from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from datetime import datetime

from ..models import Base # Ensure models are loaded if needed
from ..services.postgresql_manager import PostgreSQLManager
from ..utils.config import config

from ..services.discovery import SegmentDiscoveryService
from ..schemas.discovery import DiscoveryFilter, DiscoveryResult, CandidateSegmentSchema, SingleDiscoveryRequest


router = APIRouter()

def get_db_session():
    db_manager = PostgreSQLManager(config.DATABASE_URL)
    with db_manager.get_db_session() as session:
        yield session


@router.post("/segments", response_model=DiscoveryResult)
def discover_segments(
    filter: DiscoveryFilter,
    db: Session = Depends(get_db_session)
):
    service = SegmentDiscoveryService(db)

    
    # Defaults
    start = filter.start_date or datetime.now().replace(year=datetime.now().year - 1) # Default 1 year?
    
    candidates, debug_paths = service.discover_segments(
        activity_type=filter.activity_type,
        start_date=start,
        end_date=filter.end_date
    )

    
    # Convert to schema
    results = []
    for c in candidates:
        results.append(CandidateSegmentSchema(
            points=c.points,
            frequency=c.frequency,
            distance=c.distance,
            activity_ids=c.activity_ids
        ))
        
    return DiscoveryResult(
        candidates=results,
        generated_at=datetime.now(),
        activity_count=len(debug_paths),
        debug_paths=debug_paths
    )


@router.post("/single", response_model=DiscoveryResult)
def discover_single_activity(
    request: SingleDiscoveryRequest,
    db: Session = Depends(get_db_session)
):
    service = SegmentDiscoveryService(db)
    
    candidates = service.analyze_single_activity(request.activity_id)
    
    # Convert to schema
    results = []
    for c in candidates:
        results.append(CandidateSegmentSchema(
            points=c.points,
            frequency=c.frequency,
            distance=c.distance,
            activity_ids=c.activity_ids
        ))
        
    return DiscoveryResult(
        candidates=results,
        generated_at=datetime.now(),
        activity_count=1,
        debug_paths=None 
    )