/**
 * jsonrpc.C: JSON-RPC for Ermyth
 *
 * Copyright © 2007 Pippijn van Steenhoven / The Ermyth Team
 * Rights to this code are as documented in COPYING.
 *
 *
 * Portions of this file were derived from sources bearing the following license:
 * Copyright © 2005-2006 Jilles Tjoelker et al.
 * Rights to this code are as documented in doc/pod/license.pod.
 *
 * $Id: jsonrpc.C,v 1.10 2007/09/22 14:27:28 pippijn Exp $
 */

#include "atheme.h"
#include <libermyth.h>
#include <ermyth/module.h>
#include <account/myuser.h>
#include "datastream.h"
#include "authcookie.h"
#include "connection.h"
#include "confparse.h"

#include "httpd.h"

#include "json/json.h"
#include "json/rpc.h"

using namespace json;

static char const rcsid[] = "$Id: jsonrpc.C,v 1.10 2007/09/22 14:27:28 pippijn Exp $";

static void on_config_ready (void);

#define JSONRPC_BUFSIZE         2048
#define MAX_CMD_PARC            20

REGISTER_MODULE ("rpc/jsonrpc", false, "The Ermyth Team <http://ermyth.one09.net>");

static void handle_request (connection_t *cptr, void *requestbuf);

Value current_response;         // XXX: Hack

E pathvec pathhandlers;

static void jsonrpc_command_fail (sourceinfo_t *si, fault::code code, char const *message);
static void jsonrpc_command_success_nodata (sourceinfo_t *si, char const *message);
static void jsonrpc_command_success_string (sourceinfo_t *si, char const *result, char const *message);

static void jsonrpcmethod_login (void *conn, Value &request, Value &response);
static void jsonrpcmethod_logout (void *conn, Value &request, Value &response);
static void jsonrpcmethod_command (void *conn, Value &request, Value &response);

/* Configuration */
ConfTable::list_type conf_jsonrpc_table;

path_handler_t handle_jsonrpc =
{
  NULL,
  handle_request
};

static int
conf_jsonrpc_path (config_entry_t *ce)
{
  if (!ce->valid ())
    return -1;

  if (handle_jsonrpc.path != NULL)
    {
      if (!strcmp (handle_jsonrpc.path, ce->vardata<char *> ()))
        return 0;
      sfree (handle_jsonrpc.path);
    }
  handle_jsonrpc.path = sstrdup (ce->vardata<char *> ());

  return 0;
}

static int
conf_jsonrpc (config_entry_t *ce)
{
  subblock_handler (ce, conf_jsonrpc_table);
  return 0;
}

struct sourceinfo_vtable jsonrpc_vtable = {
  "jsonrpc",
  jsonrpc_command_fail,
  jsonrpc_command_success_nodata,
  jsonrpc_command_success_string
};

static char *
dump_buffer (connection_t *cptr, char *buf, int length)
{
  struct httpddata *hd;
  char buf1[300];

  hd = static_cast<httpddata *> (cptr->userdata);
  snprintf (buf1, sizeof buf1, "HTTP/1.1 200 OK\r\n"
                               "%s" // connection_close?
                               "Server: " PACKAGE_NAME "/%s\r\n"
                               "Content-Type: application/json\r\n"
                               "Content-Length: %d\r\n\r\n",
                               hd->connection_close ? "Connection: close\r\n" : "", version, length);
  sendq_add (cptr, buf1, strlen (buf1));
  sendq_add (cptr, buf, length);
  if (hd->connection_close)
    sendq_add_eof (cptr);
  return buf;
}

void
jsonrpc_generic_error (Value &response, int code, char const *string)
{
  Value error (objectValue);
  
  error["name"] = "JSONRPCError";
  error["code"] = Value (code);
  error["message"] = Value (string);

  response["version"] = "1.1";
  response["error"] = error;
}

static void
handle_request (connection_t *cptr, void *requestbuf)
{
  char response[JSONRPC_BUFSIZE];
  jsonrpc_process (&cptr, response, static_cast<char const *> (requestbuf), JSONRPC_BUFSIZE);
  dump_buffer (cptr, response, strlen (response));
  current_response = Value (nullValue);
}

