<?php

use League\Csv\Writer;

add_action('rest_api_init', 'podlove_analytics_api_init');

function podlove_analytics_api_init()
{
    $args = [
        'format' => [
            'sanitize_callback' => function ($param, $request, $key) {
                return $param == 'csv' ? 'csv' : 'json';
            },
            'default' => 'json',
        ],
    ];

    register_rest_route('podlove/v1', 'analytics/episodes', [
        'methods' => 'GET',
        'callback' => 'podlove_api_analytics_episodes',
        'permission_callback' => 'podlove_api_analytics_permission_callback',
        'args' => $args,
    ]);
    register_rest_route('podlove/v1', 'analytics/episodes/(?P<id>[\d]+)', [
        'methods' => 'GET',
        'callback' => 'podlove_api_analytics_episode',
        'permission_callback' => 'podlove_api_analytics_permission_callback',
        'args' => $args,
    ]);
    register_rest_route('podlove/v1', 'analytics/episodes/(?P<ids>[\d]+,[\d,]+)', [
        'methods' => 'GET',
        'callback' => 'podlove_api_analytics_episodes_selected',
        'permission_callback' => 'podlove_api_analytics_permission_callback',
        'args' => $args,
    ]);

    register_rest_route('podlove/v2', 'analytics/episodes', [
        'methods' => 'GET',
        'callback' => 'podlove_api_analytics_episodes',
        'permission_callback' => 'podlove_api_analytics_permission_callback',
        'args' => $args,
    ]);
    register_rest_route('podlove/v2', 'analytics/episodes/(?P<id>[\d]+)', [
        'methods' => 'GET',
        'callback' => 'podlove_api_analytics_episode',
        'permission_callback' => 'podlove_api_analytics_permission_callback',
        'args' => $args,
    ]);
    register_rest_route('podlove/v2', 'analytics/episodes/(?P<ids>[\d]+,[\d,]+)', [
        'methods' => 'GET',
        'callback' => 'podlove_api_analytics_episodes_selected',
        'permission_callback' => 'podlove_api_analytics_permission_callback',
        'args' => $args,
    ]);
}

function podlove_api_analytics_permission_callback($request)
{
    if (!current_user_can('podlove_read_analytics')) {
        return new WP_Error(
            'rest_forbidden',
            esc_html__('You cannot view the analytics resource.'),
            ['status' => \Podlove\Api\Permissons::authorization_status_code()]
        );
    }

    return true;
}

function podlove_api_csv_response($data)
{
    header('Content-Type: text/csv');
    header('Content-Disposition: attachment; filename=podlove-episode-downloads.csv');

    $csv = Writer::createFromFileObject(new \SplTempFileObject());
    // $csv->setEncodingFrom('utf-8');

    $headers = array_keys($data[0]);
    $csv->insertOne($headers);

    $csv->insertAll($data);

    echo $csv;
    exit;
}

function podlove_api_analytics_episodes(WP_REST_Request $request)
{
    $data = \Podlove\Downloads_List_Data::get_data();

    if ($request->get_param('format') == 'csv') {
        podlove_api_csv_response($data);
    } else {
        $data = array_map('podlove_api_analytics_prepare_episode', $data);

        return new WP_REST_Response($data);
    }
}

function podlove_api_analytics_episodes_selected(WP_REST_Request $request)
{
    $ids = explode(',', $request['ids']);
    $ids = array_map(function ($id) {
        return (int) trim($id);
    }, $ids);

    $data = \Podlove\Downloads_List_Data::get_data();

    $data = array_filter($data, function ($row) use ($ids) {
        return in_array($row['post_id'], $ids);
    });
    $data = array_values($data);

    if ($request->get_param('format') == 'csv') {
        podlove_api_csv_response($data);
    } else {
        $data = array_map('podlove_api_analytics_prepare_episode', $data);

        return new WP_REST_Response($data);
    }
}

function podlove_api_analytics_episode(WP_REST_Request $request)
{
    $id = (int) $request['id'];
    $post = get_post($id);

    if (empty($post)) {
        return new WP_REST_Response([], 404);
    }

    $data = \Podlove\Downloads_List_Data::get_data();
    $data = array_map('podlove_api_analytics_prepare_episode', $data);

    $data = array_filter($data, function ($row) use ($id) {
        return $row['post_id'] == $id;
    });
    $data = array_values($data);

    if ($request->get_param('format') == 'csv') {
        podlove_api_csv_response($data);
    } else {
        $data = array_map('podlove_api_analytics_prepare_episode', $data);

        return new WP_REST_Response($data[0]);
    }
}

function podlove_api_analytics_prepare_episode($item)
{
    $item['_links'] = [
        'self' => rest_url('podlove/v1/analytics/episodes/'.$item['post_id']),
        'podlove:episode' => rest_url('wp/v2/episodes/'.$item['post_id']),
    ];

    return $item;
}