import os
import random

from flask import Blueprint, flash, request, redirect, url_for
from flask import current_app, render_template, g

from werkzeug.utils import secure_filename
from werkzeug.exceptions import abort
from files.models import db, File, Category, FileType

from files.auth import admin_required

bp = Blueprint('files', __name__)
bp.add_url_rule('/uploads/<path:filename>', 'uploaded_file', build_only=True)


def _get_extension(filename):
    return filename.rsplit('.', 1)[1].lower()


def _get_name(filename):
    return filename.rsplit('.', 1)[0].lower()


def _get_path_in_upload(filename):
    return os.path.join(current_app.config['UPLOAD_FOLDER'], filename)


def _get_unused_name(filename):
    if os.path.exists(_get_path_in_upload(filename)):
        filename = '{}{}.{}'.format(
            _get_name(filename),
            random.randint(0, 9),
            _get_extension(filename))
        return _get_unused_name(filename)
    return filename


def _save_file(file, private, category, file_type):
    if private is None:
        is_private = 0
    else:
        is_private = 1

    filename = secure_filename(_get_unused_name(file.filename))

    if os.path.exists(_get_path_in_upload(filename)):
        abort(500)

    file.save(_get_path_in_upload(filename))
    db_file = File(filename, is_private, category.id, file_type.id)

    db.session.add(db_file)
    db.session.commit()

    return db_file


def _rename_file(file, new_name):
    new_name = secure_filename(_get_unused_name(new_name))

    os.rename(
        _get_path_in_upload(file.filename),
        _get_path_in_upload(new_name))
    file.filename = new_name

    db.session.commit()


def _delete_file(file):
    os.remove(_get_path_in_upload(file.filename))
    db.session.delete(file)
    db.session.commit()


@bp.route('/', methods=['GET', 'POST'])
def index():
    if g.user is None:
        files = File.query.filter_by(private=0).all()
    else:
        files = File.query.all()

    return render_template('files/index.html', files=files)


@bp.route('/upload', methods=['GET', 'POST'])
@admin_required
def upload_file():
    if request.method == 'POST':
        if 'file.upload.file' not in request.files:
            flash('No file part')
            return redirect(request.url)

        file = request.files['file.upload.file']

        if 'file.upload.private' not in request.form:
            private = None
        else:
            private = request.form['file.upload.private']

        if 'file.upload.category' not in request.form:
            flash('No category selected')
            return redirect(request.url)

        category = Category.query.get(request.form['file.upload.category'])
        if category is None:
            flash('The category selected won\'t exists')
            return redirect(request.url)

        if 'file.upload.file_type' not in request.form:
            flash('No file type selected')
            return redirect(request.url)

        file_type = FileType.query.get(request.form['file.upload.file_type'])
        if file_type is None:
            flash('The file type selected won\'t exists')
            return redirect(request.url)

        if file.filename == '':
            flash('No seleted file')
            return redirect(request.url)

        if file:
            _save_file(file, private, category, file_type)
            return redirect(url_for('files.index'))

    return render_template(
        'files/upload.html',
        categories=Category.query.all(),
        file_types=FileType.query.all())


@bp.route('/preview/<int:file_id>')
def preview_file(file_id):
    file = File.query.get(file_id)
    categories = Category.query.all()
    file_types = FileType.query.all()

    if (file.private == 1 and g.user is not None) or (file.private == 0):
        if file.type.name == 'Code':
            try:
                content = open(_get_path_in_upload(file.filename), 'r').read()
            except UnicodeDecodeError:
                flash('Error: file is binary, can\'t be displayed')
                content = 'Error'

            return render_template(
                'files/preview/code.html',
                file=file,
                categories=categories,
                file_types=file_types,
                content=content)

        if file.type.name == 'Image':
            return render_template(
                'files/preview/image.html',
                file=file,
                categories=categories,
                file_types=file_types)

        return render_template(
            'files/preview/default.html',
            file=file,
            categories=categories,
            file_types=file_types)

    return abort(404)


@bp.route('/rename/<int:file_id>', methods=['POST'])
@admin_required
def rename_file(file_id):
    file = File.query.get(file_id)

    new_name = request.form['new_name'].lower()
    extension = file.filename.rsplit('.', 1)[1].lower()

    if "." in new_name and _get_extension(new_name):
        new_name = new_name.rsplit('.', 1)[0] + '.' + extension
    else:
        new_name = new_name + '.' + extension

    _rename_file(file, new_name)

    return redirect(url_for('files.preview_file', file_id=file.id))


@bp.route('/recategorize/<int:file_id>', methods=['POST'])
@admin_required
def recategorize(file_id):
    file = File.query.get(file_id)

    if 'new_category' not in request.form:
        flash('No category selected')
        return redirect(request.url)

    new_category = Category.query.get(request.form['new_category'])
    if new_category is None:
        flash('The category selected won\'t exists')
        return redirect(request.url)

    file.category_id = new_category.id
    db.session.commit()

    return redirect(url_for('files.preview_file', file_id=file.id))


@bp.route('/retype/<int:file_id>', methods=['POST'])
@admin_required
def retype(file_id):
    file = File.query.get(file_id)

    if 'new_type' not in request.form:
        flash('No type selected')
        return redirect(request.url)

    new_type = FileType.query.get(request.form['new_type'])
    if new_type is None:
        flash('The file type selected won\'t exists')
        return redirect(request.url)

    file.file_type_id = new_type.id
    db.session.commit()

    return redirect(url_for('files.preview_file', file_id=file.id))


@bp.route('/delete/<int:file_id>', methods=['POST'])
@admin_required
def delete_file(file_id):
    file = File.query.get(file_id)
    _delete_file(file)
    return redirect(url_for('index'))