// Copyright (c) 2020 Cesanta Software Limited
// All rights reserved

#include <signal.h>
#include "mongoose.h"

static int s_debug_level = MG_LL_INFO;
static const char *s_root_dir = ".";
static const char *s_listening_addr = "http://0.0.0.0:8000";
static const char *s_enable_hexdump = "no";
static const char *s_ssi_pattern = "#.html";
static const char *s_upload_dir = NULL;  // File uploads disabled by default

// Self signed certificates, see
// https://github.com/cesanta/mongoose/blob/master/test/certs/generate.sh
#ifdef TLS_TWOWAY
static const char *s_tls_ca =
    "-----BEGIN CERTIFICATE-----\n"
    "MIIBFTCBvAIJAMNTFtpfcq8NMAoGCCqGSM49BAMCMBMxETAPBgNVBAMMCE1vbmdv\n"
    "b3NlMB4XDTI0MDUwNzE0MzczNloXDTM0MDUwNTE0MzczNlowEzERMA8GA1UEAwwI\n"
    "TW9uZ29vc2UwWTATBgcqhkjOPQIBBggqhkjOPQMBBwNCAASuP+86T/rOWnGpEVhl\n"
    "fxYZ+pjMbCmDZ+vdnP0rjoxudwRMRQCv5slRlDK7Lxue761sdvqxWr0Ma6TFGTNg\n"
    "epsRMAoGCCqGSM49BAMCA0gAMEUCIQCwb2CxuAKm51s81S6BIoy1IcandXSohnqs\n"
    "us64BAA7QgIgGGtUrpkgFSS0oPBlCUG6YPHFVw42vTfpTC0ySwAS0M4=\n"
    "-----END CERTIFICATE-----\n";
#endif
static const char *s_tls_cert =
    "-----BEGIN CERTIFICATE-----\n"
    "MIIBMTCB2aADAgECAgkAluqkgeuV/zUwCgYIKoZIzj0EAwIwEzERMA8GA1UEAwwI\n"
    "TW9uZ29vc2UwHhcNMjQwNTA3MTQzNzM2WhcNMzQwNTA1MTQzNzM2WjARMQ8wDQYD\n"
    "VQQDDAZzZXJ2ZXIwWTATBgcqhkjOPQIBBggqhkjOPQMBBwNCAASo3oEiG+BuTt5y\n"
    "ZRyfwNr0C+SP+4M0RG2pYkb2v+ivbpfi72NHkmXiF/kbHXtgmSrn/PeTqiA8M+mg\n"
    "BhYjDX+zoxgwFjAUBgNVHREEDTALgglsb2NhbGhvc3QwCgYIKoZIzj0EAwIDRwAw\n"
    "RAIgTXW9MITQSwzqbNTxUUdt9DcB+8pPUTbWZpiXcA26GMYCIBiYw+DSFMLHmkHF\n"
    "+5U3NXW3gVCLN9ntD5DAx8LTG8sB\n"
    "-----END CERTIFICATE-----\n";

static const char *s_tls_key =
    "-----BEGIN EC PRIVATE KEY-----\n"
    "MHcCAQEEIAVdo8UAScxG7jiuNY2UZESNX/KPH8qJ0u0gOMMsAzYWoAoGCCqGSM49\n"
    "AwEHoUQDQgAEqN6BIhvgbk7ecmUcn8Da9Avkj/uDNERtqWJG9r/or26X4u9jR5Jl\n"
    "4hf5Gx17YJkq5/z3k6ogPDPpoAYWIw1/sw==\n"
    "-----END EC PRIVATE KEY-----\n";

// Handle interrupts, like Ctrl-C
static int s_signo;
static void signal_handler(int signo) {
  s_signo = signo;
}

// Event handler for the listening connection.
// Simply serve static files from `s_root_dir`
static void cb(struct mg_connection *c, int ev, void *ev_data) {
  if (ev == MG_EV_ACCEPT && c->is_tls) {
    struct mg_tls_opts opts;
    memset(&opts, 0, sizeof(opts));
#ifdef TLS_TWOWAY
    opts.ca = mg_str(s_tls_ca);
#endif
    opts.cert = mg_str(s_tls_cert);
    opts.key = mg_str(s_tls_key);
    mg_tls_init(c, &opts);
  }
  if (ev == MG_EV_HTTP_MSG) {
    struct mg_http_message *hm = ev_data;

