var _           = require('lodash'),
    Promise     = require('bluebird'),
    db          = require('../../data/db'),
    commands    = require('../schema').commands,
    versioning  = require('../schema').versioning,
    serverUtils = require('../../utils'),
    errors      = require('../../errors'),
    settings    = require('../../api/settings'),
    i18n        = require('../../i18n'),

    excludedTables = ['accesstokens', 'refreshtokens', 'clients', 'client_trusted_domains'],
    modelOptions = {context: {internal: true}},

    // private
    getVersionAndTables,
    exportTable,

    // public
    doExport,
    exportFileName;

exportFileName = function exportFileName() {
    var datetime = (new Date()).toJSON().substring(0, 10),
        title = '';

    return settings.read(_.extend({}, {key: 'title'}, modelOptions)).then(function (result) {
        if (result) {
            title = serverUtils.safeString(result.settings[0].value) + '.';
        }
        return title + 'ghost.' + datetime + '.json';
    }).catch(function (err) {
        errors.logError(err);
        return 'ghost.' + datetime + '.json';
    });
};

getVersionAndTables = function getVersionAndTables() {
    var props = {
        version: versioning.getDatabaseVersion(),
        tables:  commands.getTables()
    };

    return Promise.props(props);
};

exportTable = function exportTable(tableName) {
    if (excludedTables.indexOf(tableName) < 0) {
        return db.knex(tableName).select();
    }
};

doExport = function doExport() {
    var tables, version;

    return getVersionAndTables().then(function exportAllTables(result) {
        tables = result.tables;
        version = result.version;

        return Promise.mapSeries(tables, exportTable);
    }).then(function formatData(tableData) {
        var exportData = {
            meta: {
                exported_on: new Date().getTime(),
                version: version
            },
            data: {
                // Filled below
            }
        };

        _.each(tables, function (name, i) {
            exportData.data[name] = tableData[i];
        });

        return exportData;
    }).catch(function (err) {
        errors.logAndThrowError(err, i18n.t('errors.data.export.errorExportingData'), '');
    });
};

module.exports = {
    doExport: doExport,
    fileName: exportFileName
};