import {
  BuilderContext,
  BuilderOutput,
  createBuilder,
} from '@angular-devkit/architect';
import { JsonObject } from '@angular-devkit/core';
import { readJsonFile } from '@nrwl/workspace';
import { writeJsonFile } from '@nrwl/workspace/src/utils/fileutils';
import { ChildProcess, fork } from 'child_process';
import { copy, removeSync } from 'fs-extra';
import * as glob from 'glob';
import { basename, dirname, join, normalize, relative } from 'path';
import { Observable, of, Subscriber } from 'rxjs';
import { map, switchMap, tap } from 'rxjs/operators';
import * as treeKill from 'tree-kill';
import {
  createProjectGraph,
  ProjectGraph,
} from '@nrwl/workspace/src/core/project-graph';
import {
  calculateProjectDependencies,
  checkDependentProjectsHaveBeenBuilt,
  createTmpTsConfig,
  DependentBuildableProjectNode,
  updateBuildableProjectPackageJsonDependencies,
} from '@nrwl/workspace/src/utils/buildable-libs-utils';

export interface NodePackageBuilderOptions extends JsonObject {
  main: string;
  tsConfig: string;
  outputPath: string;
  watch: boolean;
  sourceMap: boolean;
  assets: Array<AssetGlob | string>;
  packageJson: string;
}

interface NormalizedBuilderOptions extends NodePackageBuilderOptions {
  files: Array<FileInputOutput>;
  normalizedOutputPath: string;
  relativeMainFileOutput: string;
}

type FileInputOutput = {
  input: string;
  output: string;
};
type AssetGlob = FileInputOutput & {
  glob: string;
  ignore: string[];
};

/**
 * -----------------------------------------------------------
 */

export default createBuilder(runNodePackageBuilder);

export function runNodePackageBuilder(
  options: NodePackageBuilderOptions,
  context: BuilderContext
) {
  const projGraph = createProjectGraph();
  const normalizedOptions = normalizeOptions(options, context);
  const { target, dependencies } = calculateProjectDependencies(
    projGraph,
    context
  );

  return of(checkDependentProjectsHaveBeenBuilt(context, dependencies)).pipe(
    switchMap((result) => {
      if (result) {
        return compileTypeScriptFiles(
          normalizedOptions,
          context,
          projGraph,
          dependencies
        ).pipe(
          tap(() => {
            updatePackageJson(normalizedOptions, context);
            if (dependencies.length > 0) {
              updateBuildableProjectPackageJsonDependencies(
                context,
                target,
                dependencies
              );
            }
          }),
          switchMap(() => {
            return copyAssetFiles(normalizedOptions, context);
          })
        );
      } else {
        return of({ success: false });
      }
    }),
    map((value) => {
      return {
        ...value,
        outputPath: normalizedOptions.outputPath,
      };
    })
  );
}

function normalizeOptions(
  options: NodePackageBuilderOptions,
  context: BuilderContext
) {
  const outDir = options.outputPath;
  const files: FileInputOutput[] = [];

  const globbedFiles = (
    pattern: string,
    input: string = '',
    ignore: string[] = []
  ) => {
    return glob.sync(pattern, {
      cwd: input,
      nodir: true,
      ignore,
    });
  };

  options.assets.forEach((asset) => {
    if (typeof asset === 'string') {
      globbedFiles(asset, context.workspaceRoot).forEach((globbedFile) => {
        files.push({
          input: join(context.workspaceRoot, globbedFile),
          output: join(context.workspaceRoot, outDir, basename(globbedFile)),
        });
      });
    } else {
      globbedFiles(
        asset.glob,
        join(context.workspaceRoot, asset.input),
        asset.ignore
      ).forEach((globbedFile) => {
        files.push({
          input: join(context.workspaceRoot, asset.input, globbedFile),
          output: join(
            context.workspaceRoot,
            outDir,
            asset.output,
            globbedFile
          ),
        });
      });
    }
  });

