import sqlite3
from pathlib import Path
from typing import Any, Dict

from app_state import StateStore


def health_payload(
    data_dir: Path,
    session_dir: Path,
    state_store: StateStore,
    continuous_snapshot: Dict[str, Any],
    job_queue_size: int,
) -> Dict[str, Any]:
    checks = {
        "data_dir": _dir_check(data_dir, writable=True),
        "session_dir": _dir_check(session_dir, writable=True),
        "state_file": _state_check(state_store),
        "sqlite": _sqlite_check(),
        "continuous": _continuous_check(continuous_snapshot),
        "job_queue": {"ok": True, "size": job_queue_size},
    }
    ok = all(item.get("ok", False) for item in checks.values())
    return {"ok": ok, "status": "ok" if ok else "degraded", "checks": checks}


def _dir_check(path: Path, writable: bool = False) -> Dict[str, Any]:
    path.mkdir(parents=True, exist_ok=True)
    ok = path.exists() and path.is_dir()
    payload: Dict[str, Any] = {"ok": ok, "path": str(path)}
    if writable:
        probe = path / ".healthcheck"
        try:
            probe.write_text("ok", encoding="utf-8")
            probe.unlink(missing_ok=True)
            payload["writable"] = True
        except OSError as exc:
            payload.update({"ok": False, "writable": False, "error": str(exc)})
    return payload


def _state_check(state_store: StateStore) -> Dict[str, Any]:
    try:
        state = state_store.load()
        return {
            "ok": True,
            "path": str(state_store.path),
            "has_api_credentials": bool(state.get("api_id") and state.get("api_hash")),
            "tracked_channels": len(state.get("channels", {})),
        }
    except Exception as exc:
        return {"ok": False, "path": str(state_store.path), "error": str(exc)}


def _sqlite_check() -> Dict[str, Any]:
    try:
        conn = sqlite3.connect(":memory:")
        conn.execute("SELECT 1")
        conn.close()
        return {"ok": True}
    except sqlite3.Error as exc:
        return {"ok": False, "error": str(exc)}


def _continuous_check(snapshot: Dict[str, Any]) -> Dict[str, Any]:
    status = snapshot.get("status", {})
    config = snapshot.get("config", {})
    return {
        "ok": True,
        "enabled": bool(config.get("enabled")),
        "running": bool(status.get("running")),
        "last_error": status.get("last_error"),
    }