import os
import uuid
from flask import Flask, render_template, jsonify, redirect, url_for, request, session, send_from_directory
from werkzeug.utils import secure_filename
from .db import init_db, engine
from . import config, auth, assistant
from sqlmodel import Session, select
from .models import User, Event, GlobalStatus, Project, PortalFile
from datetime import datetime, timezone
from functools import wraps

app = Flask(__name__)
app.secret_key = config.WEB_SECRET

# Настройки для загрузки файлов (макс 100 МБ)
UPLOAD_FOLDER = '/var/lib/gitea/portal-files'
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.config['MAX_CONTENT_LENGTH'] = 100 * 1024 * 1024 

with app.app_context():
    init_db()
    with Session(engine) as db_session:
        status = db_session.exec(select(GlobalStatus)).first()
        if not status:
            db_session.add(GlobalStatus(status="free", message="Вне расписания"))
            db_session.commit()

def require_role(allowed_roles):
    if isinstance(allowed_roles, str):
        allowed_roles = [allowed_roles]
    def decorator(f):
        @wraps(f)
        def decorated_function(*args, **kwargs):
            if session.get("role") not in allowed_roles:
                return "403: Доступ запрещен. Недостаточно прав.", 403
            return f(*args, **kwargs)
        return decorated_function
    return decorator

def login_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        if not session.get("user_id"):
            return redirect(url_for("login"))
        return f(*args, **kwargs)
    return decorated_function

@app.route("/healthz")
def healthz():
    return jsonify({"status": "ok", "service": "morozovka-portal"})

@app.route("/")
def index():
    current_user = session.get("username")
    return render_template("index.html", username=current_user)

# --- АВТОРИЗАЦИЯ ---
@app.route("/login")
def login():
    gitea_auth_url = (
        f"{config.GITEA_PUBLIC_URL}/login/oauth/authorize"
        f"?client_id={config.GITEA_CLIENT_ID}&response_type=code"
        f"&redirect_uri=https://portal.morozovka.space/auth/callback"
        f"&scope=read:user"
    )
    return redirect(gitea_auth_url)

@app.route("/auth/callback")
def auth_callback():
    code = request.args.get("code")
    if not code:
        return "Ошибка: Gitea не передала код авторизации.", 400

    token = auth.get_gitea_token(code)
    if not token:
        return "Ошибка: не удалось получить токен от Gitea.", 400

    gitea_user = auth.get_gitea_user(token)
    if not gitea_user:
        return "Ошибка: не удалось получить профиль пользователя.", 400

    with Session(engine) as db_session:
        user = db_session.exec(select(User).where(User.gitea_id == gitea_user["id"])).first()
        if not user:
            new_user = User(
                gitea_id=gitea_user["id"],
                username=gitea_user["login"],
                full_name=gitea_user.get("full_name"),
                email=gitea_user.get("email"),
                role="admin" if gitea_user["login"] == "git_admin" else "student"
            )
            db_session.add(new_user)
            db_session.commit()
            user = new_user
        else:
            user.username = gitea_user["login"]
            user.full_name = gitea_user.get("full_name")
            user.email = gitea_user.get("email")
            db_session.add(user)
            db_session.commit()

        session["user_id"] = user.id
        session["username"] = user.username
        session["role"] = user.role

    return redirect(url_for("profile"))

@app.route("/profile")
@login_required
def profile():
    with Session(engine) as db_session:
        user = db_session.get(User, session.get("user_id"))
        if not user:
            session.clear()
            return redirect(url_for("login"))
    return render_template("profile.html", user=user)

@app.route("/logout")
def logout():
    session.clear()
    return redirect(url_for("index"))

# --- ФАЙЛОХРАНИЛИЩЕ ---
@app.route("/files")
@login_required
def files_list():
    with Session(engine) as db_session:
        # Сортируем по дате (новые сверху), джойним с User чтобы знать кто загрузил
        files = db_session.exec(
            select(PortalFile, User.username)
            .join(User, PortalFile.uploaded_by == User.id)
            .order_by(PortalFile.uploaded_at.desc())
        ).all()
    return render_template("files.html", files=files)

