from fastapi import APIRouter, Depends, HTTPException
from sqlalchemy.orm import Session
from typing import Optional
from .. import crud, schemas, auth
from ..database import get_db
from ..models import User

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

@router.get("/steps/{step_id}", response_model=schemas.SuccessResponse)
def get_step_content(
    step_id: int,
    db: Session = Depends(get_db),
    current_user: Optional[User] = Depends(auth.get_optional_current_user)
):
    step = crud.get_step_by_id(db, step_id=step_id)
    if not step:
        raise HTTPException(status_code=404, detail="Step not found")
    
    lesson = crud.get_lesson_by_id(db, step.lesson_id)
    if not lesson:
        raise HTTPException(status_code=404, detail="Lesson not found")
    
    module = crud.get_module_by_id(db, lesson.module_id)
    if not module:
        raise HTTPException(status_code=404, detail="Module not found")
    
    from ..models import Course
    course = db.query(Course).filter(Course.id == module.course_id).first()
    if not course:
        raise HTTPException(status_code=404, detail="Course not found")
    
    if course.status != 'published':
        if current_user is None or course.author_id != current_user.id:
            raise HTTPException(status_code=403, detail="Not authorized")
    
    return schemas.SuccessResponse(data={
        "step": {
            "id": step.id,
            "step_type": step.step_type,
            "title": step.title,
            "content": step.content,
            "content_html": step.content_html,
            "file_url": step.file_url,
            "test_settings": step.test_settings,
            "order_index": step.order_index
        }
    })

@router.get("/steps/{step_id}/test", response_model=schemas.SuccessResponse)
def get_test_for_viewing(
    step_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(auth.get_current_user)
):
    """
    Get test questions for viewing (without correct answers)
    """
    step = crud.get_step_by_id(db, step_id)
    if not step:
        raise HTTPException(status_code=404, detail="Step not found")
    
    if step.step_type != 'test':
        raise HTTPException(status_code=400, detail="Step is not a test")
    
    questions = crud.get_test_questions(db, step_id)
    
    # Prepare questions without correct answers
    questions_for_viewer = []
    for q in questions:
        question_data = {
            "id": q.id,
            "question_text": q.question_text,
            "question_type": q.question_type,
            "points": q.points,
            "order_index": q.order_index
        }
        
        if q.question_type in ['single_choice', 'multiple_choice']:
            # Return answers without is_correct flag
            question_data["answers"] = [
                {"id": a.id, "answer_text": a.answer_text, "order_index": a.order_index}
                for a in q.answers
            ]
        elif q.question_type == 'match':
            # Return match items shuffled
            question_data["match_items"] = [
                {"id": m.id, "left_text": m.left_text, "right_text": m.right_text, "order_index": m.order_index}
                for m in q.match_items
            ]
        
        questions_for_viewer.append(question_data)
    
    # Get user's previous attempts
    attempts = crud.get_test_attempts(db, current_user.id, step_id)
    attempts_data = [
        {
            "id": a.id,
            "score": float(a.score),
            "max_score": float(a.max_score),
            "passed": a.passed,
            "completed_at": a.completed_at.isoformat() if a.completed_at else None
        }
        for a in attempts
    ]
    
    return schemas.SuccessResponse(data={
        "questions": questions_for_viewer,
        "settings": step.test_settings,
        "attempts": attempts_data
    })

@router.post("/steps/{step_id}/test/submit", response_model=schemas.SuccessResponse)
def submit_test(
    step_id: int,
    attempt: schemas.TestAttemptCreate,
    db: Session = Depends(get_db),
    current_user: User = Depends(auth.get_current_user)
):
    """
    Submit test answers and get results
    """
    step = crud.get_step_by_id(db, step_id)
    if not step:
        raise HTTPException(status_code=404, detail="Step not found")
    
    if step.step_type != 'test':
        raise HTTPException(status_code=400, detail="Step is not a test")
    
    # Check max attempts limit
    settings = step.test_settings or {}
    max_attempts = settings.get('max_attempts', 0)
    
    if max_attempts > 0:
        attempts = crud.get_test_attempts(db, current_user.id, step_id)
        if len(attempts) >= max_attempts:
            raise HTTPException(status_code=400, detail="Maximum attempts reached")
    
    # Create attempt and calculate score
    test_attempt = crud.create_test_attempt(db, current_user.id, step_id, attempt.answers)
    if not test_attempt:
        raise HTTPException(status_code=500, detail="Failed to create test attempt")
    
    return schemas.SuccessResponse(data={
        "attempt": {
            "id": test_attempt.id,
            "score": float(test_attempt.score),
            "max_score": float(test_attempt.max_score),
            "passed": test_attempt.passed,
            "completed_at": test_attempt.completed_at.isoformat() if test_attempt.completed_at else None
        }
    })

@router.get("/steps/{step_id}/test/attempts", response_model=schemas.SuccessResponse)
def get_test_attempts(
    step_id: int,
    db: Session = Depends(get_db),
    current_user: User = Depends(auth.get_current_user)
):
    """
    Get user's test attempts history
    """
    step = crud.get_step_by_id(db, step_id)
    if not step:
        raise HTTPException(status_code=404, detail="Step not found")
    
    attempts = crud.get_test_attempts(db, current_user.id, step_id)
    attempts_data = [
        {
            "id": a.id,
            "score": float(a.score),
            "max_score": float(a.max_score),
            "passed": a.passed,
            "completed_at": a.completed_at.isoformat() if a.completed_at else None
        }
        for a in attempts
    ]
    
    return schemas.SuccessResponse(data={"attempts": attempts_data})