from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from modules.processing import StableDiffusionProcessing

import math
import re

import gradio as gr
from PIL import Image

import modules.scripts as scripts
from modules import devices, images, processing, shared
from modules.processing import Processed
from modules.shared import opts, state


class SDUpscale(scripts.Script):
    def title(self):
        return "SD Upscale"

    def show(self, is_img2img):
        return is_img2img

    def ui(self, is_img2img):
        gr.HTML(
            """<p align="center">Upscale the image by the selected <b>Scale Factor</b>;
            use the <b>Width</b> and <b>Height</b> to set the tile size;
            use the <b>Batch size</b> to process multiple tiles at once</p>"""
        )

        with gr.Row():
            upscaler_index = gr.Dropdown(
                label="Upscaler",
                choices=[x.name for x in shared.sd_upscalers],
                value=shared.sd_upscalers[0].name,
                type="index",
                elem_id=self.elem_id("upscaler_index"),
            )
            scale_factor = gr.Slider(
                label="Scale Factor",
                value=2.0,
                minimum=1.0,
                maximum=8.0,
                step=0.05,
                elem_id=self.elem_id("scale_factor"),
            )

        with gr.Row():
            overlap = gr.Slider(
                label="Tile Overlap",
                value=64,
                minimum=0,
                maximum=256,
                step=16,
                elem_id=self.elem_id("overlap"),
            )
            override = gr.Checkbox(
                label="Save to Extras folder instead",
                value=False,
                elem_id=self.elem_id("override"),
            )

        return [overlap, upscaler_index, scale_factor, override]

    def run(self, p: "StableDiffusionProcessing", overlap, upscaler_index, scale_factor, override):
        if isinstance(upscaler_index, str):
            upscaler = next(
                (x for x in shared.sd_upscalers if x.name == upscaler_index),
                None,
            )
            assert upscaler is not None
        else:
            assert isinstance(upscaler_index, int)
            upscaler = shared.sd_upscalers[upscaler_index]

        p.extra_generation_params["SD Upscale - Overlap"] = overlap
        p.extra_generation_params["SD Upscale - Upscaler"] = upscaler.name

        initial_info: str = None
        seed_pattern = r"Seed: (\d+)"
        size_pattern = r"Size: (\d+)x(\d+)"

        processing.fix_seed(p)
        seed: int = p.seed

        init_img = p.init_images[0]
        init_img = images.flatten(init_img, opts.img2img_background_color)

        if upscaler.name != "None":
            img = upscaler.scaler.upscale(init_img, scale_factor, upscaler.data_path)
        else:
            img = init_img

        devices.torch_gc()

        grid = images.split_grid(img, tile_w=p.width, tile_h=p.height, overlap=overlap)

        batch_size = p.batch_size
        upscale_count = p.n_iter
        p.n_iter = 1
        p.do_not_save_grid = True
        p.do_not_save_samples = True

        work = []

        for _, _, row in grid.tiles:
            for tiledata in row:
                work.append(tiledata[2])

        batch_count = math.ceil(len(work) / batch_size)
        state.job_count = batch_count * upscale_count

        print(
            f"""
[SD Upscale]
- Processing {len(grid.tiles[0][2])}x{len(grid.tiles)} tiles for each image
- totaling {len(work)}x{upscale_count} generations at a batch size of {batch_size}
- resulting in {state.job_count} iterations
            """
        )

        result_images: list[Image.Image] = []
        infotexts: list[str] = []

        for n in range(upscale_count):
            start_seed = seed + n
            p.seed = start_seed

            work_results = []
            for i in range(batch_count):
                p.batch_size = batch_size
                p.init_images = work[i * batch_size : (i + 1) * batch_size]

                state.job = f"Batch {i + 1 + n * batch_count} out of {state.job_count}"
                processed = processing.process_images(p)

                if initial_info is None:
                    initial_info = processed.info

                p.seed = processed.seed + 1
                work_results += processed.images

            image_index = 0
            for _, _, row in grid.tiles:
                for tiledata in row:
                    tiledata[2] = work_results[image_index] if image_index < len(work_results) else Image.new("RGB", (p.width, p.height))
                    image_index += 1

            combined_image = images.combine_grid(grid)
            fin_w, fin_h = combined_image.size
            _info = re.sub(size_pattern, f"Size: {fin_w}x{fin_h}", initial_info)
            _info = re.sub(seed_pattern, f"Seed: {start_seed}", _info)

            result_images.append(combined_image)
            infotexts.append(_info)

            if opts.samples_save:
                if override:
                    images.save_image(
                        combined_image,
                        path=opts.outdir_samples or opts.outdir_extras_samples,
                        basename="",
                        extension=opts.samples_format,
                        info=_info,
                        short_filename=True,
                        no_prompt=True,
                        grid=False,
                        pnginfo_section_name="extras",
                        existing_info=None,
                        forced_filename=None,
                        suffix="",
                    )
                else:
                    images.save_image(
                        combined_image,
                        p.outpath_samples,
                        "",
                        start_seed,
                        p.prompt,
                        opts.samples_format,
                        info=_info,
                        p=p,
                    )

        return Processed(p, result_images, seed, initial_info, infotexts=infotexts)