"""Application Handlers.

Requests are redirected to handlers, which are responsible for getting
information from the URL and passing it down to the logic layer. The way
each layer talks to each other is through Response objects which defines the
type status of the data and the data itself.

Please note: the Orchard uses the term handlers over views as convention
for clarity

See:
    oto.response for more details.
"""

import traceback

import boto3

from flask import g
from flask import jsonify
from flask import request

from owsresponse import response
from owsresponse.adaptors.flask import flaskify

from personalize import config
from personalize.api import app
from personalize.logic import spotify

PERSONALIZE_RUNTIME = boto3.client(
    'personalize-runtime',
    region_name='us-east-2'
)


@app.route('/track_list', methods=['GET'])
def generate_playlist():
    """Generate a playlist."""
    try:
        item_list = []
        algorithm = request.args.get('algorithm')
        campaign_arn = request.args.get('arn')
        num_results = 50
        if algorithm == 'sims':
            item_id = request.args.get('item_id')
            recommendations_response = PERSONALIZE_RUNTIME.get_recommendations(
                campaignArn=campaign_arn,
                itemId=item_id,
                numResults=num_results
            )
            item_list = recommendations_response['itemList']
        elif algorithm == 'hrnn':
            user_id = request.args.get('user_id')
            recommendations_response = PERSONALIZE_RUNTIME.get_recommendations(
                campaignArn=campaign_arn,
                userId=user_id,
                numResults=num_results
            )
            item_list = recommendations_response['itemList']
        artist_removed_track_list = spotify.remove_submitted_artist(
            item_id, item_list)
        deduped_artist_track_list = spotify.remove_duplicate_artists(
            artist_removed_track_list)
        response = jsonify(deduped_artist_track_list)
        response.headers.add('Access-Control-Allow-Origin', '*')
        return response
    except:  # noqa
        return traceback.format_exc()


@app.route(config.HEALTH_CHECK, methods=['GET'])
def health():
    """Check the health of the application."""
    return jsonify({'status': 'ok'})


@app.errorhandler(500)
def exception_handler(error):
    """Handle error when uncaught exception is raised.

    Default exception handler.
    Note: Exception will also be sent to Sentry if config.SENTRY is set.

    Returns:
        flask.Response: A 500 response with JSON 'code' & 'message' payload.
    """
    message = (
        'The server encountered an internal error '
        'and was unable to complete your request.')
    g.log.exception(error)
    return flaskify(response.create_fatal_response(message))