import {normalizePath, type Plugin} from "vite";
import color from 'picocolors'
import fs from 'fs';
import ejs from 'ejs'
import path from 'path'
import history from 'connect-history-api-fallback';

// @ts-ignore
import {name as pluginName} from '../package.json'

export function viteMpaYdPlugin(): Plugin {
    let pageMap = {}
    let inputMap = {}
    // @ts-ignore
    const pathPrefixReg = /#{./|/}/
    const template = 'index.html'
    const bodyInject = /<\/body>/;
    let root: string = ''

    function transform (code, id) {
        const page = pageMap[id]
        if (!page) return null
        return ejs.render(!page.entry ? code : code.replace(bodyInject, `<script type="module" src="${normalizePath(
            `${page.entry}`,
        )}"></script>\n</body>`), {}, {filename: id, root: root})
    }

    return {
        name: 'vite-plugin-mpa-yd',
        config(config, { command }) {
            // @ts-ignore
            const pageConfig = config.ydPages || {}
            let entries: string[] = []
            for (const pageConfigKey in pageConfig) {
                // @ts-ignore
                const transformEntry = '/' + (pageConfig[pageConfigKey]?.entry || '').replace(pathPrefixReg, '')
                // @ts-ignore
                pageMap[`${pageConfigKey}.html`] = {
                    name: pageConfigKey,
                    entry: transformEntry
                }
                entries.push(transformEntry)
                // @ts-ignore
                inputMap[pageConfigKey] = `${pageConfigKey}.html`
            }
            // @ts-ignore
            return {
                appType: 'mpa',
                clearScreen: false,
                optimizeDeps: {
                    entries,
                },
                build: {
                    rollupOptions: {
                        input: inputMap,
                    },
                },
            }
        },
        resolveId (source, importer, options) {
            // @ts-ignore
            if (options.isEntry && pageMap[source]) {
                return source
            }
        },
        load(id) {
            // @ts-ignore
            const page = pageMap[id]
            if (!page) return null
            return fs.readFileSync(template, 'utf-8');
        },
        transform,
        configureServer(server) {
            console.log('[configureServer]:', server);
            const {
                config,
                watcher,
                middlewares,
                pluginContainer,
                transformIndexHtml,
            } = server;

            const base = normalizePath(`/${config.base || '/'}/`);
            watcher.on('change', file => {
                if (file.endsWith('.html') && template === path.relative(config.root, file)) {
                    server.ws.send({
                        type: 'full-reload',
                        path: '*',
                    });
                }
            })
            middlewares.use(
                history({
                    htmlAcceptHeaders: ['text/html', 'application/xhtml+xml'],
                    rewrites: [
                        {
                            from: new RegExp(normalizePath(`/${base}/(${Object.keys(inputMap).join('|')})`)),
                            to: ctx => normalizePath(`/${inputMap[ctx.match[1]]}`),
                        },
                        {
                            from: /.*/,
                            to: ctx => {
                                const { parsedUrl: { pathname } } = ctx;
                                return normalizePath(pathname?.endsWith('.html') ? pathname : `${pathname}/index.html`);
                            },
                        },
                    ],
                }),
            );
            middlewares.use(async (req, res, next) => {
                const accept = req.headers.accept;
                const url = req.url!;

                // Ignore request that are not html.
                if (
                    res.writableEnded ||
                    accept === '*/*' ||
                    !accept?.includes('text/html')
                ) {
                    return next();
                }

                // Uniform the request url, allows visiting files directly.
                const rewritten = url.startsWith(base) ? url : normalizePath(`/${base}/${url}`);
                const fileName = rewritten.replace(base, ''); // filename in page configuration can't start with '/', because the key of inputMap is relative path.

                // print rewriting log if verbose is true
                if (req.originalUrl !== url) {
                    console.log(
                        `[${pluginName}]: Rewriting ${color.blue(req.originalUrl)} to ${color.blue(rewritten)}`,
                    );
                }

                if (!pageMap[fileName]) {
                    return next(); // This allows vite handling unmatched paths.
                }

                /**
                 * The following 2 lines fixed #12.
                 * When using cypress for e2e testing, we should manually set response header and status code.
                 * Otherwise, it causes cypress testing process of cross-entry-page jumping hanging, which results in a timeout error.
                 */
                res.setHeader('Content-Type', 'text/html');
                res.statusCode = 200;

                // load file
                let loadResult = await pluginContainer.load(fileName);
                if (!loadResult) {
                    throw new Error(`Failed to load url ${fileName}`);
                }
                loadResult = typeof loadResult === 'string'
                    ? loadResult
                    : loadResult.code;

                res.end(
                    await transformIndexHtml(
                        url,
                        // No transform applied, keep code as-is
                        transform(loadResult, fileName) ?? loadResult,
                        req.originalUrl,
                    ),
                );
            });
        }
    }
}