deals.c

/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2026 Pedro H. M. Tashima
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <jansson.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/_pthread/_pthread_mutex_t.h>

#include "../papago.h"

static papago_t *server = NULL;

typedef struct {
  char name[64];
  char category[64];
} deal_t;

#define MAX_RECORDS 100

typedef struct {
  deal_t records[MAX_RECORDS];
  size_t count;
  pthread_mutex_t mu;
} deals_store_t;

void init_store(deals_store_t *store) {
  store->count = 0;
  memset(store->records, 0, sizeof(store->records));
  pthread_mutex_init(&store->mu, NULL);
}

int add_deal(deals_store_t *store, char *name, char *category) {
  pthread_mutex_lock(&store->mu);

  if (store->count >= MAX_RECORDS) {
    pthread_mutex_unlock(&store->mu);
    return -1;
  }

  int idx = store->count;
  strncpy(store->records[idx].name, name, sizeof(store->records[idx].name) - 1);
  strncpy(store->records[idx].category, category,
          sizeof(store->records[idx].category) - 1);
  store->count++;

  pthread_mutex_unlock(&store->mu);
  return 0;
}

/**
 * Signal handler for graceful shutdown.
 */
static void signal_handler(int sig) {
  PAPAGO_UNUSED(sig);

  printf("\nShutting down...\n");
  if (server != NULL) {
    papago_stop(server);
  }
}

// HTTP route handlers

void api_list_deals_handler(papago_request_t *req, papago_response_t *res,
                            void *user_data) {
  PAPAGO_UNUSED(req);

  deals_store_t *store = (deals_store_t *)user_data;

  pthread_mutex_lock(&store->mu);

  if (!store) {
    papago_res_status(res, PAPAGO_STATUS_INTERNAL_ERROR);
    papago_res_json(res, "{\"error\": \"internal server error\"}");
    pthread_mutex_unlock(&store->mu);
    return;
  }

  json_t *json_arr = json_array();
  if (!json_arr) {
    papago_res_status(res, PAPAGO_STATUS_INTERNAL_ERROR);
    papago_res_json(res, "{\"error\": \"internal server error\"}");
    pthread_mutex_unlock(&store->mu);
    return;
  }

  for (size_t i = 0; i < store->count; ++i) {
      json_t *record_obj = json_pack("{s:s, s:s}", 
                                    "name", store->records[i].name,
                                    "category", store->records[i].category);
      if (record_obj) {
          json_array_append_new(json_arr, record_obj);
      }
  }

  char *json_str = json_dumps(json_arr, JSON_COMPACT);

  if (json_str) {
    papago_res_status(res, PAPAGO_STATUS_OK);
    papago_res_json(res, json_str);
    free(json_str);
  }

  json_decref(json_arr);
  pthread_mutex_unlock(&store->mu);
}

void api_add_deal_handler(papago_request_t *req, papago_response_t *res,
                          void *user_data) {
  PAPAGO_UNUSED(req);

  deals_store_t *store = (deals_store_t *)user_data;

  const char *body = papago_req_body(req);
  if (body == NULL) {
    papago_res_status(res, PAPAGO_STATUS_BAD_REQUEST);
    papago_res_json(res, "{\"error\":\"Missing request body\"}");
    return;
  }

  json_error_t error;
  json_t *root = json_loads(body, 0, &error);

  if (!root) {
    fprintf(stderr, "JSON Parse Error on line %d: %s\n", error.line, error.text);
    papago_res_status(res, PAPAGO_STATUS_BAD_REQUEST);
    papago_res_json(res, "{\"error\":\"Invalid JSON format\"}");
    return;
  }

  // int *id = NULL;
  char *name = NULL;
  char *category = NULL;

  if (json_unpack(root, "{s:s, s:s}", "name", &name, "category", &category) != 0) {
    fprintf(stderr, "JSON Parse Error on line %d: %s\n", error.line, error.text);
    papago_res_status(res, PAPAGO_STATUS_BAD_REQUEST);
    papago_res_json(res, "{\"error\":\"missing or invalid 'id', 'name' or 'category' strings\"}");
    
    json_decref(root);
    return;
  }

  if (add_deal(store, name, category) != 0) {
    papago_res_status(res, PAPAGO_STATUS_INTERNAL_ERROR);
    papago_res_json(res, "{\"error\":\"failed to save deal\"}");
    
    json_decref(root);
    return;
  }

  papago_res_status(res, PAPAGO_STATUS_OK);
  papago_res_json(res, "{\"message\":\"Item successfully parsed!\"}");

  json_decref(root);
}

int main(void) {
  // setup signal handling
  signal(SIGINT, signal_handler);
  signal(SIGTERM, signal_handler);

  // create server
  server = papago_new();
  if (server == NULL) {
    fprintf(stderr, "failed to create server\n");
    return 1;
  }

  papago_config_t config = papago_default_config();
  config.port = 8282;
  config.enable_logging = true;
  papago_configure(server, &config);

  deals_store_t *store = malloc(sizeof(deals_store_t) * MAX_RECORDS);
  init_store(store);

  // register HTTP routes
  papago_get(server, "/api/deals", api_list_deals_handler, store);
  papago_post(server, "/api/deal", api_add_deal_handler, store);

  printf("Server starting on:\n");
  printf("  HTTP:      http://%s:%d\n", config.host, config.port);

  printf("curl http://%s:%d/api/deals\n", config.host, config.port);

  // start server (blocking)
  if (papago_start(server) != 0) {
    fprintf(stderr, "%s\n", papago_error(server));
    papago_destroy(server);

    return 1;
  }

  // cleanup
  papago_destroy(server);

  return 0;
}