from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from sqlalchemy import func
from datetime import datetime, timedelta
from backend.database import get_db, ToolExecution
from backend.auth import get_current_user, User

router = APIRouter()


@router.get("/overview")
async def get_overview(
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    total = db.query(ToolExecution).filter(ToolExecution.user_id == current_user.id).count()
    success = db.query(ToolExecution).filter(
        ToolExecution.user_id == current_user.id,
        ToolExecution.status == "success"
    ).count()
    failed = total - success
    
    success_rate = (success / total * 100) if total > 0 else 100
    
    avg_latency = db.query(func.avg(ToolExecution.latency_ms)).filter(
        ToolExecution.user_id == current_user.id
    ).scalar() or 0
    
    return {
        "total_executions": total,
        "successful": success,
        "failed": failed,
        "success_rate": round(success_rate, 1),
        "avg_latency_ms": int(avg_latency)
    }


@router.get("/executions")
async def get_executions(
    days: int = 7,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    from sqlalchemy import cast, Date
    start_date = datetime.utcnow() - timedelta(days=days)
    
    executions = db.query(
        cast(ToolExecution.executed_at, Date).label("date"),
        func.count(ToolExecution.id).label("count")
    ).filter(
        ToolExecution.user_id == current_user.id,
        ToolExecution.executed_at >= start_date
    ).group_by("date").all()
    
    return {"executions": [{"date": str(e.date), "count": e.count} for e in executions]}


@router.get("/top-tools")
async def get_top_tools(
    limit: int = 10,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    results = db.query(
        ToolExecution.tool_id,
        func.count(ToolExecution.id).label("count")
    ).filter(
        ToolExecution.user_id == current_user.id
    ).group_by(ToolExecution.tool_id).order_by(func.count(ToolExecution.id).desc()).limit(limit).all()
    
    return {"tools": [{"tool_id": r.tool_id, "count": r.count} for r in results]}


@router.get("/errors")
async def get_errors(
    limit: int = 20,
    current_user: User = Depends(get_current_user),
    db: Session = Depends(get_db)
):
    errors = db.query(ToolExecution).filter(
        ToolExecution.user_id == current_user.id,
        ToolExecution.status == "error"
    ).order_by(ToolExecution.executed_at.desc()).limit(limit).all()
    
    return {"errors": [
        {
            "id": e.id,
            "tool_id": e.tool_id,
            "error": e.error_message,
            "executed_at": e.executed_at.isoformat()
        }
        for e in errors
    ]}