/*
  This file is part of TALER
  Copyright (C) 2018, 2019, 2020 Taler Systems SA

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU Lesser General Public License as published by the Free Software
  Foundation; either version 2.1, or (at your option) any later version.

  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License along with
  TALER; see the file COPYING.LGPL.  If not, see
  <http://www.gnu.org/licenses/>
*/
/**
 * @file merchant_api_merchant_get_order.c
 * @brief Implementation of the GET /private/orders/$ORDER request
 * @author Christian Grothoff
 * @author Marcello Stanisci
 * @author Florian Dold
 */
#include "platform.h"
#include <curl/curl.h>
#include <jansson.h>
#include <microhttpd.h> /* just for HTTP status codes */
#include <gnunet/gnunet_util_lib.h>
#include <gnunet/gnunet_curl_lib.h>
#include "taler_merchant_service.h"
#include <taler/taler_json_lib.h>
#include <taler/taler_signatures.h>


/**
 * @brief A GET /private/orders/$ORDER handle
 */
struct TALER_MERCHANT_OrderMerchantGetHandle
{

  /**
   * The url for this request.
   */
  char *url;

  /**
   * Handle for the request.
   */
  struct GNUNET_CURL_Job *job;

  /**
   * Function to call with the result.
   */
  TALER_MERCHANT_OrderMerchantGetCallback cb;

  /**
   * Closure for @a cb.
   */
  void *cb_cls;

  /**
   * Reference to the execution context.
   */
  struct GNUNET_CURL_Context *ctx;
};


/**
 * Function called when we're done processing the GET /private/orders/$ORDER
 * request and we got an HTTP status of OK and the order was unpaid. Parse
 * the response and call the callback.
 *
 * @param omgh handle for the request
 * @param[in,out] hr HTTP response we got
 */
static void
handle_unpaid (struct TALER_MERCHANT_OrderMerchantGetHandle *omgh,
               struct TALER_MERCHANT_HttpResponse *hr)
{
  const char *taler_pay_uri
    = json_string_value (json_object_get (hr->reply,
                                          "taler_pay_uri"));
  const char *already_paid_order_id
    = json_string_value (json_object_get (hr->reply,
                                          "already_paid_order_id"));
  if (NULL == taler_pay_uri)
  {
    GNUNET_break_op (0);
    hr->http_status = 0;
    hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
    omgh->cb (omgh->cb_cls,
              hr,
              NULL);
    return;
  }
  {
    struct TALER_MERCHANT_OrderStatusResponse osr = {
      .status = TALER_MERCHANT_OSC_UNPAID,
      .details.unpaid.taler_pay_uri = taler_pay_uri,
      .details.unpaid.already_paid_order_id = already_paid_order_id
    };

    omgh->cb (omgh->cb_cls,
              hr,
              &osr);
  }
}


/**
 * Function called when we're done processing the GET /private/orders/$ORDER
 * request and we got an HTTP status of OK and the order was claimed but not
 * paid. Parse the response and call the callback.
 *
 * @param omgh handle for the request
 * @param[in,out] hr HTTP response we got
 */
static void
handle_claimed (struct TALER_MERCHANT_OrderMerchantGetHandle *omgh,
                struct TALER_MERCHANT_HttpResponse *hr)
{
  struct TALER_MERCHANT_OrderStatusResponse osr = {
    .status = TALER_MERCHANT_OSC_CLAIMED
  };
  struct GNUNET_JSON_Specification spec[] = {
    GNUNET_JSON_spec_json ("contract_terms",
                           (json_t **) &osr.details.claimed.contract_terms),
    GNUNET_JSON_spec_end ()
  };

  if (GNUNET_OK !=
      GNUNET_JSON_parse (hr->reply,
                         spec,
                         NULL, NULL))
  {
    GNUNET_break_op (0);
    hr->http_status = 0;
    hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
    omgh->cb (omgh->cb_cls,
              hr,
              NULL);
    return;
  }
  omgh->cb (omgh->cb_cls,
            hr,
            &osr);
  GNUNET_JSON_parse_free (spec);
}


