"""Gradio Server app: custom HTML frontend + Gradio-managed API endpoint.

The input UI lives in `index.html` and talks to the `generate_bulletin`
endpoint below via `@gradio/client`. Report generation logic is unchanged
from the original Blocks app.
"""

import os
from pathlib import Path

from fastapi.responses import HTMLResponse
from gradio import Server

from analyze import build_report, compute_stats, digest_all, get_client
from dataset import fetch_sessions, list_sessions
from extract import events_to_transcript, truncate_transcript
from render import bulletin_html, empty_bulletin_html

DEFAULT_REPO = "julien-c/pi-sessions"

app = Server()

_INDEX = Path(__file__).parent / "index.html"


def _owner_from(repo_id: str) -> str:
    return repo_id.split("/")[0] if "/" in repo_id else repo_id


@app.api(name="generate_bulletin", concurrency_limit=1)
def generate_bulletin(
    repo_id: str, max_sessions: int
) -> tuple[str, str]:
    """Streams (status, html) updates; final tick carries the bulletin HTML."""

    yield "Connecting…", empty_bulletin_html("Connecting…")

    try:
        client = get_client()
    except Exception as e:
        yield f"❌ {e}", empty_bulletin_html("HF_TOKEN missing")
        return

    try:
        yield "Listing sessions…", empty_bulletin_html("Listing sessions…")
        paths = list_sessions(repo_id)
        if not paths:
            yield (
                "No sessions found in `sessions/**/*.jsonl`.",
                empty_bulletin_html("No sessions to roast."),
            )
            return

        n = min(int(max_sessions), len(paths))
        yield (
            f"Fetching {n} of {len(paths)} sessions…",
            empty_bulletin_html(f"Fetching {n} sessions…"),
        )
        sessions = fetch_sessions(repo_id, n)
        if not sessions:
            yield (
                "Found session files but couldn't parse any.",
                empty_bulletin_html("Parse error."),
            )
            return

        stats = compute_stats(sessions)
        transcripts = [
            (path, truncate_transcript(events_to_transcript(evs), 40_000))
            for path, evs in sessions
        ]

        yield (
            f"Reading {len(transcripts)} sessions in parallel…",
            empty_bulletin_html("Consulting the traces…"),
        )
        digests = digest_all(client, transcripts)
        if not digests:
            yield (
                "Every per-session digest failed. Try again or lower max sessions.",
                empty_bulletin_html("Digest error."),
            )
            return

        yield (
            f"Drafting bulletin from {len(digests)} digests…",
            empty_bulletin_html("Drafting bulletin…"),
        )

        owner = _owner_from(repo_id)
        try:
            report = build_report(
                client=client,
                digests=digests,
                user=owner,
                dataset_id=repo_id,
                stats=stats,
            )
        except Exception as e:
            yield (
                f"❌ Bulletin generation failed: {e}",
                empty_bulletin_html("The presses jammed."),
            )
            return

        yield (
            f"Bulletin issued for @{report['user']} — {report['archetype'][0]} {report['archetype'][1]}.",
            bulletin_html(report),
        )
    except Exception as e:
        yield (
            f"❌ {type(e).__name__}: {e}",
            empty_bulletin_html("Error."),
        )


@app.get("/", response_class=HTMLResponse)
async def homepage():
    return _INDEX.read_text(encoding="utf-8")


if __name__ == "__main__":
    if not os.environ.get("HF_TOKEN"):
        print("warning: HF_TOKEN not set; the app will error on the first click.")
    app.launch(show_error=True)