import os
import sys
import traceback
from collections import namedtuple
import re

import torch
import torch.hub

from torchvision import transforms
from torchvision.transforms.functional import InterpolationMode

import modules.shared as shared
from modules import devices, paths, lowvram, modelloader, errors

blip_image_eval_size = 384
clip_model_name = 'ViT-L/14'

Category = namedtuple("Category", ["name", "topn", "items"])

re_topn = re.compile(r"\.top(\d+)\.")


def download_default_clip_interrogate_categories(content_dir):
    print("Downloading CLIP categories...")

    tmpdir = content_dir + "_tmp"
    try:
        os.makedirs(tmpdir)

        torch.hub.download_url_to_file("https://raw.githubusercontent.com/pharmapsychotic/clip-interrogator/main/clip_interrogator/data/artists.txt", os.path.join(tmpdir, "artists.txt"))
        torch.hub.download_url_to_file("https://raw.githubusercontent.com/pharmapsychotic/clip-interrogator/main/clip_interrogator/data/flavors.txt", os.path.join(tmpdir, "flavors.top3.txt"))
        torch.hub.download_url_to_file("https://raw.githubusercontent.com/pharmapsychotic/clip-interrogator/main/clip_interrogator/data/mediums.txt", os.path.join(tmpdir, "mediums.txt"))
        torch.hub.download_url_to_file("https://raw.githubusercontent.com/pharmapsychotic/clip-interrogator/main/clip_interrogator/data/movements.txt", os.path.join(tmpdir, "movements.txt"))

        os.rename(tmpdir, content_dir)

    except Exception as e:
        errors.display(e, "downloading default CLIP interrogate categories")
    finally:
        if os.path.exists(tmpdir):
            os.remove(tmpdir)


class InterrogateModels:
    blip_model = None
    clip_model = None
    clip_preprocess = None
    dtype = None
    running_on_cpu = None

    def __init__(self, content_dir):
        self.loaded_categories = None
        self.content_dir = content_dir
        self.running_on_cpu = devices.device_interrogate == torch.device("cpu")

    def categories(self):
        if self.loaded_categories is not None:
            return self.loaded_categories

        self.loaded_categories = []

        if not os.path.exists(self.content_dir):
            download_default_clip_interrogate_categories(self.content_dir)

        if os.path.exists(self.content_dir):
            for filename in os.listdir(self.content_dir):
                m = re_topn.search(filename)
                topn = 1 if m is None else int(m.group(1))

                with open(os.path.join(self.content_dir, filename), "r", encoding="utf8") as file:
                    lines = [x.strip() for x in file.readlines()]

                self.loaded_categories.append(Category(name=filename, topn=topn, items=lines))

        return self.loaded_categories

    def load_blip_model(self):
        import models.blip

        files = modelloader.load_models(
            model_path=os.path.join(paths.models_path, "BLIP"),
            model_url='https://storage.googleapis.com/sfr-vision-language-research/BLIP/models/model_base_caption_capfilt_large.pth',
            ext_filter=[".pth"],
            download_name='model_base_caption_capfilt_large.pth',
        )

        blip_model = models.blip.blip_decoder(pretrained=files[0], image_size=blip_image_eval_size, vit='base', med_config=os.path.join(paths.paths["BLIP"], "configs", "med_config.json"))
        blip_model.eval()

        return blip_model

    def load_clip_model(self):
        import clip

        if self.running_on_cpu:
            model, preprocess = clip.load(clip_model_name, device="cpu", download_root=shared.cmd_opts.clip_models_path)
        else:
            model, preprocess = clip.load(clip_model_name, download_root=shared.cmd_opts.clip_models_path)

        model.eval()
        model = model.to(devices.device_interrogate)

        return model, preprocess

    def load(self):
        if self.blip_model is None:
            self.blip_model = self.load_blip_model()
            if not shared.cmd_opts.no_half and not self.running_on_cpu:
                self.blip_model = self.blip_model.half()

