import { copyFile, readFile } from "fs/promises";
import * as handlebars from 'handlebars';
import { join } from 'path';
import { Project } from "ts-morph";
import { IExportMethodToOpenAPIParameters } from "../openapi/nopeOpenAPIDecorators";
import { DecoratorInformation, MethodInformation } from "./analyzeTypescriptFiles";
import { createFile } from "./fileHelpers";
import { generateSchemas } from "./generateSchemas";


/**
 * Generate the Client Templates.
 * @param options 
 */
export async function generateOpenAPI(options: {
  pathToSchemaTemplate: string,
  pathToApiTemplate: string,
  tempDir: string,
  inputDir: string,
  tsConfigFilePath: string,
}) {

  // Create the Output dir (if it doenst exists)
  const { schemaMapping, analysis } = await generateSchemas(options)

  // load the File.
  const typescriptTemplate = await readFile(options.pathToApiTemplate, {
    encoding: 'utf-8'
  })

  // Renderfuncting
  const renderAPI = handlebars.compile(typescriptTemplate);

  const methods: (IExportMethodToOpenAPIParameters & MethodInformation & DecoratorInformation & {
    className: string,
    baseUri: string,
    methodUri: string,
    useCustomParameters: boolean,
    useDefaultParameters: boolean,
    customParameters: string,
    inputSchema: string,
    outputSchema: string
  })[] = []

  // Firstly copy the nopeDispatcher
  await copyFile(
    join(__dirname, '..', '..', '..', 'lib', 'dispatcher', 'nopeDispatcher.ts'),
    join(options.tempDir, 'api', 'nopeDispatcher.ts')
  );

  for (const relevantClass of analysis) {
    for (const method of relevantClass.methods) {
      const settings: {
        className: string,
        baseUri: string,
        methodUri: string,
        useCustomParameters: boolean,
        useDefaultParameters: boolean,
        customParameters: string,
        inputSchema: string,
        outputSchema: string
      } = {
        className: relevantClass.className,
        baseUri: relevantClass.classDecorator.decoratorSettings.exportsElementsToOpenAPI.uri || relevantClass.className,
        methodUri: method.decoratorSettings.exportMethodToOpenAPI.uri || method.name,
        customParameters: JSON.stringify(method.decoratorSettings.exportMethodToOpenAPI.parameters || [], undefined, 4),
        useCustomParameters: Array.isArray(method.decoratorSettings.exportMethodToOpenAPI.parameters),
        useDefaultParameters: method.params.length > 0,
        inputSchema: JSON.stringify(schemaMapping[relevantClass.className], undefined, 4),
        outputSchema: JSON.stringify(schemaMapping[relevantClass.className], undefined, 4)
      }

      const item = Object.assign(
        method,
        {
          method: method.params.length > 0 ? 'POST' : 'GET'
        },
        settings,
        method.decoratorSettings.exportMethodToOpenAPI as IExportMethodToOpenAPIParameters
      );

      methods.push(item);

      const fileName = join(options.tempDir, 'api', item.baseUri, item.methodUri + '.ts');

      // Write down the Schema:
      await createFile(
        // Generate the Path.
        fileName,
        renderAPI(item)
      );

      // Function to Determine new project files.
      const project = new Project({
        tsConfigFilePath: options.tsConfigFilePath,
        addFilesFromTsConfig: false,
      });

      project.addSourceFileAtPath(fileName);

      // Readin the Source-Files.
      const sourceFiles = project.getSourceFiles();

      for (const file of sourceFiles) {
        file.formatText();
        await file.save();
      }
    }
  }

  return schemaMapping;
}