app/api/routes.py

"""
API Routes
==========
FastAPI routes (Interface Segregation)
"""

from fastapi import APIRouter, Depends, HTTPException, status
from typing import Dict

from app.schemas.requests import AnalysisRequest
from app.schemas.responses import AnalysisResponse, HealthResponse, ErrorResponse
from app.services.analysis_service import analysis_service
from app.models.model_loader import model_loader
from app.core.config import settings
from app.core.exceptions import ModelNotLoadedException, AnalysisException


router = APIRouter()


@router.get(
    "/",
    response_model=Dict[str, str],
    summary="Root endpoint",
    tags=["General"]
)
async def root():
    """Root endpoint - API information"""
    return {
        "message": "Toxic Text Detection API",
        "version": settings.API_VERSION,
        "docs": "/docs",
        "health": "/api/v1/health"
    }


@router.get(
    "/health",
    response_model=HealthResponse,
    summary="Health check",
    tags=["General"]
)
async def health_check():
    """
    Health check endpoint
    
    Returns service status and model information
    """
    return HealthResponse(
        status="healthy" if model_loader.is_loaded() else "unhealthy",
        model_loaded=model_loader.is_loaded(),
        device=str(model_loader.device) if model_loader.is_loaded() else "unknown",
        model_name=settings.MODEL_NAME,
        version=settings.API_VERSION
    )


@router.post(
    "/analyze",
    response_model=AnalysisResponse,
    responses={
        200: {"description": "Analysis successful"},
        400: {"model": ErrorResponse, "description": "Invalid input"},
        500: {"model": ErrorResponse, "description": "Analysis failed"},
        503: {"model": ErrorResponse, "description": "Model not loaded"}
    },
    summary="Analyze text for toxicity",
    tags=["Analysis"]
)
async def analyze_text(request: AnalysisRequest):
    """
    Analyze text for toxic content
    
    This endpoint analyzes Vietnamese text to detect toxic content using
    a fine-tuned PhoBERT model with gradient-based explainability.
    
    **Features:**
    - Sentence-level toxicity detection
    - Word-level importance scores
    - HTML highlighting of toxic content
    - Detailed statistics
    
    **Parameters:**
    - **text**: Text to analyze (required)
    - **include_html**: Include HTML highlighting (default: true)
    - **include_word_scores**: Include word-level scores (default: true)
    - **include_summary_table**: Include summary table (default: false)
    
    **Returns:**
    - Overall toxicity label (toxic/clean)
    - Sentence-level analysis
    - Word-level scores and toxic words summary
    - HTML with highlighted toxic content
    - Statistical information
    """
    # Check if model is loaded
    if not model_loader.is_loaded():
        raise ModelNotLoadedException()
    
    # Perform analysis
    try:
        result = analysis_service.analyze(request)
        return result
    except AnalysisException as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=str(e)
        )
    except Exception as e:
        raise HTTPException(
            status_code=status.HTTP_500_INTERNAL_SERVER_ERROR,
            detail=f"Unexpected error: {str(e)}"
        )