import os

import svgwrite
from svgwrite.path import Path

from local_dataclasses import Glyph, Metadata

base = 16
cap = -16
svg_size = 1024
guard = 12


def generate(glyph: Glyph, metadata: Metadata):
    print(f"Generating character '{metadata.character}' for font {metadata.font_name}")

    font_path = os.path.join(os.getcwd(), 'svgs', metadata.font_name)

    left_side_bearing, right_side_bearing = _calculate_bearings(glyph)
    svg_filename = f'ascii{str(metadata.ascii_value)}_l{left_side_bearing}_r{right_side_bearing}.svg'

    dwg = svgwrite.Drawing(
        os.path.join(font_path, svg_filename),
        viewBox=f"0 0 {svg_size} {svg_size}"
    )

    points = []

    for coordinate in glyph.coordinates:
        if coordinate:
            x, y = coordinate
            x = _map_to_svg(x)
            y = _map_to_svg(y)
            points.append((x, y))
        else:
            if points:
                _add_path(dwg, points)
            points = []

    if points:
        _add_path(dwg, points)

    dwg.save()


def _add_path(dwg, points):
    if not points:
        return

    p = Path()
    p.push(f"M {points[0][0]} {points[0][1]}")
    for x, y in points[1:]:
        p.push(f"L {x} {y}")
    dwg.add(p)


def _calculate_bearings(glyph: Glyph):
    if glyph.coordinates:
        leftmost_point = _map_to_svg(min(coordinate[0] for coordinate in glyph.coordinates if coordinate))
        rightmost_point = _map_to_svg(max(coordinate[0] for coordinate in glyph.coordinates if coordinate))
    else:
        leftmost_point = rightmost_point = _map_to_svg(0)

    left_side_bearing = leftmost_point - _map_to_svg(glyph.left)
    right_side_bearing = _map_to_svg(glyph.right) - rightmost_point
    return left_side_bearing, right_side_bearing


def _map_to_svg(x):
    return x * (svg_size - 2 * guard) / (base - cap) + svg_size / 2