/**
 * @node workflow-input
 * @name Workflow Input
 * @category triggers
 * @version 1.0.0
 * @description Start a workflow that another workflow calls, and say what it expects to be given
 * @trigger
 * @icon log-in
 */

const configSchema = {
    type: 'object',
    // The names below are what this node produces, so the editor can offer
    // them to later nodes as soon as they are typed - without waiting for a run.
    outputsFromConfig: { from: 'fields', nameKey: 'name' },
    properties: {
        fields: {
            type: 'array',
            title: 'Expected Input',
            description: 'What the calling workflow must or may pass. A caller that leaves out a required one is refused here rather than failing somewhere deeper',
            items: {
                type: 'object',
                properties: {
                    name: { type: 'string', title: 'Name', description: 'Key the caller passes, such as city' },
                    required: { type: 'boolean', title: 'Required', description: 'Refuse the call when this is missing', default: true },
                    description: { type: 'string', title: 'Description', description: 'What the caller should put here' },
                    defaultValue: { type: 'string', title: 'Default', description: 'Used when an optional key is not passed' }
                }
            }
        },
        allowExtra: {
            type: 'boolean',
            title: 'Allow Anything Else',
            description: 'Pass through keys that are not listed above. Turn off to keep the contract exact and catch a caller sending the wrong thing',
            default: true
        }
    }
};

const inputSchema = { type: 'object', properties: { data: { type: 'any' } } };

const outputSchema = {
    type: 'object',
    properties: {
        calledBy: { type: 'string', description: 'Execution id of the workflow that called this one, empty when run directly' }
    }
};

async function execute(config, input, context) {
    // The caller's input arrives as the trigger data, the same way a webhook
    // body does. Internal keys the engine put there are not part of it.
    const given = (input && typeof input === 'object') ? input : {};
    const fields = config.fields || [];

    const result = {};
    const missing = [];

    for (let i = 0; i < fields.length; i++) {
        const field = fields[i] || {};
        const name = String(field.name || '').trim();
        if (!name) {
            // A row with a description or a default but no name is a filled-in
            // row whose key went in the wrong box. Skipping it silently meant
            // the caller's value was never accepted and the failure surfaced
            // somewhere else entirely - a node further on complaining that
            // something it needed was missing.
            const described = String(field.description || '').trim();
            const fallback = String(field.defaultValue || '').trim();
            if (described || fallback || field.required === true) {
                throw new Error('Workflow Input: an expected input has no name' +
                    (described ? ' (described as "' + described + '")' : '') +
                    (fallback ? ', default "' + fallback + '"' : '') +
                    '. Put the key the caller passes in the Name box');
            }
            continue;
        }

        const has = Object.prototype.hasOwnProperty.call(given, name) &&
                    given[name] !== undefined && given[name] !== null && given[name] !== '';

        if (has) {
            result[name] = given[name];
        } else if (field.required !== false) {
            missing.push(name);
        } else if (field.defaultValue !== undefined && field.defaultValue !== '') {
            result[name] = field.defaultValue;
        }
    }

    // Refusing here, naming every missing key at once, beats failing three
    // nodes later on an undefined that has to be traced back.
    if (missing.length > 0) {
        throw new Error('Workflow Input: the caller did not pass ' + missing.join(', ') +
            '. ' + (missing.length === 1 ? 'It is' : 'They are') + ' marked required on this node');
    }

    if (config.allowExtra !== false) {
        const keys = Object.keys(given);
        for (let i = 0; i < keys.length; i++) {
            const key = keys[i];
            // Engine bookkeeping, not part of what the caller sent.
            if (key.charAt(0) === '_') continue;
            if (!Object.prototype.hasOwnProperty.call(result, key)) {
                result[key] = given[key];
            }
        }
    }

    result.calledBy = (given && given._calledBy) || '';

    smartbotic.log.info('Workflow Input: accepted ' +
        Object.keys(result).filter(function (k) { return k !== 'calledBy'; }).length + ' value(s)');

    return result;
}

module.exports = { configSchema, inputSchema, outputSchema, execute };