@app.route("/files/upload", methods=["POST"])
@login_required
def file_upload():
    if 'file' not in request.files:
        return redirect(url_for('files_list'))
    
    file = request.files['file']
    if file.filename == '':
        return redirect(url_for('files_list'))

    if file:
        original_name = file.filename
        # Генерируем уникальное имя для хранения на диске (чтобы файлы с одинаковыми именами не перезаписывали друг друга)
        ext = os.path.splitext(original_name)[1]
        stored_name = f"{uuid.uuid4().hex}{ext}"
        
        filepath = os.path.join(app.config['UPLOAD_FOLDER'], stored_name)
        file.save(filepath)
        
        size_bytes = os.path.getsize(filepath)

        with Session(engine) as db_session:
            new_file = PortalFile(
                original_name=original_name,
                stored_name=stored_name,
                size_bytes=size_bytes,
                uploaded_by=session.get("user_id")
            )
            db_session.add(new_file)
            db_session.commit()

    return redirect(url_for('files_list'))

@app.route("/files/download/<int:file_id>")
@login_required
def file_download(file_id):
    with Session(engine) as db_session:
        db_file = db_session.get(PortalFile, file_id)
        if db_file:
            return send_from_directory(
                app.config['UPLOAD_FOLDER'], 
                db_file.stored_name, 
                as_attachment=True, 
                download_name=db_file.original_name
            )
    return "Файл не найден", 404

@app.route("/files/<int:file_id>/delete", methods=["POST"])
@login_required
def file_delete(file_id):
    with Session(engine) as db_session:
        db_file = db_session.get(PortalFile, file_id)
        if db_file:
            # Удалять может только админ или тот, кто загрузил
            if session.get("role") == "admin" or db_file.uploaded_by == session.get("user_id"):
                filepath = os.path.join(app.config['UPLOAD_FOLDER'], db_file.stored_name)
                if os.path.exists(filepath):
                    os.remove(filepath) # Удаляем с диска
                db_session.delete(db_file) # Удаляем из БД
                db_session.commit()
    return redirect(url_for("files_list"))

# --- ПРОЕКТЫ ---
@app.route("/projects")
def projects_list():
    with Session(engine) as db_session:
        projects = db_session.exec(select(Project).order_by(Project.created_at.desc())).all()
    return render_template("projects.html", projects=projects, role=session.get("role"))

@app.route("/projects/new", methods=["GET", "POST"])
@require_role(["admin", "professor", "lead"])
def project_new():
    if request.method == "POST":
        title = request.form.get("title")
        description = request.form.get("description")
        status = request.form.get("status")
        gitea_url = request.form.get("gitea_url")
        is_public = request.form.get("is_public") == "on"

        with Session(engine) as db_session:
            new_proj = Project(
                title=title,
                description=description,
                status=status,
                gitea_url=gitea_url,
                is_public=is_public,
                owner_id=session.get("user_id")
            )
            db_session.add(new_proj)
            db_session.commit()
        return redirect(url_for("projects_list"))
    return render_template("project_form.html")

@app.route("/projects/<int:project_id>/delete", methods=["POST"])
@require_role(["admin", "professor", "lead"])
def project_delete(project_id):
    with Session(engine) as db_session:
        proj = db_session.get(Project, project_id)
        if proj:
            if session.get("role") == "admin" or proj.owner_id == session.get("user_id"):
                db_session.delete(proj)
                db_session.commit()
    return redirect(url_for("projects_list"))

# --- АДМИНКА: ПОЛЬЗОВАТЕЛИ ---
@app.route("/admin/users")
@require_role("admin")
def admin_users():
    with Session(engine) as db_session:
        users = db_session.exec(select(User).order_by(User.username)).all()
    return render_template("admin_users.html", users=users)

