
            xmlns:xlink="http://www.w3.org/1999/xlink"
            xmlns:ev="http://www.w3.org/2001/xml-events"
            bgcolor="#e5e9e6" width="{width}" height="{height}">\n''')

    def end(self):
        self.file.write('</svg>\n')

    def path(
            self, path: str, color: str = "black", width: float = 1,
            fill: str = "none", end: str = "butt", id: str = None,
            color2: str = None, gx1: float = 0, gy1: float = 0, gx2: float = 0,
            gy2: float = 0, dash: str = None, dashoffset: str = None,
            opacity: float = 1, transform: str = None):

        if color2:
            self.index += 1
            self.file.write(
                f'<defs><linearGradient id="grad{str(self.index)}" '
                f'x1="{str(gx1)}" y1="{str(gy1)}" '
                f'x2="{str(gx2)}" y2="{str(gy2)}" '
                f'gradientUnits="userSpaceOnUse">'
                f'<stop style="stop-color:{self.get_color(color)};'
                f'stop-opacity:1;" offset="0" />'
                f'<stop style="stop-color:{self.get_color(color2)};'
                f'stop-opacity:1;" offset="1" /></linearGradient></defs>\n')

        self.file.write('  <path d = "' + path + '" ')

        if id:
            self.file.write(f'id="{id}" ')
        if transform:
            self.file.write('transform="' + transform + '" ')

        self.file.write('style = "')
        if not color2:
            self.file.write('stroke:' + self.get_color(color) + '; ')
        else:
            self.file.write('stroke:url(#grad' + str(self.index) + '); ')
        self.file.write('stroke-width:' + str(width) + '; ')
        self.file.write('fill:' + self.get_color(fill) + '; ')
        self.file.write('stroke-linecap:' + end + '; ')
        if opacity != 1:
            self.file.write('opacity:' + str(opacity) + '; ')
        if dash:
            self.file.write('stroke-dasharray:' + dash + '; ')
        if dashoffset:
            self.file.write('stroke-dashoffset:' + str(dashoffset) + '; ')
        self.file.write('" />\n')

    def line(
            self, x1, y1, x2, y2, width=1, color='black', end='butt', id_=None,
            color2=None, gx1=None, gy1=None, gx2=None, gy2=None, dash=None,
            dashoffset=None, opacity=None):

        if color2:
            if not gx1:
                gx1 = x1
            if not gy1:
                gy1 = y1
            if not gx2:
                gx2 = x2
            if not gy2:
                gy2 = y2
            self.index += 1
            self.file.write(
                f'<defs><linearGradient id="grad{str(self.index)}" '
                f'x1="{str(gx1)}" y1="{str(gy1)}" x2="{str(gx2)}" '
                f'y2="{str(gy2)}" gradientUnits="userSpaceOnUse">\n'
                f'<stop style="stop-color:#{str(color)};stop-opacity:1;" '
                f'offset="0" />'
                f'<stop style=\"stop-color:#{str(color2)};stop-opacity:1;" '
                f'offset="1" />'
                f'</linearGradient></defs>\n')
        self.file.write(
            f'  <path d = "M {str(x1)},{str(y1)} {str(x2)},{str(y2)}" ')
        if id_:
            self.file.write(f'id="{id_}" ')
        self.file.write('style="')
        if not color2:
            self.file.write(f'stroke:{self.get_color(color)}; ')
        else:
            self.file.write(f'stroke:url(#grad{self.index}); ')
        self.file.write(f'stroke-width:{width}; ')
        self.file.write(f'stroke-linecap:{end}; ')
        if dash:
            self.file.write('stroke-dasharray:' + dash + '; ')
        if dashoffset:
            self.file.write('stroke-dashoffset:' + str(dashoffset) + '; ')
        if opacity:
            self.file.write('opacity: ' + str(opacity) + '; ')
        self.file.write('" />\n')

    def rect(
            self, x, y, width, height, color='black', id=None, rx=0, ry=0,
            opacity=1.0, stroke_color='none', stroke_width=1.0):

        self.file.write('  <rect x = "' + str(x) + '" y = "' + str(y) + '" rx = "' + str(rx) + '" ry = "' + str(ry) +
                        '" ')
        self.file.write(' width = "' + str(width) + '" height = "' + str(height) + '" ')
        if id:
            self.file.write('id = "' + id + '" ')
        self.file.write('style = "')
        if opacity != 1:
            self.file.write('opacity:' + str(opacity) + '; ')
        self.file.write('fill:' + self.get_color(color) + '; ')
        self.file.write('stroke:' + self.get_color(stroke_color) + '; ')
        self.file.write('stroke-width:' + str(stroke_width) + '; ')
        self.file.write('" />\n')

    def curve(self, x1, y1, x2, y2, x3, y3, x4, y4, id=None, width=1, color='black'):
        self.file.write('  <path d = "M ' + str(x1) + ',' + str(y1) + ' C ' + str(x2) + ',' + str(y2) + ' ')
        self.file.write(str(x3) + ',' + str(y3) + ' ' + str(x4) + ',' + str(y4) + '" ')
        self.file.write('style = "')
        self.file.write('stroke:' + self.get_color(color) + '; ')
        self.file.write('stroke-width:' + str(width) + '; ')
        self.file.write('fill: none; ')
        self.file.write('" />\n')

