from __future__ import annotations

import itertools as it
import math

import moderngl
import numpy as np
import OpenGL.GL as gl
from PIL import Image
from scipy.spatial.transform import Rotation

from manimlib.constants import BLACK
from manimlib.constants import DEGREES, RADIANS
from manimlib.constants import DEFAULT_FPS
from manimlib.constants import DEFAULT_PIXEL_HEIGHT, DEFAULT_PIXEL_WIDTH
from manimlib.constants import FRAME_HEIGHT, FRAME_WIDTH
from manimlib.constants import DOWN, LEFT, ORIGIN, OUT, RIGHT, UP
from manimlib.mobject.mobject import Mobject
from manimlib.mobject.mobject import Point
from manimlib.utils.color import color_to_rgba
from manimlib.utils.config_ops import digest_config
from manimlib.utils.simple_functions import fdiv
from manimlib.utils.space_ops import normalize

from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from manimlib.shader_wrapper import ShaderWrapper


class CameraFrame(Mobject):
    CONFIG = {
        "frame_shape": (FRAME_WIDTH, FRAME_HEIGHT),
        "center_point": ORIGIN,
        "focal_dist_to_height": 2,
    }

    def init_uniforms(self) -> None:
        super().init_uniforms()
        # As a quaternion
        self.uniforms["orientation"] = Rotation.identity().as_quat()
        self.uniforms["focal_dist_to_height"] = self.focal_dist_to_height

    def init_points(self) -> None:
        self.set_points([ORIGIN, LEFT, RIGHT, DOWN, UP])
        self.set_width(self.frame_shape[0], stretch=True)
        self.set_height(self.frame_shape[1], stretch=True)
        self.move_to(self.center_point)

    def set_orientation(self, rotation: Rotation):
        self.uniforms["orientation"][:] = rotation.as_quat()
        return self

    def get_orientation(self):
        return Rotation.from_quat(self.uniforms["orientation"])

    def to_default_state(self):
        self.center()
        self.set_height(FRAME_HEIGHT)
        self.set_width(FRAME_WIDTH)
        self.set_orientation(Rotation.identity())
        return self

    def get_euler_angles(self):
        return self.get_orientation().as_euler("zxz")[::-1]

    def get_theta(self):
        return self.get_euler_angles()[0]

    def get_phi(self):
        return self.get_euler_angles()[1]

    def get_gamma(self):
        return self.get_euler_angles()[2]

    def get_inverse_camera_rotation_matrix(self):
        return self.get_orientation().as_matrix().T

    def rotate(self, angle: float, axis: np.ndarray = OUT, **kwargs):
        rot = Rotation.from_rotvec(angle * normalize(axis))
        self.set_orientation(rot * self.get_orientation())
        return self

    def set_euler_angles(
        self,
        theta: float | None = None,
        phi: float | None = None,
        gamma: float | None = None,
        units: float = RADIANS
    ):
        eulers = self.get_euler_angles()  # theta, phi, gamma
        for i, var in enumerate([theta, phi, gamma]):
            if var is not None:
                eulers[i] = var * units
        self.set_orientation(Rotation.from_euler("zxz", eulers[::-1]))
        return self

    def reorient(
        self,
        theta_degrees: float | None = None,
        phi_degrees: float | None = None,
        gamma_degrees: float | None = None,
    ):
        """
        Shortcut for set_euler_angles, defaulting to taking
        in angles in degrees
        """
        self.set_euler_angles(theta_degrees, phi_degrees, gamma_degrees, units=DEGREES)
        return self

    def set_theta(self, theta: float):
        return self.set_euler_angles(theta=theta)

    def set_phi(self, phi: float):
        return self.set_euler_angles(phi=phi)

    def set_gamma(self, gamma: float):
        return self.set_euler_angles(gamma=gamma)

    def increment_theta(self, dtheta: float):
        self.rotate(dtheta, OUT)
        return self

    def increment_phi(self, dphi: float):
        self.rotate(dphi, self.get_inverse_camera_rotation_matrix()[0])
        return self

    def increment_gamma(self, dgamma: float):
        self.rotate(dgamma, self.get_inverse_camera_rotation_matrix()[2])
        return self

    def set_focal_distance(self, focal_distance: float):
        self.uniforms["focal_dist_to_height"] = focal_distance / self.get_height()
        return self

    def set_field_of_view(self, field_of_view: float):
        self.uniforms["focal_dist_to_height"] = 2 * math.tan(field_of_view / 2)
        return self

    def get_shape(self):
        return (self.get_width(), self.get_height())

