/*
 * connection.c
 *
 * Copyright (C) 2012 - 2015 James Booth <boothj5@gmail.com>
 *
 * This file is part of Profanity.
 *
 * Profanity is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Profanity is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Profanity.  If not, see <http://www.gnu.org/licenses/>.
 *
 * In addition, as a special exception, the copyright holders give permission to
 * link the code of portions of this program with the OpenSSL library under
 * certain conditions as described in each individual source file, and
 * distribute linked combinations including the two.
 *
 * You must obey the GNU General Public License in all respects for all of the
 * code used other than OpenSSL. If you modify file(s) with this exception, you
 * may extend this exception to your version of the file(s), but you are not
 * obligated to do so. If you do not wish to do so, delete this exception
 * statement from your version. If you delete this exception statement from all
 * source files in the program, then also delete it here.
 *
 */

#include "config.h"

#include <assert.h>
#include <string.h>
#include <stdlib.h>

#ifdef HAVE_LIBMESODE
#include <mesode.h>
#endif
#ifdef HAVE_LIBSTROPHE
#include <strophe.h>
#endif

#include "chat_session.h"
#include "common.h"
#include "config/preferences.h"
#include "jid.h"
#include "log.h"
#include "muc.h"
#include "profanity.h"
#include "event/server_events.h"
#include "xmpp/bookmark.h"
#include "xmpp/capabilities.h"
#include "xmpp/connection.h"
#include "xmpp/iq.h"
#include "xmpp/message.h"
#include "xmpp/presence.h"
#include "xmpp/roster.h"
#include "xmpp/stanza.h"
#include "xmpp/xmpp.h"

static struct _jabber_conn_t {
    xmpp_log_t *log;
    xmpp_ctx_t *ctx;
    xmpp_conn_t *conn;
    jabber_conn_status_t conn_status;
    char *presence_message;
    int priority;
    char *domain;
} jabber_conn;

static GHashTable *available_resources;

// for auto reconnect
static struct {
    char *name;
    char *passwd;
} saved_account;

static struct {
    char *name;
    char *jid;
    char *passwd;
    char *altdomain;
    int port;
    char *tls_policy;
} saved_details;

static GTimer *reconnect_timer;

static log_level_t _get_log_level(xmpp_log_level_t xmpp_level);
static xmpp_log_level_t _get_xmpp_log_level();

static void _xmpp_file_logger(void *const userdata, const xmpp_log_level_t level, const char *const area,
    const char *const msg);

static xmpp_log_t* _xmpp_get_file_logger();

static jabber_conn_status_t _jabber_connect(const char *const fulljid, const char *const passwd,
    const char *const altdomain, int port, const char *const tls_policy);

static void _jabber_reconnect(void);
static void _jabber_lost_connection(void);
static void _connection_handler(xmpp_conn_t *const conn, const xmpp_conn_event_t status, const int error,
    xmpp_stream_error_t *const stream_error, void *const userdata);

void _connection_free_saved_account(void);
void _connection_free_saved_details(void);
void _connection_free_session_data(void);

void
jabber_init(void)
{
    log_info("Initialising XMPP");
    jabber_conn.conn_status = JABBER_STARTED;
    jabber_conn.presence_message = NULL;
    jabber_conn.conn = NULL;
    jabber_conn.ctx = NULL;
    jabber_conn.domain = NULL;
    presence_sub_requests_init();
    caps_init();
    available_resources = g_hash_table_new_full(g_str_hash, g_str_equal, free, (GDestroyNotify)resource_destroy);
    xmpp_initialize();
}

jabber_conn_status_t
jabber_connect_with_account(const ProfAccount *const account)
{
    assert(account != NULL);

    log_info("Connecting using account: %s", account->name);

    // save account name and password for reconnect
    if (saved_account.name) {
        free(saved_account.name);
    }
    saved_account.name = strdup(account->name);
    if (saved_account.passwd) {
        free(saved_account.passwd);
    }
    saved_account.passwd = strdup(account->password);

    // connect with fulljid
    Jid *jidp = jid_create_from_bare_and_resource(account->jid, account->resource);
    jabber_conn_status_t result =
        _jabber_connect(jidp->fulljid, account->password, account->server, account->port, account->tls_policy);
    jid_destroy(jidp);

    return result;
}

jabber_conn_status_t
jabber_connect_with_details(const char *const jid, const char *const passwd, const char *const altdomain,
    const int port, const char *const tls_policy)
{
    assert(jid != NULL);
    assert(passwd != NULL);

