"""
image utils.

Library format cheat sheet:

Library     Dim Order       Channel Order       Value Range     Type
Pillow                      R, G, B, A          0-255           PIL.Image.Image
OpenCV                      B, G, R, A          0-255           np.ndarray
Torch       (B), C, H, W    R, G, B             -1.0-1.0        torch.Tensor

"""
from typing import Sequence

import numpy as np
import PIL
import torch
from einops import rearrange, repeat
from PIL import Image, ImageDraw, ImageFont

from imaginairy.schema import LazyLoadingImage
from imaginairy.utils import get_device
from imaginairy.utils.paths import PKG_ROOT


def pillow_fit_image_within(
    image: PIL.Image.Image | LazyLoadingImage,
    max_height=512,
    max_width=512,
    convert="RGB",
    snap_size=8,
) -> PIL.Image.Image:
    image = image.convert(convert)
    w, h = image.size
    resize_ratio = 1
    if w > max_width or h > max_height:
        resize_ratio = min(max_width / w, max_height / h)
    elif w < max_width and h < max_height:
        # it's smaller than our target image, enlarge
        resize_ratio = max(max_width / w, max_height / h)

    if resize_ratio != 1:
        w, h = int(w * resize_ratio), int(h * resize_ratio)
    # resize to integer multiple of snap_size
    w -= w % snap_size
    h -= h % snap_size

    if (w, h) != image.size:
        image = image.resize((w, h), resample=Image.Resampling.LANCZOS)
    return image


def pillow_img_to_torch_image(
    img: PIL.Image.Image | LazyLoadingImage, convert="RGB"
) -> torch.Tensor:
    if convert:
        img = img.convert(convert)
    img_np = np.array(img).astype(np.float32) / 255.0
    # b, h, w, c => b, c, h, w
    img_np = img_np[None].transpose(0, 3, 1, 2)
    img_t = torch.from_numpy(img_np)
    return 2.0 * img_t - 1.0


def pillow_mask_to_latent_mask(
    mask_img: PIL.Image.Image | LazyLoadingImage, downsampling_factor
) -> torch.Tensor:
    mask_img = mask_img.resize(
        (
            mask_img.width // downsampling_factor,
            mask_img.height // downsampling_factor,
        ),
        resample=Image.Resampling.LANCZOS,
    )

    mask = np.array(mask_img).astype(np.float32) / 255.0
    mask = mask[None, None]
    mask_t = torch.from_numpy(mask)
    return mask_t


def pillow_img_to_opencv_img(img: PIL.Image.Image | LazyLoadingImage):
    open_cv_image = np.array(img)
    # Convert RGB to BGR
    open_cv_image = open_cv_image[:, :, ::-1].copy()
    return open_cv_image


def torch_image_to_openvcv_img(img: torch.Tensor) -> np.ndarray:
    img = (img + 1) / 2
    img_np = img.detach().cpu().numpy()
    # assert there is only one image
    assert img_np.shape[0] == 1
    img_np = img_np[0]
    img_np = img_np.transpose(1, 2, 0)
    img_np = (img_np * 255).astype(np.uint8)
    # RGB to BGR
    img_np = img_np[:, :, ::-1]
    return img_np


def torch_img_to_pillow_img(img_t: torch.Tensor) -> PIL.Image.Image:
    img_t = img_t.to(torch.float32).detach().cpu()
    if len(img_t.shape) == 3:
        img_t = img_t.unsqueeze(0)
    if img_t.shape[0] != 1:
        raise ValueError("Only batch size 1 supported")
    if img_t.shape[1] == 1:
        colorspace = "L"
    elif img_t.shape[1] == 3:
        colorspace = "RGB"
    else:
        msg = (
            f"Unsupported colorspace. {img_t.shape[1]} channels in {img_t.shape} shape"
        )
        raise ValueError(msg)
    img_t = rearrange(img_t, "b c h w -> b h w c")
    img_t = torch.clamp((img_t + 1.0) / 2.0, min=0.0, max=1.0)
    img_np = (255.0 * img_t).cpu().numpy().astype(np.uint8)[0]
    if colorspace == "L":
        img_np = img_np[:, :, 0]
    return Image.fromarray(img_np, colorspace)


def model_latent_to_pillow_img(latent: torch.Tensor) -> PIL.Image.Image:
    from imaginairy.utils.model_manager import get_current_diffusion_model

    if len(latent.shape) == 3:
        latent = latent.unsqueeze(0)
    if latent.shape[0] != 1:
        raise ValueError("Only batch size 1 supported")
    model = get_current_diffusion_model()
    img_t = model.lda.decode(latent)
    return torch_img_to_pillow_img(img_t)


def model_latents_to_pillow_imgs(latents: torch.Tensor) -> Sequence[PIL.Image.Image]:
    return [model_latent_to_pillow_img(latent) for latent in latents]


def pillow_img_to_model_latent(
    model, img: PIL.Image.Image | LazyLoadingImage, batch_size=1, half=True
):
    init_image = pillow_img_to_torch_image(img).to(get_device())
    init_image = repeat(init_image, "1 ... -> b ...", b=batch_size)
    if half:
        return model.get_first_stage_encoding(
            model.encode_first_stage(init_image.half())
        )
    return model.get_first_stage_encoding(model.encode_first_stage(init_image))


def imgpaths_to_imgs(imgpaths):
    imgs = []
    for imgpath in imgpaths:
        if isinstance(imgpath, str):
            img = LazyLoadingImage(filepath=imgpath)
            imgs.append(img)
        else:
            imgs.append(imgpath)

    return imgs


def add_caption_to_image(
    img: PIL.Image.Image | LazyLoadingImage,
    caption,
    font_size=16,
    font_path=f"{PKG_ROOT}/data/DejaVuSans.ttf",
):
    img_pil = img.as_pillow() if isinstance(img, LazyLoadingImage) else img
    draw = ImageDraw.Draw(img_pil)

    font = ImageFont.truetype(font_path, font_size)

    x = 15
    y = img_pil.height - 15 - font_size

    draw.text(
        (x, y),
        caption,
        font=font,
        fill=(255, 255, 255),
        stroke_width=3,
        stroke_fill=(0, 0, 0),
    )