import {Express, Router} from "express";

import ApplicationComponent from "../ApplicationComponent.js";
import AssetCompiler from "../frontend/AssetCompiler.js";
import AssetPreCompiler from "../frontend/AssetPreCompiler.js";
import ViewEngine from "../frontend/ViewEngine.js";
import LazyLocalsCoreComponent from "./core/LazyLocalsCoreComponent.js";

export default class FrontendToolsComponent extends ApplicationComponent {
    private readonly publicDir: string;
    private readonly assetPreCompilers: AssetPreCompiler[];

    public constructor(
        private readonly assetCompiler: AssetCompiler,
        ...assetPreCompilers: AssetPreCompiler[]
    ) {
        super();
        this.assetPreCompilers = assetPreCompilers;
        this.publicDir = this.assetCompiler.targetDir;

        for (const assetPreCompiler of this.assetPreCompilers) {
            if (assetPreCompiler.isPublic()) {
                this.assetCompiler.addExtension(assetPreCompiler.getExtension());
            }
        }
    }

    public async start(app: Express): Promise<void> {
        this.hookPreCompilers();

        // Setup express view engine
        let main = true;
        for (const assetPreCompiler of this.assetPreCompilers) {
            if (assetPreCompiler instanceof ViewEngine) {
                assetPreCompiler.setup(app, main, this.getApp().as(LazyLocalsCoreComponent));
                main = false;
            }
        }
    }

    public async stop(): Promise<void> {
        for (const assetPreCompiler of this.assetPreCompilers) {
            await assetPreCompiler.stop();
        }
    }

    public async initRoutes(router: Router): Promise<void> {
        router.use((req, res, next) => {
            // Request context locals
            res.locals.url = req.url;
            res.locals.params = req.params;
            res.locals.query = req.query;
            res.locals.body = req.body;

            next();
        });
    }

    public hookPreCompilers(): void {
        for (const assetPreCompiler of this.assetPreCompilers) {
            assetPreCompiler.onPreCompile(async watch => {
                await this.assetCompiler.compile(watch);
            });
            assetPreCompiler.onInputChange(async restart => {
                await this.assetCompiler.stopWatching(restart);
            });
        }
    }

    public async preCompileViews(watch: boolean): Promise<void> {
        for (const viewEngine of this.assetPreCompilers) {
            await viewEngine.preCompileAll(watch);
        }

        await this.assetCompiler.compile(watch);

        if (watch) {
            this.hookPreCompilers();
        }
    }
}