from __future__ import annotations
"""API routes for OParl sync management."""

import json
import threading
from datetime import datetime
from pathlib import Path

from fastapi import APIRouter, HTTPException

router = APIRouter(prefix="/sync", tags=["sync"])

# Sync state file (written by sync_oparl.py)
PROJECT_ROOT = Path(__file__).resolve().parents[5]
SYNC_STATE_PATH = PROJECT_ROOT / "data" / "sync_state.json"

# Background job tracking
_sync_job: dict | None = None


def _load_sync_state() -> dict:
    """Load last sync state from file."""
    if SYNC_STATE_PATH.exists():
        try:
            return json.loads(SYNC_STATE_PATH.read_text())
        except Exception:
            pass
    return {}


@router.get("/status")
def sync_status():
    """Zeigt letzten Sync-Zeitpunkt + Statistiken."""
    state = _load_sync_state()

    # Laufender Job?
    if _sync_job and _sync_job.get("status") == "running":
        return {
            "running": True,
            "started_at": _sync_job.get("started_at"),
            "last_sync": state,
        }

    if not state:
        return {
            "running": False,
            "last_sync": None,
            "message": "Noch kein Sync durchgeführt",
        }

    return {
        "running": False,
        "last_sync": state,
    }


def _run_sync():
    """Background-Thread für den Sync."""
    global _sync_job
    try:
        # Import hier, damit der Server nicht beim Start abbricht
        import sys
        sys.path.insert(0, str(PROJECT_ROOT / "scripts"))
        sys.path.insert(0, str(PROJECT_ROOT / "backend" / "src"))

        from sync_oparl import sync
        result = sync(dry_run=False)

        _sync_job = {
            "status": "done",
            "started_at": _sync_job["started_at"] if _sync_job else None,
            "finished_at": datetime.now().isoformat(),
            "result": result,
        }
    except Exception as e:
        _sync_job = {
            "status": "error",
            "error": str(e),
            "started_at": _sync_job["started_at"] if _sync_job else None,
            "finished_at": datetime.now().isoformat(),
        }


@router.post("/trigger")
def trigger_sync():
    """Triggert einen OParl-Sync als Background-Job."""
    global _sync_job

    if _sync_job and _sync_job.get("status") == "running":
        raise HTTPException(status_code=409, detail="Sync läuft bereits")

    _sync_job = {
        "status": "running",
        "started_at": datetime.now().isoformat(),
    }

    t = threading.Thread(target=_run_sync, daemon=True)
    t.start()

    return {
        "status": "started",
        "started_at": _sync_job["started_at"],
        "message": "Sync gestartet. Status unter GET /api/sync/status abrufbar.",
    }