/*
 * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */

/* DEBUG: section 46    Access Log */

#include "squid.h"
#include "AccessLogEntry.h"
#include "acl/Checklist.h"
#include "sbuf/Algorithms.h"
#if USE_ADAPTATION
#include "adaptation/Config.h"
#endif
#include "base/PackableStream.h"
#include "CachePeer.h"
#include "error/Detail.h"
#include "errorpage.h"
#include "format/Token.h"
#include "globals.h"
#include "hier_code.h"
#include "HttpReply.h"
#include "HttpRequest.h"
#include "log/access_log.h"
#include "log/Config.h"
#include "log/CustomLog.h"
#include "log/File.h"
#include "log/Formats.h"
#include "MemBuf.h"
#include "mgr/Registration.h"
#include "rfc1738.h"
#include "sbuf/SBuf.h"
#include "SquidConfig.h"
#include "Store.h"

#if USE_SQUID_EUI
#include "eui/Eui48.h"
#include "eui/Eui64.h"
#endif

#include <unordered_map>

#if USE_FORW_VIA_DB

using HeaderValueCountsElement = std::pair<const SBuf, uint64_t>;
/// counts the number of header field value occurrences
using HeaderValueCounts = std::unordered_map<SBuf, uint64_t, std::hash<SBuf>, std::equal_to<SBuf>, PoolingAllocator<HeaderValueCountsElement> >;

/// counts the number of HTTP Via header field value occurrences
static HeaderValueCounts TheViaCounts;
/// counts the number of HTTP X-Forwarded-For header field value occurrences
static HeaderValueCounts TheForwardedCounts;

static OBJH fvdbDumpVia;
static OBJH fvdbDumpForwarded;
static void fvdbClear(void);
static void fvdbRegisterWithCacheManager();
#endif

int LogfileStatus = LOG_DISABLE;

void
accessLogLogTo(CustomLog *log, const AccessLogEntryPointer &al, ACLChecklist *checklist)
{

    if (al->url.isEmpty())
        al->url = Format::Dash;

    if (!al->http.content_type || *al->http.content_type == '\0')
        al->http.content_type = dash_str;

    if (al->hier.host[0] == '\0')
        xstrncpy(al->hier.host, dash_str, SQUIDHOSTNAMELEN);

    for (; log; log = log->next) {
        if (log->aclList && checklist && !checklist->fastCheck(log->aclList).allowed())
            continue;

        // The special-case "none" type has no logfile object set
        if (log->type == Log::Format::CLF_NONE)
            return;

        if (log->logfile) {
            logfileLineStart(log->logfile);

            switch (log->type) {

            case Log::Format::CLF_SQUID:
                Log::Format::SquidNative(al, log->logfile);
                break;

            case Log::Format::CLF_COMBINED:
                Log::Format::HttpdCombined(al, log->logfile);
                break;

            case Log::Format::CLF_COMMON:
                Log::Format::HttpdCommon(al, log->logfile);
                break;

            case Log::Format::CLF_REFERER:
                Log::Format::SquidReferer(al, log->logfile);
                break;

            case Log::Format::CLF_USERAGENT:
                Log::Format::SquidUserAgent(al, log->logfile);
                break;

            case Log::Format::CLF_CUSTOM:
                Log::Format::SquidCustom(al, log);
                break;

#if ICAP_CLIENT
            case Log::Format::CLF_ICAP_SQUID:
                Log::Format::SquidIcap(al, log->logfile);
                break;
#endif

            default:
                fatalf("Unknown log format %d\n", log->type);
                break;
            }

            logfileLineEnd(log->logfile);
        }

        // NP:  WTF?  if _any_ log line has no checklist ignore the following ones?
        if (!checklist)
            break;
    }
}

void
accessLogLog(const AccessLogEntryPointer &al, ACLChecklist *checklist)
{
    if (LogfileStatus != LOG_ENABLE)
        return;

    accessLogLogTo(Config.Log.accesslogs, al, checklist);
}

void
accessLogRotate(void)
{
    CustomLog *log;
#if USE_FORW_VIA_DB

    fvdbClear();
#endif

    for (log = Config.Log.accesslogs; log; log = log->next) {
        log->rotate();
    }
}

void
accessLogClose(void)
{
    CustomLog *log;

    for (log = Config.Log.accesslogs; log; log = log->next) {
        if (log->logfile) {
            logfileClose(log->logfile);
            log->logfile = nullptr;
        }
    }
}

HierarchyLogEntry::HierarchyLogEntry() :
    code(HIER_NONE),
    cd_lookup(LOOKUP_NONE),
    n_choices(0),
    n_ichoices(0),
    peer_reply_status(Http::scNone),
    tcpServer(nullptr),
    bodyBytesRead(-1)
{
    memset(host, '\0', SQUIDHOSTNAMELEN);
    memset(cd_host, '\0', SQUIDHOSTNAMELEN);

    peer_select_start.tv_sec =0;
    peer_select_start.tv_usec =0;

    store_complete_stop.tv_sec =0;
    store_complete_stop.tv_usec =0;

    clearPeerNotes();
}

void
HierarchyLogEntry::resetPeerNotes(const Comm::ConnectionPointer &server, const char *requestedHost)
{
    clearPeerNotes();

    tcpServer = server;
    if (tcpServer == nullptr) {
        code = HIER_NONE;
        xstrncpy(host, requestedHost, sizeof(host));
    } else {
        code = tcpServer->peerType;

        if (tcpServer->getPeer()) {
            // went to peer, log peer host name
            xstrncpy(host, tcpServer->getPeer()->name, sizeof(host));
        } else {
            xstrncpy(host, requestedHost, sizeof(host));
        }
    }
}