    def get_center(self) -> np.ndarray:
        # Assumes first point is at the center
        return self.get_points()[0]

    def get_width(self) -> float:
        points = self.get_points()
        return points[2, 0] - points[1, 0]

    def get_height(self) -> float:
        points = self.get_points()
        return points[4, 1] - points[3, 1]

    def get_focal_distance(self) -> float:
        return self.uniforms["focal_dist_to_height"] * self.get_height()

    def get_field_of_view(self) -> float:
        return 2 * math.atan(self.uniforms["focal_dist_to_height"] / 2)

    def get_implied_camera_location(self) -> np.ndarray:
        to_camera = self.get_inverse_camera_rotation_matrix()[2]
        dist = self.get_focal_distance()
        return self.get_center() + dist * to_camera


class Camera(object):
    CONFIG = {
        "background_image": None,
        "frame_config": {},
        "pixel_width": DEFAULT_PIXEL_WIDTH,
        "pixel_height": DEFAULT_PIXEL_HEIGHT,
        "fps": DEFAULT_FPS,
        # Note: frame height and width will be resized to match
        # the pixel aspect ratio
        "background_color": BLACK,
        "background_opacity": 1,
        # Points in vectorized mobjects with norm greater
        # than this value will be rescaled.
        "max_allowable_norm": FRAME_WIDTH,
        "image_mode": "RGBA",
        "n_channels": 4,
        "pixel_array_dtype": 'uint8',
        "light_source_position": [-10, 10, 10],
        # Measured in pixel widths, used for vector graphics
        "anti_alias_width": 1.5,
        # Although vector graphics handle antialiasing fine
        # without multisampling, for 3d scenes one might want
        # to set samples to be greater than 0.
        "samples": 0,
    }

    def __init__(self, ctx: moderngl.Context | None = None, **kwargs):
        digest_config(self, kwargs, locals())
        self.rgb_max_val: float = np.iinfo(self.pixel_array_dtype).max
        self.background_rgba: list[float] = list(color_to_rgba(
            self.background_color, self.background_opacity
        ))
        self.init_frame()
        self.init_context(ctx)
        self.init_shaders()
        self.init_textures()
        self.init_light_source()
        self.refresh_perspective_uniforms()
        # A cached map from mobjects to their associated list of render groups
        # so that these render groups are not regenerated unnecessarily for static
        # mobjects
        self.mob_to_render_groups = {}

    def init_frame(self) -> None:
        self.frame = CameraFrame(**self.frame_config)

    def init_context(self, ctx: moderngl.Context | None = None) -> None:
        if ctx is None:
            ctx = moderngl.create_standalone_context()
            fbo = self.get_fbo(ctx, 0)
        else:
            fbo = ctx.detect_framebuffer()
        self.ctx = ctx
        self.fbo = fbo
        self.set_ctx_blending()

        # For multisample antialiasing
        fbo_msaa = self.get_fbo(ctx, self.samples)
        fbo_msaa.use()
        self.fbo_msaa = fbo_msaa

    def set_ctx_blending(self, enable: bool = True) -> None:
        if enable:
            self.ctx.enable(moderngl.BLEND)
        else:
            self.ctx.disable(moderngl.BLEND)
        self.ctx.blend_func = (
            moderngl.SRC_ALPHA, moderngl.ONE_MINUS_SRC_ALPHA,
            # moderngl.ONE, moderngl.ONE
        )

    def set_ctx_depth_test(self, enable: bool = True) -> None:
        if enable:
            self.ctx.enable(moderngl.DEPTH_TEST)
        else:
            self.ctx.disable(moderngl.DEPTH_TEST)

    def init_light_source(self) -> None:
        self.light_source = Point(self.light_source_position)

    # Methods associated with the frame buffer
    def get_fbo(
        self,
        ctx: moderngl.Context,
        samples: int = 0
    ) -> moderngl.Framebuffer:
        pw = self.pixel_width
        ph = self.pixel_height
        return ctx.framebuffer(
            color_attachments=ctx.texture(
                (pw, ph),
                components=self.n_channels,
                samples=samples,
            ),
            depth_attachment=ctx.depth_renderbuffer(
                (pw, ph),
                samples=samples
            )
        )

    def clear(self) -> None:
        self.fbo.clear(*self.background_rgba)
        self.fbo_msaa.clear(*self.background_rgba)

    def reset_pixel_shape(self, new_width: int, new_height: int) -> None:
        self.pixel_width = new_width
        self.pixel_height = new_height
        self.refresh_perspective_uniforms()