    // save details for reconnect, remember name for account creating on success
    saved_details.name = strdup(jid);
    saved_details.passwd = strdup(passwd);
    if (altdomain) {
        saved_details.altdomain = strdup(altdomain);
    } else {
        saved_details.altdomain = NULL;
    }
    if (port != 0) {
        saved_details.port = port;
    } else {
        saved_details.port = 0;
    }
    if (tls_policy) {
        saved_details.tls_policy = strdup(tls_policy);
    } else {
        saved_details.tls_policy = NULL;
    }

    // use 'profanity' when no resourcepart in provided jid
    Jid *jidp = jid_create(jid);
    if (jidp->resourcepart == NULL) {
        jid_destroy(jidp);
        jidp = jid_create_from_bare_and_resource(jid, "profanity");
        saved_details.jid = strdup(jidp->fulljid);
    } else {
        saved_details.jid = strdup(jid);
    }
    jid_destroy(jidp);

    // connect with fulljid
    log_info("Connecting without account, JID: %s", saved_details.jid);

    return _jabber_connect(
        saved_details.jid,
        passwd,
        saved_details.altdomain,
        saved_details.port,
        saved_details.tls_policy);
}

void
jabber_autoping_fail(void)
{
    if (jabber_conn.conn_status == JABBER_CONNECTED) {
        log_info("Closing connection");
        accounts_set_last_activity(jabber_get_account_name());
        jabber_conn.conn_status = JABBER_DISCONNECTING;
        xmpp_disconnect(jabber_conn.conn);

        while (jabber_get_connection_status() == JABBER_DISCONNECTING) {
            jabber_process_events(10);
        }
        if (jabber_conn.conn) {
            xmpp_conn_release(jabber_conn.conn);
            jabber_conn.conn = NULL;
        }
        if (jabber_conn.ctx) {
            xmpp_ctx_free(jabber_conn.ctx);
            jabber_conn.ctx = NULL;
        }
    }

    FREE_SET_NULL(jabber_conn.presence_message);
    FREE_SET_NULL(jabber_conn.domain);

    jabber_conn.conn_status = JABBER_DISCONNECTED;
    _jabber_lost_connection();
}

void
jabber_disconnect(void)
{
    // if connected, send end stream and wait for response
    if (jabber_conn.conn_status == JABBER_CONNECTED) {
        log_info("Closing connection");
        accounts_set_last_activity(jabber_get_account_name());
        jabber_conn.conn_status = JABBER_DISCONNECTING;
        xmpp_disconnect(jabber_conn.conn);

        while (jabber_get_connection_status() == JABBER_DISCONNECTING) {
            jabber_process_events(10);
        }
        _connection_free_saved_account();
        _connection_free_saved_details();
        _connection_free_session_data();
        if (jabber_conn.conn) {
            xmpp_conn_release(jabber_conn.conn);
            jabber_conn.conn = NULL;
        }
        if (jabber_conn.ctx) {
            xmpp_ctx_free(jabber_conn.ctx);
            jabber_conn.ctx = NULL;
        }
    }

    jabber_conn.conn_status = JABBER_STARTED;
    FREE_SET_NULL(jabber_conn.presence_message);
    FREE_SET_NULL(jabber_conn.domain);
}

void
jabber_shutdown(void)
{
    _connection_free_saved_account();
    _connection_free_saved_details();
    _connection_free_session_data();
    xmpp_shutdown();
    free(jabber_conn.log);
    jabber_conn.log = NULL;
}

void
jabber_process_events(int millis)
{
    int reconnect_sec;

    switch (jabber_conn.conn_status)
    {
        case JABBER_CONNECTED:
        case JABBER_CONNECTING:
        case JABBER_DISCONNECTING:
            xmpp_run_once(jabber_conn.ctx, millis);
            break;
        case JABBER_DISCONNECTED:
            reconnect_sec = prefs_get_reconnect();
            if ((reconnect_sec != 0) && reconnect_timer) {
                int elapsed_sec = g_timer_elapsed(reconnect_timer, NULL);
                if (elapsed_sec > reconnect_sec) {
                    _jabber_reconnect();
                }
            }
            break;
        default:
            break;
    }
}

