// This file is part of BOINC.
// http://boinc.berkeley.edu
// Copyright (C) 2008 University of California
//
// BOINC is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License
// as published by the Free Software Foundation,
// either version 3 of the License, or (at your option) any later version.
//
// BOINC 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with BOINC.  If not, see <http://www.gnu.org/licenses/>.

// NET_STATS estimates average network throughput,
// i.e. the average total throughput in both the up and down directions.
//
// NET_STATUS keeps track of whether we have a physical connection,
// and whether we need one

#include "cpp.h"

#ifdef _WIN32
#include "boinc_win.h"
#else
#include "config.h"
#include <cstring>
#include <cmath>
#endif

#include "parse.h"
#include "time.h"
#include "str_util.h"
#include "error_numbers.h"
#include "util.h"
#include "filesys.h"

#include "client_msgs.h"
#include "client_state.h"
#include "file_names.h"
#include "cs_proxy.h"

#include "net_stats.h"

#define NET_RATE_HALF_LIFE  (7*86400)

DAILY_XFER_HISTORY daily_xfer_history;
NET_STATUS net_status;

NET_STATS::NET_STATS() {
    memset(&up, 0, sizeof(up));
    memset(&down, 0, sizeof(down));
}

// called after file xfer to update rates
//
void NET_INFO::update(double nbytes, double dt) {
    if (nbytes == 0 || dt==0) return;
    double bytes_sec = nbytes/dt;
    if (max_rate == 0) {
        max_rate = bytes_sec;   // first time
    } else {
        // somewhat arbitrary weighting formula
        //
        double w = log(nbytes)/500;
        if (w>1) w = 1;
        max_rate = w*bytes_sec + (1-w)*max_rate;
    }
    double start_time = gstate.now - dt;
    update_average(
        gstate.now,
        start_time,
        nbytes,
        NET_RATE_HALF_LIFE,
        avg_rate,
        avg_time
    );
}

int NET_STATS::write(MIOFILE& out) {
    out.printf(
        "<net_stats>\n"
        "    <bwup>%f</bwup>\n"
        "    <avg_up>%f</avg_up>\n"
        "    <avg_time_up>%f</avg_time_up>\n"
        "    <bwdown>%f</bwdown>\n"
        "    <avg_down>%f</avg_down>\n"
        "    <avg_time_down>%f</avg_time_down>\n"
        "</net_stats>\n",
        up.max_rate,
        up.avg_rate,
        up.avg_time,
        down.max_rate,
        down.avg_rate,
        down.avg_time
    );
    return 0;
}

int NET_STATS::parse(MIOFILE& in) {
    char buf[256];

    memset(this, 0, sizeof(NET_STATS));
    while (in.fgets(buf, 256)) {
        if (match_tag(buf, "</net_stats>")) return 0;
        if (parse_double(buf, "<bwup>", up.max_rate)) continue;
        if (parse_double(buf, "<avg_up>", up.avg_rate)) continue;
        if (parse_double(buf, "<avg_time_up>", up.avg_time)) continue;
        if (parse_double(buf, "<bwdown>", down.max_rate)) continue;
        if (parse_double(buf, "<avg_down>", down.avg_rate)) continue;
        if (parse_double(buf, "<avg_time_down>", down.avg_time)) continue;
        if (log_flags.unparsed_xml) {
            msg_printf(NULL, MSG_INFO,
                "[unparsed_xml] Unrecognized network statistics line: %s", buf
            );
        }
    }
    return ERR_XML_PARSE;
}

// Return:
// ONLINE if we have network connections open
// WANT_CONNECTION  if we need a physical connection
// WANT_DISCONNECT if we don't have any connections, and don't need any
// LOOKUP_PENDING if a website lookup is pending (try again later)
//
// There's a 10-second slop factor;
// if we've done network comm in the last 10 seconds,
// we act as if we're doing it now.
// (so that polling mechanisms have a chance to start other xfers,
// in the case of a modem connection waiting to be closed by the mgr)
//
int NET_STATUS::network_status() {
    int retval;

