/**
*    Copyright (C) 2009 10gen Inc.
*
*    This program is free software: you can redistribute it and/or  modify
*    it under the terms of the GNU Affero General Public License, version 3,
*    as published by the Free Software Foundation.
*
*    This program 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 Affero General Public License for more details.
*
*    You should have received a copy of the GNU Affero General Public License
*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
*    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 program with the OpenSSL library. You
*    must comply with the GNU Affero General Public License in all respects for
*    all of the code used other than as permitted herein. 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 in the license file.
*/

// CHECK_LOG_REDACTION

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault

#include "mongo/platform/basic.h"

#include "mongo/db/curop.h"

#include "mongo/base/disallow_copying.h"
#include "mongo/bson/mutable/document.h"
#include "mongo/db/client.h"
#include "mongo/db/commands.h"
#include "mongo/db/commands/server_status_metric.h"
#include "mongo/db/json.h"
#include "mongo/db/query/getmore_request.h"
#include "mongo/db/query/plan_summary_stats.h"
#include "mongo/rpc/metadata/client_metadata.h"
#include "mongo/rpc/metadata/client_metadata_ismaster.h"
#include "mongo/util/log.h"
#include "mongo/util/stringutils.h"

namespace mongo {

using std::string;

namespace {

// Lists the $-prefixed query options that can be passed alongside a wrapped query predicate for
// OP_QUERY find. The $orderby field is omitted because "orderby" (no dollar sign) is also allowed,
// and this requires special handling.
const std::vector<const char*> kDollarQueryModifiers = {
    "$hint",
    "$comment",
    "$maxScan",
    "$max",
    "$min",
    "$returnKey",
    "$showDiskLoc",
    "$snapshot",
    "$maxTimeMS",
};

}  // namespace

BSONObj upconvertQueryEntry(const BSONObj& query,
                            const NamespaceString& nss,
                            int ntoreturn,
                            int ntoskip) {
    BSONObjBuilder bob;

    bob.append("find", nss.coll());

    // Whether or not the query predicate is wrapped inside a "query" or "$query" field so that
    // other options can be passed alongside the predicate.
    bool predicateIsWrapped = false;

    // Extract the query predicate.
    BSONObj filter;
    if (auto elem = query["query"]) {
        predicateIsWrapped = true;
        bob.appendAs(elem, "filter");
    } else if (auto elem = query["$query"]) {
        predicateIsWrapped = true;
        bob.appendAs(elem, "filter");
    } else if (!query.isEmpty()) {
        bob.append("filter", query);
    }

    if (ntoskip) {
        bob.append("skip", ntoskip);
    }
    if (ntoreturn) {
        bob.append("ntoreturn", ntoreturn);
    }

    // The remainder of the query options are only available if the predicate is passed in wrapped
    // form. If the predicate is not wrapped, we're done.
    if (!predicateIsWrapped) {
        return bob.obj();
    }

    // Extract the sort.
    if (auto elem = query["orderby"]) {
        bob.appendAs(elem, "sort");
    } else if (auto elem = query["$orderby"]) {
        bob.appendAs(elem, "sort");
    }

    // Add $-prefixed OP_QUERY modifiers, like $hint.
    for (auto modifier : kDollarQueryModifiers) {
        if (auto elem = query[modifier]) {
            // Use "+ 1" to omit the leading dollar sign.
            bob.appendAs(elem, modifier + 1);
        }
    }

    return bob.obj();
}

BSONObj upconvertGetMoreEntry(const NamespaceString& nss, CursorId cursorId, int ntoreturn) {
    return GetMoreRequest(nss,
                          cursorId,
                          ntoreturn,
                          boost::none,  // awaitDataTimeout
                          boost::none,  // term
                          boost::none   // lastKnownCommittedOpTime
                          )
        .toBSON();
}

/**
 * This type decorates a Client object with a stack of active CurOp objects.
 *
 * It encapsulates the nesting logic for curops attached to a Client, along with
 * the notion that there is always a root CurOp attached to a Client.
 *
 * The stack itself is represented in the _parent pointers of the CurOp class.
 */
class CurOp::CurOpStack {
    MONGO_DISALLOW_COPYING(CurOpStack);

public:
    CurOpStack() : _base(nullptr, this) {}

    /**
     * Returns the top of the CurOp stack.
     */
    CurOp* top() const {
        return _top;
    }

