/* Copyright (C) 2025 awy <awy@awy.one>

   stweath is free software: you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation,
   either version 3 of the License, or (at your option) any later version.

   stweath 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
   General Public License for more details.

   You should have received a copy of the GNU General Public
   License along with stweath. If not, see
   <https://www.gnu.org/licenses/>. */

#include <curl/curl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>

#include "../lib/cjson/cJSON.h"
#include "../lib/util.h"

typedef struct {
  int code;
  const char *icon;
} WeatherIcon;

const char
*geticon(int code)
{
  static const WeatherIcon icons[] = {
    {113, ""},
    {116, ""},
    {119, ""}, {122, ""}, {143, ""}, {248, ""}, {260, ""},
    {176, ""}, {179, ""}, {182, ""}, {185, ""}, {263, ""},
    {266, ""}, {281, ""}, {284, ""}, {293, ""}, {296, ""},
    {299, ""}, {302, ""}, {305, ""}, {308, ""}, {311, ""},
    {314, ""}, {317, ""}, {350, ""}, {353, ""}, {356, ""},
    {359, ""}, {362, ""}, {365, ""}, {368, ""}, {392, ""},
    {200, ""},
    {227, ""}, {230, ""}, {320, ""}, {323, ""}, {326, ""},
    {374, ""}, {377, ""}, {386, ""}, {389, ""},
    {329, ""}, {332, ""}, {335, ""}, {338, ""}, {371, ""}, {395, ""}
  };
  size_t n = sizeof(icons) / sizeof(icons[0]);
  for (size_t i = 0; i < n; i++) {
    if (icons[i].code == code) { return icons[i].icon; }
  }
  return "unknown";
}

int
getforecast(const char *path)
{
  FILE *fp;
  CURL* handle;
  CURLcode res;

  if (!(fp = fopen(path, "w")))
    die("failed to open report:");

  handle = curl_easy_init();

  if (!handle) {
    fclose(fp);
    die("failed to create curl handle");
  }

  curl_easy_setopt(handle, CURLOPT_URL, "https://wttr.in/?format=j1");
  curl_easy_setopt(handle, CURLOPT_WRITEFUNCTION, NULL);
  curl_easy_setopt(handle, CURLOPT_WRITEDATA, fp);

  res = curl_easy_perform(handle);

  if (res != CURLE_OK) {
    fclose(fp);
    die("curl failed");
  }

  curl_easy_cleanup(handle);

  fclose(fp);
  return 0;
}

int
showforecast(const char *path)
{
  FILE *fp;
  long size;
  char *data;
  const char *icon;
  cJSON *root, *temp, *wcode, *rain;

  if (!(fp = fopen(path, "rb")))
    die("fopen:");

  fseek(fp, 0, SEEK_END);
  size = ftell(fp);
  fseek(fp, 0, SEEK_SET);

  data = malloc(size + 1);
  if (!(data = malloc(size + 1))) {
    fclose(fp);
    die("failed to allocate memory");
  }

  fread(data, 1, size, fp);
  data[size] = '\0';
  fclose(fp);

  if (!(root = cJSON_Parse(data))) {
    free(data);
    die("failed to parse json");
  }

  rain = cJSON_GetArrayItem(cJSON_GetObjectItem(root, "weather"), 0);
  rain = cJSON_GetArrayItem(cJSON_GetObjectItem(rain, "hourly"), 0);
  rain = cJSON_GetObjectItem(rain, "chanceofrain");
  temp = cJSON_GetObjectItem(root, "current_condition");
  temp = cJSON_GetArrayItem(temp, 0);
  wcode = cJSON_GetObjectItem(temp, "weatherCode");
  temp = cJSON_GetObjectItem(temp, "temp_C");

  icon = geticon(atoi(wcode->valuestring));

  if (atoi(rain->valuestring) != 0)
    printf(" %s%% ", rain->valuestring);

  printf("%s %s°C", icon, temp->valuestring);

  cJSON_Delete(root);
  return 0;
}

int
checkforecast(const char *path)
{
  time_t now;
  char *buff;
  struct stat st;
  int tries, force;

  /* check if there is WEATHERFORCEUPDATE
     environment variable */
  force = 0;
  buff = getenv("WEATHERFORCEUPDATE");
  if (buff && buff[0] == '1') { force = 1; }

  if (access(path, F_OK) != -1) {
    if (stat(path, &st) != 0)
      die("failed to get modification time");
  } else {
    force = 1;
  }

  now = time(NULL);
  if (now == ((time_t)-1)) { return 1; }

  /* check if 30 mins passed
     then get new forecast */
  if (((now - st.st_mtime) >= 1800) || force) {
    tries = 0;
    /* try 100 fast retries */
    while (tries < 100) {
      if(getforecast(path) == 0) {
        break;
      }
      tries++;
      sleep(1);
    }
  }

  showforecast(path);
  return 0;
}

int
main(void)
{
  char *env;
  char path[1024];

  if (!(env = getenv("XDG_CACHE_HOME")))
    die("XDG_CACHE_HOME is not set");

  strcpy(path, env);
  strcat(path, "/weatherreport.json");

  curl_global_init(CURL_GLOBAL_ALL);

  checkforecast(path);

  curl_global_cleanup();
  return 0;
}