GList*
jabber_get_available_resources(void)
{
    return g_hash_table_get_values(available_resources);
}

jabber_conn_status_t
jabber_get_connection_status(void)
{
    return (jabber_conn.conn_status);
}

void
jabber_set_connection_status(jabber_conn_status_t status)
{
    jabber_conn.conn_status = status;
}

xmpp_conn_t*
connection_get_conn(void)
{
    return jabber_conn.conn;
}

xmpp_ctx_t*
connection_get_ctx(void)
{
    return jabber_conn.ctx;
}

const char*
jabber_get_fulljid(void)
{
    return xmpp_conn_get_jid(jabber_conn.conn);
}

const char*
jabber_get_domain(void)
{
    return jabber_conn.domain;
}

char*
jabber_get_presence_message(void)
{
    return jabber_conn.presence_message;
}

char*
jabber_get_account_name(void)
{
    return saved_account.name;
}

char*
jabber_create_uuid(void)
{
    return xmpp_uuid_gen(jabber_conn.ctx);
}

void
jabber_free_uuid(char *uuid)
{
    if (uuid) {
        xmpp_free(jabber_conn.ctx, uuid);
    }
}

void
connection_set_presence_message(const char *const message)
{
    FREE_SET_NULL(jabber_conn.presence_message);
    if (message) {
        jabber_conn.presence_message = strdup(message);
    }
}

void
connection_set_priority(const int priority)
{
    jabber_conn.priority = priority;
}

void
connection_add_available_resource(Resource *resource)
{
    g_hash_table_replace(available_resources, strdup(resource->name), resource);
}

void
connection_remove_available_resource(const char *const resource)
{
    g_hash_table_remove(available_resources, resource);
}

void
_connection_free_saved_account(void)
{
    FREE_SET_NULL(saved_account.name);
    FREE_SET_NULL(saved_account.passwd);
}

void
_connection_free_saved_details(void)
{
    FREE_SET_NULL(saved_details.name);
    FREE_SET_NULL(saved_details.jid);
    FREE_SET_NULL(saved_details.passwd);
    FREE_SET_NULL(saved_details.altdomain);
    FREE_SET_NULL(saved_details.tls_policy);
}

void
_connection_free_session_data(void)
{
    g_hash_table_remove_all(available_resources);
    chat_sessions_clear();
    presence_clear_sub_requests();
}

#ifdef HAVE_LIBMESODE
static int
_connection_certfail_cb(xmpp_tlscert_t *xmpptlscert, const char *const errormsg)
{
    int version = xmpp_conn_tlscert_version(xmpptlscert);
    char *serialnumber = xmpp_conn_tlscert_serialnumber(xmpptlscert);
    char *subjectname = xmpp_conn_tlscert_subjectname(xmpptlscert);
    char *issuername = xmpp_conn_tlscert_issuername(xmpptlscert);
    char *fingerprint = xmpp_conn_tlscert_fingerprint(xmpptlscert);
    char *notbefore = xmpp_conn_tlscert_notbefore(xmpptlscert);
    char *notafter = xmpp_conn_tlscert_notafter(xmpptlscert);
    char *key_alg = xmpp_conn_tlscert_key_algorithm(xmpptlscert);
    char *signature_alg = xmpp_conn_tlscert_signature_algorithm(xmpptlscert);

    TLSCertificate *cert = tlscerts_new(fingerprint, version, serialnumber, subjectname, issuername, notbefore,
        notafter, key_alg, signature_alg);
    int res = sv_ev_certfail(errormsg, cert);
    tlscerts_free(cert);

    return res;
}

TLSCertificate*
jabber_get_tls_peer_cert(void)
{
    xmpp_tlscert_t *xmpptlscert = xmpp_conn_tls_peer_cert(jabber_conn.conn);
    int version = xmpp_conn_tlscert_version(xmpptlscert);
    char *serialnumber = xmpp_conn_tlscert_serialnumber(xmpptlscert);
    char *subjectname = xmpp_conn_tlscert_subjectname(xmpptlscert);
    char *issuername = xmpp_conn_tlscert_issuername(xmpptlscert);
    char *fingerprint = xmpp_conn_tlscert_fingerprint(xmpptlscert);
    char *notbefore = xmpp_conn_tlscert_notbefore(xmpptlscert);
    char *notafter = xmpp_conn_tlscert_notafter(xmpptlscert);
    char *key_alg = xmpp_conn_tlscert_key_algorithm(xmpptlscert);
    char *signature_alg = xmpp_conn_tlscert_signature_algorithm(xmpptlscert);

