/*
 * $Id$
 *
 * This file is part of the Cloud Services Integration Platform (CSIP),
 * a Model-as-a-Service framework, API and application suite.
 *
 * 2012-2017, Olaf David and others, OMSLab, Colorado State University.
 *
 * OMSLab licenses this file to you under the MIT license.
 * See the LICENSE file in the project root for more information.
 */
package csip;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.DBObject;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import com.mongodb.WriteResult;
import com.mongodb.gridfs.GridFS;
import com.mongodb.gridfs.GridFSDBFile;
import com.mongodb.gridfs.GridFSInputFile;
import csip.utils.Binaries;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.LinkedHashSet;
import java.util.Set;

/**
 *
 */
class MongoArchiveStore implements ArchiveStore {

    MongoClient mongo;
    String dbname;
    static final String fsColl = "fs";


    MongoArchiveStore(String uri) {
        // "mongodb://user:pass@host:port/db"
        MongoClientURI u = new MongoClientURI(uri);
        dbname = u.getDatabase();
        if (dbname == null) {
            dbname = "csip";
        }
        mongo = new MongoClient(u);
        Config.LOG.info("Connected to archive csip store : " + uri);
    } // "mongodb://user:pass@host:port/db"


    public synchronized void removeAll() {
        DB db = mongo.getDB(dbname);
        //Let's store the standard data in regular collection
        DBCollection collection = db.getCollection(fsColl);
        collection.remove(new BasicDBObject());
        // remove all file in the bucket
        GridFS fileStore = new GridFS(db, fsColl);
        fileStore.remove((DBObject) null);
    }


    @Override
    public synchronized void archiveSession(String sid, ModelArchive ma, File f) throws Exception {
        DB db = mongo.getDB(dbname);
        //Let's store the standard data in regular collection
        DBCollection collection = db.getCollection(fsColl);
        String max = Config.getString(Config.CSIP_ARCHIVE_MAX_FILE_SIZE);
        long limit = Binaries.parseByteSize(max);
        String filename = null;
        long filesize = 0;
        InputStream is = null;
        if (f.length() <= limit) {
            filename = f.getName();
            filesize = f.length();
            is = new FileInputStream(f);
        } else {
            filename = sid + ".txt";
            filesize = ARCHIVE_TOO_BIG.length();
            is = new ByteArrayInputStream(ARCHIVE_TOO_BIG.getBytes());
        }
        // Let's query to ensure ID does not already exist in Mongo
        // if it does, we will alert the user
        BasicDBObject query = new BasicDBObject("_id", sid);
        DBCursor cursor = collection.find(query);
        if (!cursor.hasNext()) {
            // Build our document and add all the fields
            BasicDBObject doc = new BasicDBObject();
            doc.append("_id", sid);
            doc.append("service", ma.getService());
            doc.append("status", ma.getStatus());
            doc.append("ctime", ma.getCtime());
            doc.append("etime", ma.getEtime());
            doc.append("req_ip", ma.getReqIP());
            doc.append("filename", "files-" + filename);
            doc.append("filelength", filesize);
            //insert the document into the collection
            collection.insert(doc);
            // Now let's store the binary file data using filestore GridFS
            GridFS fileStore = new GridFS(db, fsColl);
            GridFSInputFile file = fileStore.createFile(is);
            file.setId(sid);
            file.setFilename("files-" + filename);
            file.save();
        } else {
            Config.LOG.warning("Unable to archive record with ID: " + sid + " as record already exists!!!");
        }
    }


    @Override
    public synchronized ModelArchive getArchive(String suid) throws Exception {
        DB db = mongo.getDB(dbname);
        DBCollection collection = db.getCollection(fsColl);
        BasicDBObject findQuery = new BasicDBObject("_id", suid);
        DBObject doc = collection.findOne(findQuery);
        if (doc != null) {
            ModelArchive ma = new ModelArchive(
                    doc.get("ctime").toString(),
                    doc.get("etime").toString(),
                    doc.get("service").toString(),
                    doc.get("status").toString(),
                    doc.get("req_ip").toString());
            return ma;
        }
        return null;
    }


    @Override
    public synchronized void removeArchive(String suid) {
        DB db = mongo.getDB(dbname);
        DBCollection collection = db.getCollection(fsColl);
        BasicDBObject q = new BasicDBObject("_id", suid);
        WriteResult res = collection.remove(q);
        GridFS fileStore = new GridFS(db, fsColl);
        fileStore.remove(q);
    }


    @Override
    public synchronized byte[] getFile(String suid, String filename) throws Exception {
        DB db = mongo.getDB(dbname);
        GridFS fileStore = new GridFS(db, fsColl);
        BasicDBObject query = new BasicDBObject("_id", suid);
        GridFSDBFile gridFile = fileStore.findOne(query);
        if (gridFile != null) {
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            gridFile.writeTo(out);
            return out.toByteArray();
        }
        return null;
    }


    @Override
    public synchronized void shutdown() throws Exception {
        mongo.close();
    }


    @Override
    public synchronized long getCount() {
        DB db = mongo.getDB(dbname);
        return db.getCollection(fsColl).count();
    }


    // new keys implementation.
    public synchronized Set<String> keys(int skip, int limit, String sortby, boolean sortAsc) {
        if (sortby == null) {
            sortby = "ctime";
            sortAsc = false;
        }
        BasicDBObject sort = new BasicDBObject(sortby, sortAsc ? 1 : -1);
        Set<String> l = new LinkedHashSet<>();
        DB db = mongo.getDB(dbname);
        DBCollection c = db.getCollection(fsColl);
        DBCursor cursor = c.find().sort(sort).skip(skip).limit(limit);
        while (cursor.hasNext()) {
            DBObject o = cursor.next();
            l.add(o.get("_id").toString());
        }
        return l;
    }


    @Override
    public synchronized boolean hasArchive(String suid) throws Exception {
        DB db = mongo.getDB(dbname);
        DBCollection c = db.getCollection(fsColl);
        return c.count(new BasicDBObject("_id", suid)) == 1;
    }

}