import os
from typing import Optional

import gradio as gr
from huggingface_hub import HfApi

from convert import convert


DATASET_REPO_URL = "https://huggingface.co/datasets/safetensors/conversions"
HF_TOKEN = os.environ.get("HF_TOKEN")  # Bot token (recommended for opening PRs)


def _format_error(msg: str) -> str:
    return f"""
### Error 😢

{msg}
"""


def _format_invalid(msg: str) -> str:
    return f"""
### Invalid input 🐞

{msg}
"""


def run(model_id: str, is_private: bool, token: Optional[str] = None) -> str:
    model_id = (model_id or "").strip()
    token = (token or "").strip() if token else None

    if not model_id:
        return _format_invalid("Please provide a valid `model_id`.")

    # Token policy:
    # - Public model: use bot token if available; otherwise unauthenticated may fail for PR creation.
    # - Private model: must use user-provided token to read; PR should still be created with bot if allowed.
    if is_private and not token:
        return _format_invalid("Private model checked: please provide a read-access HF token.")

    # Default API client:
    # - If private: use user's token to read model info (must have access).
    # - Else: use bot token if available, else try unauthenticated.
    api = HfApi(token=token if is_private else (HF_TOKEN if HF_TOKEN else None))

    try:
        info = api.model_info(repo_id=model_id)
        hf_is_private = bool(getattr(info, "private", False))

        # If user checked "private" but the model is actually public, switch to bot token for PR creation.
        # This mirrors your original intent: PR should be created "on behalf of bot" when possible.
        if is_private and not hf_is_private:
            api = HfApi(token=HF_TOKEN if HF_TOKEN else None)

        # If model is public but we don't have a token, conversion may run but PR creation can fail.
        if (not is_private) and (HF_TOKEN is None):
            # Still attempt, but give a clear warning if it fails.
            pass

        commit_info, errors = convert(api=api, model_id=model_id)

        pr_url = getattr(commit_info, "pr_url", None)
        if not pr_url:
            # Some implementations might return commit URL instead of PR url.
            pr_url = getattr(commit_info, "url", None)

        out = """
### Success 🔥

Yay! This model was successfully converted.
"""
        if pr_url:
            out += f"\nPR/Discussion URL:\n\n[{pr_url}]({pr_url})\n"
        else:
            out += "\n(Conversion succeeded, but no PR URL was returned by `convert()`.)\n"

        if errors:
            out += "\n\n### Conversion warnings\n"
            out += "\n".join(
                f"- `{filename}`: {e} (skipped)"
                for filename, e in errors
            )

        # Helpful note if bot token is missing
        if (not is_private) and (HF_TOKEN is None):
            out += "\n\n⚠️ Note: `HF_TOKEN` is not set. If PR creation fails, set `HF_TOKEN` in the environment."

        return out

    except Exception as e:
        return _format_error(str(e))


DESCRIPTION = """
The steps are the following:

- (Optional) Set `HF_TOKEN` as an environment variable for your bot/account token to open PRs reliably.
- If the model is private, paste a read-access token from hf.co/settings/tokens.
- Input a model id from the Hub (e.g. `org/model_name`)
- Click "Submit"
- You'll get the URL of the opened PR (or discussion) if successful.

⚠️ For now only `pytorch_model.bin` files are supported but we’ll extend in the future.
"""

title = "Convert any model to Safetensors and open a PR"


def toggle_token_visibility(is_private: bool):
    # Update component configuration (visibility) the Gradio-recommended way.
    return gr.Textbox(visible=is_private)


with gr.Blocks(title=title) as demo:
    gr.Markdown(f"# {title}")
    gr.Markdown(DESCRIPTION)

    with gr.Row():
        with gr.Column():
            model_id = gr.Textbox(label="model_id", placeholder="e.g. bigscience/bloom", max_lines=1)
            is_private = gr.Checkbox(label="Private model", value=False)

            token = gr.Textbox(
                label="your_hf_token",
                placeholder="hf_...",
                max_lines=1,
                type="password",
                visible=False,
            )

            with gr.Row():
                submit = gr.Button("Submit", variant="primary")
                # ClearButton should be instantiated with components to clear
                clean = gr.ClearButton([model_id, is_private, token])

        with gr.Column():
            output = gr.Markdown()

    is_private.change(fn=toggle_token_visibility, inputs=is_private, outputs=token)
    submit.click(fn=run, inputs=[model_id, is_private, token], outputs=output, concurrency_limit=1)

demo.queue(max_size=10).launch(show_api=True)