    if (mg_match(hm->uri, mg_str("/upload"), NULL)) {
      // Serve file upload
      if (s_upload_dir == NULL) {
        mg_http_reply(c, 403, "", "Denied: file upload directory not set\n");
      } else {
        struct mg_http_part part;
        size_t pos = 0, total_bytes = 0, num_files = 0;
        while ((pos = mg_http_next_multipart(hm->body, pos, &part)) > 0) {
          char path[MG_PATH_MAX];
          MG_INFO(("Chunk name: [%.*s] filename: [%.*s] length: %lu bytes",
                   part.name.len, part.name.buf, part.filename.len,
                   part.filename.buf, part.body.len));
          mg_snprintf(path, sizeof(path), "%s/%.*s", s_upload_dir,
                      part.filename.len, part.filename.buf);
          if (mg_path_is_sane(mg_str(path))) {
            mg_file_write(&mg_fs_posix, path, part.body.buf, part.body.len);
            total_bytes += part.body.len;
            num_files++;
          } else {
            MG_ERROR(("Rejecting dangerous path %s", path));
          }
        }
        mg_http_reply(c, 200, "", "Uploaded %lu files, %lu bytes\n", num_files,
                      total_bytes);
      }
    } else {
      // Serve web root directory
      struct mg_http_serve_opts opts = {0};
      opts.root_dir = s_root_dir;
      opts.ssi_pattern = s_ssi_pattern;
      mg_http_serve_dir(c, hm, &opts);
    }

    // Log request
    MG_INFO(("%.*s %.*s %lu -> %.*s %lu", hm->method.len, hm->method.buf,
             hm->uri.len, hm->uri.buf, hm->body.len, 3, c->send.buf + 9,
             c->send.len));
  }
}

static void usage(const char *prog) {
  fprintf(stderr,
          "Mongoose v.%s\n"
          "Usage: %s OPTIONS\n"
          "  -H yes|no - enable traffic hexdump, default: '%s'\n"
          "  -S PAT    - SSI filename pattern, default: '%s'\n"
          "  -d DIR    - directory to serve, default: '%s'\n"
          "  -l ADDR   - listening HTTP address, default: '%s'\n"
          "  -u DIR    - file upload directory, default: unset\n"
          "  -v LEVEL  - debug level, from 0 to 4, default: %d\n",
          MG_VERSION, prog, s_enable_hexdump, s_ssi_pattern, s_root_dir,
          s_listening_addr, s_debug_level);
  exit(EXIT_FAILURE);
}

int main(int argc, char *argv[]) {
  char path[MG_PATH_MAX] = ".";
  struct mg_mgr mgr;
  struct mg_connection *c;
  int i;

  // Parse command-line flags
  for (i = 1; i < argc; i++) {
    if (strcmp(argv[i], "-d") == 0) {
      s_root_dir = argv[++i];
    } else if (strcmp(argv[i], "-H") == 0) {
      s_enable_hexdump = argv[++i];
    } else if (strcmp(argv[i], "-S") == 0) {
      s_ssi_pattern = argv[++i];
    } else if (strcmp(argv[i], "-l") == 0) {
      s_listening_addr = argv[++i];
    } else if (strcmp(argv[i], "-u") == 0) {
      s_upload_dir = argv[++i];
    } else if (strcmp(argv[i], "-v") == 0) {
      s_debug_level = atoi(argv[++i]);
    } else {
      usage(argv[0]);
    }
  }

  // Root directory must not contain double dots. Make it absolute
  // Do the conversion only if the root dir spec does not contain overrides
  if (strchr(s_root_dir, ',') == NULL) {
    realpath(s_root_dir, path);
    s_root_dir = path;
  }

  // Initialise stuff
  signal(SIGINT, signal_handler);
  signal(SIGTERM, signal_handler);
  mg_log_set(s_debug_level);
  mg_mgr_init(&mgr);
  if ((c = mg_http_listen(&mgr, s_listening_addr, cb, NULL)) == NULL) {
    MG_ERROR(("Cannot listen on %s. Use http://ADDR:PORT or :PORT",
              s_listening_addr));
    exit(EXIT_FAILURE);
  }
  if (mg_casecmp(s_enable_hexdump, "yes") == 0) c->is_hexdumping = 1;

  // Start infinite event loop
  MG_INFO(("Mongoose version : v%s", MG_VERSION));
  MG_INFO(("Listening on     : %s", s_listening_addr));
  MG_INFO(("Web root         : %s", s_root_dir));
  MG_INFO(("Upload dir       : %s", s_upload_dir ? s_upload_dir : "(unset)"));
  while (s_signo == 0) {
    mg_mgr_poll(&mgr, 1000);
  }
  mg_mgr_free(&mgr);
  MG_INFO(("Exiting on signal %d", s_signo));
  return 0;
}
