net.c

// Copyright (c) 2023 Cesanta Software Limited
// All rights reserved

#include "net.h"
#include "blink.h"

// Event log entry
struct event {
  int type, prio;
  unsigned long timestamp;
  const char *text;
};

// Settings
struct settings {
  bool log_enabled;
  int log_level;
  long brightness;
  char *device_name;
};

static struct settings s_settings = {true, 1, 57, NULL};

// Mocked events
static struct event s_events[] = {
    {.type = 0, .prio = 0, .text = "here goes event 1"},
    {.type = 1, .prio = 2, .text = "event 2..."},
    {.type = 2, .prio = 1, .text = "another event"},
    {.type = 1, .prio = 1, .text = "something happened!"},
    {.type = 2, .prio = 0, .text = "once more..."},
    {.type = 2, .prio = 0, .text = "more again..."},
    {.type = 1, .prio = 1, .text = "oops. it happened again"},
};

static const char *s_json_header =
    "Content-Type: application/json\r\n"
    "Cache-Control: no-cache\r\n";
static uint64_t s_boot_timestamp = 0;  // Updated by SNTP

// Certificate generation procedure:
// openssl ecparam -name prime256v1 -genkey -noout -out key.pem
// openssl req -new -key key.pem -x509 -nodes -days 3650 -out cert.pem
static const char *s_ssl_cert =
    "-----BEGIN CERTIFICATE-----\n"
    "MIIBCTCBsAIJAK9wbIDkHnAoMAoGCCqGSM49BAMCMA0xCzAJBgNVBAYTAklFMB4X\n"
    "DTIzMDEyOTIxMjEzOFoXDTMzMDEyNjIxMjEzOFowDTELMAkGA1UEBhMCSUUwWTAT\n"
    "BgcqhkjOPQIBBggqhkjOPQMBBwNCAARzSQS5OHd17lUeNI+6kp9WYu0cxuEIi/JT\n"
    "jphbCmdJD1cUvhmzM9/phvJT9ka10Z9toZhgnBq0o0xfTQ4jC1vwMAoGCCqGSM49\n"
    "BAMCA0gAMEUCIQCe0T2E0GOiVe9KwvIEPeX1J1J0T7TNacgR0Ya33HV9VgIgNvdn\n"
    "aEWiBp1xshs4iz6WbpxrS1IHucrqkZuJLfNZGZI=\n"
    "-----END CERTIFICATE-----\n";

static const char *s_ssl_key =
    "-----BEGIN EC PRIVATE KEY-----\n"
    "MHcCAQEEICBz3HOkQLPBDtdknqC7k1PNsWj6HfhyNB5MenfjmqiooAoGCCqGSM49\n"
    "AwEHoUQDQgAEc0kEuTh3de5VHjSPupKfVmLtHMbhCIvyU46YWwpnSQ9XFL4ZszPf\n"
    "6YbyU/ZGtdGfbaGYYJwatKNMX00OIwtb8A==\n"
    "-----END EC PRIVATE KEY-----\n";

static int event_next(int no, struct event *e) {
  if (no < 0 || no >= (int) (sizeof(s_events) / sizeof(s_events[0]))) return 0;
  *e = s_events[no];
  return no + 1;
}

// SNTP connection event handler. When we get a response from an SNTP server,
// adjust s_boot_timestamp. We'll get a valid time from that point on
static void sfn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
  uint64_t *expiration_time = (uint64_t *) c->data;
  if (ev == MG_EV_OPEN) {
    *expiration_time = mg_millis() + 3000;  // Store expiration time in 3s
  } else if (ev == MG_EV_SNTP_TIME) {
    uint64_t t = *(uint64_t *) ev_data;
    s_boot_timestamp = t - mg_millis();
    c->is_closing = 1;
  } else if (ev == MG_EV_POLL) {
    if (mg_millis() > *expiration_time) c->is_closing = 1;
  }
  (void) fn_data;
}

static void timer_sntp_fn(void *param) {  // SNTP timer function. Sync up time
  mg_sntp_connect(param, "udp://time.google.com:123", sfn, NULL);
}

static void handle_debug(struct mg_connection *c, struct mg_http_message *hm) {
  int level = mg_json_get_long(hm->body, "$.level", MG_LL_DEBUG);
  mg_log_set(level);
  mg_http_reply(c, 200, "", "Debug level set to %d\n", level);
}

static size_t print_int_arr(void (*out)(char, void *), void *ptr, va_list *ap) {
  size_t len = 0, num = va_arg(*ap, size_t);  // Number of items in the array
  int *arr = va_arg(*ap, int *);              // Array ptr
  for (size_t i = 0; i < num; i++) {
    len += mg_xprintf(out, ptr, "%s%d", i == 0 ? "" : ",", arr[i]);
  }
  return len;
}

static size_t print_events(void (*out)(char, void *), void *ptr, va_list *ap) {
  size_t len = 0;
  struct event e;
  int no = 0;
  while ((no = event_next(no, &e)) != 0) {
    len += mg_xprintf(out, ptr, "%s{%m:%lu,%m:%d,%m:%d,%m:%m}",  //
                      len == 0 ? "" : ",",                       //
                      MG_ESC("time"), e.timestamp,               //
                      MG_ESC("type"), e.type,                    //
                      MG_ESC("prio"), e.prio,                    //
                      MG_ESC("text"), MG_ESC(e.text));
  }
  (void) ap;
  return len;
}


static void handle_blink_get(struct mg_connection *c) {
  mg_http_reply(c, 200, s_json_header, "{%m:%d}", MG_ESC("count"), count);
}

// HTTP request handler function
static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
  if (ev == MG_EV_ACCEPT && fn_data != NULL) {
    struct mg_tls_opts opts = {.cert = s_ssl_cert, .certkey = s_ssl_key};
    mg_tls_init(c, &opts);
  } else if (ev == MG_EV_HTTP_MSG) {
    struct mg_http_message *hm = (struct mg_http_message *) ev_data;

    // Match API routes.
    if (mg_http_match_uri(hm, "/api/blink")) {
      handle_blink_get(c);
    } 
    else {
      struct mg_http_serve_opts opts;
      memset(&opts, 0, sizeof(opts));
#if MG_ENABLE_PACKED_FS
      opts.root_dir = "/web_root";
      opts.fs = &mg_fs_packed;
#else
      opts.root_dir = "web_root";
#endif
      mg_http_serve_dir(c, ev_data, &opts);
    }
    MG_DEBUG(("%lu %.*s %.*s -> %.*s", c->id, (int) hm->method.len,
              hm->method.ptr, (int) hm->uri.len, hm->uri.ptr, (int) 3,
              &c->send.buf[9]));
  }
}

void web_init(struct mg_mgr *mgr) {
  s_settings.device_name = strdup("My Device");

  mg_http_listen(mgr, HTTP_URL, fn, NULL);
#if MG_ENABLE_MBEDTLS || MG_ENABLE_OPENSSL
  mg_http_listen(mgr, HTTPS_URL, fn, "");
#endif

  // mg_timer_add(c->mgr, 1000, MG_TIMER_REPEAT, timer_mqtt_fn, c->mgr);
  mg_timer_add(mgr, 3600 * 1000, MG_TIMER_RUN_NOW | MG_TIMER_REPEAT,
               timer_sntp_fn, mgr);
}