/* WirePlumber
 *
 * Copyright © 2019 Collabora Ltd.
 *    @author George Kiagiadakis <george.kiagiadakis@collabora.com>
 *
 * SPDX-License-Identifier: LGPL-2.1-or-later
 */

#include <wp/wp.h>
#include <gio/gio.h>
#include <glib-unix.h>

static GOptionEntry entries[] =
{
  { NULL }
};

#define WP_DOMAIN_DAEMON (wp_domain_daemon_quark ())
static G_DEFINE_QUARK (wireplumber-daemon, wp_domain_daemon);

enum WpExitCode
{
  WP_CODE_DISCONNECTED = 0,
  WP_CODE_INTERRUPTED,
  WP_CODE_OPERATION_FAILED,
  WP_CODE_INVALID_ARGUMENT,
};

struct WpDaemonData
{
  WpCore *core;
  GMainLoop *loop;

  gint exit_code;
  gchar *exit_message;
  GDestroyNotify free_message;
};

static void
daemon_exit (struct WpDaemonData * d, gint code, const gchar *format, ...)
{
  va_list args;
  va_start (args, format);
  d->exit_code = code;
  d->exit_message = g_strdup_vprintf (format, args);
  d->free_message = g_free;
  va_end (args);
  g_main_loop_quit (d->loop);
}

static void
daemon_exit_static_str (struct WpDaemonData * d, gint code, const gchar *str)
{
  d->exit_code = code;
  d->exit_message = (gchar *) str;
  d->free_message = NULL;
  g_main_loop_quit (d->loop);
}

static gboolean
signal_handler (gpointer data)
{
  struct WpDaemonData *d = data;
  daemon_exit_static_str (d, WP_CODE_INTERRUPTED, "interrupted by signal");
  return G_SOURCE_CONTINUE;
}

static gboolean
parse_commands_file (struct WpDaemonData *d, GInputStream * stream,
    GError ** error)
{
  gchar buffer[4096];
  gssize bytes_read;
  gchar *cur, *linestart, *saveptr;
  gchar *cmd, *abi, *module;
  gint lineno = 1;
  gboolean eof = FALSE;

  linestart = cur = buffer;

  do {
    bytes_read = g_input_stream_read (stream, cur, sizeof (buffer), NULL, error);
    if (bytes_read < 0)
      return FALSE;
    else if (bytes_read == 0) {
      eof = TRUE;
      /* terminate the remaining data, so that we consume it all */
      if (cur != linestart) {
        *cur = '\n';
      }
    }

    bytes_read += (cur - linestart);

    while (cur - buffer < bytes_read) {
      while (cur - buffer < bytes_read && *cur != '\n')
        cur++;

      if (*cur == '\n') {
        /* found the end of a line */
        *cur = '\0';

        /* tokenize and execute */
        cmd = strtok_r (linestart, " ", &saveptr);

        if (!g_strcmp0 (cmd, "load-module")) {
          abi = strtok_r (NULL, " ", &saveptr);
          module = strtok_r (NULL, " ", &saveptr);

          if (!abi || !module) {
            g_set_error (error, WP_DOMAIN_DAEMON, WP_CODE_INVALID_ARGUMENT,
                "expected ABI and MODULE at line %i", lineno);
            return FALSE;
          }

          if (!wp_module_load (d->core, abi, module, NULL, error)) {
            return FALSE;
          }
        } else {
          g_set_error (error, WP_DOMAIN_DAEMON, WP_CODE_INVALID_ARGUMENT,
              "unknown command '%s' at line %i", cmd, lineno);
          return FALSE;
        }

        /* continue with the next line */
        linestart = ++cur;
        lineno++;
      }
    }

    /* reached the end of the data that was read */

    if (cur - linestart >= sizeof (buffer)) {
      g_set_error (error, WP_DOMAIN_DAEMON, WP_CODE_OPERATION_FAILED,
          "line %i exceeds the maximum allowed line size (%d bytes)",
          lineno, (gint) sizeof (buffer));
      return FALSE;
    } else if (cur - linestart > 0) {
      /* we have unparsed data, move it to the
       * beginning of the buffer and continue */
      strncpy (buffer, linestart, cur - linestart);
      linestart = buffer;
      cur = buffer + (cur - linestart);
    }
  } while (!eof);

  return TRUE;
}

static gboolean
load_commands_file (struct WpDaemonData *d)
{
  g_autoptr (GFile) file = NULL;
  g_autoptr (GError) error = NULL;
  g_autoptr (GFileInputStream) istream = NULL;
  const gchar *filename;

  filename = g_getenv ("WIREPLUMBER_CONFIG_FILE");
  if (!filename)
    filename = WIREPLUMBER_DEFAULT_CONFIG_FILE;

  file = g_file_new_for_path (filename);
  istream = g_file_read (file, NULL, &error);
  if (!istream) {
    daemon_exit (d, WP_CODE_INVALID_ARGUMENT, "%s", error->message);
    return G_SOURCE_REMOVE;
  }

  if (!parse_commands_file (d, G_INPUT_STREAM (istream), &error)) {
    daemon_exit (d, error->code, "Failed to read '%s': %s", filename,
        error->message);
    return G_SOURCE_REMOVE;
  }

  return G_SOURCE_REMOVE;
}

gint
main (gint argc, gchar **argv)
{
  struct WpDaemonData data = {0};
  g_autoptr (GOptionContext) context = NULL;
  g_autoptr (GError) error = NULL;
  g_autoptr (WpCore) core = NULL;
  g_autoptr (GMainLoop) loop = NULL;

  context = g_option_context_new ("- PipeWire Session/Policy Manager");
  g_option_context_add_main_entries (context, entries, NULL);
  if (!g_option_context_parse (context, &argc, &argv, &error)) {
    data.exit_message = error->message;
    data.exit_code = WP_CODE_INVALID_ARGUMENT;
    goto out;
  }

  /* init wireplumber */
  data.core = core = wp_core_new ();

  /* init main loop */
  data.loop = loop = g_main_loop_new (NULL, FALSE);

  /* watch for exit signals */

  g_unix_signal_add (SIGINT, signal_handler, &data);
  g_unix_signal_add (SIGTERM, signal_handler, &data);
  g_unix_signal_add (SIGHUP, signal_handler, &data);

  /* run */

  g_idle_add ((GSourceFunc) load_commands_file, &data);
  g_main_loop_run (data.loop);

out:
  if (data.exit_message) {
    g_message ("%s", data.exit_message);
    if (data.free_message)
      data.free_message (data.exit_message);
  }
  return data.exit_code;
}