/**
 * Translates to a readable values
 * @param {Object} instance - The model or context instance
 * @param {Object} changes - Object containing changes
 */
exports.translateValues = async(instance, changes) => {
    const models = instance.app.models;

    function getRelation(instance, property) {
        const relations = instance.definition.settings.relations;
        for (let relationName in relations) {
            const relation = relations[relationName];
            if (relation.foreignKey == property)
                return relation;
        }

        return;
    }

    function getValue(rawData) {
        const row = JSON.parse(JSON.stringify(rawData));
        for (column in row)
            return row[column];
    }

    function formatDate(date) {
        return new Intl.DateTimeFormat('es', {
            year: '2-digit',
            month: '2-digit',
            day: '2-digit',
            hour: '2-digit',
            minute: '2-digit',
            second: '2-digit'
        }).format(date);
    }

    const properties = Object.assign({}, changes);
    for (let property in properties) {
        const relation = getRelation(instance, property);
        const value = properties[property];

        let finalValue = value;
        if (relation) {
            const model = relation.model;
            const row = await models[model].findById(value, {
                fields: ['alias', 'name', 'code', 'description']
            });
            const newValue = getValue(row);
            if (newValue) finalValue = newValue;
        }

        if (finalValue instanceof Date)
            finalValue = formatDate(finalValue);

        properties[property] = finalValue;
    }

    return properties;
};

/**
 * Returns the changes between two objects
 * @param {Object} original - Original object
 * @param {Object} changes - New changes
 * @return {Object} Old and new values
 */
exports.getChanges = (original, changes) => {
    const oldChanges = {};
    const newChanges = {};
    for (let property in changes) {
        if (changes[property] != original[property]) {
            newChanges[property] = changes[property];

            if (original[property] != undefined)
                oldChanges[property] = original[property];
        }
    }

    return {
        old: oldChanges,
        new: newChanges
    };
};