    if (gstate.http_ops->nops()) {
        last_comm_time = gstate.now;
    }
    if (need_to_contact_reference_site) {
        retval = NETWORK_STATUS_LOOKUP_PENDING;
    } else if (gstate.lookup_website_op.error_num == ERR_IN_PROGRESS) {
        retval = NETWORK_STATUS_LOOKUP_PENDING;
    } else if (gstate.now - last_comm_time < 10) {
        retval = NETWORK_STATUS_ONLINE;
    } else if (need_physical_connection) {
        retval = NETWORK_STATUS_WANT_CONNECTION;
    } else if (gstate.active_tasks.want_network()) {
        retval = NETWORK_STATUS_WANT_CONNECTION;
    } else {
        have_sporadic_connection = false;
        retval = NETWORK_STATUS_WANT_DISCONNECT;
    }
    if (log_flags.network_status_debug) {
        msg_printf(NULL, MSG_INFO, "[network_status] status: %s", network_status_string(retval));
    }
    return retval;
}

// There's now a network connection, after some period of disconnection.
// Do all communication that we can.
//
void NET_STATUS::network_available() {
    unsigned int i;

    have_sporadic_connection = true;
    for (i=0; i<gstate.pers_file_xfers->pers_file_xfers.size(); i++) {
        PERS_FILE_XFER* pfx = gstate.pers_file_xfers->pers_file_xfers[i];
        pfx->next_request_time = 0;
    }
    for (i=0; i<gstate.projects.size(); i++) {
        PROJECT* p = gstate.projects[i];
        p->min_rpc_time = 0;
    }

    // tell active tasks that network is available (for Folding@home)
    //
    gstate.active_tasks.network_available();
}

// An HTTP operation failed;
// it could be because there's no physical network connection.
// Find out for sure by trying to contact a reference site
//
void NET_STATUS::got_http_error() {
    // Cause a round of proxy detections to occur
    if (working_proxy_info.autodetect_proxy_supported) {
        working_proxy_info.need_autodetect_proxy_settings = true;
        working_proxy_info.have_autodetect_proxy_settings = false;
    }

    if (gstate.lookup_website_op.error_num == ERR_IN_PROGRESS) return;

    // Don't spam the reference site when a project is down
    if (need_physical_connection) return;

    if (config.dont_contact_ref_site) return;

    if (log_flags.network_status_debug) {
        msg_printf(0, MSG_INFO,
            "[network_status] got HTTP error - checking ref site"
        );
    }
    need_to_contact_reference_site = true;
    show_ref_message = true;
}

void NET_STATUS::contact_reference_site() {
    if (log_flags.network_status_debug) {
        msg_printf(0, MSG_INFO,
            "[network_status] need_phys_conn %d; trying %s",
            need_physical_connection, config.network_test_url.c_str()
        );
    }
    gstate.lookup_website_op.do_rpc(config.network_test_url);
    need_to_contact_reference_site = false;
}

static void show_fail_msg() {
    msg_printf(0, MSG_USER_ALERT, NEED_NETWORK_MSG);
}

int LOOKUP_WEBSITE_OP::do_rpc(string& url) {
    int retval;

    if (net_status.show_ref_message) {
        msg_printf(0, MSG_INFO,
            "Project communication failed: attempting access to reference site"
        );
    }
    retval = gui_http->do_rpc(
        this, (char*)url.c_str(), LOOKUP_WEBSITE_FILENAME, true
    );
    if (retval) {
        error_num = retval;
        net_status.need_physical_connection = true;
        net_status.last_comm_time = 0;

        show_fail_msg();
    } else {
        error_num = ERR_IN_PROGRESS;
    }
    return retval;
}

void LOOKUP_WEBSITE_OP::handle_reply(int http_op_retval) {
    error_num = http_op_retval;

    // if we couldn't contact a reference web site,
    // we can assume there's a problem that requires user attention
    // (usually no physical network connection).
    // Set a flag that will signal the Manager to that effect
    //
    if (http_op_retval) {
        net_status.need_physical_connection = true;
        net_status.last_comm_time = 0;
        show_fail_msg();
    } else {
        if (net_status.show_ref_message) {
            msg_printf(0, MSG_INFO,
                "Internet access OK - project servers may be temporarily down."
            );
        }
    }
}

void NET_STATUS::poll() {
    // for 30 seconds after wakeup, the network system (DNS etc.)
    // may still be coming up, so defer the reference site check;
    // otherwise might show spurious "need connection" message
    //
    if (gstate.now < gstate.last_wakeup_time + 30) return;
    // wait until after a round of automatic proxy detection 
    // before attempting to contact the reference site
    //
    if (working_proxy_info.autodetect_proxy_supported && 
        working_proxy_info.need_autodetect_proxy_settings &&
        !working_proxy_info.have_autodetect_proxy_settings) return;

