import asyncio
import logging
from contextlib import asynccontextmanager

from fastapi import FastAPI, Request, status
from fastapi.exceptions import RequestValidationError
from fastapi.responses import FileResponse, JSONResponse
from fastapi.staticfiles import StaticFiles
from starlette.exceptions import HTTPException as StarletteHTTPException

from app.logging_config import setup_logging

setup_logging()

import app.bets.confirmation  # noqa: F401  (registers the "bet" confirmation handler)
import app.rounds.confirmation  # noqa: F401  (registers the "payout" confirmation handler)
import app.withdrawals.confirmation  # noqa: F401  (registers the "withdrawal" confirmation handler)
from app.api.routes.admin import router as admin_router
from app.api.routes.bets import router as bets_router
from app.api.routes.bug_reports import router as bug_reports_router
from app.api.routes.qr import router as qr_router
from app.api.routes.rounds import router as rounds_router
from app.api.routes.users import router as users_router
from app.api.routes.withdrawals import router as withdrawals_router
from app.auth.routes import router as auth_router
from app.api.errors import ApiError
from app.config import settings, validate_quorum_servers, validate_runtime_secrets
from app.db.base import AsyncSessionLocal
from app.deposits.reconcile import DepositReconciler
from app.electrum.client import ElectrumClient, ElectrumEndpoint, parse_endpoints
from app.electrum.listener import ElectrumListener
from app.rounds.scheduler import RoundScheduler
from app.rounds.pause import pause_by_operator
from app.tx.broadcast import RbfBumper
from app.tx.confirmation import ConfirmationPoller
from app.tx.locks import UserLocks
from app.tx.reconcile import PendingTransactionReconciler
from app.wallet.verify import verify_master_key

logger = logging.getLogger(__name__)


def _make_electrum_client(endpoint: ElectrumEndpoint) -> ElectrumClient:
    return ElectrumClient(endpoint.host, endpoint.port, endpoint.use_ssl, endpoint.pin)


@asynccontextmanager
async def lifespan(app: FastAPI):
    # Refuses to serve rather than starting up half-configured (B-15).
    validate_runtime_secrets()

    endpoints = parse_endpoints(
        settings.electrum_host,
        settings.electrum_port,
        settings.electrum_use_ssl,
        settings.electrum_fallback_servers,
        settings.electrum_cert_pin,
    )
    validate_quorum_servers(endpoints)  # B-84: refuses to serve without a usable quorum
    verify_master_key()  # B-89: refuses to serve with a key that did not produce the stored addresses
    if settings.start_paused:  # B-90 (OPS-27): before the scheduler exists, so no round can open first
        async with AsyncSessionLocal() as session:
            await pause_by_operator(session, "START_PAUSED")
            await session.commit()
        logger.warning("START_PAUSED=true: the lottery starts paused (resume it from /admin)")
    logger.info("Electrum endpoints (in rotation order): %s", ", ".join(str(e) for e in endpoints))

    listener = ElectrumListener(
        _make_electrum_client, AsyncSessionLocal, endpoints, allow_no_quorum=settings.allow_no_quorum
    )
    app.state.electrum_listener = listener
    app.state.user_locks = UserLocks()

    scheduler = RoundScheduler(AsyncSessionLocal, listener)
    poller = ConfirmationPoller(AsyncSessionLocal, lambda: listener.client, network=listener)
    bumper = RbfBumper(AsyncSessionLocal, lambda: listener.client, network=listener)
    # Resolves in-flight transactions against the chain — the piece that lets the
    # system recover on its own from a broadcast that never confirmed (B-04/B-08).
    reconciler = PendingTransactionReconciler(AsyncSessionLocal, lambda: listener.client, network=listener)
    # Periodic safety net for deposit crediting/external-spend detection,
    # independent of scripthash-change notifications — catches a subscription
    # silently lost on an otherwise healthy connection (B-30).
    deposit_reconciler = DepositReconciler(AsyncSessionLocal, listener)

    tasks = [
        asyncio.create_task(listener.run()),
        asyncio.create_task(scheduler.run()),
        asyncio.create_task(poller.run()),
        asyncio.create_task(bumper.run()),
        asyncio.create_task(reconciler.run()),
        asyncio.create_task(deposit_reconciler.run()),
    ]
    try:
        yield
    finally:
        for task in tasks:
            task.cancel()
        if listener.client is not None:
            await listener.client.close()


