routes/analysis.py

"""Analysis endpoints for processing arguments, extracting topics, and predicting stance"""

from fastapi import APIRouter, HTTPException, Header, UploadFile, File
from typing import Optional
import logging
import csv
import io
from datetime import datetime

from services.analysis_service import analysis_service
from models.analysis import (
    AnalysisRequest,
    AnalysisResponse,
    AnalysisResult,
    GetAnalysisRequest,
    GetAnalysisResponse,
)

router = APIRouter()
logger = logging.getLogger(__name__)


def parse_csv_file(file_content: bytes) -> List[str]:
    """
    Parse CSV file and extract arguments
    
    Args:
        file_content: CSV file content as bytes
        
    Returns:
        List of argument strings
    """
    try:
        # Decode bytes to string
        content = file_content.decode('utf-8')
        
        # Parse CSV
        csv_reader = csv.reader(io.StringIO(content))
        arguments = []
        
        # Skip header row if present, extract arguments from first column or 'argument' column
        rows = list(csv_reader)
        if len(rows) == 0:
            return []
        
        # Check if first row is header
        header = rows[0] if rows else []
        start_idx = 1 if any(col.lower() in ['argument', 'text', 'content'] for col in header) else 0
        
        # Find argument column index
        arg_col_idx = 0
        if start_idx == 1:
            for idx, col in enumerate(header):
                if col.lower() in ['argument', 'text', 'content']:
                    arg_col_idx = idx
                    break
        
        # Extract arguments
        for row in rows[start_idx:]:
            if row and len(row) > arg_col_idx:
                arg = row[arg_col_idx].strip()
                if arg:  # Only add non-empty arguments
                    arguments.append(arg)
        
        return arguments
        
    except Exception as e:
        logger.error(f"Error parsing CSV file: {str(e)}")
        raise ValueError(f"Failed to parse CSV file: {str(e)}")


@router.post("/analyse", response_model=AnalysisResponse, tags=["Analysis"])
async def analyse_arguments(
    request: Optional[AnalysisRequest] = None,
    file: Optional[UploadFile] = File(None),
    x_user_id: Optional[str] = Header(None, alias="X-User-ID")
):
    """
    Analyze arguments: extract topics and predict stance
    
    Accepts either:
    - JSON body with `arguments` array, OR
    - CSV file upload with arguments
    
    - **X-User-ID**: User UUID (required in header)
    - **arguments**: List of argument texts (if using JSON)
    - **file**: CSV file with arguments (if using file upload)
    
    Returns analysis results with extracted topics and stance predictions
    """
    if not x_user_id:
        raise HTTPException(status_code=400, detail="X-User-ID header is required")
    
    try:
        arguments = []
        
        # Get arguments from either JSON body or CSV file
        if file:
            # Read CSV file
            file_content = await file.read()
            arguments = parse_csv_file(file_content)
            
            if not arguments:
                raise HTTPException(
                    status_code=400,
                    detail="CSV file is empty or contains no valid arguments"
                )
            
            logger.info(f"Parsed {len(arguments)} arguments from CSV file")
            
        elif request and request.arguments:
            arguments = request.arguments
            logger.info(f"Received {len(arguments)} arguments from JSON body")
        else:
            raise HTTPException(
                status_code=400,
                detail="Either 'arguments' in JSON body or CSV 'file' must be provided"
            )
        
        # Analyze arguments
        results = analysis_service.analyze_arguments(
            user_id=x_user_id,
            arguments=arguments
        )
        
        # Convert to response models
        analysis_results = [
            AnalysisResult(**result) for result in results
        ]
        
        logger.info(f"Analysis completed: {len(analysis_results)} results")
        
        return AnalysisResponse(
            results=analysis_results,
            total_processed=len(analysis_results),
            timestamp=datetime.now().isoformat()
        )
        
    except HTTPException:
        raise
    except ValueError as e:
        logger.error(f"Validation error: {str(e)}")
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Analysis error: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Analysis failed: {str(e)}")


@router.get("/analyse", response_model=GetAnalysisResponse, tags=["Analysis"])
async def get_analysis_results(
    limit: int = 100,
    offset: int = 0,
    x_user_id: Optional[str] = Header(None, alias="X-User-ID")
):
    """
    Get user's analysis results
    
    - **X-User-ID**: User UUID (required in header)
    - **limit**: Maximum number of results to return (default: 100, max: 1000)
    - **offset**: Number of results to skip (default: 0)
    
    Returns paginated analysis results
    """
    if not x_user_id:
        raise HTTPException(status_code=400, detail="X-User-ID header is required")
    
    try:
        results = analysis_service.get_user_analysis_results(
            user_id=x_user_id,
            limit=limit,
            offset=offset
        )
        
        # Convert to response models
        analysis_results = [
            AnalysisResult(**result) for result in results
        ]
        
        return GetAnalysisResponse(
            results=analysis_results,
            total=len(analysis_results),
            limit=limit,
            offset=offset
        )
        
    except Exception as e:
        logger.error(f"Error getting analysis results: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Failed to get analysis results: {str(e)}")