buchwerk/backend/main.py

import json
import logging
from contextlib import asynccontextmanager

from fastapi import FastAPI, HTTPException
from fastapi.responses import FileResponse, PlainTextResponse
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.gzip import GZipMiddleware
from pydantic import BaseModel

from . import config, montage, pipeline, state

logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s: %(message)s")


@asynccontextmanager
async def lifespan(app: FastAPI):
    config.STORAGE.mkdir(exist_ok=True)
    state.migrieren()
    yield
    for name in list(pipeline._laeufe):
        await pipeline.pausieren(name)


app = FastAPI(title="buchwerk", lifespan=lifespan)
app.add_middleware(GZipMiddleware, minimum_size=1000)  # Buchdaten sind 1–2 MB JSON


class ThemaNeu(BaseModel):
    name: str
    hinweise: str = ""


class Position(BaseModel):
    abschnitt: str | None = None
    lesemodus: str | int | None = None  # neu: key des Bildschirms, alt: Index
    zuletzt: str | None = None  # 'buch' oder 'lesen': welche Ansicht zuletzt gelesen wurde


def _thema(slug: str) -> dict:
    name = state.name_von_slug(slug)
    t = state.thema(name) if name else None
    if not t:
        raise HTTPException(404, "Thema unbekannt")
    return t


def _key(slug: str, n: int) -> str:
    """Slug + Versionsnummer → interner Schlüssel „Thema/vN“."""
    t = _thema(slug)
    key = state.schluessel(t["name"], n)
    if not key:
        raise HTTPException(404, "Version unbekannt")
    return key


def _version_info(name: str, n: int) -> dict:
    key = f"{name}/v{n}"
    st = state.zustand(key)
    angelegt = st.get("angelegt") or (state.thema(name) or {}).get("angelegt", "")  # migrierte v1 hat kein eigenes Datum
    return {"v": n, "status": st["status"], "laeuft": pipeline.laeuft(key), "stufe": st["stufe"],
            "angelegt": angelegt, "kosten_usd": st.get("kosten_usd", 0)}


def _thema_info(t: dict) -> dict | None:
    vs = [_version_info(t["name"], n) for n in state.versionen(t["name"])]
    if not vs:
        return None
    neueste = vs[-1]
    return {"slug": t["slug"], "name": t["name"], "titel": t["titel"], "hinweise": t.get("hinweise", ""),
            "angelegt": t.get("angelegt", ""), "status": neueste["status"], "laeuft": neueste["laeuft"],
            "stufe": neueste["stufe"], "versionen": vs}


@app.get("/api/themen")
async def themen():
    return [i for t in state.themen() if (i := _thema_info(t))]


@app.post("/api/themen")
async def thema_anlegen(body: ThemaNeu):
    name = body.name.strip()
    if not state.name_ok(name):
        raise HTTPException(400, "Ungültiger Name")
    try:
        return _thema_info(state.anlegen(name, body.hinweise))
    except ValueError as e:
        raise HTTPException(409, str(e))


@app.get("/api/themen/{slug}")
async def thema(slug: str):
    return _thema_info(_thema(slug))


@app.delete("/api/themen/{slug}")
async def thema_loeschen(slug: str):
    t = _thema(slug)
    for n in state.versionen(t["name"]):
        await pipeline.pausieren(f"{t['name']}/v{n}")
    state.loeschen(t["name"])
    return {"ok": True}


@app.post("/api/themen/{slug}/versionen")
async def version_anlegen(slug: str):
    """Neue Version: gleiche Eingaben, frischer Lauf, ohne Wissen über die Vorgänger."""
    key = state.version_anlegen(_thema(slug)["name"])
    return {"v": int(key.rsplit("/v", 1)[1])}


@app.get("/api/themen/{slug}/v{n}")
async def zustand(slug: str, n: int):
    key = _key(slug, n)
    t = _thema(slug)
    st = state.zustand(key)
    return {"slug": slug, "name": t["name"], "version": n, "titel": t["titel"], "hinweise": t.get("hinweise", ""), **st,
            "deutung": st.get("deutung") or state.deutung(key), "ereignisse": st["ereignisse"][-100:]}


@app.delete("/api/themen/{slug}/v{n}")
async def version_loeschen(slug: str, n: int):
    key = _key(slug, n)
    await pipeline.pausieren(key)
    state.version_loeschen(key)
    return {"ok": True}


@app.post("/api/themen/{slug}/v{n}/start")
async def start(slug: str, n: int):
    key = _key(slug, n)
    if state.zustand(key)["status"] == "fertig":
        raise HTTPException(400, "Lauf ist fertig – erst zurücksetzen")
    pipeline.starten(key)
    return {"ok": True}


@app.post("/api/themen/{slug}/v{n}/pause")
async def pause(slug: str, n: int):
    await pipeline.pausieren(_key(slug, n))
    return {"ok": True}


@app.post("/api/themen/{slug}/v{n}/reset")
async def reset(slug: str, n: int):
    key = _key(slug, n)
    await pipeline.pausieren(key)
    state.zuruecksetzen(key)
    return {"ok": True}


@app.get("/api/themen/{slug}/v{n}/position")
async def position_lesen(slug: str, n: int):
    return state.position(_key(slug, n))


@app.put("/api/themen/{slug}/v{n}/position")
async def position_schreiben(slug: str, n: int, body: Position):
    return state.position_setzen(_key(slug, n), {k: val for k, val in body.model_dump().items() if val is not None})


@app.get("/api/themen/{slug}/v{n}/buch")
async def buch(slug: str, n: int):
    return montage.guide(_key(slug, n))


@app.get("/api/themen/{slug}/v{n}/buch.md", response_class=PlainTextResponse)
async def buch_md(slug: str, n: int):
    return montage.markdown(_key(slug, n))


@app.get("/api/themen/{slug}/v{n}/kern.md", response_class=PlainTextResponse)
async def kern_md(slug: str, n: int):
    return montage.kern(_key(slug, n))


@app.get("/api/themen/{slug}/v{n}/buch.pdf")
async def buch_pdf(slug: str, n: int):
    key = _key(slug, n)
    p = state.verzeichnis(key) / "buch" / "buch.pdf"
    if not p.exists():
        raise HTTPException(404, "PDF noch nicht gebaut")
    return FileResponse(p, media_type="application/pdf", filename=f"{slug}-v{n}.pdf")


if config.FRONTEND_DIST.exists():
    app.mount("/assets", StaticFiles(directory=config.FRONTEND_DIST / "assets"), name="assets")

    @app.get("/{pfad:path}")
    async def spa(pfad: str):
        if pfad.startswith("api/"):
            raise HTTPException(404, "Unbekannter API-Pfad")
        return FileResponse(config.FRONTEND_DIST / "index.html")