# -*- encoding: utf-8 -*-
##
## Copyright (C) 2011 Thibaut Girka <thib@sitedethib.com>
##
## 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.
##

from libc.stdlib cimport malloc, free
from itertools import chain

from pytouhou.lib.opengl cimport \
         (glClear, glMatrixMode, glLoadIdentity, glLoadMatrixf, glDisable,
          glEnable, glFogi, glFogf, glFogfv, GL_PROJECTION, GL_MODELVIEW,
          GL_FOG, GL_FOG_MODE, GL_LINEAR, GL_FOG_START, GL_FOG_END,
          GL_FOG_COLOR, GL_COLOR_BUFFER_BIT, GLfloat, glViewport, glScissor,
          GL_SCISSOR_TEST, GL_DEPTH_BUFFER_BIT, glPushDebugGroup,
          GL_DEBUG_SOURCE_APPLICATION, glPopDebugGroup, glBindTexture,
          glGetTexImage, GL_TEXTURE_2D, GL_RGB, GL_UNSIGNED_BYTE)

from pytouhou.utils.matrix cimport mul, new_identity
from pytouhou.utils.maths cimport perspective, setup_camera, ortho_2d
from pytouhou.game.text cimport NativeText, GlyphCollection
from pytouhou.ui.window cimport Window
from .shaders.eosd import GameShader, BackgroundShader, PassthroughShader
from .renderer cimport Texture
from .backend cimport is_legacy, use_debug_group, use_pack_invert

from collections import namedtuple
Rect = namedtuple('Rect', 'x y w h')
Color = namedtuple('Color', 'r g b a')


cdef class GameRenderer(Renderer):
    def __init__(self, resource_loader, Window window):
        Renderer.__init__(self, resource_loader)

        if not is_legacy:
            self.game_shader = GameShader()
            self.background_shader = BackgroundShader()
            self.interface_shader = self.game_shader
            self.passthrough_shader = PassthroughShader()

            self.framebuffer = Framebuffer(0, 0, window.width, window.height)


    def __dealloc__(self):
        if self.game_mvp != NULL:
            free(self.game_mvp)
        if self.interface_mvp != NULL:
            free(self.interface_mvp)
        if self.proj != NULL:
            free(self.proj)


    property size:
        # We never need to get back the computed size, so size is write-only.
        def __set__(self, tuple size):
            self.x, self.y, self.width, self.height = size


    def load_textures(self, dict anms):
        self.texture_manager.load(anms)


    def load_background(self, background):
        self.background = background
        if background is not None:
            self.background_renderer = BackgroundRenderer()
            self.background_renderer.load(background, self.textures)
        else:
            self.background_renderer = None


    def start(self, common):
        self.proj = perspective(30, float(common.width) / float(common.height),
                                101010101./2010101., 101010101./10101.)
        self.game_mvp = setup_camera(0, 0, 1)
        mul(self.game_mvp, self.proj)
        self.interface_mvp = ortho_2d(0., float(common.interface.width),
                                      float(common.interface.height), 0.)


    def render(self, Game game):
        if not is_legacy:
            self.framebuffer.bind()

        self.render_game(game)
        self.render_text(game.texts)
        self.render_interface(game.interface, game.boss)

        if not is_legacy:
            if use_debug_group:
                glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, "Scaled rendering")

            self.passthrough_shader.bind()
            self.passthrough_shader.uniform_matrix('mvp', self.interface_mvp)
            self.framebuffer.render(self.x, self.y, self.width, self.height)

            if use_debug_group:
                glPopDebugGroup()


    def capture(self, filename, int width, int height):
        capture_memory = <char*>malloc(width * height * 3)

        glBindTexture(GL_TEXTURE_2D, self.framebuffer.texture)
        glGetTexImage(GL_TEXTURE_2D, 0, GL_RGB, GL_UNSIGNED_BYTE, capture_memory)
        glBindTexture(GL_TEXTURE_2D, 0)

        # TODO: output to PNG instead.

        # PPM output, bottom to top.
        with open(filename, 'wb') as ppm:
            ppm.write(('P6\n%d %d\n 255\n' % (width, height)).encode())
            if use_pack_invert:
                ppm.write(capture_memory[:width * height * 3])
            else:
                for i in range(width * (height - 1), -1, -width):
                    ppm.write(capture_memory[i * 3:(i + width) * 3])

        # Cleanup.
        free(capture_memory)


    cdef void render_game(self, Game game):
        cdef long game_x, game_y
        cdef float x, y, z, dx, dy, dz
        cdef float fog_data[4]
        cdef float fog_start, fog_end
        cdef unsigned char fog_r, fog_g, fog_b
        cdef Matrix *mvp

        if use_debug_group:
            glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, "Game rendering")

        game_x, game_y = game.interface.game_pos
        glViewport(game_x, game_y, game.width, game.height)
        glClear(GL_DEPTH_BUFFER_BIT)
        glScissor(game_x, game_y, game.width, game.height)
        glEnable(GL_SCISSOR_TEST)

        if is_legacy:
            glMatrixMode(GL_PROJECTION)
            glLoadIdentity()

        if self.background_renderer is None:
            glClear(GL_COLOR_BUFFER_BIT)
        elif game is not None and game.spellcard_effect is not None:
            if is_legacy:
                glMatrixMode(GL_MODELVIEW)
                glLoadMatrixf(<GLfloat*>self.game_mvp)
                glDisable(GL_FOG)
            else:
                self.game_shader.bind()
                self.game_shader.uniform_matrix('mvp', self.game_mvp)

            self.render_elements([game.spellcard_effect])
        else:
            back = self.background
            x, y, z = back.position_interpolator.values
            dx, dy, dz = back.position2_interpolator.values
            fog_b, fog_g, fog_r, fog_start, fog_end = back.fog_interpolator.values