/**
 * Function called when we're done processing the GET /private/orders/$ORDER
 * request and we got an HTTP status of OK and the order was paid. Parse
 * the response and call the callback.
 *
 * @param omgh handle for the request
 * @param[in,out] hr HTTP response we got
 */
static void
handle_paid (struct TALER_MERCHANT_OrderMerchantGetHandle *omgh,
             struct TALER_MERCHANT_HttpResponse *hr)
{
  uint32_t ec32;
  uint32_t hc32;
  json_t *wire_details;
  json_t *wire_reports;
  json_t *refund_details;
  struct TALER_MERCHANT_OrderStatusResponse osr = {
    .status = TALER_MERCHANT_OSC_PAID
  };
  struct GNUNET_JSON_Specification spec[] = {
    GNUNET_JSON_spec_bool ("refunded",
                           &osr.details.paid.refunded),
    GNUNET_JSON_spec_bool ("refund_pending",
                           &osr.details.paid.refund_pending),
    GNUNET_JSON_spec_bool ("wired",
                           &osr.details.paid.wired),
    TALER_JSON_spec_amount ("deposit_total",
                            &osr.details.paid.deposit_total),
    GNUNET_JSON_spec_uint32 ("exchange_ec",
                             &ec32),
    GNUNET_JSON_spec_uint32 ("exchange_hc",
                             &hc32),
    TALER_JSON_spec_amount ("refund_amount",
                            &osr.details.paid.refund_amount),
    GNUNET_JSON_spec_json ("contract_terms",
                           (json_t **) &osr.details.paid.contract_terms),
    GNUNET_JSON_spec_json ("wire_details",
                           &wire_details),
    GNUNET_JSON_spec_json ("wire_reports",
                           &wire_reports),
    GNUNET_JSON_spec_json ("refund_details",
                           &refund_details),
    GNUNET_JSON_spec_end ()
  };

  if (GNUNET_OK !=
      GNUNET_JSON_parse (hr->reply,
                         spec,
                         NULL, NULL))
  {
    GNUNET_break_op (0);
    hr->http_status = 0;
    hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
    omgh->cb (omgh->cb_cls,
              hr,
              NULL);
    return;
  }
  if (! (json_is_array (wire_details) &&
         json_is_array (wire_reports) &&
         json_is_array (refund_details) &&
         json_is_object (osr.details.paid.contract_terms)) )
  {
    GNUNET_break_op (0);
    hr->http_status = 0;
    hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
    omgh->cb (omgh->cb_cls,
              hr,
              NULL);
    GNUNET_JSON_parse_free (spec);
    return;
  }
  osr.details.paid.exchange_ec = (enum TALER_ErrorCode) ec32;
  osr.details.paid.exchange_hc = (unsigned int) hc32;
  {
    unsigned int wts_len = json_array_size (wire_details);
    unsigned int wrs_len = json_array_size (wire_reports);
    unsigned int ref_len = json_array_size (refund_details);
    struct TALER_MERCHANT_WireTransfer wts[wts_len];
    struct TALER_MERCHANT_WireReport wrs[wrs_len];
    struct TALER_MERCHANT_RefundOrderDetail ref[ref_len];

    for (unsigned int i = 0; i<wts_len; i++)
    {
      struct TALER_MERCHANT_WireTransfer *wt = &wts[i];
      const json_t *w = json_array_get (wire_details,
                                        i);
      struct GNUNET_JSON_Specification ispec[] = {
        GNUNET_JSON_spec_string ("exchange_url",
                                 &wt->exchange_url),
        GNUNET_JSON_spec_fixed_auto ("wtid",
                                     &wt->wtid),
        TALER_JSON_spec_absolute_time ("execution_time",
                                       &wt->execution_time),
        TALER_JSON_spec_amount ("amount",
                                &wt->total_amount),
        GNUNET_JSON_spec_bool ("confirmed",
                               &wt->confirmed),
        GNUNET_JSON_spec_end ()
      };

      if (GNUNET_OK !=
          GNUNET_JSON_parse (w,
                             ispec,
                             NULL, NULL))
      {
        GNUNET_break_op (0);
        hr->http_status = 0;
        hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
        omgh->cb (omgh->cb_cls,
                  hr,
                  NULL);
        GNUNET_JSON_parse_free (spec);
        return;
      }
    }

