"""Dashboard API.

Two access levels share these routes:
- Admins (is_admin) see ALL teachers' data and can manage users.
- Regular teachers see ONLY their own data (their quizzes/students/results) and
  cannot reach user-management or other teachers' records.

Scoping is enforced server-side: list endpoints filter by the caller's teacher
id, and detail endpoints verify ownership before returning anything.
"""

from __future__ import annotations

from typing import Optional

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel

from .auth import get_current_admin, get_current_user
from .database import (
    admin_list_sessions,
    admin_list_students,
    delete_session,
    delete_user,
    get_parsed_data,
    get_quiz_results,
    get_raw_files,
    get_schema_version,
    get_session,
    get_stats,
    get_student,
    get_student_timeline,
    list_all_users,
    set_user_admin,
)
from .storage import create_signed_url

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


def _scope(user: dict) -> Optional[int]:
    """None for admins (see everything), else the teacher id to scope to."""
    return None if user.get("is_admin") else user["id"]


def _owns_quiz(user: dict, quiz: dict) -> bool:
    return user.get("is_admin") or quiz.get("teacher_id") == user["id"]


def _owns_student(user: dict, student: dict) -> bool:
    return user.get("is_admin") or student.get("teacher_id") == user["id"]


@router.get("/stats")
async def dashboard_stats(user=Depends(get_current_user)):
    stats = await get_stats(_scope(user))
    stats["is_admin"] = bool(user.get("is_admin"))
    if user.get("is_admin"):
        stats["schema_version"] = await get_schema_version()
    return stats


# ---- User management (admin only) ----

@router.get("/users")
async def admin_users(_admin=Depends(get_current_admin)):
    return {"users": await list_all_users()}


class SetAdminRequest(BaseModel):
    is_admin: bool


@router.put("/users/{user_id}/admin")
async def admin_set_admin(user_id: int, body: SetAdminRequest, admin=Depends(get_current_admin)):
    if user_id == admin["id"] and not body.is_admin:
        raise HTTPException(status_code=400, detail="You cannot remove your own admin access")
    await set_user_admin(user_id, body.is_admin)
    return {"status": "ok", "user_id": user_id, "is_admin": body.is_admin}


@router.delete("/users/{user_id}")
async def admin_delete_user(user_id: int, admin=Depends(get_current_admin)):
    if user_id == admin["id"]:
        raise HTTPException(status_code=400, detail="You cannot delete your own account here")
    await delete_user(user_id)
    return {"status": "deleted"}


# ---- Sessions / quizzes (scoped) ----

@router.get("/sessions")
async def dashboard_sessions(user=Depends(get_current_user)):
    return {"sessions": await admin_list_sessions(_scope(user))}


@router.get("/sessions/{session_id}")
async def dashboard_session_detail(session_id: int, user=Depends(get_current_user)):
    """Full quiz detail: raw files (signed URLs), structured parsed data, results."""
    quiz = await get_session(session_id)
    if not quiz or not _owns_quiz(user, quiz):
        raise HTTPException(status_code=404, detail="Session not found")

    parsed = {}
    for item in await get_parsed_data(session_id):
        parsed[item["data_type"]] = item["structured_data"]

    raw_files = []
    for f in await get_raw_files(session_id):
        f["download_url"] = await create_signed_url(f.get("storage_path", ""))
        raw_files.append(f)

    return {
        "quiz": quiz,
        "raw_files": raw_files,
        "parsed_data": parsed,
        "results": await get_quiz_results(session_id),
    }


@router.delete("/sessions/{session_id}")
async def dashboard_delete_session(session_id: int, user=Depends(get_current_user)):
    quiz = await get_session(session_id)
    if not quiz or not _owns_quiz(user, quiz):
        raise HTTPException(status_code=404, detail="Session not found")
    await delete_session(session_id)
    return {"status": "deleted"}


# ---- Students (scoped) ----

@router.get("/students")
async def dashboard_students(user=Depends(get_current_user)):
    return {"students": await admin_list_students(_scope(user))}


@router.get("/students/{student_id}")
async def dashboard_student_detail(student_id: int, user=Depends(get_current_user)):
    student = await get_student(student_id)
    if not student or not _owns_student(user, student):
        raise HTTPException(status_code=404, detail="Student not found")
    return {"student": student, "timeline": await get_student_timeline(student_id)}