# Swagger/ReDoc/the raw OpenAPI JSON enumerate the entire API surface, admin
# endpoints included, to anyone who requests them (B-42) — disabled unless
# ENABLE_API_DOCS is explicitly set, which should only happen in development.
app = FastAPI(
    title="PLM Lottery",
    lifespan=lifespan,
    docs_url="/docs" if settings.enable_api_docs else None,
    redoc_url="/redoc" if settings.enable_api_docs else None,
    openapi_url="/openapi.json" if settings.enable_api_docs else None,
)
app.include_router(auth_router)
app.include_router(users_router)
app.include_router(bets_router)
app.include_router(withdrawals_router)
app.include_router(admin_router)
app.include_router(bug_reports_router)
app.include_router(qr_router)
app.include_router(rounds_router)


# B-94 (API-15, API-16): no error answers with a bare-string or list `detail`; the framework's
# own 401/404/405 and request-validation failures take the structured shape too.
_FRAMEWORK_CODES = {401: "not_authenticated", 404: "not_found", 405: "method_not_allowed"}


@app.exception_handler(StarletteHTTPException)
async def structured_http_exception(request: Request, exc: StarletteHTTPException) -> JSONResponse:
    if isinstance(exc.detail, dict) and "code" in exc.detail:
        return JSONResponse(status_code=exc.status_code, content={"detail": exc.detail}, headers=exc.headers)
    code = _FRAMEWORK_CODES.get(exc.status_code, f"http_{exc.status_code}")
    detail = ApiError(code, str(exc.detail)).as_detail()
    return JSONResponse(status_code=exc.status_code, content={"detail": detail}, headers=exc.headers)


@app.exception_handler(RequestValidationError)
async def structured_validation_error(request: Request, exc: RequestValidationError) -> JSONResponse:
    """`input` is left out on purpose: an over-long password must not come back in the response."""
    errors = [{"loc": list(e["loc"]), "msg": e["msg"], "type": e["type"]} for e in exc.errors()]
    detail = ApiError("invalid_request", "invalid request", errors=errors).as_detail()
    return JSONResponse(status_code=status.HTTP_422_UNPROCESSABLE_CONTENT, content={"detail": detail})


@app.exception_handler(Exception)
async def log_unhandled_exception(request: Request, exc: Exception) -> JSONResponse:
    """Answers with the same structured `detail` shape as every deliberate failure
    (app/api/errors.py) so clients never have to special-case unexpected errors.
    The exception itself stays in logs/app.log only — never in the response body."""
    logger.exception("Unhandled error on %s %s", request.method, request.url.path)
    return JSONResponse(
        status_code=500,
        content={"detail": ApiError("internal_error", "internal server error").as_detail()},
    )


@app.get("/health")
async def health() -> dict[str, str]:
    return {"status": "ok"}


_NO_STORE_HEADERS = {"Cache-Control": "no-store"}


@app.get("/", include_in_schema=False)
async def index_page() -> FileResponse:
    return FileResponse("app/static/index.html", headers=_NO_STORE_HEADERS)


@app.get("/admin", include_in_schema=False)
async def admin_panel() -> FileResponse:
    return FileResponse("app/static/admin.html", headers=_NO_STORE_HEADERS)


@app.get("/guida", include_in_schema=False)
async def user_guide() -> FileResponse:
    return FileResponse("app/static/guida.html", headers=_NO_STORE_HEADERS)


@app.get("/report-bug", include_in_schema=False)
async def report_bug_page() -> FileResponse:
    return FileResponse("app/static/report-bug.html", headers=_NO_STORE_HEADERS)


class NoCacheStaticFiles(StaticFiles):
    """B-94 (API-09): the browser may keep a copy but revalidates it on every use, so after an
    update it does not run an old app.js against the new API."""

    async def get_response(self, path, scope):
        response = await super().get_response(path, scope)
        response.headers["Cache-Control"] = "no-cache"
        return response


app.mount("/", NoCacheStaticFiles(directory="app/static", html=True), name="static")