    def rhombus(self, x, y, width, height, color='black', id=None):
        self.file.write('''  <path d = "M %5.1f %5.1f L %5.1f %5.1f L %5.1f %5.1f
                L %5.1f %5.1f L %5.1f %5.1f" ''' % (x, y - height, x + width, y, x, y + height, x - width, y, x,
                                                    y - height))
        if id:
            self.file.write('id = "' + id + '" ')
        self.file.write('style = "')
        self.file.write('fill:' + self.get_color(color) + '; ')
        self.file.write('" />\n')

    def circle(self, x, y, d, color='black', color2='white', fill='none', 
            opacity=None, width=1, id_=None, gx=0, gy=0, gr=0, fx=0, fy=0):
        is_grad = gx != 0 or gy != 0 or gr != 0
        if is_grad:
            self.index += 1
            self.file.write(
                f'<defs><radialGradient id="grad{str(self.index)}" '
                f'cx="{gx}%" cy="{gy}%" r="{gr}%" fx="{fx}%" fy="{fy}%">'
                f'<stop offset="0%" style="stop-color:rgb(255,255,255);'
                f'stop-opacity:0" /><stop offset="100%" '
                f'style="stop-color:{self.get_color(color)};stop-opacity:1" />'
                f'</radialGradient></defs>\n')
        c = 0.577
        self.file.write(
            f'  <path d = "'
            f'M {x:5.1f} {y + d:5.1f} '
            f'C {x - d * c:5.1f} {y + d:5.1f} {x - d:5.1f} {y + d * c:5.1f} '
            f'{x - d:5.1f} {y:5.1f} '
            f'C {x - d:5.1f} {y - d * c:5.1f} {x - d * c:5.1f} {y - d:5.1f} '
            f'{x:5.1f} {y - d:5.1f} '
            f'C {x + d * c:5.1f} {y - d:5.1f} {x + d:5.1f} {y - d * c:5.1f} '
            f'{x + d:5.1f} {y:5.1f} '
            f'C {x + d:5.1f} {y + d * c:5.1f} {x + d * c:5.1f} {y + d:5.1f} '
            f'{x:5.1f} {y + d:5.1f}" ')

        if id_:
            self.file.write('id = "' + id_ + '" ')
        self.file.write('style = "')
        if is_grad:
            self.file.write('fill:url(#grad' + str(self.index) + '); ')
        else:
            self.file.write('fill:' + self.get_color(fill) + '; ')
        self.file.write('stroke-width:' + str(width) + '; ')
        self.file.write('stroke:' + self.get_color(color) + '; ')
        if opacity:
            self.file.write('opacity:' + str(opacity) + '; ')
        self.file.write('" />\n')

    def text(self, x, y, text, font='Myriad Pro', size='10', align='left',
        color='black', id=None, weight=None, letter_spacing=None, angle=None,
        opacity=None):
        """
        Drawing SVG <text> element.
        """
        if angle is None:
            self.file.write(f'  <text x="{str(x)}" y="{str(y)}" ')
        else:
            self.file.write('  <text x="0" y="0" ')
        self.file.write('font-size = "' + str(size) + '" ')
        if id:
            self.file.write('id = "' + id + '" ')
        if not (angle is None) and angle <= 0:
            align = 'end'
        if align == 'right':
            align = 'end'
        if align == 'center':
            align = 'middle'
        self.file.write('style = "')
        self.file.write('text-anchor:' + align + '; ')
        if opacity:
            self.file.write('opacity:' + str(opacity) + '; ')
        self.file.write('font-family: ' + font + '; ')
        self.file.write('fill: ' + self.get_color(color) + '; ')
        if weight == 'bold':
            self.file.write('font-weight:bold; ')
        if letter_spacing:
            self.file.write('letter-spacing:' + str(letter_spacing) + '; ')
        self.file.write('"')
        if not (angle is None):
            if math.sin(angle) > 0:
                trans = 'transform = "matrix(' + str(math.sin(angle)) + ',' + str(math.cos(angle)) + ',' + \
                        str(-math.cos(angle)) + ',' + str(math.sin(angle)) + ',' + str(x) + ',' + str(y) + ')"'
            else:
                trans = 'transform = "matrix(' + str(math.sin(angle + math.pi)) + ',' + str(math.cos(angle + math.pi)) + ',' + \
                        str(-math.cos(angle + math.pi)) + ',' + str(math.sin(angle + math.pi)) + ',' + str(x) + ',' + str(y) + ')"'
            self.file.write(' ' + trans)
        self.file.write('>')
        self.file.write(text)
        self.file.write('</text>\n')

    @staticmethod
    def get_color(color):
        if color == 'none':
            return 'none'
        if color == 'black':
            return 'black'
        return '#' + str(color)

    def begin_layer(self, name):
        self.file.write(f'<g id="{name}" label="{name}" ')
        self.file.write('inkscape:groupmode="layer">\n')

    def end_layer(self):
        self.file.write('</g>\n')

    def write(self, raw_code):
        self.file.write(raw_code)