/** @file resetapi.cpp
    web rest api
*/
/**
*    Copyright (C) 2008 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.
*/

#define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kNetwork

#include "mongo/platform/basic.h"

#include "mongo/db/restapi.h"

#include "mongo/db/auth/authorization_manager.h"
#include "mongo/db/auth/authorization_session.h"
#include "mongo/db/auth/user_name.h"
#include "mongo/db/background.h"
#include "mongo/db/clientcursor.h"
#include "mongo/db/dbdirectclient.h"
#include "mongo/db/dbhelpers.h"
#include "mongo/db/dbwebserver.h"
#include "mongo/db/repl/master_slave.h"
#include "mongo/db/repl/replication_coordinator_global.h"
#include "mongo/util/log.h"
#include "mongo/util/md5.hpp"
#include "mongo/util/mongoutils/html.h"
#include "mongo/util/net/miniwebserver.h"

namespace mongo {

bool getInitialSyncCompleted();

using std::unique_ptr;
using std::string;
using std::stringstream;
using std::endl;
using std::vector;

using namespace html;

class RESTHandler : public DbWebHandler {
public:
    RESTHandler() : DbWebHandler("DUMMY REST", 1000, true) {}

    virtual bool handles(const string& url) const {
        return url[0] == '/' && url.find_last_of('/') > 0;
    }

    virtual void handle(OperationContext* txn,
                        const char* rq,
                        const std::string& url,
                        BSONObj params,
                        string& responseMsg,
                        int& responseCode,
                        vector<string>& headers,
                        const SockAddr& from) {
        DBDirectClient db(txn);

        string::size_type first = url.find("/", 1);
        if (first == string::npos) {
            responseCode = 400;
            return;
        }

        string method = MiniWebServer::parseMethod(rq);
        string dbname = url.substr(1, first - 1);
        string coll = url.substr(first + 1);
        string action = "";

        string::size_type last = coll.find_last_of("/");
        if (last == string::npos) {
            action = coll;
            coll = "_defaultCollection";
        } else {
            action = coll.substr(last + 1);
            coll = coll.substr(0, last);
        }

        for (string::size_type i = 0; i < coll.size(); i++)
            if (coll[i] == '/')
                coll[i] = '.';

        string fullns = MiniWebServer::urlDecode(dbname + "." + coll);

        headers.push_back((string) "x-action: " + action);
        headers.push_back((string) "x-ns: " + fullns);

        bool html = false;

        stringstream ss;

        if (method == "GET") {
            responseCode = 200;
            html = handleRESTQuery(txn, fullns, action, params, responseCode, ss);
        } else if (method == "POST") {
            responseCode = 201;
            handlePost(txn, fullns, MiniWebServer::body(rq), params, responseCode, ss);
        } else {
            responseCode = 400;
            headers.push_back("X_err: bad request");
            ss << "don't know how to handle a [" << method << "]";
            log() << "don't know how to handle a [" << method << "]" << endl;
        }

        if (html)
            headers.push_back("Content-Type: text/html;charset=utf-8");
        else
            headers.push_back("Content-Type: text/plain;charset=utf-8");

        responseMsg = ss.str();
    }

    bool handleRESTQuery(OperationContext* txn,
                         const std::string& ns,
                         const std::string& action,
                         BSONObj& params,
                         int& responseCode,
                         stringstream& out) {
        Timer t;

        int html = _getOption(params["html"], 0);
        int skip = _getOption(params["skip"], 0);
        int num = _getOption(params["limit"],
                             _getOption(params["count"], 1000));  // count is old, limit is new

        int one = 0;
        if (params["one"].type() == String && tolower(params["one"].valuestr()[0]) == 't') {
            num = 1;
            one = 1;
        }

        BSONObjBuilder queryBuilder;

        BSONObjIterator i(params);
        while (i.more()) {
            BSONElement e = i.next();
            string name = e.fieldName();
            if (name.find("filter_") != 0)
                continue;

            string field = name.substr(7);
            const char* val = e.valuestr();

            char* temp;

            // TODO: this is how i guess if something is a number.  pretty lame right now
            double number = strtod(val, &temp);
            if (temp != val)
                queryBuilder.append(field, number);
            else
                queryBuilder.append(field, val);
        }

        BSONObj query = queryBuilder.obj();

