"""Pipeline-Grundbausteine: Agent-Races, Single-Slot, Check→Fix, Prompts, Guide-Status.

Hält den mutablen Pipeline-Zustand (Generierungs-Semaphore, Cancel-Set).
Zugriff auf das Cancel-Set NUR über die Funktionen hier — kopierte Referenzen
in anderen Modulen würden bei einem Re-Assign auseinanderlaufen.
"""

import asyncio
import logging
from dataclasses import dataclass
from datetime import datetime, timezone
from pathlib import Path
from typing import Callable

from agents import run_agent, kill_process
from config import MAX_CONCURRENT_GENERATIONS, TEMPLATES_DIR, TIMEOUTS
from database import update_guide
from jsonio import read_json_file as _json_datei

log = logging.getLogger("creator.pipeline")

_semaphore = asyncio.Semaphore(MAX_CONCURRENT_GENERATIONS)
_cancelled: set[str] = set()


async def cancel_guide(guide_id: str) -> bool:
    _cancelled.add(guide_id)
    kill_process(guide_id)
    now = datetime.now(timezone.utc).isoformat()
    await update_guide(guide_id, status="error", progress=None, error_msg="Abgebrochen — Fortschritt bleibt erhalten", updated_at=now)
    return True


def is_guide_cancelled(guide_id: str) -> bool:
    return guide_id in _cancelled


def clear_guide_cancelled(guide_id: str) -> None:
    _cancelled.discard(guide_id)


async def _set_progress(guide_id: str, progress: str) -> None:
    now = datetime.now(timezone.utc).isoformat()
    await update_guide(guide_id, progress=progress, updated_at=now)


async def _set_step(guide_id: str, step: int, progress: str) -> None:
    now = datetime.now(timezone.utc).isoformat()
    await update_guide(guide_id, step=step, progress=progress, updated_at=now)


async def _fail(guide_id: str, msg: str) -> None:
    now = datetime.now(timezone.utc).isoformat()
    await update_guide(guide_id, status="error", progress=None, error_msg=msg, updated_at=now)


def _prompt(name: str, **kwargs) -> str:
    template = (TEMPLATES_DIR / "Prompt" / f"{name}.md").read_text(encoding="utf-8")
    return template.format(**kwargs)


def _extra(instructions: str) -> str:
    return f"\n\nZUSÄTZLICHE ANWEISUNGEN VOM NUTZER:\n{instructions}\n" if instructions else ""


def _log(topic: str, msg: str) -> None:
    log.info("[%s] %s", topic, msg)


def _claude_error(label: str, returncode: int, stdout: str, stderr: str) -> str:
    stderr = (stderr or "").strip()
    if stderr:
        return f"{label}: {stderr[:1000]}"
    tail = (stdout or "").strip()[-500:]
    if tail:
        return f"{label} (exit {returncode}, stderr leer): …{tail}"
    return f"{label} (exit {returncode}, ohne Ausgabe)"


def _gather_error(label: str, results: list) -> str:
    for r in results:
        if isinstance(r, BaseException):
            return f"{label}: {type(r).__name__}: {r}"
        returncode, stdout, stderr = r
        if returncode != 0:
            return _claude_error(label, returncode, stdout, stderr)
    return f"{label}: kein verwertbares Ergebnis"


def _timeout(step: str, n: int = 0) -> int:
    base, per = TIMEOUTS[step]
    return base + per * n


def _probleme_schema(data):
    """{"ok": true} → [] · {"probleme": [str]} → Liste · sonst None."""
    if not isinstance(data, dict):
        return None
    if data.get("ok") is True:
        return []
    p = data.get("probleme")
    if not isinstance(p, list) or not p:
        return None
    out = [str(x).strip() for x in p if str(x).strip()]
    return out or None


_MAX_RESTARTS = 2


async def _race(topic: str, label: str, slots: list[dict], quorum: int, timeout: int, provider: str, on_update=None, cancelled=None) -> list | None:
    """Startet alle Slots parallel und sammelt `quorum` gültige Ergebnisse.

    Slot-Spec: {key, prompt, role, capabilities, payload}. `payload(result)`
    prüft die Gültigkeit und liefert das Slot-Ergebnis oder None.
    Fehler/Timeout/ungültig → Slot-Neustart (max. _MAX_RESTARTS). Sobald das
    Quorum steht, werden die übrigen Agenten gekillt. None = Quorum verfehlt.
    `cancelled()` → True bricht ab (keine Restarts, Rückgabe None).
    """
    attempts = {i: 0 for i in range(len(slots))}
    tasks: dict[asyncio.Task, int] = {}

    def spawn(i: int) -> None:
        slot = slots[i]
        task = asyncio.create_task(run_agent(
            slot["key"], slot["prompt"], timeout,
            provider=provider, role=slot["role"], capabilities=slot["capabilities"],
        ))
        tasks[task] = i

