# -*- coding: utf-8 -*-

import os

from flask import render_template, flash, redirect, url_for, current_app

from werkzeug.utils import secure_filename

from app import db
from app.admin import bp
from app.admin.datasets import get_name_from_dataset, md5sum
from app.admin.decorators import admin_required
from app.admin.forms import AdminManageTaskForm, AdminAddDatasetForm
from app.models import User, Dataset, Task, Annotation


@bp.route("/manage", methods=("GET", "POST"))
@admin_required
def manage():
    user_list = [(u.id, u.username) for u in User.query.all()]
    dataset_list = [(d.id, d.name) for d in Dataset.query.all()]

    form = AdminManageTaskForm()
    form.username.choices = user_list
    form.dataset.choices = dataset_list

    if form.validate_on_submit():
        user = User.query.filter_by(id=form.username.data).first()
        if user is None:
            flash("User does not exist.")
            return redirect(url_for("admin.manage"))
        dataset = Dataset.query.filter_by(id=form.dataset.data).first()
        if dataset is None:
            flash("Dataset does not exist.")
            return redirect(url_for("admin.manage"))

        action = None
        if form.assign.data:
            action = "assign"
        elif form.delete.data:
            action = "delete"
        else:
            flash("Internal error: no button is true but form was submitted.")
            return redirect(url_for("admin.manage"))

        task = Task.query.filter_by(
            annotator_id=user.id, dataset_id=dataset.id
        ).first()
        if task is None:
            if action == "delete":
                flash("Can't delete a task that doesn't exist.")
                return redirect(url_for("admin.manage"))
            else:
                task = Task(annotator_id=user.id, dataset_id=dataset.id)
                db.session.add(task)
                db.session.commit()
                flash("Task registered successfully.")
        else:
            if action == "assign":
                flash("Task assignment already exists.")
                return redirect(url_for("admin.manage"))
            else:
                # delete annotations too
                for ann in Annotation.query.filter_by(task_id=task.id).all():
                    db.session.delete(ann)
                db.session.delete(task)
                db.session.commit()
                flash("Task deleted successfully.")

    tasks = Task.query.all()
    return render_template(
        "admin/manage.html", title="Assign Task", form=form, tasks=tasks
    )


@bp.route("/add", methods=("GET", "POST"))
@admin_required
def add_dataset():
    tmp_dir = os.path.join(
        current_app.instance_path, current_app.config["TEMP_DIR"]
    )
    dataset_dir = os.path.join(
        current_app.instance_path, current_app.config["DATASET_DIR"]
    )
    form = AdminAddDatasetForm()
    if form.validate_on_submit():
        temp_filename = os.path.join(
            tmp_dir, secure_filename(form.file_.data.filename)
        )
        if not os.path.exists(temp_filename):
            flash("Internal error: temporary dataset disappeared.")
            return redirect(url_for("admin.add_dataset"))
        name = get_name_from_dataset(temp_filename)
        target_filename = os.path.join(dataset_dir, name + ".json")
        if os.path.exists(target_filename):
            flash("Internal error: file already exists!")
            return redirect(url_for("admin.add_dataset"))
        os.rename(temp_filename, target_filename)
        if not os.path.exists(target_filename):
            flash("Internal error: file moving failed")
            return redirect(url_for("admin.add_dataset"))

        dataset = Dataset(name=name, md5sum=md5sum(target_filename))
        db.session.add(dataset)
        db.session.commit()
        flash("Dataset %r added successfully." % name)
        return redirect(url_for("admin.add_dataset"))
    return render_template("admin/add.html", title="Add Dataset", form=form)


@bp.route("/", methods=("GET",))
@admin_required
def index():
    return render_template("admin/index.html", title="Admin Home")