apps/api/main.py

"""FastAPI application exposing cancer risk assessment endpoints."""

from pathlib import Path

from fastapi import FastAPI, HTTPException

from sentinel.config import AppConfig, ModelConfig, ResourcePaths
from sentinel.factory import SentinelFactory
from sentinel.models import InitialAssessment
from sentinel.user_input import UserInput

app = FastAPI(
    title="Cancer Risk Assessment Assistant",
    description="API for assessing cancer risks using LLMs.",
)

# Define base paths relative to the project root
BASE_DIR = Path(__file__).resolve().parents[2]  # Go up to project root
CONFIGS_DIR = BASE_DIR / "configs"
PROMPTS_DIR = BASE_DIR / "prompts"


def create_knowledge_base_paths() -> ResourcePaths:
    """Build resource path configuration resolved from the repository root.

    Returns:
        ResourcePaths: Paths pointing to persona, prompt, and configuration
        assets required by the API routes.
    """

    return ResourcePaths(
        persona=PROMPTS_DIR / "persona" / "default.md",
        instruction_assessment=PROMPTS_DIR / "instruction" / "assessment.md",
        instruction_conversation=PROMPTS_DIR / "instruction" / "conversation.md",
        output_format_assessment=CONFIGS_DIR / "output_format" / "assessment.yaml",
        output_format_conversation=CONFIGS_DIR / "output_format" / "conversation.yaml",
        cancer_modules_dir=CONFIGS_DIR / "knowledge_base" / "cancer_modules",
        dx_protocols_dir=CONFIGS_DIR / "knowledge_base" / "dx_protocols",
    )


@app.get("/")
async def read_root() -> dict:
    """Return a simple greeting message.

    Returns:
        dict: A dictionary containing a greeting message.
    """
    return {"message": "Hello, world!"}


@app.post("/assess/{provider}", response_model=InitialAssessment)
async def assess(
    provider: str,
    user_input: UserInput,
    model: str | None = None,
    cancer_modules: list[str] | None = None,
    dx_protocols: list[str] | None = None,
) -> InitialAssessment:
    """Assess cancer risk for a user.

    Args:
        provider (str): LLM provider identifier (for example ``"openai"`` or
            ``"anthropic"``).
        user_input (UserInput): Structured demographics and clinical
            information supplied by the client.
        model (str | None): Optional model name overriding the provider
            default.
        cancer_modules (list[str] | None): Optional list of cancer module slugs
            to include in the knowledge base.
        dx_protocols (list[str] | None): Optional list of diagnostic protocol
            slugs to include.

    Returns:
        InitialAssessment: Parsed model output describing the initial
        assessment.

    Raises:
        HTTPException: 400 for invalid input, 500 for unexpected errors.
    """
    try:
        # Create knowledge base paths
        knowledge_base_paths = create_knowledge_base_paths()

        # Set default model name if not provided
        if model is None:
            model_defaults = {
                "openai": "gpt-4o-mini",
                "anthropic": "claude-3-5-sonnet-20241022",
                "google": "gemini-1.5-pro",
            }
            model = model_defaults.get(provider, "gpt-4o-mini")

        # Set default modules if not provided
        if cancer_modules is None:
            cancer_modules_dir = knowledge_base_paths.cancer_modules_dir
            cancer_modules = [p.stem for p in cancer_modules_dir.glob("*.yaml")]

        if dx_protocols is None:
            dx_protocols_dir = knowledge_base_paths.dx_protocols_dir
            dx_protocols = [p.stem for p in dx_protocols_dir.glob("*.yaml")]

        # Create AppConfig
        app_config = AppConfig(
            model=ModelConfig(provider=provider, model_name=model),
            knowledge_base_paths=knowledge_base_paths,
            selected_cancer_modules=cancer_modules,
            selected_dx_protocols=dx_protocols,
        )

        # Create factory and conversation manager
        factory = SentinelFactory(app_config)
        conversation_manager = factory.create_conversation_manager()

        # Run assessment
        response = conversation_manager.initial_assessment(user_input)
        return response

    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Internal Server Error: {e!s}")