    /**
     * Adds "curOp" to the top of the CurOp stack for a client. Called by CurOp's constructor.
     */
    void push(OperationContext* opCtx, CurOp* curOp) {
        invariant(opCtx);
        if (_opCtx) {
            invariant(_opCtx == opCtx);
        } else {
            _opCtx = opCtx;
        }
        stdx::lock_guard<Client> lk(*_opCtx->getClient());
        push_nolock(curOp);
    }

    void push_nolock(CurOp* curOp) {
        invariant(!curOp->_parent);
        curOp->_parent = _top;
        _top = curOp;
    }

    /**
     * Pops the top off the CurOp stack for a Client. Called by CurOp's destructor.
     */
    CurOp* pop() {
        // It is not necessary to lock when popping the final item off of the curop stack. This
        // is because the item at the base of the stack is owned by the stack itself, and is not
        // popped until the stack is being destroyed.  By the time the stack is being destroyed,
        // no other threads can be observing the Client that owns the stack, because it has been
        // removed from its ServiceContext's set of owned clients.  Further, because the last
        // item is popped in the destructor of the stack, and that destructor runs during
        // destruction of the owning client, it is not safe to access other member variables of
        // the client during the final pop.
        const bool shouldLock = _top->_parent;
        if (shouldLock) {
            invariant(_opCtx);
            _opCtx->getClient()->lock();
        }
        invariant(_top);
        CurOp* retval = _top;
        _top = _top->_parent;
        if (shouldLock) {
            _opCtx->getClient()->unlock();
        }
        return retval;
    }

private:
    OperationContext* _opCtx = nullptr;

    // Top of the stack of CurOps for a Client.
    CurOp* _top = nullptr;

    // The bottom-most CurOp for a client.
    const CurOp _base;
};

const OperationContext::Decoration<CurOp::CurOpStack> CurOp::_curopStack =
    OperationContext::declareDecoration<CurOp::CurOpStack>();

CurOp* CurOp::get(const OperationContext* opCtx) {
    return get(*opCtx);
}

CurOp* CurOp::get(const OperationContext& opCtx) {
    return _curopStack(opCtx).top();
}

CurOp::CurOp(OperationContext* opCtx) : CurOp(opCtx, &_curopStack(opCtx)) {}

CurOp::CurOp(OperationContext* opCtx, CurOpStack* stack) : _stack(stack) {
    if (opCtx) {
        _stack->push(opCtx, this);
    } else {
        _stack->push_nolock(this);
    }
}

ProgressMeter& CurOp::setMessage_inlock(const char* msg,
                                        std::string name,
                                        unsigned long long progressMeterTotal,
                                        int secondsBetween) {
    if (progressMeterTotal) {
        if (_progressMeter.isActive()) {
            error() << "old _message: " << redact(_message) << " new message:" << redact(msg);
            verify(!_progressMeter.isActive());
        }
        _progressMeter.reset(progressMeterTotal, secondsBetween);
        _progressMeter.setName(name);
    } else {
        _progressMeter.finished();
    }
    _message = msg;
    return _progressMeter;
}

CurOp::~CurOp() {
    invariant(this == _stack->pop());
}

void CurOp::setNS_inlock(StringData ns) {
    _ns = ns.toString();
}

void CurOp::ensureStarted() {
    if (_start == 0) {
        _start = curTimeMicros64();
    }
}

void CurOp::enter_inlock(const char* ns, boost::optional<int> dbProfileLevel) {
    ensureStarted();
    _ns = ns;
    if (dbProfileLevel) {
        raiseDbProfileLevel(*dbProfileLevel);
    }
}

void CurOp::raiseDbProfileLevel(int dbProfileLevel) {
    _dbprofile = std::max(dbProfileLevel, _dbprofile);
}