    def get_raw_fbo_data(self, dtype: str = 'f1') -> bytes:
        # Copy blocks from the fbo_msaa to the drawn fbo using Blit
        pw, ph = (self.pixel_width, self.pixel_height)
        gl.glBindFramebuffer(gl.GL_READ_FRAMEBUFFER, self.fbo_msaa.glo)
        gl.glBindFramebuffer(gl.GL_DRAW_FRAMEBUFFER, self.fbo.glo)
        gl.glBlitFramebuffer(0, 0, pw, ph, 0, 0, pw, ph, gl.GL_COLOR_BUFFER_BIT, gl.GL_LINEAR)
        return self.fbo.read(
            viewport=self.fbo.viewport,
            components=self.n_channels,
            dtype=dtype,
        )

    def get_image(self) -> Image.Image:
        return Image.frombytes(
            'RGBA',
            self.get_pixel_shape(),
            self.get_raw_fbo_data(),
            'raw', 'RGBA', 0, -1
        )

    def get_pixel_array(self) -> np.ndarray:
        raw = self.get_raw_fbo_data(dtype='f4')
        flat_arr = np.frombuffer(raw, dtype='f4')
        arr = flat_arr.reshape([*self.fbo.size, self.n_channels])
        # Convert from float
        return (self.rgb_max_val * arr).astype(self.pixel_array_dtype)

    # Needed?
    def get_texture(self) -> moderngl.Texture:
        texture = self.ctx.texture(
            size=self.fbo.size,
            components=4,
            data=self.get_raw_fbo_data(),
            dtype='f4'
        )
        return texture

    # Getting camera attributes
    def get_pixel_shape(self) -> tuple[int, int]:
        return self.fbo.viewport[2:4]
        # return (self.pixel_width, self.pixel_height)

    def get_pixel_width(self) -> int:
        return self.get_pixel_shape()[0]

    def get_pixel_height(self) -> int:
        return self.get_pixel_shape()[1]

    def get_frame_height(self) -> float:
        return self.frame.get_height()

    def get_frame_width(self) -> float:
        return self.frame.get_width()

    def get_frame_shape(self) -> tuple[float, float]:
        return (self.get_frame_width(), self.get_frame_height())

    def get_frame_center(self) -> np.ndarray:
        return self.frame.get_center()

    def get_location(self) -> tuple[float, float, float]:
        return self.frame.get_implied_camera_location()

    def resize_frame_shape(self, fixed_dimension: bool = False) -> None:
        """
        Changes frame_shape to match the aspect ratio
        of the pixels, where fixed_dimension determines
        whether frame_height or frame_width
        remains fixed while the other changes accordingly.
        """
        pixel_height = self.get_pixel_height()
        pixel_width = self.get_pixel_width()
        frame_height = self.get_frame_height()
        frame_width = self.get_frame_width()
        aspect_ratio = fdiv(pixel_width, pixel_height)
        if not fixed_dimension:
            frame_height = frame_width / aspect_ratio
        else:
            frame_width = aspect_ratio * frame_height
        self.frame.set_height(frame_height)
        self.frame.set_width(frame_width)

    # Rendering
    def capture(self, *mobjects: Mobject, **kwargs) -> None:
        self.refresh_perspective_uniforms()
        for mobject in mobjects:
            for render_group in self.get_render_group_list(mobject):
                self.render(render_group)

    def render(self, render_group: dict[str]) -> None:
        shader_wrapper = render_group["shader_wrapper"]
        shader_program = render_group["prog"]
        self.set_shader_uniforms(shader_program, shader_wrapper)
        self.set_ctx_depth_test(shader_wrapper.depth_test)
        render_group["vao"].render(int(shader_wrapper.render_primitive))
        if render_group["single_use"]:
            self.release_render_group(render_group)

    def get_render_group_list(self, mobject: Mobject) -> Iterable[dict[str]]:
        if mobject.is_changing():
            return self.generate_render_group_list(mobject)

        # Otherwise, cache result for later use
        key = id(mobject)
        if key not in self.mob_to_render_groups:
            self.mob_to_render_groups[key] = list(self.generate_render_group_list(mobject))
        return self.mob_to_render_groups[key]

    def generate_render_group_list(self, mobject: Mobject) -> Iterable[dict[str]]:
        return (
            self.get_render_group(sw, single_use=mobject.is_changing())
            for sw in mobject.get_shader_wrapper_list()
        )

    def get_render_group(
        self,
        shader_wrapper: ShaderWrapper,
        single_use: bool = True
    ) -> dict[str]:
        # Data buffers
        vbo = self.ctx.buffer(shader_wrapper.vert_data.tobytes())
        if shader_wrapper.vert_indices is None:
            ibo = None
        else:
            vert_index_data = shader_wrapper.vert_indices.astype('i4').tobytes()
            if vert_index_data:
                ibo = self.ctx.buffer(vert_index_data)
            else:
                ibo = None

