import csv
from datetime import datetime
import io
import os

from flask import Blueprint, render_template, request
from loguru import logger

from app.models.collection import Collection
from app.extensions import db

collections = Blueprint("collections", __name__, url_prefix="/collections", template_folder="templates")

@collections.route('/', methods=["POST"])
def create_collection():
    data = request.form
    name = data.get('collection_name')
    
    if not name:
        return render_template('collections/create_form.j2', collections_error='Введите название базы!')
    
    if Collection.exists(name):
        return render_template('collections/create_form.j2', collections_error='База уже существует!')
    
    swap = 'afterbegin' if len(Collection.query.all()) > 0 else 'innerHTML'
    
    collection = Collection(name=name)
    
    db.session.add(collection)
    db.session.commit()
    
    return f"<option value=\"{collection.id}\" selected>{ collection.name }</option>", 200, {'Hx-Reswap': swap, 'HX-Retarget': '#collection-select'}

@collections.route("/<int:id>", methods=["DELETE"])
def delete_collection(id: int):
    
    collection: Collection = Collection.query.get_or_404(id)

    length = len(Collection.query.all()) - 1
    
    db.session.delete(collection)
    db.session.commit()
    
    if length <= 0:
        return "<small class=\"form-text\">Здесь ничего нет</small>", 200
    
    return "", 200

@collections.route("/<int:id>/csv", methods=["GET"])
def export_users_to_csv(id: int):
    collection: Collection = Collection.query.get_or_404(id)
    
    if len(collection.users) <= 0:
        return "", 204
    
    filename = f"{collection.name} - {datetime.now()}.csv"
    
    fieldnames = collection.users[0].to_dict().keys()
    si = io.StringIO()
    
    writer = csv.DictWriter(si, fieldnames)

    writer.writeheader()
    writer.writerows(map(lambda user: user.to_dict(), collection.users))
    
    return si, 200, {'Content-Disposition': f'attachment; filename={filename}', 'Content-type': 'text/csv; charset=utf-8'}