# Copyright (c) 2019-2020 Manfred Moitzi
# License: MIT License
import math
import ezdxf
from pathlib import Path

OUT_DIR = Path('~/Desktop/Outbox').expanduser()

from ezdxf.lldxf.const import MIRROR_X
from ezdxf.math import UCS, Vec3, Matrix44, Y_AXIS, X_AXIS, Z_AXIS

RED = 1
GREEN = 3
BLUE = 5


def setup_csys(blk, size=3):
    # draw axis
    blk.add_line((0, 0), (size, 0), dxfattribs={'color': RED})  # x-axis
    blk.add_line((0, 0), (0, size), dxfattribs={'color': GREEN})  # y-axis
    blk.add_line((0, 0), (0, 0, size), dxfattribs={'color': BLUE})  # z-axis

    # place text
    size2 = size / 2
    txt_props = {
        'style': 'OpenSans',
        'height': size / 2,
        'color': RED,
    }
    # XY-plane text
    blk.add_text('XY', dxfattribs=txt_props).set_pos((size2, size2), align='MIDDLE_CENTER')

    # YZ-plane text
    ucs = UCS(ux=(0, 1, 0), uy=(0, 0, 1))
    txt_props['extrusion'] = ucs.uz
    txt_props['color'] = GREEN
    blk.add_text('YZ', dxfattribs=txt_props).set_pos(ucs.to_ocs((size2, size2)), align='MIDDLE_CENTER')

    # XZ-plane text
    ucs = UCS(ux=(1, 0, 0), uy=(0, 0, 1))
    txt_props['extrusion'] = ucs.uz
    txt_props['color'] = BLUE
    txt_props['text_generation_flag'] = MIRROR_X
    blk.add_text('XZ', dxfattribs=txt_props).set_pos(ucs.to_ocs((size2, size2)), align='MIDDLE_CENTER')


# rotate UCS around an arbitrary axis:
def ucs_rotation(ucs: UCS, axis: Vec3, angle: float):
    # new in ezdxf v0.11: UCS.rotate(axis, angle)
    t = Matrix44.axis_rotate(axis, math.radians(angle))
    ux, uy, uz = t.transform_vertices([ucs.ux, ucs.uy, ucs.uz])
    return UCS(origin=ucs.origin, ux=ux, uy=uy, uz=uz)



doc = ezdxf.new('R2010', setup=True)
blk = doc.blocks.new('CSYS')
setup_csys(blk)
msp = doc.modelspace()

ucs = ucs_rotation(UCS(), axis=Y_AXIS, angle=90)
# transform insert location to OCS
insert = ucs.to_ocs((0, 0, 0))
# rotation angle about the z-axis (= WCS x-axis)
rotation = ucs.to_ocs_angle_deg(15)
msp.add_blockref('CSYS', insert, dxfattribs={
   'extrusion': ucs.uz,
   'rotation': rotation,
})

# To rotate a block reference around the block x-axis,
# you have to find the rotated z-axis (= extrusion vector)
# of the rotated block reference:
# t is a transformation matrix to rotate 15 degree around the x-axis
t = Matrix44.axis_rotate(axis=X_AXIS, angle=math.radians(15))
# transform block z-axis into new UCS z-axis (= extrusion vector)
uz = Vec3(t.transform(Z_AXIS))
# create new UCS at the insertion point, because we are rotating around the x-axis,
# ux is the same as the WCS x-axis and uz is the rotated z-axis.
ucs = UCS(origin=(1, 2, 0), ux=X_AXIS, uz=uz)
# transform insert location to OCS, block base_point=(0, 0, 0)
insert = ucs.to_ocs((0, 0, 0))
# for this case a rotation around the z-axis is not required
rotation = 0
blockref = msp.add_blockref('CSYS', insert, dxfattribs={
    'extrusion': ucs.uz,
    'rotation': rotation,
})

# translate a block references with an established OCS
translation = Vec3(-3, -1, 1)
# get established OCS
ocs = blockref.ocs()
# get insert location in WCS
actual_wcs_location = ocs.to_wcs(blockref.dxf.insert)
# translate location
new_wcs_location = actual_wcs_location + translation
# convert WCS location to OCS location
blockref.dxf.insert = ocs.from_wcs(new_wcs_location)

# rotate a block references with an established OCS around the block y-axis about 90 degree
ocs = blockref.ocs()
# convert block y-axis (= rotation axis) into WCS vector
rotation_axis = ocs.to_wcs((0, 1, 0))
# convert local z-axis (=extrusion vector) into WCS vector
local_z_axis = ocs.to_wcs((0, 0, 1))
# build transformation matrix
t = Matrix44.axis_rotate(axis=rotation_axis, angle=math.radians(-90))
uz = t.transform(local_z_axis)
uy = rotation_axis
# the block reference origin stays at the same location, no rotation needed
wcs_insert = ocs.to_wcs(blockref.dxf.insert)
# build new UCS to convert WCS locations and angles into OCS
ucs = UCS(origin=wcs_insert, uy=uy, uz=uz)

# set new OCS
blockref.dxf.extrusion = ucs.uz
# set new insert
blockref.dxf.insert = ucs.to_ocs((0, 0, 0))
# set new rotation: we do not rotate the block reference around the local z-axis,
# but the new block x-axis (0 deg) differs from OCS x-axis and has to be adjusted
blockref.dxf.rotation = ucs.to_ocs_angle_deg(0)

doc.set_modelspace_vport(5)
doc.saveas(OUT_DIR / 'ocs_insert.dxf')