    TLSCertificate *cert = tlscerts_new(fingerprint, version, serialnumber, subjectname, issuername, notbefore,
        notafter, key_alg, signature_alg);

    xmpp_conn_free_tlscert(jabber_conn.ctx, xmpptlscert);

    return cert;
}
#endif

gboolean
jabber_conn_is_secured(void)
{
    if (jabber_conn.conn_status == JABBER_CONNECTED) {
        return xmpp_conn_is_secured(jabber_conn.conn) == 0 ? FALSE : TRUE;
    } else {
        return FALSE;
    }
}

static jabber_conn_status_t
_jabber_connect(const char *const fulljid, const char *const passwd, const char *const altdomain, int port,
    const char *const tls_policy)
{
    assert(fulljid != NULL);
    assert(passwd != NULL);

    Jid *jid = jid_create(fulljid);

    if (jid == NULL) {
        log_error("Malformed JID not able to connect: %s", fulljid);
        jabber_conn.conn_status = JABBER_DISCONNECTED;
        return jabber_conn.conn_status;
    } else if (jid->fulljid == NULL) {
        log_error("Full JID required to connect, received: %s", fulljid);
        jabber_conn.conn_status = JABBER_DISCONNECTED;
        jid_destroy(jid);
        return jabber_conn.conn_status;
    }

    jid_destroy(jid);

    log_info("Connecting as %s", fulljid);
    if (jabber_conn.log) {
        free(jabber_conn.log);
    }
    jabber_conn.log = _xmpp_get_file_logger();

    if (jabber_conn.conn) {
        xmpp_conn_release(jabber_conn.conn);
    }
    if (jabber_conn.ctx) {
        xmpp_ctx_free(jabber_conn.ctx);
    }
    jabber_conn.ctx = xmpp_ctx_new(NULL, jabber_conn.log);
    if (jabber_conn.ctx == NULL) {
        log_warning("Failed to get libstrophe ctx during connect");
        return JABBER_DISCONNECTED;
    }
    jabber_conn.conn = xmpp_conn_new(jabber_conn.ctx);
    if (jabber_conn.conn == NULL) {
        log_warning("Failed to get libstrophe conn during connect");
        return JABBER_DISCONNECTED;
    }
    xmpp_conn_set_jid(jabber_conn.conn, fulljid);
    xmpp_conn_set_pass(jabber_conn.conn, passwd);

    if (!tls_policy || (g_strcmp0(tls_policy, "force") == 0)) {
        xmpp_conn_set_flags(jabber_conn.conn, XMPP_CONN_FLAG_MANDATORY_TLS);
    } else if (g_strcmp0(tls_policy, "disable") == 0) {
        xmpp_conn_set_flags(jabber_conn.conn, XMPP_CONN_FLAG_DISABLE_TLS);
    }

#ifdef HAVE_LIBMESODE
    char *cert_path = prefs_get_string(PREF_TLS_CERTPATH);
    if (cert_path) {
        xmpp_conn_tlscert_path(jabber_conn.conn, cert_path);
    }
    prefs_free_string(cert_path);
#endif

#ifdef HAVE_LIBMESODE
    int connect_status = xmpp_connect_client(
        jabber_conn.conn,
        altdomain,
        port,
        _connection_certfail_cb,
        _connection_handler,
        jabber_conn.ctx);
#else
    int connect_status = xmpp_connect_client(
        jabber_conn.conn,
        altdomain,
        port,
        _connection_handler,
        jabber_conn.ctx);
#endif

    if (connect_status == 0) {
        jabber_conn.conn_status = JABBER_CONNECTING;
    } else {
        jabber_conn.conn_status = JABBER_DISCONNECTED;
    }

    return jabber_conn.conn_status;
}

static void
_jabber_reconnect(void)
{
    // reconnect with account.
    ProfAccount *account = accounts_get_account(saved_account.name);

    if (account == NULL) {
        log_error("Unable to reconnect, account no longer exists: %s", saved_account.name);
    } else {
        char *fulljid = create_fulljid(account->jid, account->resource);
        log_debug("Attempting reconnect with account %s", account->name);
        _jabber_connect(fulljid, saved_account.passwd, account->server, account->port, account->tls_policy);
        free(fulljid);
        g_timer_start(reconnect_timer);
    }
}

static void
_jabber_lost_connection(void)
{
    sv_ev_lost_connection();
    if (prefs_get_reconnect() != 0) {
        assert(reconnect_timer == NULL);
        reconnect_timer = g_timer_new();
    } else {
        _connection_free_saved_account();
        _connection_free_saved_details();
    }
    _connection_free_session_data();
}

static void
_connection_handler(xmpp_conn_t *const conn, const xmpp_conn_event_t status, const int error,
    xmpp_stream_error_t *const stream_error, void *const userdata)
{
    // login success
    if (status == XMPP_CONN_CONNECT) {
        log_debug("Connection handler: XMPP_CONN_CONNECT");
        jabber_conn.conn_status = JABBER_CONNECTED;

        int secured = xmpp_conn_is_secured(jabber_conn.conn);