        DBDirectClient db(txn);
        unique_ptr<DBClientCursor> cursor = db.query(ns.c_str(), query, num, skip);
        uassert(13085, "query failed for dbwebserver", cursor.get());

        if (one) {
            if (cursor->more()) {
                BSONObj obj = cursor->next();
                out << obj.jsonString(Strict, html ? 1 : 0) << '\n';
            } else {
                responseCode = 404;
            }
            return html != 0;
        }

        if (html) {
            string title = string("query ") + ns;
            out << start(title) << p(title) << "<pre>";
        } else {
            out << "{\n";
            out << "  \"offset\" : " << skip << ",\n";
            out << "  \"rows\": [\n";
        }

        int howMany = 0;
        while (cursor->more()) {
            if (howMany++ && html == 0)
                out << " ,\n";
            BSONObj obj = cursor->next();
            if (html) {
                if (out.tellp() > 4 * 1024 * 1024) {
                    out << "Stopping output: more than 4MB returned and in html mode\n";
                    break;
                }
                out << obj.jsonString(Strict, html ? 1 : 0) << "\n\n";
            } else {
                if (out.tellp() > 50 * 1024 * 1024)  // 50MB limit - we are using ram
                    break;
                out << "    " << obj.jsonString();
            }
        }

        if (html) {
            out << "</pre>\n";
            if (howMany == 0)
                out << p("Collection is empty");
            out << _end();
        } else {
            out << "\n  ],\n\n";
            out << "  \"total_rows\" : " << howMany << " ,\n";
            out << "  \"query\" : " << query.jsonString() << " ,\n";
            out << "  \"millis\" : " << t.millis() << '\n';
            out << "}\n";
        }

        return html != 0;
    }

    // TODO Generate id and revision per couch POST spec
    void handlePost(OperationContext* txn,
                    const std::string& ns,
                    const char* body,
                    BSONObj& params,
                    int& responseCode,
                    stringstream& out) {
        try {
            BSONObj obj = fromjson(body);

            DBDirectClient db(txn);
            db.insert(ns.c_str(), obj);
        } catch (...) {
            responseCode = 400;  // Bad Request.  Seems reasonable for now.
            out << "{ \"ok\" : false }";
            return;
        }

        responseCode = 201;
        out << "{ \"ok\" : true }";
    }

    int _getOption(BSONElement e, int def) {
        if (e.isNumber())
            return e.numberInt();
        if (e.type() == String)
            return atoi(e.valuestr());
        return def;
    }
} restHandler;

bool RestAdminAccess::haveAdminUsers(OperationContext* txn) const {
    AuthorizationSession* authzSession = AuthorizationSession::get(txn->getClient());
    return authzSession->getAuthorizationManager().hasAnyPrivilegeDocuments(txn);
}

class LowLevelMongodStatus : public WebStatusPlugin {
public:
    LowLevelMongodStatus()
        : WebStatusPlugin("overview", 5, "(only reported if can acquire read lock quickly)") {}

    virtual void init() {}

    void _gotLock(int millis, stringstream& ss) {
        const repl::ReplSettings& replSettings =
            repl::getGlobalReplicationCoordinator()->getSettings();
        ss << "<pre>\n";
        ss << "time to get readlock: " << millis << "ms\n";
        ss << "# Cursors: " << ClientCursor::totalOpen() << '\n';
        ss << "replication: ";
        if (*repl::replInfo)
            ss << "\nreplInfo:  " << repl::replInfo << "\n\n";
        if (repl::getGlobalReplicationCoordinator()->getReplicationMode() ==
            repl::ReplicationCoordinator::modeReplSet) {
            ss << a("", "see replSetGetStatus link top of page") << "--replSet </a>"
               << replSettings.getReplSetString();
        }
        // TODO(dannenberg) replAllDead is bad and should be removed when masterslave is removed
        if (repl::replAllDead)
            ss << "\n<b>replication replAllDead=" << repl::replAllDead << "</b>\n";
        else {
            ss << "\nmaster: " << replSettings.isMaster() << '\n';
            ss << "slave:  " << replSettings.isSlave() << '\n';
            ss << '\n';
        }

        BackgroundOperation::dump(ss);
        ss << "</pre>\n";
    }

    virtual void run(OperationContext* txn, stringstream& ss) {
        Timer t;
        Lock::GlobalLock globalSLock(txn->lockState(), MODE_S, 300);
        if (globalSLock.isLocked()) {
            _gotLock(t.millis(), ss);
        } else {
            ss << "\n<b>timed out getting lock</b>\n";
        }
    }

} lowLevelMongodStatus;
}