'use strict';

/**
 * 使用 msg.crudFlow.create 配置创建请求；若未提供则保持旧有注入负载。
 */

return configureCreateRequest(msg, node);

function configureCreateRequest(message, node) {
    if (!message.crudFlow || !message.crudFlow.create) {
        return message;
    }

    const create = message.crudFlow.create;
    const baseUrl = message.crudFlow.baseUrl || '';
    const payload = selectCreatePayload(create);

    message.method = (create.method || 'POST').toUpperCase();
    message.url = mergeUrl(baseUrl, create.path || '');
    message.headers = Object.assign({}, message.crudFlow.headers || {}, create.headers || {});

    if (payload !== undefined) {
        message.payload = clone(payload);
    } else if (message.payload !== undefined) {
        delete message.payload;
    }

    const identityField = message.crudFlow.identityField || message.identityField || 'dsid';
    const keyValue = payload && typeof payload === 'object'
        ? extractPrimaryKey(payload, identityField)
        : undefined;

    if (keyValue !== undefined) {
        message.primaryKeyValue = keyValue;
        message.crudFlow.delete = message.crudFlow.delete || {};
        message.crudFlow.delete.actualKey = keyValue;
    }

    return message;
}

function selectCreatePayload(create) {
    if (create.payload && Object.keys(create.payload).length > 0) {
        return create.payload;
    }
    if (create.samplePayload) {
        return create.samplePayload;
    }
    return undefined;
}

function extractPrimaryKey(payload, identityField) {
    if (!payload) {
        return undefined;
    }
    if (Object.prototype.hasOwnProperty.call(payload, identityField)) {
        return payload[identityField];
    }
    if (Array.isArray(payload.data) && payload.data.length > 0 && payload.data[0][identityField] !== undefined) {
        return payload.data[0][identityField];
    }
    return undefined;
}

function mergeUrl(base, path) {
    const prefix = (base || '').replace(/\/+$/, '');
    const suffix = (path || '').replace(/^\/+/, '');
    if (!prefix) {
        return `/${suffix}`;
    }
    if (!suffix) {
        return prefix;
    }
    return `${prefix}/${suffix}`;
}

function clone(value) {
    return value == null ? value : JSON.parse(JSON.stringify(value));
}