            # Those two lines may come from the difference between Direct3D and
            # OpenGL’s distance handling.  The first one seem to calculate fog
            # from the eye, while the second does that starting from the near
            # plane.
            #TODO: investigate, and use a variable to keep the near plane
            # distance at a single place.
            fog_start -= 101010101./2010101.
            fog_end -= 101010101./2010101.

            mvp = new_identity()
            mvp_data = <GLfloat*>mvp
            mvp_data[12] = -x
            mvp_data[13] = -y
            mvp_data[14] = -z
            view = setup_camera(dx, dy, dz)
            mul(mvp, view)
            free(view)
            mul(mvp, self.proj)

            if is_legacy:
                glMatrixMode(GL_MODELVIEW)
                glLoadMatrixf(mvp_data)

                glEnable(GL_FOG)
                glFogi(GL_FOG_MODE, GL_LINEAR)
                glFogf(GL_FOG_START, fog_start)
                glFogf(GL_FOG_END,  fog_end)

                fog_data[0] = fog_r / 255.
                fog_data[1] = fog_g / 255.
                fog_data[2] = fog_b / 255.
                fog_data[3] = 1.
                glFogfv(GL_FOG_COLOR, fog_data)
            else:
                self.background_shader.bind()
                self.background_shader.uniform_matrix('mvp', mvp)

                self.background_shader.uniform_1('fog_scale', 1. / (fog_end - fog_start))
                self.background_shader.uniform_1('fog_end', fog_end)
                self.background_shader.uniform_4('fog_color', fog_r / 255., fog_g / 255., fog_b / 255., 1.)

            free(mvp)
            self.background_renderer.render_background()

        if game is not None:
            if is_legacy:
                glMatrixMode(GL_MODELVIEW)
                glLoadMatrixf(<GLfloat*>self.game_mvp)
                glDisable(GL_FOG)
            else:
                self.game_shader.bind()
                self.game_shader.uniform_matrix('mvp', self.game_mvp)

            self.render_elements([enemy for enemy in game.enemies if enemy.visible])
            self.render_elements(game.effects)
            self.render_elements(chain(game.players_bullets,
                                       game.lasers_sprites(),
                                       game.players,
                                       game.msg_sprites()))
            self.render_elements(chain(game.bullets, game.lasers,
                                       game.cancelled_bullets, game.items,
                                       game.labels))

        if game.msg_runner is not None:
            rect = Rect(48, 368, 288, 48)
            color1 = Color(0, 0, 0, 192)
            color2 = Color(0, 0, 0, 128)
            self.render_quads([rect], [(color1, color1, color2, color2)], 0)

        glDisable(GL_SCISSOR_TEST)

        if use_debug_group:
            glPopDebugGroup()


    cdef void render_text(self, dict texts):
        cdef NativeText label

        if self.font_manager is None:
            return

        self.font_manager.load(texts)

        black = Color(0, 0, 0, 255)

        for label in texts.values():
            texture = (<Texture>label.texture).texture
            rect = Rect(label.x, label.y, label.width, label.height)
            gradient = [Color(*color, a=label.alpha) for color in label.gradient]

            if label.shadow:
                shadow_rect = Rect(label.x + 1, label.y + 1, label.width, label.height)
                shadow = [black._replace(a=label.alpha)] * 4
                self.render_quads([shadow_rect, rect], [shadow, gradient], texture)
            else:
                self.render_quads([rect], [gradient], texture)


    cdef void render_interface(self, interface, game_boss):
        cdef GlyphCollection label

        elements = []

        if use_debug_group:
            glPushDebugGroup(GL_DEBUG_SOURCE_APPLICATION, 0, -1, "Interface rendering")

        if is_legacy:
            glMatrixMode(GL_MODELVIEW)
            glLoadMatrixf(<GLfloat*>self.interface_mvp)
            glDisable(GL_FOG)
        else:
            self.interface_shader.bind()
            self.interface_shader.uniform_matrix('mvp', self.interface_mvp)
        glViewport(0, 0, interface.width, interface.height)

        items = [item for item in interface.items if item.anmrunner and item.anmrunner.running]
        labels = interface.labels.values()

        if items:
            # Redraw all the interface
            elements.extend(items)
        else:
            # Redraw only changed labels
            labels = [label for label in labels if label.changed]

        elements.extend(interface.level_start)

        if game_boss is not None:
            elements.extend(interface.boss_items)

        elements.extend(labels)
        self.render_elements(elements)
        for label in labels:
            label.changed = False

        if use_debug_group:
            glPopDebugGroup()