from __future__ import print_function, division

import pyglet.gl as pgl

from sympy.core import S
from sympy.core.compatibility import range
from sympy.plotting.pygletplot.plot_mode_base import PlotModeBase


class PlotSurface(PlotModeBase):

    default_rot_preset = 'perspective'

    def _on_calculate_verts(self):
        self.u_interval = self.intervals[0]
        self.u_set = list(self.u_interval.frange())
        self.v_interval = self.intervals[1]
        self.v_set = list(self.v_interval.frange())
        self.bounds = [[S.Infinity, -S.Infinity, 0],
                       [S.Infinity, -S.Infinity, 0],
                       [S.Infinity, -S.Infinity, 0]]
        evaluate = self._get_evaluator()

        self._calculating_verts_pos = 0.0
        self._calculating_verts_len = float(
            self.u_interval.v_len*self.v_interval.v_len)

        verts = list()
        b = self.bounds
        for u in self.u_set:
            column = list()
            for v in self.v_set:
                try:
                    _e = evaluate(u, v)  # calculate vertex
                except ZeroDivisionError:
                    _e = None
                if _e is not None:  # update bounding box
                    for axis in range(3):
                        b[axis][0] = min([b[axis][0], _e[axis]])
                        b[axis][1] = max([b[axis][1], _e[axis]])
                column.append(_e)
                self._calculating_verts_pos += 1.0

            verts.append(column)
        for axis in range(3):
            b[axis][2] = b[axis][1] - b[axis][0]
            if b[axis][2] == 0.0:
                b[axis][2] = 1.0

        self.verts = verts
        self.push_wireframe(self.draw_verts(False, False))
        self.push_solid(self.draw_verts(False, True))

    def _on_calculate_cverts(self):
        if not self.verts or not self.color:
            return

        def set_work_len(n):
            self._calculating_cverts_len = float(n)

        def inc_work_pos():
            self._calculating_cverts_pos += 1.0
        set_work_len(1)
        self._calculating_cverts_pos = 0
        self.cverts = self.color.apply_to_surface(self.verts,
                                                  self.u_set,
                                                  self.v_set,
                                                  set_len=set_work_len,
                                                  inc_pos=inc_work_pos)
        self.push_solid(self.draw_verts(True, True))

    def calculate_one_cvert(self, u, v):
        vert = self.verts[u][v]
        return self.color(vert[0], vert[1], vert[2],
                          self.u_set[u], self.v_set[v])

    def draw_verts(self, use_cverts, use_solid_color):
        def f():
            for u in range(1, len(self.u_set)):
                pgl.glBegin(pgl.GL_QUAD_STRIP)
                for v in range(len(self.v_set)):
                    pa = self.verts[u - 1][v]
                    pb = self.verts[u][v]
                    if pa is None or pb is None:
                        pgl.glEnd()
                        pgl.glBegin(pgl.GL_QUAD_STRIP)
                        continue
                    if use_cverts:
                        ca = self.cverts[u - 1][v]
                        cb = self.cverts[u][v]
                        if ca is None:
                            ca = (0, 0, 0)
                        if cb is None:
                            cb = (0, 0, 0)
                    else:
                        if use_solid_color:
                            ca = cb = self.default_solid_color
                        else:
                            ca = cb = self.default_wireframe_color
                    pgl.glColor3f(*ca)
                    pgl.glVertex3f(*pa)
                    pgl.glColor3f(*cb)
                    pgl.glVertex3f(*pb)
                pgl.glEnd()
        return f
