/* Copyright IBM Corp. 2017 */
import { join, normalize, parse, resolve } from 'path';
import { combineLatest, merge, Observable, of } from 'rxjs';
import { filter, map, mergeMap, shareReplay, tap } from 'rxjs/operators';

import { getDistDir } from '../utils/angular.utils';
import { firstOf } from '../utils/file.utils';
import { CMD_COPY, OPTION_DATA, OPTION_NAME, OPTION_ROOT, OPTION_SOURCE, OPTION_VERBOSE } from './../constants';
import { Options } from './../options';
import { configIndexDirFromContextRoot, configTrimSlashes } from './../utils/config';
import { rxCopyDir } from './../utils/rx.copy';
import { rxDeleteDir } from './../utils/rx.delete';
import { rxMoveFile } from './../utils/rx.move';
import { AbstractCommand } from './abstract.command';
import { Command } from './command';
import { HELP_APPLICATION_NAME, HELP_CONTEXT_ROOT, HELP_COPY_SOURCE, HELP_DATA_DIRECTORY, HELP_VERBOSE } from './help';

const ROOT_RESOURCE: { [key: string]: boolean } = {
    'index.html': true,
    'favicon.ico': true
};

function _isRootResource(aFilename: string): boolean {
    const parsed = parse(aFilename);
    return !!ROOT_RESOURCE[parsed.base];
}

/**
 * Copies the build output to the correct location
*/
export class CopyBuildCommand extends AbstractCommand implements Command {

    static readonly TYPE = 'build';
    static readonly COMMAND = CMD_COPY;

    constructor(options: Options) {
        super(options);
    }

    printHelp(): void {
        // log the command line
        console.log(CopyBuildCommand.COMMAND, CopyBuildCommand.TYPE,
            `--${OPTION_SOURCE} <SOURCE>`,
            `--${OPTION_DATA} <DATA>`,
            `--${OPTION_NAME} <NAME>`,
            `[--${OPTION_ROOT} <ROOT>]`,
            `[--${OPTION_VERBOSE}]`);
        // log the parameters
        console.log(`--${OPTION_SOURCE} <SOURCE>`, ':', HELP_COPY_SOURCE);
        console.log(`--${OPTION_DATA} <DATA>`, ':', HELP_DATA_DIRECTORY);
        console.log(`--${OPTION_NAME} <NAME>`, ':', HELP_APPLICATION_NAME);
        console.log(`--${OPTION_ROOT}`, ':', HELP_CONTEXT_ROOT);
        console.log(`--${OPTION_VERBOSE}`, ':', HELP_VERBOSE);
    }

    process(): Observable<string> {
        // the options
        const opts = this.getOptions();
        const appName = opts.name || this.getAppName();
        const contextRoot = `/${configTrimSlashes(opts.root || this.getContextRoot(appName))}`;
        // logger
        const logger = this.getLogger();
        // the directories
        const dataDir = this.getDataDir();
        // source directory is the build output
        const firstSrc = firstOf(opts.src);
        const rxSrcDir = firstSrc ? of(resolve(firstSrc)) : this.getAngularCliConfig().pipe(
            map(getDistDir),
            map(dir => resolve(dir))
        );
        // name of the target directory for the main files
        const assetDir = resolve(normalize(join(dataDir, 'assets', appName)));
        // directory for index file
        const idxDir = configIndexDirFromContextRoot(contextRoot, dataDir);
        // delete the files in the asset dir
        const rxDeletedAssets = rxDeleteDir(assetDir);
        // copy files into the assets directory
        const rxCopiedAssets = combineLatest(rxSrcDir, rxDeletedAssets).pipe(
            tap(([srcDir, dstDir]) => logger.next(`Copying from [${srcDir}] to [${dstDir}].`)),
            mergeMap(([srcDir, dstDir]) => rxCopyDir(srcDir, dstDir)),
            shareReplay()
        );
        // copy some selected files to the context root dir
        const rxRoot = rxCopiedAssets.pipe(
            filter(_isRootResource)
        );
        const rxApp = rxCopiedAssets.pipe(
            filter(res => !_isRootResource(res))
        );
        // move the root resources
        const rxMovedRoot = rxRoot.pipe(
            mergeMap(file => rxMoveFile(file, join(idxDir, parse(file).base)))
        );
        // merge
        const rxResult = merge(rxApp, rxMovedRoot);

        return rxResult;
    }
}