"""FlowDeck — v5.2.0 Security: per-user API tokens & active sessions.

Backend for the Settings → API tokens / Sessions UI.
"""
from __future__ import annotations

import hashlib
import logging
from secrets import token_urlsafe

from fastapi import APIRouter, HTTPException, Request

from app.auth.session import SessionManager
from app.db import get_conn

logger = logging.getLogger(__name__)
router = APIRouter(tags=["security"], prefix="/api/settings")


def _hash_token(token: str) -> str:
    return hashlib.sha256(token.encode("utf-8")).hexdigest()


def _current_user_id(request: Request) -> int:
    user = SessionManager.decode_session(request.cookies.get("flowdeck_session", ""))
    if not user or not user.get("id"):
        raise HTTPException(status_code=401, detail="Not authenticated")
    return user["id"]


# ═══════════ API tokens ═══════════


@router.get("/tokens")
def list_tokens(request: Request):
    """List the current user's API tokens (prefix only, no secrets)."""
    uid = _current_user_id(request)
    with get_conn() as conn:
        rows = conn.execute(
            "SELECT id, name, token_prefix, last_used_at, revoked, created_at "
            "FROM api_tokens WHERE user_id=? ORDER BY created_at DESC",
            (uid,),
        ).fetchall()
    return {"tokens": [dict(r) for r in rows]}


@router.post("/tokens")
async def create_token(request: Request):
    """Create an API token for the current user. The secret is returned once."""
    uid = _current_user_id(request)
    body = await request.json()
    name = (body.get("name") or "").strip() or "API token"
    token = f"fd_{token_urlsafe(24)}"
    with get_conn() as conn:
        cur = conn.execute(
            "INSERT INTO api_tokens (user_id, name, token_hash, token_prefix) VALUES (?, ?, ?, ?)",
            (uid, name[:80], _hash_token(token), token[:12]),
        )
        conn.commit()
        tid = cur.lastrowid
    return {"id": tid, "name": name, "token": token,
            "note": "Copy this token now — it won't be shown again."}


@router.delete("/tokens/{token_id:int}")
def revoke_token(token_id: int, request: Request):
    """Revoke an API token (soft delete)."""
    uid = _current_user_id(request)
    with get_conn() as conn:
        row = conn.execute(
            "SELECT id FROM api_tokens WHERE id=? AND user_id=?", (token_id, uid)
        ).fetchone()
        if not row:
            raise HTTPException(status_code=404, detail="Token not found")
        conn.execute("UPDATE api_tokens SET revoked=1 WHERE id=?", (token_id,))
        conn.commit()
    return {"status": "revoked"}


# ═══════════ Active sessions ═══════════


@router.get("/sessions")
def list_sessions(request: Request):
    """List the current user's active sessions with their devices."""
    uid = _current_user_id(request)
    current_sid = SessionManager.session_id(request.cookies.get("flowdeck_session", ""))
    sessions = SessionManager.list_sessions(uid)
    now = __import__("datetime").datetime.now()
    for s in sessions:
        s["is_current"] = (s["id"] == current_sid)
        # A session older than 7 days is implicitly expired (cookie max-age).
        created = s.get("created_at") or ""
        try:
            from datetime import datetime
            created_dt = datetime.fromisoformat(str(created).replace("Z", ""))
            s["expired"] = (now - created_dt).days >= 7
        except Exception:
            s["expired"] = False
    return {"sessions": sessions}


@router.post("/sessions/{sid}/revoke")
def revoke_session(sid: str, request: Request):
    """Revoke an active session. If it's the current one, the user is logged out."""
    uid = _current_user_id(request)
    with get_conn() as conn:
        row = conn.execute(
            "SELECT id FROM user_sessions WHERE id=? AND user_id=?", (sid, uid)
        ).fetchone()
    if not row:
        raise HTTPException(status_code=404, detail="Session not found")
    SessionManager.revoke_session(sid)
    # Also wipe the OAuth state cookie if the current session was revoked.
    current_sid = SessionManager.session_id(request.cookies.get("flowdeck_session", ""))
    if current_sid == sid:
        try:
            request.session.clear()
        except Exception:
            logger.exception("revoke_session")
    return {"status": "revoked"}