import path from 'path'
import fs from 'fs/promises'

import dotenv from 'dotenv'

import express, { Handler, Router } from 'express'
import morgan from 'morgan'

import { createServer as createViteServer } from 'vite'

import { createApiRouter } from './server/routes'
import { RenderFunction } from './shared/ssr'
import { DatabaseConnection } from './shared/database'

// Load ".env"
dotenv.config()

const config = {
    isDevelopment: process.env.MODE === 'development',
    port: process.env.PORT || 3000,
}

if (config.isDevelopment) {
    console.log(`[Config] Running in development mode`)
    console.log(`[Config] PORT = ${config.port}`)
}

async function createDevRouter(db: DatabaseConnection) {
    const r = express.Router()

    const vite = await createViteServer({
        server: { middlewareMode: true },
        appType: 'custom',
    })

    r.use(vite.middlewares)
    r.use('*', async (req, res, next) => {
        try {
            const indexHtml = await fs.readFile(path.resolve('./index.html'), 'utf-8')
            const transformedTemplate = await vite.transformIndexHtml(req.originalUrl, indexHtml)

            // Load (to be bundled) entry point for server side rendering
            const render: RenderFunction = (await vite.ssrLoadModule('./client/entry-server.tsx')).default

            const { html, metadata, asyncCallbacks } = render(req.originalUrl, db)
            await Promise.all(asyncCallbacks.map(fn => fn()))

            const fullUrl = `https://${req.get('host')}${req.originalUrl}`
            const metaTagsHtml =
                '' +
                (metadata.title ? `<meta property="og:title" content="${metadata.title ?? 'PHC | Problemi'}">\n` : '') +
                (metadata.description
                    ? `
                    <meta name="description" content="${metadata.description}">
                    <meta property="og:description" content="${metadata.description ?? 'Bacheca di problemi di matematica creato dal PHC'}">\n`
                    : '') +
                `<meta property="og:url" content="${fullUrl}">\n`

            res.send(transformedTemplate.replace('<!-- INJECT META TAGS -->', metaTagsHtml).replace('<!-- SSR OUTLET -->', html))
        } catch (error: any) {
            vite.ssrFixStacktrace(error)
            next(error)
        }
    })

    return r
}

async function createProductionRouter(db: DatabaseConnection) {
    // Load bundled entry point for server side rendering

    // @ts-ignore
    const render: RenderFunction = (await import('./dist/entry-server/entry-server.js')).default

    const r = express.Router()

    const handleSSR = async (req, res) => {
        const transformedTemplate = await fs.readFile(path.resolve('./dist/entry-client/index.html'), 'utf-8')

        const { html, metadata, asyncCallbacks } = render(req.originalUrl, db)
        await Promise.all(asyncCallbacks.map(fn => fn()))

        const fullUrl = `https://${req.get('host')}${req.originalUrl}`
        const metaTagsHtml =
            '' +
            (metadata.title
                ? `<meta property="og:title" content="${metadata.title}">\n`
                : `<meta property="og:title" content="PHC | Problemi">\n`) +
            (metadata.description
                ? `<meta name="description" content="${metadata.description}">
                <meta property="og:description" content="${metadata.description}">\n`
                : `<meta name="description" content="Bacheca di problemi di matematica creato dal PHC">
                <meta property="og:description" content="Bacheca di problemi di matematica creato dal PHC">\n`) +
            `<meta property="og:url" content="${fullUrl}">\n`

        const finalHtml = transformedTemplate.replace('<!-- INJECT META TAGS -->', metaTagsHtml).replace('<!-- SSR OUTLET -->', html)

        console.dir(finalHtml, { depth: null })

        res.send(finalHtml)
    }

    r.get('/', handleSSR)
    r.use('/', express.static('dist/entry-client'))

    r.use('*', handleSSR)

    return r
}

async function main() {
    const app = express()

    app.use(morgan('[Request] :method :url :status :response-time ms - :res[content-length]'))

    const [r, db] = await createApiRouter()

    app.use(process.env.BASE_URL ?? '/', r)

    if (config.isDevelopment) {
        app.use(process.env.BASE_URL ?? '/', await createDevRouter(db))
    } else {
        app.use(process.env.BASE_URL ?? '/', await createProductionRouter(db))
    }

    app.listen(config.port, () => {
        console.log(`[Server] Listening on port ${config.port}...`)
    })
}

main()