static void
on_config_ready (void)
{
  if (handle_jsonrpc.handler != NULL)
    {
      if (std::find_if (pathhandlers.begin (), pathhandlers.end (), pathhandler_eq (handle_jsonrpc.path))
          != pathhandlers.end ())
        {
	  slog (LG_INFO, "jsonrpc/main.C: handler already in the list");
	  return;
	}

      pathhandlers.push_back (handle_jsonrpc);
    }
  else
    slog (LG_ERROR, "on_config_ready (): jsonrpc { } block missing or invalid");
}

static void
jsonrpc_generic_reply (Value &response, char const *message)
{
  Value entry (objectValue);

  entry["result"] = Value (message);
  response["result"] = entry;
}

static void
jsonrpc_command_fail (sourceinfo_t *si, fault::code code, char const *message)
{
  connection_t *cptr;
  struct httpddata *hd;

  cptr = si->connection;
  hd = static_cast<httpddata *> (cptr->userdata);

  if (hd->sent_reply)
    return;

  jsonrpc_generic_error (current_response, code, message);
  hd->sent_reply = true;
}

static void
jsonrpc_command_success_nodata (sourceinfo_t *si, char const *message)
{
  char *p;
  char const *q;
  size_t msglen;
  connection_t *cptr;
  httpddata *hd;

  cptr = si->connection;
  hd = static_cast<httpddata *> (cptr->userdata);

  msglen = strlen (message);

  if (hd->sent_reply)
    return;

  if (hd->replybuf == NULL)
    {
      hd->replybuf = salloc<char> (msglen + 1);
      p = hd->replybuf;
    }
  else
    {
      size_t replybuf_len = strlen (hd->replybuf);
      hd->replybuf = salloc (replybuf_len + msglen + 2, hd->replybuf);
      p = hd->replybuf + replybuf_len;
      *p++ = '\n';
    }

  q = message;

  /* What this code does is the following:
   *   - set *p to *q
   *   - increment q (go to the next character in q
   *   - if *p is below 0x1f (the space character ' '), then
   *       do not increment p
   *     if *p is above or the same as the space character, then
   *       do increment p
   *
   * This incrementing/not incrementing effectively skips any character below the
   * space character, as by not incrementing p, *p gets overwritten in the next cycle.
   */
  while (msglen--)
    {
      *p = *q++;
      p += !!(*p & ~0x1f);
    }

  *p = '\0';
}

static void
jsonrpc_command_success_string (sourceinfo_t *si, char const *result, char const *message)
{
  connection_t *cptr;
  struct httpddata *hd;

  cptr = si->connection;
  hd = static_cast<httpddata *> (cptr->userdata);
  if (hd->sent_reply)
    return;
  jsonrpc_generic_reply (current_response, result);
  hd->sent_reply = true;
}

/* These taken from the old modules/jsonrpc/account.c */
/*
 * ermyth.login
 *
 * JSON Inputs:
 *       account name, password, source ip (optional)
 *
 * JSON Outputs:
 *       fault 1 - insufficient parameters
 *       fault 3 - account is not registered
 *       fault 5 - invalid username and password
 *       fault 6 - account is frozen
 *       default - success (authcookie)
 *
 * Side Effects:
 *       an authcookie ticket is created for the myuser_t.
 *       the user's lastlogin is updated
 */
static void
jsonrpcmethod_login (void *conn, Value &request, Value &response)
{
  myuser_t *mu;
  authcookie_t *ac;
  char const *sourceip;

