#**********************************************************************
# Copyright 2020 Advanced Micro Devices, Inc
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#********************************************************************
import numpy as np
import os
from pathlib import Path

import bpy
import bpy_extras

from rprblender import utils
from rprblender.engine import context

from rprblender.utils import logging
from rprblender.utils import get_sequence_frame_file_path

log = logging.Log(tag='export.image')


UNSUPPORTED_IMAGES = ('.tiff', '.tif', '.exr')

# image format conversion for packed pixel/generated images
IMAGE_FORMATS = {
    'OPEN_EXR_MULTILAYER': ('OPEN_EXR', 'exr'),
    'OPEN_EXR': ('OPEN_EXR', 'exr'),
    'HDR': ('HDR', 'hdr'),
    # 'TIFF': ('TIFF', 'tiff'), # Seems tiff is not working properly in RPR
    'TARGA': ('TARGA', 'tga'),
    'TARGA_RAW': ('TARGA', 'tga'),
    # everything else will be stored as PNG
}
DEFAULT_FORMAT = ('PNG', 'png')


def key(image: bpy.types.Image, color_space, frame_number=None, UDIM_tile=0):
    """ Generate image key for RPR """
    if frame_number is not None:
        return (image.name, color_space, frame_number)
    if UDIM_tile:
        return (image.name, color_space, 0, UDIM_tile)
    return (image.name, color_space)


def sync(rpr_context, image: bpy.types.Image, use_color_space=None, frame_number=None):
    """ Creates pyrpr.Image from bpy.types.Image """
    from rprblender.engine.export_engine import ExportEngine

    color_space = image.colorspace_settings.name
    if use_color_space:
        color_space = use_color_space

    if image.source == 'SEQUENCE':
        image_key = key(image, color_space, frame_number=frame_number)
    else:
        if image.size[0] * image.size[1] * image.channels == 0:
            log.warn("Image has no data", image)
            return None
        image_key = key(image, color_space)

    if image_key in rpr_context.images:
        return rpr_context.images[image_key]

    log("sync", image)

    if image.source == 'TILED':  # UDIM Tiles
        rpr_image = rpr_context.create_tiled_image(key=image_key)
        if rpr_image:  # if context doesn't support tiles - export as regular image
            udim_path_split = image.filepath_from_user().split('.')
            for tile in image.tiles:
                tile_path = '.'.join(udim_path_split[:-2] + [tile.label] + udim_path_split[-1:])
                tile_key = key(image, color_space, UDIM_tile=tile.label)

                tile_image = rpr_context.create_image_file(tile_key, tile_path)
                set_image_gamma(tile_image, image, color_space, rpr_context)
                tile_image.set_name(str(tile_key))

                rpr_image.set_udim_tile(tile.number, tile_image)

            rpr_image.set_name(str(image_key))

            return rpr_image

    pixels = image.pixels
    if image.source == 'SEQUENCE':
        file_path = get_sequence_frame_file_path(image.filepath_from_user(), frame_number)
        if not file_path:
            return None
        rpr_image = rpr_context.create_image_file(image_key, file_path)

    elif rpr_context.engine_type != ExportEngine.TYPE and hasattr(pixels, 'foreach_get'):
        data = utils.get_prop_array_data(pixels)
        data = np.flipud(data.reshape(image.size[1], image.size[0], image.channels))
        rpr_image = rpr_context.create_image_data(image_key, np.ascontiguousarray(data))

    elif image.source in ('FILE', 'GENERATED'):
        file_path = cache_image_file(image, rpr_context.blender_data['depsgraph'])
        rpr_image = rpr_context.create_image_file(image_key, file_path)

    else:
        # loading image by pixels
        data = utils.get_prop_array_data(pixels)
        data = np.flipud(data.reshape(image.size[1], image.size[0], image.channels))
        rpr_image = rpr_context.create_image_data(image_key, np.ascontiguousarray(data))

    rpr_image.set_name(str(image_key))

    set_image_gamma(rpr_image, image, color_space, rpr_context)

    return rpr_image


def set_image_gamma(rpr_image, image, color_space, rpr_context):
   # RPRImageTexture node color space names are in caps, unlike in Blender
    if isinstance(rpr_context, context.RPRContext2):
        rpr_image.set_colorspace(color_space)
    elif color_space in ('sRGB', 'BD16', 'Filmic Log', 'SRGB'):
        rpr_image.set_gamma(2.2)
    elif color_space not in ('Non-Color', 'Raw', 'Linear', 'LINEAR'):
        log.warn("Ignoring unsupported image color space type",
                 color_space, image)


class ImagePixels:
    """This class stores source image pixels. Exports as tile image and clipped to render size"""

