"""Runtime configuration warnings for Phase 1/2 feature alignment."""

from __future__ import annotations

from app.config import settings
from app.redis_client import job_queue_enabled, redis_configured
from app.retrieval.semantic_cache import is_semantic_cache_active


def collect_optimization_warnings() -> list[str]:
    """Return human-readable misconfiguration / feature-gap warnings."""
    warnings: list[str] = []
    backend = (settings.vectorstore_backend or "faiss").strip().lower()

    if settings.enable_async_pipeline and backend != "qdrant":
        warnings.append(
            "ENABLE_ASYNC_PIPELINE=true but VECTORSTORE_BACKEND is not qdrant; "
            "hybrid retrieval and semantic cache require Qdrant."
        )
    if settings.semantic_cache_enabled and not is_semantic_cache_active():
        warnings.append(
            "SEMANTIC_CACHE_ENABLED=true but semantic cache is inactive "
            "(requires VECTORSTORE_BACKEND=qdrant)."
        )
    if settings.enable_hybrid_retrieval and backend != "qdrant":
        warnings.append(
            "ENABLE_HYBRID_RETRIEVAL=true has no effect unless VECTORSTORE_BACKEND=qdrant."
        )
    if (
        settings.enable_speculative_executor
        and settings.enable_async_pipeline
        and settings.notes_only_generation
        and not settings.agentic_inspector_when_notes_only
    ):
        warnings.append(
            "ENABLE_SPECULATIVE_EXECUTOR=true but notes_only_generation=true forces the "
            "standard pipeline on POST /generate (inspector/speculation skipped). "
            "Set AGENTIC_INSPECTOR_WHEN_NOTES_ONLY=true or NOTES_ONLY_GENERATION=false."
        )
    if settings.enable_prompt_caching and not settings.enable_async_pipeline:
        warnings.append(
            "ENABLE_PROMPT_CACHING=true requires ENABLE_ASYNC_PIPELINE=true."
        )
    if settings.enable_temporal_workflow and "sqlite" in (settings.database_url or "").lower():
        if not settings.allow_sqlite_parallel_sections:
            warnings.append(
                "Temporal + SQLite: parallel section activities are disabled by default; "
                "use PostgreSQL for parallel Temporal sections."
            )
    if backend == "qdrant":
        from pathlib import Path

        faiss_dir = Path(settings.faiss_index_path)
        try:
            if faiss_dir.is_dir() and any(faiss_dir.iterdir()):
                warnings.append(
                    "FAISS index data still present on disk; re-ingest into Qdrant "
                    "(scripts/reingest_qdrant.py) if you migrated backends."
                )
        except OSError:
            pass
    if settings.enable_job_queue and not redis_configured():
        warnings.append(
            "ENABLE_JOB_QUEUE=true requires REDIS_URL; "
            "generation will fall back to in-process tasks until Redis is configured."
        )
    if settings.enable_rag_upload_sanitisation and not (settings.openai_api_key or "").strip():
        warnings.append(
            "ENABLE_RAG_UPLOAD_SANITISATION=true but OPENAI_API_KEY is unset; "
            "uploads are indexed using regex-only redaction (weaker than the LLM sanitiser)."
        )
    return warnings


def collect_optimization_hints() -> list[str]:
    """Non-blocking operational hints (not misconfigurations)."""
    hints: list[str] = []
    if job_queue_enabled():
        hints.append(
            "Job queue enabled: ensure `python jobs_worker.py` is running "
            "(or `docker compose --profile redis --profile jobs up`)."
        )
    if redis_configured() and not settings.enable_job_queue:
        hints.append(
            "REDIS_URL is set: distributed rate limits are active across API replicas."
        )
    return hints