Command::ReadWriteType CurOp::getReadWriteType() const {
    if (_command) {
        return _command->getReadWriteType();
    }
    switch (_logicalOp) {
        case LogicalOp::opGetMore:
        case LogicalOp::opQuery:
            return Command::ReadWriteType::kRead;
        case LogicalOp::opUpdate:
        case LogicalOp::opInsert:
        case LogicalOp::opDelete:
            return Command::ReadWriteType::kWrite;
        default:
            return Command::ReadWriteType::kCommand;
    }
}

namespace {

/**
 * Appends {<name>: obj} to the provided builder.  If obj is greater than maxSize, appends a string
 * summary of obj as { <name>: { $truncated: "obj" } }. If a comment parameter is present, add it to
 * the truncation object.
 */
void appendAsObjOrString(StringData name,
                         const BSONObj& obj,
                         const boost::optional<size_t> maxSize,
                         BSONObjBuilder* builder) {
    if (!maxSize || static_cast<size_t>(obj.objsize()) <= *maxSize) {
        builder->append(name, obj);
    } else {
        // Generate an abbreviated serialization for the object, by passing false as the
        // "full" argument to obj.toString().
        std::string objToString = obj.toString();
        if (objToString.size() > *maxSize) {
            // objToString is still too long, so we append to the builder a truncated form
            // of objToString concatenated with "...".  Instead of creating a new string
            // temporary, mutate objToString to do this (we know that we can mutate
            // characters in objToString up to and including objToString[maxSize]).
            objToString[*maxSize - 3] = '.';
            objToString[*maxSize - 2] = '.';
            objToString[*maxSize - 1] = '.';
        }

        StringData truncation = StringData(objToString).substr(0, *maxSize);

        // Append the truncated representation of the object to the builder. If a comment parameter
        // is present, write it to the object alongside the truncated op. This object will appear as
        // {$truncated: "{find: \"collection\", filter: {x: 1, ...", comment: "comment text" }
        BSONObjBuilder truncatedBuilder(builder->subobjStart(name));
        truncatedBuilder.append("$truncated", truncation);

        if (auto comment = obj["comment"]) {
            truncatedBuilder.append(comment);
        }

        truncatedBuilder.doneFast();
    }
}
}  // namespace

void CurOp::reportState(BSONObjBuilder* builder, bool truncateOps) {
    if (_start) {
        builder->append("secs_running", durationCount<Seconds>(elapsedTimeTotal()));
        builder->append("microsecs_running", durationCount<Microseconds>(elapsedTimeTotal()));
    }

    builder->append("op", logicalOpToString(_logicalOp));
    builder->append("ns", _ns);

    // When the currentOp command is run, it returns a single response object containing all current
    // operations; this request will fail if the response exceeds the 16MB document limit. By
    // contrast, the $currentOp aggregation stage does not have this restriction. If 'truncateOps'
    // is true, limit the size of each op to 1000 bytes. Otherwise, do not truncate.
    const boost::optional<size_t> maxQuerySize{truncateOps, 1000};

    if (!_command && _networkOp == dbQuery) {
        // This is a legacy OP_QUERY. We upconvert the "query" field of the currentOp output to look
        // similar to a find command.
        //
        // CurOp doesn't have access to the ntoreturn or ntoskip values. By setting them to zero, we
        // will omit mention of them in the currentOp output.
        const int ntoreturn = 0;
        const int ntoskip = 0;

        appendAsObjOrString(
            "command",
            upconvertQueryEntry(_opDescription, NamespaceString(_ns), ntoreturn, ntoskip),
            maxQuerySize,
            builder);
    } else {
        appendAsObjOrString("command", _opDescription, maxQuerySize, builder);
    }

    if (!_originatingCommand.isEmpty()) {
        appendAsObjOrString("originatingCommand", _originatingCommand, maxQuerySize, builder);
    }

    if (!_planSummary.empty()) {
        builder->append("planSummary", _planSummary);
    }

    if (!_message.empty()) {
        if (_progressMeter.isActive()) {
            StringBuilder buf;
            buf << _message << " " << _progressMeter.toString();
            builder->append("msg", buf.str());
            BSONObjBuilder sub(builder->subobjStart("progress"));
            sub.appendNumber("done", (long long)_progressMeter.done());
            sub.appendNumber("total", (long long)_progressMeter.total());
            sub.done();
        } else {
            builder->append("msg", _message);
        }
    }

    builder->append("numYields", _numYields);
}

namespace {
StringData getProtoString(int op) {
    if (op == dbMsg) {
        return "op_msg";
    } else if (op == dbQuery) {
        return "op_query";
    } else if (op == dbCommand) {
        return "op_command";
    }
    MONGO_UNREACHABLE;
}
}  // namespace