/// forget previous notePeerRead() and notePeerWrite() calls (if any)
void
HierarchyLogEntry::clearPeerNotes()
{
    peer_last_read_.tv_sec = 0;
    peer_last_read_.tv_usec = 0;

    peer_last_write_.tv_sec = 0;
    peer_last_write_.tv_usec = 0;

    bodyBytesRead = -1;
}

void
HierarchyLogEntry::notePeerRead()
{
    peer_last_read_ = current_time;
}

void
HierarchyLogEntry::notePeerWrite()
{
    peer_last_write_ = current_time;
}

bool
HierarchyLogEntry::peerResponseTime(struct timeval &responseTime)
{
    // no I/O whatsoever
    if (peer_last_write_.tv_sec <= 0 && peer_last_read_.tv_sec <= 0)
        return false;

    // accommodate read without (completed) write
    const auto last_write = peer_last_write_.tv_sec > 0 ?
                            peer_last_write_ : peer_last_read_;

    // accommodate write without (completed) read
    const auto last_read = peer_last_read_.tv_sec > 0 ?
                           peer_last_read_ : peer_last_write_;

    tvSub(responseTime, last_write, last_read);
    // The peer response time (%<pt) stopwatch is currently defined to start
    // when we wrote the entire request. Thus, if we wrote something after the
    // last read, report zero peer response time.
    if (responseTime.tv_sec < 0) {
        responseTime.tv_sec = 0;
        responseTime.tv_usec = 0;
    }

    return true;
}

static void
accessLogRegisterWithCacheManager(void)
{
#if USE_FORW_VIA_DB
    fvdbRegisterWithCacheManager();
#endif
}

void
accessLogInit(void)
{
    CustomLog *log;

    accessLogRegisterWithCacheManager();

#if USE_ADAPTATION
    Log::TheConfig.hasAdaptToken = false;
#endif
#if ICAP_CLIENT
    Log::TheConfig.hasIcapToken = false;
#endif

    for (log = Config.Log.accesslogs; log; log = log->next) {
        if (log->type == Log::Format::CLF_NONE)
            continue;

        log->logfile = logfileOpen(log->filename, log->bufferSize, log->fatal);

        LogfileStatus = LOG_ENABLE;

#if USE_ADAPTATION
        for (Format::Token * curr_token = (log->logFormat?log->logFormat->format:nullptr); curr_token; curr_token = curr_token->next) {
            if (curr_token->type == Format::LFT_ADAPTATION_SUM_XACT_TIMES ||
                    curr_token->type == Format::LFT_ADAPTATION_ALL_XACT_TIMES ||
                    curr_token->type == Format::LFT_ADAPTATION_LAST_HEADER ||
                    curr_token->type == Format::LFT_ADAPTATION_LAST_HEADER_ELEM ||
                    curr_token->type == Format::LFT_ADAPTATION_LAST_ALL_HEADERS||
                    (curr_token->type == Format::LFT_NOTE && !Adaptation::Config::metaHeaders().empty())) {
                Log::TheConfig.hasAdaptToken = true;
            }
#if ICAP_CLIENT
            if (curr_token->type == Format::LFT_ICAP_TOTAL_TIME) {
                Log::TheConfig.hasIcapToken = true;
            }
#endif
        }
#endif
    }
}

#if USE_FORW_VIA_DB

static void
fvdbRegisterWithCacheManager(void)
{
    Mgr::RegisterAction("via_headers", "Via Request Headers", fvdbDumpVia, 0, 1);
    Mgr::RegisterAction("forw_headers", "X-Forwarded-For Request Headers",
                        fvdbDumpForwarded, 0, 1);
}

void
fvdbCountVia(const SBuf &headerValue)
{
    ++TheViaCounts[headerValue];
}

void
fvdbCountForwarded(const SBuf &key)
{
    ++TheForwardedCounts[key];
}

static void
fvdbDumpCounts(StoreEntry &e, const HeaderValueCounts &counts)
{
    PackableStream os(e);
    for (const auto &i : counts)
        os << std::setw(9) << i.second << ' ' << i.first << "\n";
}

static void
fvdbDumpVia(StoreEntry * e)
{
    assert(e);
    fvdbDumpCounts(*e, TheViaCounts);
}

static void
fvdbDumpForwarded(StoreEntry * e)
{
    assert(e);
    fvdbDumpCounts(*e, TheForwardedCounts);
}

static void
fvdbClear(void)
{
    TheViaCounts.clear();
    TheForwardedCounts.clear();
}

#endif