        // logged in with account
        if (saved_account.name) {
            log_debug("Connection handler: logged in with account name: %s", saved_account.name);
            sv_ev_login_account_success(saved_account.name, secured);

        // logged in without account, use details to create new account
        } else {
            log_debug("Connection handler: logged in with jid: %s", saved_details.name);
            accounts_add(saved_details.name, saved_details.altdomain, saved_details.port, saved_details.tls_policy);
            accounts_set_jid(saved_details.name, saved_details.jid);

            sv_ev_login_account_success(saved_details.name, secured);
            saved_account.name = strdup(saved_details.name);
            saved_account.passwd = strdup(saved_details.passwd);

            _connection_free_saved_details();
        }

        Jid *my_jid = jid_create(jabber_get_fulljid());
        jabber_conn.domain = strdup(my_jid->domainpart);
        jid_destroy(my_jid);

        chat_sessions_init();

        roster_add_handlers();
        message_add_handlers();
        presence_add_handlers();
        iq_add_handlers();

        roster_request();
        bookmark_request();

        if (prefs_get_boolean(PREF_CARBONS)){
            iq_enable_carbons();
        }

        if ((prefs_get_reconnect() != 0) && reconnect_timer) {
            g_timer_destroy(reconnect_timer);
            reconnect_timer = NULL;
        }

    } else if (status == XMPP_CONN_DISCONNECT) {
        log_debug("Connection handler: XMPP_CONN_DISCONNECT");

        // lost connection for unknown reason
        if (jabber_conn.conn_status == JABBER_CONNECTED) {
            log_debug("Connection handler: Lost connection for unknown reason");
            _jabber_lost_connection();

        // login attempt failed
        } else if (jabber_conn.conn_status != JABBER_DISCONNECTING) {
            log_debug("Connection handler: Login failed");
            if (reconnect_timer == NULL) {
                log_debug("Connection handler: No reconnect timer");
                sv_ev_failed_login();
                _connection_free_saved_account();
                _connection_free_saved_details();
                _connection_free_session_data();
            } else {
                log_debug("Connection handler: Restarting reconnect timer");
                if (prefs_get_reconnect() != 0) {
                    g_timer_start(reconnect_timer);
                }
                // free resources but leave saved_user untouched
                _connection_free_session_data();
            }
        }

        // close stream response from server after disconnect is handled too
        jabber_conn.conn_status = JABBER_DISCONNECTED;
    } else if (status == XMPP_CONN_FAIL) {
        log_debug("Connection handler: XMPP_CONN_FAIL");
    } else {
        log_error("Connection handler: Unknown status");
    }
}

static log_level_t
_get_log_level(const xmpp_log_level_t xmpp_level)
{
    if (xmpp_level == XMPP_LEVEL_DEBUG) {
        return PROF_LEVEL_DEBUG;
    } else if (xmpp_level == XMPP_LEVEL_INFO) {
        return PROF_LEVEL_INFO;
    } else if (xmpp_level == XMPP_LEVEL_WARN) {
        return PROF_LEVEL_WARN;
    } else {
        return PROF_LEVEL_ERROR;
    }
}

static xmpp_log_level_t
_get_xmpp_log_level()
{
    log_level_t prof_level = log_get_filter();

    if (prof_level == PROF_LEVEL_DEBUG) {
        return XMPP_LEVEL_DEBUG;
    } else if (prof_level == PROF_LEVEL_INFO) {
        return XMPP_LEVEL_INFO;
    } else if (prof_level == PROF_LEVEL_WARN) {
        return XMPP_LEVEL_WARN;
    } else {
        return XMPP_LEVEL_ERROR;
    }
}

static void
_xmpp_file_logger(void *const userdata, const xmpp_log_level_t level, const char *const area, const char *const msg)
{
    log_level_t prof_level = _get_log_level(level);
    log_msg(prof_level, area, msg);
    if ((g_strcmp0(area, "xmpp") == 0) || (g_strcmp0(area, "conn")) == 0) {
        sv_ev_xmpp_stanza(msg);
    }
}

static xmpp_log_t*
_xmpp_get_file_logger()
{
    xmpp_log_level_t level = _get_xmpp_log_level();
    xmpp_log_t *file_log = malloc(sizeof(xmpp_log_t));

    file_log->handler = _xmpp_file_logger;
    file_log->userdata = &level;

    return file_log;
}