  // Relative path for the dist directory
  const tsconfig = readJsonFile(join(context.workspaceRoot, options.tsConfig));
  const rootDir = tsconfig.compilerOptions.rootDir || '';
  const mainFileDir = dirname(options.main);
  const tsconfigDir = dirname(options.tsConfig);

  const relativeMainFileOutput = relative(
    `${tsconfigDir}/${rootDir}`,
    mainFileDir
  );

  return {
    ...options,
    files,
    relativeMainFileOutput,
    normalizedOutputPath: join(context.workspaceRoot, options.outputPath),
  };
}

let tscProcess: ChildProcess;
function compileTypeScriptFiles(
  options: NormalizedBuilderOptions,
  context: BuilderContext,
  projGraph: ProjectGraph,
  projectDependencies: DependentBuildableProjectNode[]
): Observable<BuilderOutput> {
  if (tscProcess) {
    killProcess(context);
  }
  // Cleaning the /dist folder
  removeSync(options.normalizedOutputPath);
  let tsConfigPath = join(context.workspaceRoot, options.tsConfig);

  return Observable.create((subscriber: Subscriber<BuilderOutput>) => {
    if (projectDependencies.length > 0) {
      const libRoot = projGraph.nodes[context.target.project].data.root;
      tsConfigPath = createTmpTsConfig(
        tsConfigPath,
        context.workspaceRoot,
        libRoot,
        projectDependencies
      );
    }

    try {
      let args = ['-p', tsConfigPath, '--outDir', options.normalizedOutputPath];

      if (options.sourceMap) {
        args.push('--sourceMap');
      }

      const tscPath = join(
        context.workspaceRoot,
        '/node_modules/typescript/bin/tsc'
      );
      if (options.watch) {
        context.logger.info('Starting TypeScript watch');
        args.push('--watch');
        tscProcess = fork(tscPath, args, { stdio: [0, 1, 2, 'ipc'] });
        subscriber.next({ success: true });
      } else {
        context.logger.info(
          `Compiling TypeScript files for library ${context.target.project}...`
        );
        tscProcess = fork(tscPath, args, { stdio: [0, 1, 2, 'ipc'] });
        tscProcess.on('exit', (code) => {
          if (code === 0) {
            context.logger.info(
              `Done compiling TypeScript files for library ${context.target.project}`
            );
            subscriber.next({ success: true });
          } else {
            subscriber.error('Could not compile Typescript files');
          }
          subscriber.complete();
        });
      }
    } catch (error) {
      if (tscProcess) {
        killProcess(context);
      }
      subscriber.error(
        new Error(`Could not compile Typescript files: \n ${error}`)
      );
    }
  });
}

function killProcess(context: BuilderContext): void {
  return treeKill(tscProcess.pid, 'SIGTERM', (error) => {
    tscProcess = null;
    if (error) {
      if (Array.isArray(error) && error[0] && error[2]) {
        const errorMessage = error[2];
        context.logger.error(errorMessage);
      } else if (error.message) {
        context.logger.error(error.message);
      }
    }
  });
}

function updatePackageJson(
  options: NormalizedBuilderOptions,
  context: BuilderContext
) {
  const mainFile = basename(options.main, '.ts');
  const typingsFile = `${mainFile}.d.ts`;
  const mainJsFile = `${mainFile}.js`;
  const packageJson = readJsonFile(
    join(context.workspaceRoot, options.packageJson)
  );

  packageJson.main = normalize(
    `./${options.relativeMainFileOutput}/${mainJsFile}`
  );
  packageJson.typings = normalize(
    `./${options.relativeMainFileOutput}/${typingsFile}`
  );

  writeJsonFile(`${options.outputPath}/package.json`, packageJson);
}

function copyAssetFiles(
  options: NormalizedBuilderOptions,
  context: BuilderContext
): Promise<BuilderOutput> {
  context.logger.info('Copying asset files...');
  return Promise.all(options.files.map((file) => copy(file.input, file.output)))
    .then(() => {
      context.logger.info('Done copying asset files.');
      return {
        success: true,
      };
    })
    .catch((err: Error) => {
      return {
        error: err.message,
        success: false,
      };
    });
}