    for i in range(len(slots)):
        spawn(i)

    results: list = []
    try:
        while tasks:
            if cancelled and cancelled():
                return None
            done, _ = await asyncio.wait(tasks.keys(), return_when=asyncio.FIRST_COMPLETED)
            for task in done:
                i = tasks.pop(task)
                payload, err = None, None
                try:
                    result = task.result()
                    if result[0] != 0:
                        err = _claude_error("Fehler", *result)
                    else:
                        payload = slots[i]["payload"](result)
                        if payload is None:
                            err = "Ergebnis ungültig/nicht parsebar"
                except asyncio.TimeoutError:
                    err = f"Timeout nach {timeout}s"
                except Exception as e:
                    err = f"{type(e).__name__}: {e}"

                if payload is not None:
                    results.append(payload)
                    if on_update:
                        on_update(len(results))
                    if len(results) >= quorum:
                        return results
                    continue

                _log(topic, f"{label} {i + 1} (Versuch {attempts[i] + 1}): {err}")
                attempts[i] += 1
                if attempts[i] <= _MAX_RESTARTS and not (cancelled and cancelled()):
                    spawn(i)
        _log(topic, f"{label}: Quorum {quorum} nicht erreicht ({len(results)} gültig)")
        return None
    finally:
        for task, i in tasks.items():
            kill_process(slots[i]["key"])
            task.cancel()
        if tasks:
            await asyncio.gather(*tasks.keys(), return_exceptions=True)


@dataclass
class GenContext:
    """Durchgereichte Pipeline-Parameter — erspart lange Argument-Signaturen."""
    topic: str
    provider: str
    is_cancelled: Callable[[], bool]
    guide_id: str | None = None


# Ergebnis-Status von run_single_slot/_check_then_fix
OK, CANCELLED, FAILED = "ok", "cancelled", "failed"


async def run_single_slot(
    ctx: GenContext, label: str, *,
    key: str, prompt: str, role: str, capabilities: str, payload, timeout: int,
) -> tuple[str, object]:
    """Ein Agent, ein gültiges Ergebnis (Race mit Quorum 1).

    → (OK, wert) | (CANCELLED, None) | (FAILED, None)
    """
    slots = [{"key": key, "prompt": prompt, "role": role, "capabilities": capabilities, "payload": payload}]
    res = await _race(ctx.topic, label, slots, 1, timeout, ctx.provider, cancelled=ctx.is_cancelled)
    if ctx.is_cancelled():
        return CANCELLED, None
    if res is None:
        return FAILED, None
    return OK, res[0]


async def _check_then_fix(
    ctx: GenContext, *, name: str, step: int,
    check_key: str, check_prompt: str, check_path: Path, check_timeout: int,
    fix_key: str, build_fix_prompt, fix_payload, fix_timeout: int,
    fix_role: str = "fast", fix_caps: str = "files",
    on_fix_invalid=None,
) -> tuple[str, object]:
    """Check→Fix-Muster: Prüf-Agent notiert Probleme (JSON), Fix-Agent behebt sie.

    Resume: existierende Check-Datei überspringt den ganzen Schritt.
    Check ist fatal (FAILED), Fix nicht — Original bleibt; on_fix_invalid kann
    das kanonische Original zurückschreiben, falls der Fix-Agent die
    Artefakt-Datei zerschrieben hat.
    Lese-Check (Multi-Slot, Section-genau) und Bausteine-Auswahl-Check
    (Patch-Semantik) passen bewusst NICHT in dieses Muster.
    → (OK, neues_artefakt | None=unverändert) | (CANCELLED, None) | (FAILED, None)
    """
    if check_path.exists():
        return OK, None
    await _set_step(ctx.guide_id, step, f"Prüfe {name}…")
    status, probleme = await run_single_slot(
        ctx, f"{name}-Prüfung", key=check_key, prompt=check_prompt,
        role="fast", capabilities="files",
        payload=lambda result: _probleme_schema(_json_datei(check_path)),
        timeout=check_timeout,
    )
    if status != OK:
        return status, None
    if not probleme:
        return OK, None
    _log(ctx.topic, f"{name}-Prüfung: {len(probleme)} Problem(e) notiert")
    await _set_step(ctx.guide_id, step, f"Passe {name} an…")
    status, fixed = await run_single_slot(
        ctx, f"{name}-Fix", key=fix_key, prompt=build_fix_prompt(probleme),
        role=fix_role, capabilities=fix_caps, payload=fix_payload, timeout=fix_timeout,
    )
    if status == CANCELLED:
        return CANCELLED, None
    if status == FAILED:
        _log(ctx.topic, f"{name}-Fix ungültig — Original bleibt")
        if on_fix_invalid:
            on_fix_invalid()
        return OK, None
    return OK, fixed