#define OPDEBUG_TOSTRING_HELP(x) \
    if (x >= 0)                  \
    s << " " #x ":" << (x)
#define OPDEBUG_TOSTRING_HELP_BOOL(x) \
    if (x)                            \
    s << " " #x ":" << (x)

string OpDebug::report(Client* client,
                       const CurOp& curop,
                       const SingleThreadedLockStats& lockStats) const {
    StringBuilder s;
    if (iscommand)
        s << "command ";
    else
        s << networkOpToString(networkOp) << ' ';

    s << curop.getNS();

    const auto& clientMetadata = ClientMetadataIsMasterState::get(client).getClientMetadata();
    if (clientMetadata) {
        auto appName = clientMetadata.get().getApplicationName();
        if (!appName.empty()) {
            s << " appName: \"" << escape(appName) << '\"';
        }
    }

    BSONObj query;

    // If necessary, upconvert legacy find operations so that their log lines resemble their find
    // command counterpart.
    if (!iscommand && networkOp == dbQuery) {
        query = upconvertQueryEntry(
            curop.opDescription(), NamespaceString(curop.getNS()), ntoreturn, ntoskip);
    } else {
        query = curop.opDescription();
    }

    if (!query.isEmpty()) {
        s << " command: ";
        if (iscommand) {
            Command* curCommand = curop.getCommand();
            if (curCommand) {
                mutablebson::Document cmdToLog(query, mutablebson::Document::kInPlaceDisabled);
                curCommand->redactForLogging(&cmdToLog);
                s << curCommand->getName() << " ";
                s << redact(cmdToLog.getObject());
            } else {  // Should not happen but we need to handle curCommand == NULL gracefully.
                s << redact(query);
            }
        } else {
            s << redact(query);
        }
    }

    auto originatingCommand = curop.originatingCommand();
    if (!originatingCommand.isEmpty()) {
        s << " originatingCommand: " << redact(originatingCommand);
    }

    if (!curop.getPlanSummary().empty()) {
        s << " planSummary: " << redact(curop.getPlanSummary().toString());
    }

    OPDEBUG_TOSTRING_HELP(cursorid);
    OPDEBUG_TOSTRING_HELP(ntoreturn);
    OPDEBUG_TOSTRING_HELP(ntoskip);
    OPDEBUG_TOSTRING_HELP_BOOL(exhaust);

    OPDEBUG_TOSTRING_HELP(keysExamined);
    OPDEBUG_TOSTRING_HELP(docsExamined);
    OPDEBUG_TOSTRING_HELP_BOOL(hasSortStage);
    OPDEBUG_TOSTRING_HELP_BOOL(fromMultiPlanner);
    OPDEBUG_TOSTRING_HELP_BOOL(replanned);
    OPDEBUG_TOSTRING_HELP(nMatched);
    OPDEBUG_TOSTRING_HELP(nModified);
    OPDEBUG_TOSTRING_HELP(ninserted);
    OPDEBUG_TOSTRING_HELP(ndeleted);
    OPDEBUG_TOSTRING_HELP_BOOL(fastmodinsert);
    OPDEBUG_TOSTRING_HELP_BOOL(upsert);
    OPDEBUG_TOSTRING_HELP_BOOL(cursorExhausted);

    if (nmoved > 0) {
        s << " nmoved:" << nmoved;
    }

    if (keysInserted > 0) {
        s << " keysInserted:" << keysInserted;
    }

    if (keysDeleted > 0) {
        s << " keysDeleted:" << keysDeleted;
    }

    if (writeConflicts > 0) {
        s << " writeConflicts:" << writeConflicts;
    }

    if (!exceptionInfo.empty()) {
        s << " exception: " << redact(exceptionInfo.msg);
        if (exceptionInfo.code)
            s << " code:" << exceptionInfo.code;
    }

    s << " numYields:" << curop.numYields();

