codegen.js

const yaml = require('js-yaml');
const fs = require('fs');
const path = require('path');
const schemaRoot = './openapi/schema.yaml';
const destination = './src/'

const openapiFile = fs.readFileSync(schemaRoot, 'utf8');
const openapiSchema = yaml.load(openapiFile);

const classes = generateClasses(parseModelSchema(openapiSchema));
const methods = parseMethodSchema(openapiSchema);

// Generate JavaScript classes
const jsClasses = classes.concat(methods);

// Write the generated classes to a file
fs.writeFileSync(destination.concat("apiclient.js"), jsClasses);

console.log('JavaScript classes generated successfully!');

function parseMethodSchema(fullSchema) {
    let classes = `
async function fetchData(url, params, factoryFn, token) {
  try {
    // Construct query string from params
    const queryString = new URLSearchParams(params).toString();
    const fullUrl = \`\${url}?\${queryString}\`;
    
    const response = await fetch(url, {
      method: 'GET',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': \`Bearer \${token}\`
      }
    });

   if (response.status === 418) {
      throw new Error(response.headers.get("Error-Message"));
    }

    const responseData = await response.json();
    const returnedData = factoryFn(responseData);
    console.log('Successful registration:', returnedData);
    return returnedData;
  } catch (error) {
    console.error('Error:', error);
    throw new Error(error.message)
  }
}

async function postData(url, data, factoryFn, token) {
  try {
    const response = await fetch(url, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': \`Bearer \${token}\`
      },
      body: JSON.stringify(data)
    });

    if (response.status === 418) {
      throw new Error(response.headers.get("Error-Message"));
    }

    const responseData = await response.json();
    const returnedData = factoryFn(responseData);
    console.log('Successful registration:', returnedData);
    return returnedData;
  } catch (error) {
    console.error('Error:', error);
    throw new Error(error.message)
  }
}
`;
    let serverUrl = fullSchema.servers[0].url;

    for (const [path, methods] of Object.entries(fullSchema.paths)) {
        for (const [method, details] of Object.entries(methods)) {

            const methodName = details.summary.replace(/\s+/g, '');
            let factoryFn = "(data) => (data)";

            if(details.responses && details.responses['200'] && details.responses['200'].content) {
                let className = details.responses['200'].content['application/json'].schema.$ref.split('/').pop();
                factoryFn = `(data) => Object.assign(new ${className}(), data)`;
            }

            if (method.toUpperCase() === 'GET') {
                classes += `
  export async function ${methodName}(token = "", params = {}) {
    return fetchData(\`${serverUrl}${path}\`, params, ${factoryFn}, token);
  }\n`;
            } else if (method.toUpperCase() === 'POST') {
                classes += `
  export async function ${methodName}(data, token = "") {
    return postData(\`${serverUrl}${path}\`, data, ${factoryFn}, token);
  }\n`;
            }
        }
    }

    return classes;
}

function parseModelSchema(fullSchema) {
    let schemas = {};
    for (const [name, schemaRef] of Object.entries(fullSchema.components.schemas)) {
        if (schemaRef.$ref) {
            let refSchema = loadSchema(schemaRef.$ref);
            schemas[name] = refSchema;
        } else {
            schemas[name] = schemaRef;
        }
    }
    return schemas;
}

function loadSchema(ref) {
    const refPath = path.join(path.dirname(schemaRoot), ref);
    const schemaFile = fs.readFileSync(refPath, 'utf8');
    return yaml.load(schemaFile);
}

function generateClasses(schemas) {
    let classes = '/** Do not edit this file. It is autogenerated **/\n\n';

    for (const [className, schema] of Object.entries(schemas)) {
        if (schema.type === 'object' && schema.properties) {
            classes += `export class ${className} {\n`;
            classes += '  constructor(data = {}) {\n';

            for (const [propName, propDef] of Object.entries(schema.properties)) {
                if(propDef.$ref) {
                    classes += `    this.${propName} = data['${propName}']? data['${propName}'] : new ${propDef.$ref.split("/").pop().replace(".yaml", "")}();\n`;
                } else {
                    classes += `    this.${propName} = data['${propName}']? data['${propName}'] : undefined ;\n`;
                }
            }

            classes += '  }\n';
            classes += '}\n\n';
        }
    }

    return classes;
}