  Value params = request["params"];
  int parc, i;
  char **parv = salloc<char *> (MAX_CMD_PARC);
  connection_t *cptr = static_cast<connection_t *> (conn);

  parc = params.size ();

  if (parc < 2)
    {
      jsonrpc_generic_error (response, fault::needmoreparams, "Insufficient parameters.");
      sfree (parv);
      return;
    }

  for (i = 0; i < parc; i++)
    parv[i] = const_cast<char *> (static_cast<char const *> ((params[i])));

  sourceip = parc >= 3 && *parv[2] != '\0' ? parv[2] : NULL;

  if (! (mu = myuser_t::find (parv[0])))
    {
      jsonrpc_generic_error (response, fault::nosuch_source, "The account is not registered.");
      sfree (parv);
      return;
    }

  if (mu->find_metadata ("private:freeze:freezer") != NULL)
    {
      logcommand_external (nicksvs.me, "jsonrpc", cptr, sourceip, NULL, CMDLOG_LOGIN, "failed LOGIN to %s (frozen)", mu->name);
      jsonrpc_generic_error (response, fault::noprivs, "The account has been frozen.");
      sfree (parv);
      return;
    }

  if (!mu->verify_password (parv[1]))
    {
      logcommand_external (nicksvs.me, "jsonrpc", cptr, sourceip, NULL, CMDLOG_LOGIN, "failed LOGIN to %s (bad password)", mu->name);
      jsonrpc_generic_error (response, fault::authfail, "The password is not valid for this account.");
      sfree (parv);
      return;
    }

  mu->lastlogin = NOW;

  ac = authcookie_create (mu);

  logcommand_external (nicksvs.me, "jsonrpc", cptr, sourceip, mu, CMDLOG_LOGIN, "LOGIN");

  jsonrpc_generic_reply (response, ac->ticket);

  sfree (parv);
}

/*
 * ermyth.logout
 *
 * JSON inputs:
 *       authcookie, and account name.
 *
 * JSON outputs:
 *       fault 1 - insufficient parameters
 *       fault 3 - unknown user
 *       fault 5 - validation failed
 *       default - success message
 *
 * Side Effects:
 *       an authcookie ticket is destroyed.
 */
static void
jsonrpcmethod_logout (void *conn, Value &request, Value &response)
{
  authcookie_t *ac;
  myuser_t *mu;

  Value params = request["params"];
  int parc, i;
  char **parv = salloc<char *> (MAX_CMD_PARC);
  connection_t *cptr = static_cast<connection_t *> (conn);

  parc = params.size ();

  if (parc < 2)
    {
      jsonrpc_generic_error (response, fault::needmoreparams, "Insufficient parameters.");
      sfree (parv);
      return;
    }

  for (i = 0; i < parc; i++)
    parv[i] = const_cast<char *> (static_cast<char const *> ((params[i])));

  if ( (mu = myuser_t::find (parv[1])) == NULL)
    {
      jsonrpc_generic_error (response, fault::nosuch_source, "Unknown user.");
      sfree (parv);
      return;
    }

  if (authcookie_validate (parv[0], mu) == false)
    {
      jsonrpc_generic_error (response, fault::authfail, "Invalid authcookie for this account.");
      sfree (parv);
      return;
    }

  logcommand_external (nicksvs.me, "jsonrpc", cptr, NULL, mu, CMDLOG_LOGIN, "LOGOUT");

  ac = authcookie_find (parv[0], mu);
  authcookie_destroy (ac);

  jsonrpc_generic_reply (response, "You are now logged out.");

  sfree (parv);
}

/*
 * ermyth.command
 *
 * JSON inputs:
 *       authcookie, account name, source ip, service name, command name,
 *       parameters.
 *
 * JSON outputs:
 *       depends on command
 *
 * Side Effects:
 *       command is executed
 */
static void
jsonrpcmethod_command (void *conn, Value &request, Value &response)
{
  myuser_t *mu;
  service_t *svs;
  command_t const *cmd;
  sourceinfo_t si;
  int newparc;
  char *newparv[MAX_CMD_PARC];
  connection_t *cptr = static_cast<connection_t *> (conn);
  struct httpddata *hd = static_cast<httpddata *> (cptr->userdata);

