#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <time.h>
#include "mongoose.h"

static void send_file(struct mg_connection *conn, const char *path) {
  char buf[1024];
  struct stat st;
  int n;
  FILE *fp;

  if (stat(path, &st) == 0 && (fp = fopen(path, "rb")) != NULL) {
    mg_printf(conn, "--myboundary\r\nContent-Type: image/jpeg\r\n"
              "Content-Length: %llu\r\n\r\n", (unsigned long long) st.st_size);
    while ((n = fread(buf, 1, sizeof(buf), fp)) > 0) {
      mg_write(conn, buf, n);
    }
    fclose(fp);
    mg_write(conn, "\r\n", 2);
  }
}

struct conn_state {
  int file_index;
  time_t last_poll;
};

static int ev_handler(struct mg_connection *conn, enum mg_event ev) {
  const char **file_names = (const char **) conn->server_param;
  struct conn_state *state;
  int result = MG_FALSE;

  if (ev == MG_REQUEST) {
    mg_printf(conn, "%s",
              "HTTP/1.0 200 OK\r\n" "Cache-Control: no-cache\r\n"
              "Pragma: no-cache\r\nExpires: Thu, 01 Dec 1994 16:00:00 GMT\r\n"
              "Connection: close\r\nContent-Type: multipart/x-mixed-replace; "
              "boundary=--myboundary\r\n\r\n");

    send_file(conn, file_names[0]);

    state = (struct conn_state *) malloc(sizeof(*state));
    conn->connection_param = state;
    state->file_index = 1;  // First file is already sent
    state->last_poll = time(NULL);
    result = MG_MORE;

  } else if (ev == MG_POLL) {

    time_t now = time(NULL);
    state = (struct conn_state *) conn->connection_param;

    if (state != NULL && now > state->last_poll) {
      if (file_names[state->file_index] != NULL) {
        send_file(conn, file_names[state->file_index]);
        state->file_index++;
        if (file_names[state->file_index] == NULL) {
          result = MG_TRUE;  // No more images, close connection
        }
      }
      state->last_poll = now;
    }

  } else if (ev == MG_CLOSE) {
    free(conn->connection_param);
    conn->connection_param = NULL;
  } else if (ev == MG_AUTH) {
    result = MG_TRUE;
  }

  return result;
}

int main(int argc, char *argv[]) {
  struct mg_server *server;

  if (argc < 3) {
    printf("Usage: %s image1.jpg image2.jpg ...\n", argv[0]);
    return 1;
  }

  server = mg_create_server(&argv[1], ev_handler);
  mg_set_option(server, "listening_port", "8080");

  printf("Starting on port %s\n", mg_get_option(server, "listening_port"));
  for (;;) {
    mg_poll_server(server, 1000);
  }
  mg_destroy_server(&server);

  return 0;
}