"""
Scanner control endpoints — kill switch + per-scanner toggle + status.

GET /scanners is public (read-only status, polled by the UI).

ALL mutating endpoints (toggle / all-disable / all-enable) require a SIGNED
request from a SUBSCRIBED wallet. Rationale: the scanner switch is a global
control — flipping it OFF stops the signal engine for every user. Before, it
was unauthenticated and any anonymous visitor could kill it. Now the caller
must prove wallet ownership (EIP-191 signature) AND already be a subscriber.

  # See what's running (still public)
  curl http://localhost:8000/api/scanners

Mutations are no longer curl-able without a wallet signature — that's the
point. Use the dashboard (which signs via the connected wallet).
"""

from __future__ import annotations

import logging
from typing import Optional

from fastapi import APIRouter, Depends, HTTPException, Request
from pydantic import BaseModel
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.models import Subscription
from app.services import scanner_state
from app.services.signed_request import verify_signed_request

router = APIRouter()
logger = logging.getLogger(__name__)

ACTION_TOGGLE_SCANNER = "toggle_scanner"
ACTION_SCANNER_KILL   = "scanner_kill_all"
ACTION_SCANNER_REVIVE = "scanner_revive_all"


class ScannerSummary(BaseModel):
    name:               str
    enabled:            bool
    last_run_at:        Optional[str] = None
    last_status:        str
    last_message:       Optional[str] = None
    last_fired_at:      Optional[str] = None
    total_runs:         int
    total_fires:        int
    consecutive_errors: int


class ScannersResponse(BaseModel):
    count:    int
    enabled:  int
    scanners: list[ScannerSummary]


class ToggleResponse(BaseModel):
    status:  str
    name:    Optional[str] = None
    enabled: Optional[bool] = None
    count:   Optional[int]  = None


async def _require_subscribed_signer(
    request: Request,
    db: AsyncSession,
    *,
    action: str,
    body: Optional[dict],
) -> str:
    """Verify the signed envelope and that the signer is a subscriber.

    Expects JSON body: { wallet, timestamp, signature, ...body fields }.
    `body` is the canonical signed payload (must match what the client
    hashed) — pass None for no-body actions (kill/revive).
    Returns the verified lower-cased wallet.
    """
    raw = await request.json()
    wallet    = (raw.get("wallet") or "").lower().strip()
    timestamp = raw.get("timestamp")
    signature = raw.get("signature")

    if not wallet:
        raise HTTPException(422, "wallet required")
    if not isinstance(timestamp, int):
        raise HTTPException(422, "timestamp (ms) required")
    if not isinstance(signature, str) or not signature:
        raise HTTPException(422, "signature required")

    verify_signed_request(
        action=action,
        wallet=wallet,
        timestamp_ms=timestamp,
        signature=signature,
        body=body,
    )

    sub = (await db.execute(
        select(Subscription).where(Subscription.wallet_address == wallet)
    )).scalar_one_or_none()
    if sub is None:
        raise HTTPException(403, "Wallet is not a subscriber — scanner control denied")
    return wallet


@router.get("/scanners", response_model=ScannersResponse)
async def list_scanners() -> ScannersResponse:
    """Operational snapshot of every registered scanner. Polled by the UI
    every 15-30s. Idempotent + cheap (in-memory dict read). Public."""
    all_states = scanner_state.get_all()
    return ScannersResponse(
        count=len(all_states),
        enabled=sum(1 for s in all_states if s.enabled),
        scanners=[ScannerSummary(**s.to_dict()) for s in all_states],
    )


@router.post("/scanners/{name}/toggle", response_model=ToggleResponse)
async def toggle_scanner(
    name: str,
    request: Request,
    db: AsyncSession = Depends(get_db),
) -> ToggleResponse:
    """Flip ONE scanner. Signed + subscriber-gated.

    Body: { wallet, timestamp, signature, name, enabled }
    The signed body is { "enabled": <bool>, "name": <str> }.
    """
    raw = await request.json()
    enabled = raw.get("enabled")
    body_name = raw.get("name")
    if not isinstance(enabled, bool):
        raise HTTPException(422, "enabled (bool) required")
    if body_name != name:
        raise HTTPException(400, "scanner name mismatch (path vs signed body)")

    # NOTE: request.json() is cached by Starlette, so re-reading inside the
    # helper returns the same payload.
    wallet = await _require_subscribed_signer(
        request, db, action=ACTION_TOGGLE_SCANNER,
        body={"enabled": enabled, "name": name},
    )

    s = scanner_state.set_enabled(name, enabled)
    if s is None:
        raise HTTPException(404, f"unknown scanner {name!r}")
    logger.info("Scanner %s set enabled=%s by %s", name, s.enabled, wallet)
    return ToggleResponse(status="ok", name=name, enabled=s.enabled)


@router.post("/scanners/all/disable", response_model=ToggleResponse)
async def kill_switch(
    request: Request,
    db: AsyncSession = Depends(get_db),
) -> ToggleResponse:
    """Emergency stop — disables ALL scanners. Signed + subscriber-gated.
    Body: { wallet, timestamp, signature }. Does NOT close open positions —
    manage those via /positions/{id}/close or the Trades page."""
    wallet = await _require_subscribed_signer(
        request, db, action=ACTION_SCANNER_KILL, body=None,
    )
    n = scanner_state.disable_all()
    logger.warning("ALL scanners disabled (%d) by %s", n, wallet)
    return ToggleResponse(status="killed", count=n)


@router.post("/scanners/all/enable", response_model=ToggleResponse)
async def revive_all(
    request: Request,
    db: AsyncSession = Depends(get_db),
) -> ToggleResponse:
    """Re-enable every scanner that was disabled. Signed + subscriber-gated.
    Body: { wallet, timestamp, signature }."""
    wallet = await _require_subscribed_signer(
        request, db, action=ACTION_SCANNER_REVIVE, body=None,
    )
    n = scanner_state.enable_all()
    logger.info("ALL scanners re-enabled (%d) by %s", n, wallet)
    return ToggleResponse(status="revived", count=n)