    OPDEBUG_TOSTRING_HELP(nreturned);
    if (responseLength > 0) {
        s << " reslen:" << responseLength;
    }

    {
        BSONObjBuilder locks;
        lockStats.report(&locks);
        s << " locks:" << locks.obj().toString();
    }

    if (iscommand) {
        s << " protocol:" << getProtoString(networkOp);
    }

    s << " " << (executionTimeMicros / 1000) << "ms";

    return s.str();
}

#define OPDEBUG_APPEND_NUMBER(x) \
    if (x != -1)                 \
    b.appendNumber(#x, (x))
#define OPDEBUG_APPEND_BOOL(x) \
    if (x)                     \
    b.appendBool(#x, (x))

void OpDebug::append(const CurOp& curop,
                     const SingleThreadedLockStats& lockStats,
                     BSONObjBuilder& b) const {
    const size_t maxElementSize = 50 * 1024;

    b.append("op", logicalOpToString(logicalOp));

    NamespaceString nss = NamespaceString(curop.getNS());
    b.append("ns", nss.ns());

    if (!iscommand && networkOp == dbQuery) {
        appendAsObjOrString("command",
                            upconvertQueryEntry(curop.opDescription(), nss, ntoreturn, ntoskip),
                            maxElementSize,
                            &b);
    } else if (curop.haveOpDescription()) {
        appendAsObjOrString("command", curop.opDescription(), maxElementSize, &b);
    }

    auto originatingCommand = curop.originatingCommand();
    if (!originatingCommand.isEmpty()) {
        appendAsObjOrString("originatingCommand", originatingCommand, maxElementSize, &b);
    }

    OPDEBUG_APPEND_NUMBER(cursorid);
    OPDEBUG_APPEND_BOOL(exhaust);

    OPDEBUG_APPEND_NUMBER(keysExamined);
    OPDEBUG_APPEND_NUMBER(docsExamined);
    OPDEBUG_APPEND_BOOL(hasSortStage);
    OPDEBUG_APPEND_BOOL(fromMultiPlanner);
    OPDEBUG_APPEND_BOOL(replanned);
    OPDEBUG_APPEND_NUMBER(nMatched);
    OPDEBUG_APPEND_NUMBER(nModified);
    OPDEBUG_APPEND_NUMBER(ninserted);
    OPDEBUG_APPEND_NUMBER(ndeleted);
    OPDEBUG_APPEND_BOOL(fastmodinsert);
    OPDEBUG_APPEND_BOOL(upsert);
    OPDEBUG_APPEND_BOOL(cursorExhausted);

    if (nmoved > 0) {
        b.appendNumber("nmoved", nmoved);
    }

    if (keysInserted > 0) {
        b.appendNumber("keysInserted", keysInserted);
    }

    if (keysDeleted > 0) {
        b.appendNumber("keysDeleted", keysDeleted);
    }

    if (writeConflicts > 0) {
        b.appendNumber("writeConflicts", writeConflicts);
    }

    b.appendNumber("numYield", curop.numYields());

    {
        BSONObjBuilder locks(b.subobjStart("locks"));
        lockStats.report(&locks);
    }

    if (!exceptionInfo.empty()) {
        exceptionInfo.append(b, "exception", "exceptionCode");
    }

    OPDEBUG_APPEND_NUMBER(nreturned);
    OPDEBUG_APPEND_NUMBER(responseLength);
    if (iscommand) {
        b.append("protocol", getProtoString(networkOp));
    }
    b.appendIntOrLL("millis", executionTimeMicros / 1000);

    if (!curop.getPlanSummary().empty()) {
        b.append("planSummary", curop.getPlanSummary());
    }

    if (!execStats.isEmpty()) {
        b.append("execStats", execStats);
    }
}

void OpDebug::setPlanSummaryMetrics(const PlanSummaryStats& planSummaryStats) {
    keysExamined = planSummaryStats.totalKeysExamined;
    docsExamined = planSummaryStats.totalDocsExamined;
    hasSortStage = planSummaryStats.hasSortStage;
    fromMultiPlanner = planSummaryStats.fromMultiPlanner;
    replanned = planSummaryStats.replanned;
}

}  // namespace mongo