<?php
namespace Domain\Finances;

class FakturowniaApiClient
{
  private $baseUrl;
  private $apiToken;
  private $pageLimit;
  private $timeout;

  public function __construct( $baseUrl, $apiToken, $pageLimit = 100, $timeout = 20 )
  {
    $this -> baseUrl = rtrim( (string)$baseUrl, '/' );
    $this -> apiToken = (string)$apiToken;
    $this -> pageLimit = max( 1, (int)$pageLimit );
    $this -> timeout = max( 5, (int)$timeout );
  }

  public function fetchSalesDocuments( $startDate, $page = 1 )
  {
    $query = [
      'page' => (int)$page,
      'per_page' => $this -> pageLimit
    ];

    if ( $this -> canUseCurrentMonthPeriod( $startDate ) )
      $query['period'] = 'this_month';

    return $this -> requestList( '/invoices.json', $query );
  }

  public function fetchCostDocuments( $startDate, $page = 1 )
  {
    $queries = [
      [
        'page' => (int)$page,
        'per_page' => $this -> pageLimit,
        'income' => 'no'
      ]
    ];

    if ( $this -> canUseCurrentMonthPeriod( $startDate ) )
      $queries[0]['period'] = 'this_month';

    $paths = [ '/costs.json', '/expenses.json', '/invoices.json' ];

    foreach ( $paths as $path )
    {
      foreach ( $queries as $query )
      {
        $response = $this -> requestList( $path, $query, true );
        if ( $response['ok'] )
          return $response['data'];
      }
    }

    throw new \RuntimeException( 'Nie udalo sie pobrac faktur kosztowych z API Fakturowni.' );
  }

  public function fetchInvoiceDetails( $invoiceId )
  {
    $invoiceId = (int)$invoiceId;
    if ( $invoiceId <= 0 )
      return null;

    $result = $this -> request( '/invoices/' . $invoiceId . '.json', [] );
    if ( $result['http_code'] >= 400 )
      return null;

    $data = json_decode( $result['body'], true );
    return is_array( $data ) ? $data : null;
  }

  private function requestList( $path, $query, $softFail = false )
  {
    $result = $this -> request( $path, $query );

    if ( $result['http_code'] >= 400 )
    {
      if ( $softFail )
        return [ 'ok' => false, 'data' => [] ];

      throw new \RuntimeException( 'Blad API Fakturowni: HTTP ' . $result['http_code'] . ' dla ' . $path );
    }

    $data = json_decode( $result['body'], true );
    if ( !is_array( $data ) )
    {
      if ( $softFail )
        return [ 'ok' => false, 'data' => [] ];

      throw new \RuntimeException( 'API Fakturowni zwrocilo niepoprawny JSON.' );
    }

    $list = $this -> extractList( $data );
    return $softFail ? [ 'ok' => true, 'data' => $list ] : $list;
  }

  private function request( $path, $query )
  {
    $query['api_token'] = $this -> apiToken;
    $url = $this -> baseUrl . $path . '?' . http_build_query( $query );

    $ch = curl_init( $url );
    curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
    curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT, $this -> timeout );
    curl_setopt( $ch, CURLOPT_TIMEOUT, $this -> timeout );
    curl_setopt( $ch, CURLOPT_HTTPHEADER, [
      'Accept: application/json'
    ] );

    $body = curl_exec( $ch );
    $httpCode = (int)curl_getinfo( $ch, CURLINFO_HTTP_CODE );
    $error = curl_error( $ch );
    curl_close( $ch );

    if ( $body === false )
      throw new \RuntimeException( 'Blad polaczenia z API Fakturowni: ' . $error );

    return [
      'http_code' => $httpCode,
      'body' => $body
    ];
  }

  private function extractList( $data )
  {
    if ( $this -> isList( $data ) )
      return $data;

    $keys = [ 'invoices', 'costs', 'expenses', 'data' ];
    foreach ( $keys as $key )
    {
      if ( isset( $data[ $key ] ) && is_array( $data[ $key ] ) )
      {
        if ( $this -> isList( $data[ $key ] ) )
          return $data[ $key ];
      }
    }

    return [];
  }

  private function isList( $value )
  {
    if ( !is_array( $value ) )
      return false;

    if ( $value === [] )
      return true;

    return array_keys( $value ) === range( 0, count( $value ) - 1 );
  }

  private function canUseCurrentMonthPeriod( $startDate )
  {
    if ( !is_string( $startDate ) || !preg_match( '/^\d{4}-\d{2}-\d{2}$/', $startDate ) )
      return false;

    return $startDate === date( 'Y-m-01' );
  }
}