  Value params = request["params"];
  int parc, i;
  char **parv = salloc<char *> (MAX_CMD_PARC);

  parc = params.size ();

  if (parc < 5)
    {
      jsonrpc_generic_error (response, fault::needmoreparams, "Insufficient parameters.");
      sfree (parv);
      return;
    }

  for (i = 0; i < parc; i++)
    parv[i] = const_cast<char *> (static_cast<char const *> (params[i]));

  for (i = 0; i < parc; i++)
    {
      if (strchr (parv[i], '\r') || strchr (parv[i], '\n'))
	{
	  jsonrpc_generic_error (response, fault::badparams, "Invalid parameters.");
	  return;
	}
    }

  if (*parv[1] != '\0' && strlen (parv[0]) > 1)
    {
      if ( (mu = myuser_t::find (parv[1])) == NULL)
	{
	  jsonrpc_generic_error (response, fault::nosuch_source, "Unknown user.");
	  sfree (parv);
	  return;
	}

      if (authcookie_validate (parv[0], mu) == false)
	{
	  jsonrpc_generic_error (response, fault::authfail, "Invalid authcookie for this account.");
	  sfree (parv);
	  return;
	}
    }
  else
    mu = NULL;

  svs = find_service (parv[3]);
  if (svs == NULL || svs->cmdtree == NULL)
    {
      slog (LG_DEBUG, "jsonrpcmethod_command (): invalid service %s", parv[3]);
      jsonrpc_generic_error (response, fault::nosuch_source, "Invalid service name.");
      sfree (parv);
      return;
    }

  cmd = svs->cmdtree->find (parv[4]);
  if (cmd == NULL)
    {
      jsonrpc_generic_error (response, fault::nosuch_source, "Invalid command name.");
      sfree (parv);
      return;
    }

  memset (newparv, '\0', sizeof newparv);
  newparc = parc - 5;
  if (newparc > MAX_CMD_PARC)
    newparc = MAX_CMD_PARC;
  if (newparc > 0)
    memcpy (newparv, parv + 5, newparc * sizeof (parv[0]));
  memset (&si, '\0', sizeof si);
  si.smu = mu;
  si.service = svs;
  si.sourcedesc = parv[2][0] != '\0' ? parv[2] : NULL;
  si.connection = cptr;
  si.v = &jsonrpc_vtable;
  cmd->exec (svs, &si, newparc, newparv);

  response = current_response;

  if (!hd->sent_reply)
    {
      if (hd->replybuf != NULL)
        jsonrpc_generic_reply (response, hd->replybuf);
      else
        jsonrpc_generic_error (response, fault::unimplemented, "Command did not return a result.");
    }

  sfree (parv);
}

bool
_modinit (module *m)
{
  ConfTable::callback.ready.attach (on_config_ready);

  add_top_conf ("JSONRPC", conf_jsonrpc);
  add_conf_item ("PATH", conf_jsonrpc_table, conf_jsonrpc_path);
  
  jsonrpc_add_method (PACKAGE_NAME ".login", jsonrpcmethod_login);
  jsonrpc_add_method (PACKAGE_NAME ".logout", jsonrpcmethod_logout);
  jsonrpc_add_method (PACKAGE_NAME ".command", jsonrpcmethod_command);

  return true;
}

void
_moddeinit (void)
{
#if 0
  jsonrpc_unregister_method (PACKAGE_NAME ".login");
  jsonrpc_unregister_method (PACKAGE_NAME ".logout");
  jsonrpc_unregister_method (PACKAGE_NAME ".command");
#endif
  
  if (std::find_if (pathhandlers.begin (), pathhandlers.end (), pathhandler_eq (handle_jsonrpc.path))
      == pathhandlers.end ())
    {
      slog (LG_INFO, "jsonrpc/main.c: handler was not registered.");
      return;
    }
  
  pathhandlers.erase (std::find_if (pathhandlers.begin (), pathhandlers.end (), pathhandler_eq (handle_jsonrpc.path)));

  del_conf_item ("PATH", conf_jsonrpc_table);
  del_top_conf ("JSONRPC");
  if (handle_jsonrpc.path != NULL)
    sfree (handle_jsonrpc.path);
  handle_jsonrpc.path = NULL;

  ConfTable::callback.ready.detach (on_config_ready);
}