    def __init__(self, image: bpy.types.Image):
        if image.size[0] * image.size[1] * image.channels == 0:
            raise ValueError("Image has no data", image)

        pixels = image.pixels
        if hasattr(pixels, 'foreach_get'):
            data = utils.get_prop_array_data(pixels)
        else:
            # loading image by pixels
            data = np.fromiter(pixels, dtype=np.float32,
                               count=image.size[0] * image.size[1] * image.channels)

        self.pixels = data.reshape(image.size[1], image.size[0], image.channels)

        self.name = image.name
        self.color_space = image.colorspace_settings.name

    def export(self, rpr_context, render_size=None, tile=((0, 0), (1, 1))):
        """Export pixels cropped to render and tile size as RPR image"""

        image_size = self.pixels.shape[1], self.pixels.shape[0]
        if render_size:
            image_ratio = image_size[0] / image_size[1]
            render_ratio = render_size[0] / render_size[1]

            if image_ratio > render_ratio:
                size = image_size[1] * render_ratio, image_size[1]
            else:
                size = image_size[0], image_size[0] / render_ratio

            x1, y1 = (image_size[0] - size[0]) / 2, (image_size[1] - size[1]) / 2
            x2, y2 = x1 + size[0], y1 + size[1]

        else:
            x1, y1 = 0, 0
            x2, y2 = image_size

        x1, y1, x2, y2 = (
            int(x1 + (x2 - x1) * tile[0][0]),
            int(y1 + (y2 - y1) * tile[0][1]),
            int(x1 + (x2 - x1) * (tile[0][0] + tile[1][0])),
            int(y1 + (y2 - y1) * (tile[0][1] + tile[1][1]))
        )

        if x1 == x2 or y1 == y2:
            return None

        pixels = self.pixels[y1:y2, x1:x2, :]
        rpr_image = rpr_context.create_image_data(None, np.ascontiguousarray(np.flipud(pixels)))
        rpr_image.set_name(self.name)

        if isinstance(rpr_context, context.RPRContext2):
            rpr_image.set_colorspace(self.color_space)
        elif self.color_space in ('sRGB', 'BD16', 'Filmic Log'):
            rpr_image.set_gamma(2.2)

        return rpr_image


def _get_temp_image_path(image: [bpy.types.Image, str], extension="png") -> str:
    h = abs(hash(image if isinstance(image, str) else image.name))
    return str(utils.get_temp_pid_dir() / f"{h}.{extension}")


def _save_temp_image(image, target_format, temp_path, depsgraph):
    scene = depsgraph.scene_eval

    # set desired output image file format
    scene.render.image_settings.file_format = target_format
    image.save_render(temp_path, scene=scene)


def cache_image_file(image: bpy.types.Image, depsgraph) -> str:
    """
    See if image is a file, cache image pixels to temporary folder if not.
    Return image file path.
    """
    if image.source != 'FILE':
        temp_path = _get_temp_image_path(image)
        if image.is_dirty or not os.path.isfile(temp_path):
            image.save_render(temp_path)

        return temp_path

    file_path = image.filepath_from_user()

    if file_path.lower().endswith('.ies'):
        if os.path.isfile(file_path):
            return file_path

        if not image.packed_file:
            log.warn("Can't load image", image, file_path)
            return None

        temp_path = _get_temp_image_path(image, "ies")
        if not os.path.isfile(temp_path):
            # save data of packed file
            Path(temp_path).write_bytes(image.packed_file.data)

        return temp_path

    if image.is_dirty or not os.path.isfile(file_path) \
            or file_path.lower().endswith(UNSUPPORTED_IMAGES):
        target_format, target_extension = IMAGE_FORMATS.get(image.file_format, DEFAULT_FORMAT)

        # getting file path from image cache and if such file not exist saving image to cache
        temp_path = _get_temp_image_path(image, target_extension)
        if image.is_dirty or not os.path.isfile(temp_path):
            _save_temp_image(image, target_format, temp_path, depsgraph)

        return temp_path

    return file_path


def cache_image_file_path(file_path: str, depsgraph) -> str:
    """ Cache Blender integrated and user-defined LookDev IBL files """
    if not file_path.lower().endswith(UNSUPPORTED_IMAGES):
        return file_path

    if file_path.lower().endswith('.exr'):
        target_format, target_extension = IMAGE_FORMATS['OPEN_EXR']
    else:
        target_format, target_extension = IMAGE_FORMATS['TIFF']

    temp_path = _get_temp_image_path(file_path, target_extension)
    if os.path.isfile(temp_path):
        return temp_path

    image = bpy_extras.image_utils.load_image(file_path)
    try:
        _save_temp_image(image, target_format, temp_path, depsgraph)
    finally:
        bpy.data.images.remove(image)

    return temp_path
