# -*- encoding: utf-8 -*-
##
## Copyright (C) 2013 Emmanuel Gil Peyrot <linkmauve@linkmauve.fr>
##
## 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; version 3 only.
##
## 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.
##

IF USE_OPENGL:
    from pytouhou.lib.opengl cimport \
             (glEnable, glHint, glEnableClientState, GL_TEXTURE_2D, GL_BLEND,
              GL_PERSPECTIVE_CORRECTION_HINT, GL_FOG_HINT, GL_NICEST,
              GL_COLOR_ARRAY, GL_VERTEX_ARRAY, GL_TEXTURE_COORD_ARRAY)

    IF USE_GLEW:
        from pytouhou.lib.opengl cimport glewInit


cdef class Clock:
    def __init__(self, long fps=-1):
        self._target_fps = 0
        self._ref_tick = 0
        self._ref_frame = 0
        self._fps_tick = 0
        self._fps_frame = 0
        self._rate = 0
        self.set_target_fps(fps)


    cdef void set_target_fps(self, long fps) nogil:
        self._target_fps = fps
        self._ref_tick = 0
        self._fps_tick = 0


    cdef double get_fps(self) nogil:
        return self._rate


    cdef void tick(self) nogil except *:
        current = sdl.get_ticks()

        if not self._ref_tick:
            self._ref_tick = current
            self._ref_frame = 0

        if self._fps_frame >= (self._target_fps if self._target_fps > 0 else 60):
            self._rate = self._fps_frame * 1000. / (current - self._fps_tick)
            self._fps_tick = current
            self._fps_frame = 0
            # If we are relying on vsync, but vsync doesn't work or is higher
            # than 60 fps, limit ourselves to 60 fps.
            if self._target_fps < 0 and self._rate > 64.:
                self._target_fps = 60

        self._ref_frame += 1
        self._fps_frame += 1

        target_tick = self._ref_tick
        if self._target_fps > 0:
            target_tick += <unsigned long>(self._ref_frame * 1000 / self._target_fps)

        if current <= target_tick:
            sdl.delay(target_tick - current)
        else:
            self._ref_tick = current
            self._ref_frame = 0



cdef class Runner:
    cdef void start(self) except *:
        pass

    cdef void finish(self) except *:
        pass

    cdef bint update(self) except *:
        return False



cdef class Window:
    def __init__(self, bint double_buffer=True, long fps_limit=-1,
                 bint fixed_pipeline=False, bint sound=True, bint opengl=True):
        self.fps_limit = fps_limit
        self.use_fixed_pipeline = fixed_pipeline
        self.runner = None

        flags = sdl.WINDOW_SHOWN

        if USE_OPENGL and opengl:
            sdl.gl_set_attribute(sdl.GL_CONTEXT_MAJOR_VERSION, 2)
            sdl.gl_set_attribute(sdl.GL_CONTEXT_MINOR_VERSION, 1)
            sdl.gl_set_attribute(sdl.GL_DOUBLEBUFFER, int(double_buffer))
            sdl.gl_set_attribute(sdl.GL_DEPTH_SIZE, 24)

            flags |= sdl.WINDOW_OPENGL

            #TODO: implement it in the SDL backend too.
            if not self.use_fixed_pipeline:
                flags |= sdl.WINDOW_RESIZABLE

        self.win = sdl.Window('PyTouhou',
                              sdl.WINDOWPOS_CENTERED, sdl.WINDOWPOS_CENTERED,
                              640, 480, #XXX
                              flags)

        if USE_OPENGL and opengl:
            self.win.gl_create_context()

            IF USE_GLEW:
                if glewInit() != 0:
                    raise Exception('GLEW init fail!')

            # Initialize OpenGL
            glEnable(GL_BLEND)
            if self.use_fixed_pipeline:
                glEnable(GL_TEXTURE_2D)
                glHint(GL_FOG_HINT, GL_NICEST)
                glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
                glEnableClientState(GL_COLOR_ARRAY)
                glEnableClientState(GL_VERTEX_ARRAY)
                glEnableClientState(GL_TEXTURE_COORD_ARRAY)
        else:
            self.win.create_renderer(0)

        self.clock = Clock(self.fps_limit)


    cdef void set_size(self, int width, int height) nogil:
        self.win.set_window_size(width, height)


    cpdef set_runner(self, Runner runner=None):
        self.runner = runner
        if runner is not None:
            runner.start()


    cpdef run(self):
        try:
            while self.run_frame():
                pass
        finally:
            self.runner.finish()


    cdef bint run_frame(self) except? False:
        cdef bint running = False
        if self.runner is not None:
            running = self.runner.update()
        self.win.present()
        self.clock.tick()
        return running


    cdef double get_fps(self) nogil:
        return self.clock.get_fps()