from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy.orm import Session
from typing import List
from .. import crud, schemas, auth
from ..database import get_db
from ..auth import get_current_user

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

@router.get("/", response_model=List[schemas.ProgressResponse])
def get_my_progress(
    db: Session = Depends(get_db),
    current_user: schemas.UserResponse = Depends(get_current_user)
):
    progress_list = crud.get_user_progress(db, user_id=current_user.id)
    # Calculate percentage for each progress
    result = []
    for progress in progress_list:
        percentage = (progress.completed_lessons / progress.total_lessons * 100) if progress.total_lessons > 0 else 0
        result.append({
            "user_id": progress.user_id,
            "course_id": progress.course_id,
            "completed_lessons": progress.completed_lessons,
            "total_lessons": progress.total_lessons,
            "percentage": percentage,
            "updated_at": progress.updated_at
        })
    return result

@router.get("/{course_id}", response_model=schemas.ProgressResponse)
def get_course_progress(
    course_id: int,
    db: Session = Depends(get_db),
    current_user: schemas.UserResponse = Depends(get_current_user)
):
    progress = crud.get_progress(db, user_id=current_user.id, course_id=course_id)
    if not progress:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Progress not found for this course"
        )
    
    percentage = (progress.completed_lessons / progress.total_lessons * 100) if progress.total_lessons > 0 else 0
    return {
        "user_id": progress.user_id,
        "course_id": progress.course_id,
        "completed_lessons": progress.completed_lessons,
        "total_lessons": progress.total_lessons,
        "percentage": percentage,
        "updated_at": progress.updated_at
    }

@router.post("/{course_id}", response_model=schemas.ProgressResponse)
def update_progress(
    course_id: int,
    progress_update: schemas.ProgressUpdate,
    db: Session = Depends(get_db),
    current_user: schemas.UserResponse = Depends(get_current_user)
):
    # Check if course exists
    course = crud.get_course_by_id(db, course_id)
    if not course:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Course not found"
        )
    
    # Validate completed_lessons <= total_lessons
    if progress_update.completed_lessons > progress_update.total_lessons:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Completed lessons cannot exceed total lessons"
        )
    
    progress = crud.create_or_update_progress(
        db,
        user_id=current_user.id,
        course_id=course_id,
        completed_lessons=progress_update.completed_lessons,
        total_lessons=progress_update.total_lessons
    )
    
    percentage = (progress.completed_lessons / progress.total_lessons * 100) if progress.total_lessons > 0 else 0
    return {
        "user_id": progress.user_id,
        "course_id": progress.course_id,
        "completed_lessons": progress.completed_lessons,
        "total_lessons": progress.total_lessons,
        "percentage": percentage,
        "updated_at": progress.updated_at
    }

@router.delete("/{course_id}", response_model=schemas.SuccessResponse)
def delete_progress(
    course_id: int,
    db: Session = Depends(get_db),
    current_user: schemas.UserResponse = Depends(get_current_user)
):
    success = crud.delete_progress(db, user_id=current_user.id, course_id=course_id)
    if not success:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="Progress not found"
        )
    
    return {"success": True, "message": "Progress deleted"}