from __future__ import annotations

import logging

from fastapi import FastAPI, Header, HTTPException, Query, status
from redis.asyncio import Redis

from app.audit_logger import AuditLogger
from app.config import settings
from app.models import IngestAck, ProcessorForwardEnvelope
from app.queue_repo import RedisQueueRepository


logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s %(levelname)s %(name)s %(message)s",
)

logger = logging.getLogger(__name__)

app = FastAPI(
    title="alert-processor-ingest",
    version="2.1.0",
    description="Ingress endpoint that queues normalized events for async processing.",
)

redis_client: Redis | None = None
queue_repo: RedisQueueRepository | None = None
audit_logger: AuditLogger | None = None


def _extract_token(
    x_internal_token: str | None,
    authorization: str | None,
) -> str | None:
    if x_internal_token:
        return x_internal_token.strip()

    if authorization:
        auth = authorization.strip()
        if auth.lower().startswith("bearer "):
            return auth[7:].strip()
        return auth

    return None


def _validate_token(
    x_internal_token: str | None,
    authorization: str | None,
) -> None:
    if not settings.require_internal_api_token:
        return

    provided = _extract_token(x_internal_token, authorization)
    if not provided or provided != settings.internal_api_token:
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Invalid or missing internal API token",
        )


@app.on_event("startup")
async def startup_check() -> None:
    global redis_client, queue_repo, audit_logger

    if settings.require_internal_api_token and not settings.internal_api_token:
        raise RuntimeError(
            "INTERNAL_API_TOKEN is required, but not set. "
            "Set it in environment variables or in .env file."
        )

    if not settings.redis_enabled:
        raise RuntimeError("REDIS_ENABLED must be true for async queue mode")

    if not settings.queue_enabled:
        raise RuntimeError("QUEUE_ENABLED must be true for async queue mode")

    redis_client = Redis.from_url(
        settings.redis_url,
        encoding="utf-8",
        decode_responses=False,
    )
    queue_repo = RedisQueueRepository(
        client=redis_client,
        queue_name=settings.queue_name,
        processing_name=settings.queue_processing_name,
        deadletter_name=settings.queue_deadletter_name,
        dedup_ttl_seconds=settings.queue_dedup_ttl_seconds,
    )
    await queue_repo.ping()

    if settings.audit_enabled:
        audit_logger = AuditLogger(
            client=redis_client,
            key_prefix=settings.audit_key_prefix,
            ttl_seconds=settings.audit_ttl_seconds,
            max_stage_records=settings.audit_max_stage_records,
        )

    logger.info(
        "Async ingest initialized: redis_url=%s queue_name=%s processing_name=%s deadletter_name=%s audit_enabled=%s",
        settings.redis_url,
        settings.queue_name,
        settings.queue_processing_name,
        settings.queue_deadletter_name,
        settings.audit_enabled,
    )


@app.on_event("shutdown")
async def shutdown_event() -> None:
    global redis_client

    if redis_client is not None:
        await redis_client.close()
        logger.info("Redis connection closed")


@app.get("/health")
async def health() -> dict[str, str | bool | int]:
    return {
        "status": "ok",
        "service": settings.app_name,
        "mode": "async_ingest",
        "redis_enabled": settings.redis_enabled,
        "redis_connected": redis_client is not None,
        "queue_enabled": settings.queue_enabled,
        "queue_configured": queue_repo is not None,
        "queue_name": settings.queue_name,
        "queue_processing_name": settings.queue_processing_name,
        "queue_deadletter_name": settings.queue_deadletter_name,
        "audit_enabled": settings.audit_enabled,
        "audit_configured": audit_logger is not None,
    }


@app.post(
    "/internal/events",
    response_model=IngestAck,
    status_code=status.HTTP_202_ACCEPTED,
)
async def receive_internal_event(
    envelope: ProcessorForwardEnvelope,
    x_internal_token: str | None = Header(default=None),
    authorization: str | None = Header(default=None),
) -> IngestAck:
    _validate_token(x_internal_token, authorization)

    if queue_repo is None:
        raise HTTPException(
            status_code=status.HTTP_503_SERVICE_UNAVAILABLE,
            detail="Queue repository is not initialized",
        )

    event = envelope.event
    job_id = await queue_repo.enqueue_event(envelope)

    if audit_logger is not None:
        await audit_logger.log_ingest_queued(
            envelope=envelope,
            job_id=job_id,
            queue_name=settings.queue_name,
        )

    logger.info(
        "Queued event for async processing: job_id=%s correlation_id=%s event_id=%s severity=%s host=%s trigger=%s",
        job_id,
        event.correlation_id,
        event.event_id,
        event.severity,
        event.host,
        event.trigger_name,
    )

    return IngestAck(
        accepted=True,
        correlation_id=event.correlation_id,
        queued=True,
        job_id=job_id,
        message="Event queued for async processing",
    )


@app.get("/audit/events/{correlation_id}")
async def get_audit_by_correlation(correlation_id: str) -> dict:
    if audit_logger is None:
        raise HTTPException(status_code=503, detail="Audit logger is not enabled")

    payload = await audit_logger.get_event_audit(correlation_id=correlation_id)
    if payload is None:
        raise HTTPException(status_code=404, detail="Audit record not found")

    return payload


@app.get("/audit/by-event/{event_id}")
async def get_audit_by_event_id(event_id: str) -> dict:
    if audit_logger is None:
        raise HTTPException(status_code=503, detail="Audit logger is not enabled")

    payload = await audit_logger.get_event_audit(event_id=event_id)
    if payload is None:
        raise HTTPException(status_code=404, detail="Audit record not found")

    return payload


@app.get("/audit/recent")
async def get_recent_audit(
    limit: int = Query(default=20, ge=1, le=100),
) -> list[dict]:
    if audit_logger is None:
        raise HTTPException(status_code=503, detail="Audit logger is not enabled")

    return await audit_logger.list_recent(limit=limit)