    for (unsigned int i = 0; i<wrs_len; i++)
    {
      struct TALER_MERCHANT_WireReport *wr = &wrs[i];
      const json_t *w = json_array_get (wire_reports, i);
      uint32_t c32;
      uint32_t eec32;
      uint32_t ehs32;
      struct GNUNET_JSON_Specification ispec[] = {
        GNUNET_JSON_spec_uint32 ("code",
                                 &c32),
        GNUNET_JSON_spec_string ("hint",
                                 &wr->hint), /* FIXME: should return "detail" instead! */
        GNUNET_JSON_spec_uint32 ("exchange_ec",
                                 &eec32),
        GNUNET_JSON_spec_uint32 ("exchange_hc",
                                 &ehs32),
        GNUNET_JSON_spec_fixed_auto ("coin_pub",
                                     &wr->coin_pub),
        GNUNET_JSON_spec_end ()
      };

      if (GNUNET_OK !=
          GNUNET_JSON_parse (w,
                             ispec,
                             NULL, NULL))
      {
        GNUNET_break_op (0);
        hr->http_status = 0;
        hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
        omgh->cb (omgh->cb_cls,
                  hr,
                  NULL);
        GNUNET_JSON_parse_free (spec);
        return;
      }
      wr->code = (enum TALER_ErrorCode) c32;
      wr->hr.ec = (enum TALER_ErrorCode) eec32;
      wr->hr.http_status = (unsigned int) ehs32;
    }

    for (unsigned int i = 0; i<ref_len; i++)
    {
      struct TALER_MERCHANT_RefundOrderDetail *ro = &ref[i];
      const json_t *w = json_array_get (refund_details,
                                        i);
      struct GNUNET_JSON_Specification ispec[] = {
        TALER_JSON_spec_amount ("amount",
                                &ro->refund_amount),
        GNUNET_JSON_spec_string ("reason",
                                 &ro->reason),
        TALER_JSON_spec_absolute_time ("timestamp",
                                       &ro->refund_time),
        GNUNET_JSON_spec_end ()
      };

      if (GNUNET_OK !=
          GNUNET_JSON_parse (w,
                             ispec,
                             NULL, NULL))
      {
        GNUNET_break_op (0);
        hr->http_status = 0;
        hr->ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
        omgh->cb (omgh->cb_cls,
                  hr,
                  NULL);
        GNUNET_JSON_parse_free (spec);
        return;
      }
    }

    osr.details.paid.wts = wts;
    osr.details.paid.wts_len = wts_len;
    osr.details.paid.wrs = wrs;
    osr.details.paid.wrs_len = wrs_len;
    osr.details.paid.refunds = ref;
    osr.details.paid.refunds_len = ref_len;
    omgh->cb (omgh->cb_cls,
              hr,
              &osr);
  }
  GNUNET_JSON_parse_free (spec);
}


/**
 * Function called when we're done processing the GET /private/orders/$ORDER
 * request.
 *
 * @param cls the `struct TALER_MERCHANT_OrderMerchantGetHandle`
 * @param response_code HTTP response code, 0 on error
 * @param response response body, NULL if not in JSON
 */
static void
handle_merchant_order_get_finished (void *cls,
                                    long response_code,
                                    const void *response)
{
  struct TALER_MERCHANT_OrderMerchantGetHandle *omgh = cls;
  const json_t *json = response;
  const char *order_status;
  struct TALER_MERCHANT_HttpResponse hr = {
    .http_status = (unsigned int) response_code,
    .reply = json
  };

  omgh->job = NULL;
  switch (response_code)
  {
  case MHD_HTTP_NOT_FOUND:
    hr.ec = TALER_JSON_get_error_code (json);
    hr.hint = TALER_JSON_get_error_hint (json);
    omgh->cb (omgh->cb_cls,
              &hr,
              NULL);
    TALER_MERCHANT_merchant_order_get_cancel (omgh);
    return;
  case MHD_HTTP_OK:
    /* see below */
    break;
  default:
    hr.ec = TALER_JSON_get_error_code (json);
    hr.hint = TALER_JSON_get_error_hint (json);
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "Polling payment failed with HTTP status code %u/%d\n",
                (unsigned int) response_code,
                (int) hr.ec);
    GNUNET_break_op (0);
    omgh->cb (omgh->cb_cls,
              &hr,
              NULL);
    TALER_MERCHANT_merchant_order_get_cancel (omgh);
    return;
  }

  order_status = json_string_value (json_object_get (json, "order_status"));

  if (NULL == order_status)
  {
    GNUNET_break_op (0);
    hr.http_status = 0;
    hr.ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
    omgh->cb (omgh->cb_cls,
              &hr,
              NULL);
    TALER_MERCHANT_merchant_order_get_cancel (omgh);
    return;
  }

