from collections import defaultdict
from datetime import datetime
from operator import itemgetter

from flask import abort, render_template, url_for
from werkzeug.utils import redirect

from app import format_date_numeric, provider_client
from app.main import main
from app.main.forms import ProviderForm, ProviderRatioForm
from app.utils import user_is_platform_admin

PROVIDER_PRIORITY_MEANING_SWITCHOVER = datetime(2019, 11, 29, 11, 0)


@main.route("/providers")
@user_is_platform_admin
def view_providers():
    providers = provider_client.get_all_providers()['provider_details']
    domestic_email_providers, domestic_sms_providers, intl_sms_providers = [], [], []
    for provider in providers:
        if provider['notification_type'] == 'sms':
            domestic_sms_providers.append(provider)
            if provider.get('supports_international', None):
                intl_sms_providers.append(provider)
        elif provider['notification_type'] == 'email':
            domestic_email_providers.append(provider)

    add_monthly_traffic(domestic_sms_providers)

    return render_template(
        'views/providers/providers.html',
        email_providers=domestic_email_providers,
        domestic_sms_providers=domestic_sms_providers,
        intl_sms_providers=intl_sms_providers
    )


def add_monthly_traffic(domestic_sms_providers):
    total_sms_sent = sum(provider['current_month_billable_sms'] for provider in domestic_sms_providers)

    for provider in domestic_sms_providers:
        percentage = (provider['current_month_billable_sms'] / total_sms_sent * 100) if total_sms_sent else 0
        provider['monthly_traffic'] = round(percentage)


@main.route("/provider/<uuid:provider_id>/edit", methods=['GET', 'POST'])
@user_is_platform_admin
def edit_provider(provider_id):
    provider = provider_client.get_provider_by_id(provider_id)['provider_details']
    form = ProviderForm(active=provider['active'], priority=provider['priority'])

    if form.validate_on_submit():
        provider_client.update_provider(provider_id, form.priority.data)
        return redirect(url_for('.view_providers'))

    return render_template('views/providers/edit-provider.html', form=form, provider=provider)


@main.route("/provider/edit-sms-provider-ratio", methods=['GET', 'POST'])
@user_is_platform_admin
def edit_sms_provider_ratio():

    providers = sorted([
        provider
        for provider in provider_client.get_all_providers()['provider_details']
        if provider['notification_type'] == 'sms'
    ], key=itemgetter('identifier'), reverse=True)

    form = ProviderRatioForm(ratio=providers[0]['priority'])

    if form.validate_on_submit():
        provider_client.update_provider(providers[0]['id'], form.percentage_left)
        provider_client.update_provider(providers[1]['id'], form.percentage_right)

    if len(providers) < 2:
        abort(400)

    return render_template(
        'views/providers/edit-sms-provider-ratio.html',
        versions=_chunk_versions_by_day(_get_versions(providers[0], providers[1])),
        form=form,
    )


def _get_versions(provider0, provider1):

    versions = sorted((
        provider_client.get_provider_versions(provider0['id'])['data'] +
        provider_client.get_provider_versions(provider1['id'])['data']
    ), key=lambda version: version['updated_at'] or '', reverse=True)

    for index, version in enumerate(versions):

        previous_version = get_previous_version(
            versions,
            index,
            version['identifier'],
        )

        if (
            (version['updated_at'] or '0') < str(PROVIDER_PRIORITY_MEANING_SWITCHOVER)
        ):
            version['priority'], previous_version['priority'] = (
                int(version['priority'] > previous_version['priority']),
                int(version['priority'] <= previous_version['priority'])
            )

        if version['identifier'] == provider0['identifier']:
            fresh_version = version.copy()
            fresh_version['other_provider'] = previous_version.copy()
            yield fresh_version
        elif previous_version['identifier'] in {provider0['identifier'], None}:
            fresh_version = previous_version.copy()
            fresh_version['other_provider'] = version.copy()
            yield fresh_version


def get_previous_version(versions, start_index, current_provider_identifier):
    for index, version in enumerate(versions):
        if index < start_index:
            continue
        if current_provider_identifier == version['identifier']:
            continue
        return version
    return {
        'identifier': None,
        'priority': 999,
        'updated_at': None,
    }


def _chunk_versions_by_day(versions):

    days = defaultdict(list)

    for version in sorted(versions, key=lambda version: version['updated_at'] or '', reverse=True):
        days[
            format_date_numeric(version['updated_at']) if version['updated_at'] else ''
        ].append(version)

    return sorted(days.items(), reverse=True)


@main.route("/provider/<uuid:provider_id>")
@user_is_platform_admin
def view_provider(provider_id):
    versions = provider_client.get_provider_versions(provider_id)
    return render_template('views/providers/provider.html', provider_versions=versions['data'])