        self.blip_model = self.blip_model.to(devices.device_interrogate)

        if self.clip_model is None:
            self.clip_model, self.clip_preprocess = self.load_clip_model()
            if not shared.cmd_opts.no_half and not self.running_on_cpu:
                self.clip_model = self.clip_model.half()

        self.clip_model = self.clip_model.to(devices.device_interrogate)

        self.dtype = next(self.clip_model.parameters()).dtype

    def send_clip_to_ram(self):
        if not shared.opts.interrogate_keep_models_in_memory:
            if self.clip_model is not None:
                self.clip_model = self.clip_model.to(devices.cpu)

    def send_blip_to_ram(self):
        if not shared.opts.interrogate_keep_models_in_memory:
            if self.blip_model is not None:
                self.blip_model = self.blip_model.to(devices.cpu)

    def unload(self):
        self.send_clip_to_ram()
        self.send_blip_to_ram()

        devices.torch_gc()

    def rank(self, image_features, text_array, top_count=1):
        import clip

        if shared.opts.interrogate_clip_dict_limit != 0:
            text_array = text_array[0:int(shared.opts.interrogate_clip_dict_limit)]

        top_count = min(top_count, len(text_array))
        text_tokens = clip.tokenize([text for text in text_array], truncate=True).to(devices.device_interrogate)
        text_features = self.clip_model.encode_text(text_tokens).type(self.dtype)
        text_features /= text_features.norm(dim=-1, keepdim=True)

        similarity = torch.zeros((1, len(text_array))).to(devices.device_interrogate)
        for i in range(image_features.shape[0]):
            similarity += (100.0 * image_features[i].unsqueeze(0) @ text_features.T).softmax(dim=-1)
        similarity /= image_features.shape[0]

        top_probs, top_labels = similarity.cpu().topk(top_count, dim=-1)
        return [(text_array[top_labels[0][i].numpy()], (top_probs[0][i].numpy()*100)) for i in range(top_count)]

    def generate_caption(self, pil_image):
        gpu_image = transforms.Compose([
            transforms.Resize((blip_image_eval_size, blip_image_eval_size), interpolation=InterpolationMode.BICUBIC),
            transforms.ToTensor(),
            transforms.Normalize((0.48145466, 0.4578275, 0.40821073), (0.26862954, 0.26130258, 0.27577711))
        ])(pil_image).unsqueeze(0).type(self.dtype).to(devices.device_interrogate)

        with torch.no_grad():
            caption = self.blip_model.generate(gpu_image, sample=False, num_beams=shared.opts.interrogate_clip_num_beams, min_length=shared.opts.interrogate_clip_min_length, max_length=shared.opts.interrogate_clip_max_length)

        return caption[0]

    def interrogate(self, pil_image):
        res = ""
        shared.state.begin()
        shared.state.job = 'interrogate'
        try:
            if shared.cmd_opts.lowvram or shared.cmd_opts.medvram:
                lowvram.send_everything_to_cpu()
                devices.torch_gc()

            self.load()

            caption = self.generate_caption(pil_image)
            self.send_blip_to_ram()
            devices.torch_gc()

            res = caption

            clip_image = self.clip_preprocess(pil_image).unsqueeze(0).type(self.dtype).to(devices.device_interrogate)

            with torch.no_grad(), devices.autocast():
                image_features = self.clip_model.encode_image(clip_image).type(self.dtype)

                image_features /= image_features.norm(dim=-1, keepdim=True)

                for name, topn, items in self.categories():
                    matches = self.rank(image_features, items, top_count=topn)
                    for match, score in matches:
                        if shared.opts.interrogate_return_ranks:
                            res += f", ({match}:{score/100:.3f})"
                        else:
                            res += ", " + match

        except Exception:
            print("Error interrogating", file=sys.stderr)
            print(traceback.format_exc(), file=sys.stderr)
            res += "<error>"

        self.unload()
        shared.state.end()

        return res
