import os
from datetime import datetime as dt, timezone as tz
from flask import request, redirect, url_for, flash, render_template, Blueprint, session, current_app
from flask_security import hash_password, roles_required, roles_accepted, current_user
from werkzeug.utils import secure_filename

from ..models.document import Document, DocumentLanguage, DocumentVersion
from ..extensions import db
from .document_forms import AddDocumentForm
from ..utils.database import Database
from ..utils.middleware import mw_before_request

document_bp = Blueprint('document_bp', __name__, url_prefix='/document')


@document_bp.before_request
def before_request():
    mw_before_request()


@document_bp.route('/add_document', methods=['GET', 'POST'])
@roles_accepted('Super User', 'Tenant Admin')
def add_document():
    form = AddDocumentForm()
    error = None

    # If the form is submitted
    if request.method == 'POST' and form.validate_on_submit():
        file = form.file.data
        filename = secure_filename(file.filename)
        extension = filename.rsplit('.', 1)[1].lower()

        # Create the Document
        new_doc = Document()
        if form.name.data == '':
            new_doc.name = filename.rsplit('.', 1)[0]
        else:
            new_doc.name = form.name.data

        timestamp = dt.now(tz.utc)
        if form.valid_from.data or form.valid_from.data != '':
            new_doc.valid_from = form.valid_from.data
        else:
            new_doc.valid_from = timestamp
            
        new_doc.tenant_id = session['tenant']['id']

        new_doc.created_at = timestamp
        new_doc.updated_at = timestamp
        new_doc.created_by = current_user.id
        new_doc.updated_by = current_user.id

        # Create the DocumentLanguage
        new_doc_lang = DocumentLanguage()
        if form.language.data == '':
            new_doc_lang.language = session['default_language']
        else:
            new_doc_lang.language = form.language.data
        
        new_doc_lang.document = new_doc

        new_doc_lang.created_at = timestamp
        new_doc_lang.updated_at = timestamp
        new_doc_lang.created_by = current_user.id
        new_doc_lang.updated_by = current_user.id

        # Create the DocumentVersion
        new_doc_vers = DocumentVersion()
        new_doc_vers.document_language = new_doc_lang

        new_doc_vers.created_at = timestamp
        new_doc_vers.updated_at = timestamp
        new_doc_vers.created_by = current_user.id
        new_doc_vers.updated_by = current_user.id

        try:
            db.session.add(new_doc)
            db.session.add(new_doc_lang)
            db.session.add(new_doc_vers)
            db.session.commit()
        except Exception as e:
            db.session.rollback()
            error = e.args

        # Save the file and process the document
        if error is None:
            flash('Document added successfully.')
            new_doc_vers.file_type = extension
            new_doc_vers.file_name = new_doc_vers.calc_file_name()
            new_doc_vers.file_location = new_doc_vers.calc_file_location()

            upload_path = os.path.join(current_app.config['UPLOAD_FOLDER'], new_doc_vers.file_location)
            if not os.path.exists(upload_path):
                os.makedirs(upload_path, exist_ok=True)
            file.save(os.path.join(upload_path, new_doc_vers.file_name))
            try:
                db.session.commit()
            except Exception as e:
                db.session.rollback()
                error = e.args
            if error is None:
                flash('Document saved successfully.')
                # TODO: processing of document to embeddings (async)
                flash('Document processing started.')
            else:
                    flash('Error saving document.')
        else:
            flash('Error adding document.')

    return render_template('document/add_document.html', form=form)