    if (net_status.need_to_contact_reference_site && !gstate.gui_http.is_busy()) {
        net_status.contact_reference_site();
    }
}

int DAILY_XFER::parse(XML_PARSER& xp) {
    char tag[1024];
    bool is_tag;

    while (!xp.get(tag, sizeof(tag), is_tag)) {
        if (!strcmp(tag, "/dx")) return 0;
        if (xp.parse_int(tag, "when", when)) continue;
        if (xp.parse_double(tag, "up", up)) continue;
        if (xp.parse_double(tag, "down", down)) continue;
    }
    return ERR_XML_PARSE;
}

void DAILY_XFER::write(FILE* f) {
    fprintf(f,
        "<dx>\n"
        "   <when>%d</when>\n"
        "   <up>%f</up>\n"
        "   <down>%f</down>\n"
        "</dx>\n",
        when, up, down
    );
}

inline int current_day() {
    return (int)((gstate.now + gstate.host_info.timezone)/86400);
}

DAILY_XFER* DAILY_XFER_HISTORY::today() {
    int d = current_day();
    for (unsigned int i=0; i<daily_xfers.size(); i++) {
        DAILY_XFER& dx = daily_xfers[i];
        if (dx.when == d) {
            return &dx;
        }
    }
    DAILY_XFER dx;
    dx.when = d;
    daily_xfers.push_front(dx);
    return &(daily_xfers.front());
}

void DAILY_XFER_HISTORY::add(size_t x, bool upload) {
    DAILY_XFER* dxp = today();
    if (upload) {
        dxp->up += x;
    } else {
        dxp->down += x;
    }
    dirty = true;
}

void DAILY_XFER_HISTORY::init() {
    FILE* f = fopen(DAILY_XFER_HISTORY_FILENAME, "r");
    if (!f) return;

    MIOFILE mf;
    XML_PARSER xp(&mf);
    mf.init_file(f);
    bool is_tag;
    char tag[256];

    int d = current_day();

    if (!xp.parse_start("daily_xfers")) {
        fclose(f);
        return;
    }
    while (!xp.get(tag, sizeof(tag), is_tag)) {
        if (!is_tag) continue;
        if (!strcmp(tag, "dx")) {
            DAILY_XFER dx;
            int retval = dx.parse(xp);
            if (!retval && d - dx.when < 365) {
                // discard records after a year
                daily_xfers.push_back(dx);
            }
        }
    }
    fclose(f);
}

void DAILY_XFER_HISTORY::poll() {
    static double last_time= 0;

    if (!dirty) return;
    if (gstate.now - last_time < DAILY_XFER_HISTORY_PERIOD) return;
    last_time = gstate.now;
    write_state();
}


void DAILY_XFER_HISTORY::write_state() {
    FILE* f = fopen(TEMP_FILE_NAME, "w");
    if (!f) return;
    fprintf(f, "<daily_xfers>\n");
    for (unsigned int i=0; i<daily_xfers.size(); i++) {
        DAILY_XFER& dx = daily_xfers[i];
        dx.write(f);
    }
    int n = fprintf(f, "</daily_xfers>\n");
    fclose(f);
    if (n > 0) {
        int retval = boinc_rename(TEMP_FILE_NAME, DAILY_XFER_HISTORY_FILENAME);
        if (!retval) {
            dirty = false;
        }
    }
}

void DAILY_XFER_HISTORY::totals(int ndays, double& up, double& down) {
    int d = (current_day() - ndays);
    up = down = 0;
    for (unsigned int i=0; i<daily_xfers.size(); i++) {
        DAILY_XFER& dx = daily_xfers[i];
        if (dx.when <= d) break;
        up += dx.up;
        down += dx.down;
    }
}

void DAILY_XFER_HISTORY::write_scheduler_request(MIOFILE& mf, int ndays) {
    double up, down;
    totals(ndays, up, down);
    mf.printf(
        "<daily_xfer_history>\n"
        "   <ndays>%d</ndays>\n"
        "   <up>%f</up>\n"
        "   <down>%f</down>\n"
        "</daily_xfer_history>\n",
        ndays, up, down
    );
}