  if (0 == strcmp ("paid", order_status))
  {
    handle_paid (omgh,
                 &hr);
  }
  else if (0 == strcmp ("claimed", order_status))
  {
    handle_claimed (omgh,
                    &hr);
  }
  else if (0 == strcmp ("unpaid", order_status))
  {
    handle_unpaid (omgh,
                   &hr);
  }
  else
  {
    GNUNET_break_op (0);
    hr.http_status = 0;
    hr.ec = TALER_EC_MERCHANT_ORDER_GET_REPLY_MALFORMED;
    omgh->cb (omgh->cb_cls,
              &hr,
              NULL);
    TALER_MERCHANT_merchant_order_get_cancel (omgh);
  }
}


struct TALER_MERCHANT_OrderMerchantGetHandle *
TALER_MERCHANT_merchant_order_get (struct GNUNET_CURL_Context *ctx,
                                   const char *backend_url,
                                   const char *order_id,
                                   const char *session_id,
                                   bool transfer,
                                   struct GNUNET_TIME_Relative timeout,
                                   TALER_MERCHANT_OrderMerchantGetCallback cb,
                                   void *cb_cls)
{
  struct TALER_MERCHANT_OrderMerchantGetHandle *omgh;
  unsigned long long tms;
  long tlong;

  GNUNET_assert (NULL != backend_url);
  GNUNET_assert (NULL != order_id);
  tms = (unsigned long long) (timeout.rel_value_us
                              / GNUNET_TIME_UNIT_MILLISECONDS.rel_value_us);
  /* set curl timeout to *our* long poll timeout plus one minute
     (for network latency and processing delays) */
  tlong = (long) (GNUNET_TIME_relative_add (timeout,
                                            GNUNET_TIME_UNIT_MINUTES).
                  rel_value_us
                  / GNUNET_TIME_UNIT_MILLISECONDS.rel_value_us);
  omgh = GNUNET_new (struct TALER_MERCHANT_OrderMerchantGetHandle);
  omgh->ctx = ctx;
  omgh->cb = cb;
  omgh->cb_cls = cb_cls;
  {
    char *path;
    char timeout_ms[32];

    GNUNET_snprintf (timeout_ms,
                     sizeof (timeout_ms),
                     "%llu",
                     tms);
    GNUNET_asprintf (&path,
                     "private/orders/%s",
                     order_id);
    omgh->url = TALER_url_join (backend_url,
                                path,
                                "session_id", session_id,
                                "transfer", transfer ? "YES" : "NO",
                                (0 != tms) ? "timeout_ms" : NULL,
                                timeout_ms,
                                NULL);
  }
  if (NULL == omgh->url)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Could not construct request URL.\n");
    GNUNET_free (omgh);
    return NULL;
  }

  {
    CURL *eh;

    eh = curl_easy_init ();
    if (NULL == eh)
    {
      GNUNET_break (0);
      GNUNET_free (omgh->url);
      GNUNET_free (omgh);
      return NULL;
    }
    if (CURLE_OK != curl_easy_setopt (eh,
                                      CURLOPT_URL,
                                      omgh->url))
    {
      GNUNET_break (0);
      curl_easy_cleanup (eh);
      GNUNET_free (omgh->url);
      GNUNET_free (omgh);
      return NULL;
    }
    if (CURLE_OK != curl_easy_setopt (eh,
                                      CURLOPT_TIMEOUT_MS,
                                      tlong))
    {
      GNUNET_break (0);
      curl_easy_cleanup (eh);
      GNUNET_free (omgh->url);
      GNUNET_free (omgh);
      return NULL;
    }

    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                "Getting order status from %s\n",
                omgh->url);
    if (NULL == (omgh->job =
                   GNUNET_CURL_job_add (ctx,
                                        eh,
                                        &handle_merchant_order_get_finished,
                                        omgh)))
    {
      GNUNET_break (0);
      GNUNET_free (omgh->url);
      GNUNET_free (omgh);
      return NULL;
    }
  }
  return omgh;
}


void
TALER_MERCHANT_merchant_order_get_cancel (
  struct TALER_MERCHANT_OrderMerchantGetHandle *omgh)
{
  if (NULL != omgh->job)
  {
    GNUNET_CURL_job_cancel (omgh->job);
    omgh->job = NULL;
  }
  GNUNET_free (omgh->url);
  GNUNET_free (omgh);
}


/* end of merchant_api_merchant_get_order.c */