import-csv.js

var fs = require('fs'),
    path = require('path'),
    readline = require('readline'),
    csv = require('csv-parser'),
    levelup = require('levelup'),
    key = require('./lib/key.js');

if (process.stdin.isTTY) {
    if (process.argv[2] === undefined) {
        return console.log('file argument required \n`node import-csv.js [source csv]`');
    }
    loadTask(process.argv[2]);
} else {
    process.stdin.on('readable', function() {
        var buf = process.stdin.read();
        if (buf === null) return;
        buf.toString().split('\n').forEach(function(file) {
            if (file.length) loadTask(file, process.argv[2]);
        });
    });
}

function loadTask(fileLoc) {
    var task = path.basename(fileLoc).split('.')[0],
        db = levelup('./ldb/' + task + '.ldb'),
        fixed_list = [],
        count = 0;

    var tracking = levelup('./ldb/' + task + '-tracking.ldb');
    tracking.close();

    if (fs.existsSync('./fixed') && fs.readdirSync('./fixed').indexOf(task) > -1) {
        var rl = readline.createInterface({
            input: fs.createReadStream('./fixed/' + task),
            output: new require('stream')
        });

        rl.on('line', function(line) {
            fixed_list.push(line);
        });

        rl.on('end', function() {
            doImport(fileLoc);
        });
    } else {
        doImport(fileLoc);
    }

    function doImport(fileLoc) {
        console.log('importing ' + task);
        fs.createReadStream(fileLoc)
            .pipe(csv())
            .on('data', function(data) {
                var object_hash = key.hashObject(data);
                if (fixed_list.indexOf(object_hash) === -1) {
                    // item is not fixed
                    var object_id = key.compose(1, object_hash);
                    db.put(object_id, JSON.stringify(data), function (err) {
                        if (err) console.log('-- error --', err);
                    });
                    count++;
                }
            })
            .on('end', function() {
                setTimeout(function() {
                    // insert a dummy object in unfixed keyspace if nothing has been inserted
                    // prevents blocking on levelup readstream creation against an empty db
                    if (count === 0) {
                        var keyval = key.compose(1, 'random');
                        db.put(keyval, JSON.stringify({ignore: true}));
                    }
                    db.close();

                    console.log('done with ' + task + '. ' + count + ' items imported');
                }, 5000);
            });
    }
}