#====================== BEGIN GPL LICENSE BLOCK ======================
#
#  This program is free software; you can redistribute it and/or
#  modify it under the terms of the GNU General Public License
#  as published by the Free Software Foundation; either version 2
#  of the License, or (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
#
#======================= END GPL LICENSE BLOCK ========================

import bpy
import blf

from . import utils
from mathutils import Vector, Matrix

callbacks = {}

def callbacks_clear():
    for region, handle_pixel, handle_view in callbacks.values():
        region.callback_remove(handle_pixel)
        region.callback_remove(handle_view)
    callbacks.clear()


def draw_callback_px(self, context):
    from bgl import glColor3f
    font_id = 0 # XXX, need to find out how best to get this.
    blf.size(font_id, 12, 72)

    data_matrix, data_quat, data_euler, data_vector, data_vector_array = utils.console_math_data()

    if not data_matrix and not data_quat and not data_euler and not data_vector and not data_vector_array:

        # draw some text
        glColor3f(1.0, 0.0, 0.0)
        blf.position(font_id, 180, 10, 0)
        blf.draw(font_id, "Python Console has no mathutils definitions")
        return

    glColor3f(1.0, 1.0, 1.0)

    region = context.region
    region3d = context.space_data.region_3d
    
    region_mid_width = region.width / 2.0
    region_mid_height = region.height / 2.0

    # vars for projection
    perspective_matrix = region3d.perspective_matrix.copy()

    def draw_text(text, vec):
        vec_4d = Vector((vec.x, vec.y, vec.z, 1.0))
        vec_4d *= perspective_matrix
        if vec_4d.w > 0.0:
            x = region_mid_width + region_mid_width * (vec_4d.x / vec_4d.w)
            y = region_mid_height + region_mid_height * (vec_4d.y / vec_4d.w)

            blf.position(font_id, x + 3.0, y - 4.0, 0.0)
            blf.draw(font_id, text)

    # points
    if data_vector:
        for key, vec in data_vector.items():
            draw_text(key, vec)

    # lines
    if data_vector_array:
        for key, vec in data_vector_array.items():
            draw_text(key, vec[0])

    # matrix
    if data_matrix:
        for key, mat in data_matrix.items():
            draw_text(key, mat[3])
    
    if data_quat:
        loc = context.scene.cursor_location.copy()
        for key, mat in data_quat.items():
            draw_text(key, loc)

    if data_euler:
        loc = context.scene.cursor_location.copy()
        for key, mat in data_euler.items():
            draw_text(key, loc)


def draw_callback_view(self, context):
    from bgl import glEnable, glDisable, glColor3f, glVertex3f, glPointSize, glLineWidth, glBegin, glEnd, glLineStipple, GL_POINTS, GL_LINE_STRIP, GL_LINES, GL_LINE_STIPPLE

    data_matrix, data_quat, data_euler, data_vector, data_vector_array = utils.console_math_data()


    # draw_matrix vars
    zero = Vector((0.0, 0.0, 0.0))
    x_p = Vector((1.0, 0.0, 0.0))
    x_n = Vector((-1.0, 0.0, 0.0))
    y_p = Vector((0.0, 1.0, 0.0))
    y_n = Vector((0.0, -1.0, 0.0))
    z_p = Vector((0.0, 0.0, 1.0))
    z_n = Vector((0.0, 0.0, -1.0))        
    bb = [Vector() for i in range(8)]

    def draw_matrix(mat):
        zero_tx = zero * mat
        
        glLineWidth(2.0)
        
        # x
        glColor3f(1.0, 0.2, 0.2)
        glBegin(GL_LINES)
        glVertex3f(*(zero_tx))
        glVertex3f(*(x_p * mat))
        glEnd()

        glColor3f(0.6, 0.0, 0.0)
        glBegin(GL_LINES)
        glVertex3f(*(zero_tx))
        glVertex3f(*(x_n * mat))
        glEnd()

        # y
        glColor3f(0.2, 1.0, 0.2)
        glBegin(GL_LINES)
        glVertex3f(*(zero_tx))
        glVertex3f(*(y_p * mat))
        glEnd()

        glColor3f(0.0, 0.6, 0.0)
        glBegin(GL_LINES)
        glVertex3f(*(zero_tx))
        glVertex3f(*(y_n * mat))
        glEnd()
        
        # z
        glColor3f(0.2, 0.2, 1.0)
        glBegin(GL_LINES)
        glVertex3f(*(zero_tx))
        glVertex3f(*(z_p * mat))
        glEnd()

        glColor3f(0.0, 0.0, 0.6)
        glBegin(GL_LINES)
        glVertex3f(*(zero_tx))
        glVertex3f(*(z_n * mat))
        glEnd()
        
        # bounding box
        i = 0
        glColor3f(1.0, 1.0, 1.0)
        for x in (-1.0, 1.0):
            for y in (-1.0, 1.0):
                for z in (-1.0, 1.0):
                    bb[i][:] = x, y, z
                    bb[i] *= mat
                    i += 1

        # strip
        glLineWidth(1.0)
        glLineStipple(1, 0xAAAA)
        glEnable(GL_LINE_STIPPLE)

        glBegin(GL_LINE_STRIP)
        for i in 0, 1, 3, 2, 0, 4, 5, 7, 6, 4:
            glVertex3f(*bb[i])
        glEnd()

        # not done by the strip
        glBegin(GL_LINES)
        glVertex3f(*bb[1])
        glVertex3f(*bb[5])
        
        glVertex3f(*bb[2])
        glVertex3f(*bb[6])
        
        glVertex3f(*bb[3])
        glVertex3f(*bb[7])
        glEnd()
        glDisable(GL_LINE_STIPPLE)


    # points
    if data_vector:
        glPointSize(3.0);
        glBegin(GL_POINTS)
        glColor3f(0.5, 0.5, 1)
        for key, vec in data_vector.items():
            glVertex3f(*vec.copy().resize3D())
        glEnd();
        glPointSize(1.0)

    # lines
    if data_vector_array:
        glColor3f(0.5, 0.5, 1)
        glLineWidth(2.0)

        for line in data_vector_array.values():
            glBegin(GL_LINE_STRIP)
            for vec in line:
                glVertex3f(*vec)
            glEnd();
            glPointSize(1.0)

        glLineWidth(1.0)

    # matrix
    if data_matrix:
        for mat in data_matrix.values():
            draw_matrix(mat)

    if data_quat:
        loc = context.scene.cursor_location.copy()
        for quat in data_quat.values():
            mat = quat.to_matrix().resize4x4()
            mat[3][0:3] = loc
            draw_matrix(mat)

    if data_euler:
        loc = context.scene.cursor_location.copy()
        for eul in data_euler.values():
            mat = eul.to_matrix().resize4x4()
            mat[3][0:3] = loc
            draw_matrix(mat)