        # Program and vertex array
        shader_program, vert_format = self.get_shader_program(shader_wrapper)
        vao = self.ctx.vertex_array(
            program=shader_program,
            content=[(vbo, vert_format, *shader_wrapper.vert_attributes)],
            index_buffer=ibo,
        )
        return {
            "vbo": vbo,
            "ibo": ibo,
            "vao": vao,
            "prog": shader_program,
            "shader_wrapper": shader_wrapper,
            "single_use": single_use,
        }

    def release_render_group(self, render_group: dict[str]) -> None:
        for key in ["vbo", "ibo", "vao"]:
            if render_group[key] is not None:
                render_group[key].release()

    def refresh_static_mobjects(self) -> None:
        for render_group in it.chain(*self.mob_to_render_groups.values()):
            self.release_render_group(render_group)
        self.mob_to_render_groups = {}

    # Shaders
    def init_shaders(self) -> None:
        # Initialize with the null id going to None
        self.id_to_shader_program: dict[
            int | str, tuple[moderngl.Program, str] | None
        ] = {"": None}

    def get_shader_program(
        self,
        shader_wrapper: ShaderWrapper
    ) -> tuple[moderngl.Program, str]:
        sid = shader_wrapper.get_program_id()
        if sid not in self.id_to_shader_program:
            # Create shader program for the first time, then cache
            # in the id_to_shader_program dictionary
            program = self.ctx.program(**shader_wrapper.get_program_code())
            vert_format = moderngl.detect_format(program, shader_wrapper.vert_attributes)
            self.id_to_shader_program[sid] = (program, vert_format)
        return self.id_to_shader_program[sid]

    def set_shader_uniforms(
        self,
        shader: moderngl.Program,
        shader_wrapper: ShaderWrapper
    ) -> None:
        for name, path in shader_wrapper.texture_paths.items():
            tid = self.get_texture_id(path)
            shader[name].value = tid
        for name, value in it.chain(self.perspective_uniforms.items(), shader_wrapper.uniforms.items()):
            try:
                if isinstance(value, np.ndarray) and value.ndim > 0:
                    value = tuple(value)
                shader[name].value = value
            except KeyError:
                pass

    def refresh_perspective_uniforms(self) -> None:
        frame = self.frame
        pw, ph = self.get_pixel_shape()
        fw, fh = frame.get_shape()
        # TODO, this should probably be a mobject uniform, with
        # the camera taking care of the conversion factor
        anti_alias_width = self.anti_alias_width / (ph / fh)
        # Orient light
        rotation = frame.get_inverse_camera_rotation_matrix()
        offset = frame.get_center()
        light_pos = np.dot(
            rotation, self.light_source.get_location() + offset
        )
        cam_pos = self.frame.get_implied_camera_location()  # TODO

        self.perspective_uniforms = {
            "frame_shape": frame.get_shape(),
            "anti_alias_width": anti_alias_width,
            "camera_offset": tuple(offset),
            "camera_rotation": tuple(np.array(rotation).T.flatten()),
            "camera_position": tuple(cam_pos),
            "light_source_position": tuple(light_pos),
            "focal_distance": frame.get_focal_distance(),
        }

    def init_textures(self) -> None:
        self.n_textures: int = 0
        self.path_to_texture: dict[
            str, tuple[int, moderngl.Texture]
        ] = {}

    def get_texture_id(self, path: str) -> int:
        if path not in self.path_to_texture:
            if self.n_textures == 15:  # I have no clue why this is needed
                self.n_textures += 1
            tid = self.n_textures
            self.n_textures += 1
            im = Image.open(path).convert("RGBA")
            texture = self.ctx.texture(
                size=im.size,
                components=len(im.getbands()),
                data=im.tobytes(),
            )
            texture.use(location=tid)
            self.path_to_texture[path] = (tid, texture)
        return self.path_to_texture[path][0]

    def release_texture(self, path: str):
        tid_and_texture = self.path_to_texture.pop(path, None)
        if tid_and_texture:
            tid_and_texture[1].release()
        return self


# Mostly just defined so old scenes don't break
class ThreeDCamera(Camera):
    CONFIG = {
        "samples": 4,
        "anti_alias_width": 0,
    }
