CIA/e-voting-system/backend/routes/elections.py

"""
Routes pour les élections et les candidats.

Elections are stored immutably in blockchain with cryptographic security:
- SHA-256 hash chain prevents tampering
- RSA-PSS signatures authenticate election data
- Merkle tree verification for candidates
- Complete audit trail on blockchain
"""

from fastapi import APIRouter, HTTPException, status, Depends
from sqlalchemy.orm import Session
from .. import schemas, services
from ..dependencies import get_db, get_current_voter
from ..models import Voter
from ..blockchain_elections import (
    record_election_to_blockchain,
    verify_election_in_blockchain,
    get_elections_blockchain_data,
)

router = APIRouter(prefix="/api/elections", tags=["elections"])


@router.get("/debug/all")
def debug_all_elections(db: Session = Depends(get_db)):
    """DEBUG: Return all elections with dates for troubleshooting"""
    from datetime import datetime
    from .. import models

    now = datetime.utcnow()
    all_elections = db.query(models.Election).all()

    return {
        "current_time": now.isoformat(),
        "elections": [
            {
                "id": e.id,
                "name": e.name,
                "is_active": e.is_active,
                "start_date": e.start_date.isoformat() if e.start_date else None,
                "end_date": e.end_date.isoformat() if e.end_date else None,
                "should_be_active": (
                    e.start_date <= now <= e.end_date and e.is_active
                    if e.start_date and e.end_date
                    else False
                ),
            }
            for e in all_elections
        ],
    }


@router.get("/active", response_model=list[schemas.ElectionResponse])
def get_active_elections(db: Session = Depends(get_db)):
    """Récupérer toutes les élections actives en cours"""
    from datetime import datetime, timedelta
    from .. import models

    now = datetime.utcnow()
    # Allow 1 hour buffer for timezone issues
    start_buffer = now - timedelta(hours=1)
    end_buffer = now + timedelta(hours=1)

    active = db.query(models.Election).filter(
        (models.Election.start_date <= end_buffer) &
        (models.Election.end_date >= start_buffer) &
        (models.Election.is_active == True)
    ).order_by(models.Election.id.asc()).all()

    return active


@router.get("/blockchain")
def get_elections_blockchain():
    """
    Retrieve the complete elections blockchain.

    Returns all election records stored immutably with cryptographic verification.
    Useful for auditing election creation and verifying no tampering occurred.
    """
    return get_elections_blockchain_data()


@router.get("/{election_id}/blockchain-verify")
def verify_election_blockchain(election_id: int, db: Session = Depends(get_db)):
    """
    Verify an election's blockchain integrity.

    Returns verification report:
    - hash_valid: Block hash matches computed hash
    - chain_valid: Entire chain integrity is valid
    - signature_valid: Block is properly signed
    - verified: All checks passed
    """
    # First verify it exists in database
    election = services.ElectionService.get_election(db, election_id)
    if not election:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Election not found in database"
        )

    # Then verify it's in blockchain
    verification = verify_election_in_blockchain(election_id)

    if not verification.get("verified"):
        # Still return data but mark as unverified
        return {
            **verification,
            "warning": "Election blockchain verification failed - possible tampering"
        }

    return verification


# Routes with path parameters must come AFTER specific routes
@router.get("/active/results")
def get_active_election_results(db: Session = Depends(get_db)):
    """Récupérer les résultats de l'élection active"""

    election = services.ElectionService.get_active_election(db)

    if not election:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="No active election"
        )

    results = services.VoteService.get_election_results(db, election.id)

    return results


@router.get("/{election_id}/candidates")
def get_election_candidates(election_id: int, db: Session = Depends(get_db)):
    """Récupérer les candidats d'une élection"""

    election = services.ElectionService.get_election(db, election_id)

    if not election:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Election not found"
        )

    return election.candidates


@router.get("/{election_id}/results", response_model=schemas.ElectionResultResponse)
def get_election_results(
    election_id: int,
    db: Session = Depends(get_db)
):
    """
    Récupérer les résultats d'une élection.
    Disponible après la fermeture du scrutin.
    """

    election = services.ElectionService.get_election(db, election_id)

    if not election:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Election not found"
        )

    if not election.results_published:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="Results not yet published"
        )

    results = services.VoteService.get_election_results(db, election_id)

    return schemas.ElectionResultResponse(
        election_id=election.id,
        election_name=election.name,
        total_votes=sum(r.vote_count for r in results),
        results=results
    )


@router.post("/{election_id}/publish-results")
def publish_results(
    election_id: int,
    db: Session = Depends(get_db)
):
    """
    Publier les résultats d'une élection (admin only).
    À utiliser après la fermeture du scrutin.
    """

    election = services.ElectionService.get_election(db, election_id)

    if not election:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Election not found"
        )

    # Marquer les résultats comme publiés
    election.results_published = True
    db.commit()

    return {
        "message": "Results published successfully",
        "election_id": election.id,
        "election_name": election.name
    }


@router.get("/{election_id}", response_model=schemas.ElectionResponse)
def get_election(election_id: int, db: Session = Depends(get_db)):
    """Récupérer une élection par son ID"""

    election = services.ElectionService.get_election(db, election_id)

    if not election:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Election not found"
        )

    return election