@app.route("/admin/users/<int:user_id>/role", methods=["POST"])
@require_role("admin")
def change_user_role(user_id):
    new_role = request.form.get("role")
    valid_roles = ["admin", "professor", "lead", "member", "student", "guest"]
    if new_role not in valid_roles:
        return "Ошибка: неверная роль", 400

    with Session(engine) as db_session:
        user = db_session.get(User, user_id)
        if user:
            if user.id == session.get("user_id") and new_role != "admin":
                return "Ошибка: нельзя лишить самого себя прав администратора", 400
            user.role = new_role
            db_session.add(user)
            db_session.commit()
    return redirect(url_for("admin_users"))

# --- РАСПИСАНИЕ: ПУБЛИЧНАЯ ЧАСТЬ ---
@app.route("/schedule")
def public_schedule():
    with Session(engine) as db_session:
        current_status = db_session.exec(select(GlobalStatus)).first()
        now = datetime.now(timezone.utc)
        events = db_session.exec(
            select(Event)
            .where(Event.is_public == True)
            .where(Event.start_time >= now)
            .order_by(Event.start_time)
            .limit(10)
        ).all()
    return render_template("schedule.html", status=current_status, events=events)

# --- АССИСТЕНТ: API ---
@app.route("/api/assistant", methods=["POST"])
def api_assistant():
    data = request.get_json()
    if not data or "message" not in data:
        return jsonify({"error": "Нет сообщения"}), 400
    reply = assistant.get_response(data["message"])
    return jsonify({"reply": reply})

# --- РАСПИСАНИЕ: АДМИН-ПАНЕЛЬ ---
@app.route("/admin/schedule")
@require_role(["admin", "professor"])
def admin_schedule():
    with Session(engine) as db_session:
        current_status = db_session.exec(select(GlobalStatus)).first()
        now = datetime.now(timezone.utc)
        events = db_session.exec(
            select(Event)
            .where(Event.start_time >= now)
            .order_by(Event.start_time)
        ).all()
    return render_template("admin_schedule.html", status=current_status, events=events)

@app.route("/admin/schedule/status", methods=["POST"])
@require_role(["admin", "professor"])
def update_status():
    status_val = request.form.get("status")
    delay = int(request.form.get("delay_minutes") or 0)
    message = request.form.get("message")

    with Session(engine) as db_session:
        current_status = db_session.exec(select(GlobalStatus)).first()
        if current_status:
            current_status.status = status_val
            current_status.delay_minutes = delay
            current_status.message = message
            current_status.updated_at = datetime.now(timezone.utc)
            db_session.add(current_status)
            db_session.commit()
    return redirect(url_for("admin_schedule"))

@app.route("/admin/schedule/event/add", methods=["POST"])
@require_role(["admin", "professor"])
def add_event():
    title = request.form.get("title")
    event_type = request.form.get("event_type")
    start_str = request.form.get("start_time")
    end_str = request.form.get("end_time")
    location = request.form.get("location")
    description = request.form.get("description")
    is_public = request.form.get("is_public") == "on"

    start_time = datetime.strptime(start_str, "%Y-%m-%dT%H:%M").replace(tzinfo=timezone.utc)
    end_time = datetime.strptime(end_str, "%Y-%m-%dT%H:%M").replace(tzinfo=timezone.utc)

    with Session(engine) as db_session:
        new_event = Event(
            title=title,
            event_type=event_type,
            start_time=start_time,
            end_time=end_time,
            location=location,
            description=description,
            is_public=is_public
        )
        db_session.add(new_event)
        db_session.commit()
    return redirect(url_for("admin_schedule"))

@app.route("/admin/schedule/event/<int:event_id>/delete", methods=["POST"])
@require_role(["admin", "professor"])
def delete_event(event_id):
    with Session(engine) as db_session:
        event = db_session.get(Event, event_id)
        if event:
            db_session.delete(event)
            db_session.commit()
    return redirect(url_for("admin_schedule"))