import { Hono } from 'hono'
import { cors } from 'hono/cors'
import { logger } from 'hono/logger'
import { join } from 'node:path'
import { existsSync } from 'node:fs'
import { serveStatic } from 'hono/bun'
import { configuration } from '../configuration'
import type { SyncEngine } from '../sync/syncEngine'
import { createAuthMiddleware, type WebAppEnv } from './middleware/auth'
import { createAuthRoutes } from './routes/auth'
import { createSessionsRoutes } from './routes/sessions'
import { createMessagesRoutes } from './routes/messages'
import { createPermissionsRoutes } from './routes/permissions'
import { createMachinesRoutes } from './routes/machines'
import { createCliRoutes } from './routes/cli'
import type { Server as BunServer } from 'bun'
import type { Server as SocketEngine } from '@socket.io/bun-engine'
import type { WebSocketData } from '@socket.io/bun-engine'

function findWebappDistDir(): { distDir: string; indexHtmlPath: string } {
    const candidates = [
        join(process.cwd(), '..', 'web', 'dist'),
        join(import.meta.dir, '..', '..', '..', 'web', 'dist'),
        join(process.cwd(), 'web', 'dist')
    ]

    for (const distDir of candidates) {
        const indexHtmlPath = join(distDir, 'index.html')
        if (existsSync(indexHtmlPath)) {
            return { distDir, indexHtmlPath }
        }
    }

    const distDir = candidates[0]
    return { distDir, indexHtmlPath: join(distDir, 'index.html') }
}

function createWebApp(options: {
    getSyncEngine: () => SyncEngine | null
    jwtSecret: Uint8Array
}): Hono<WebAppEnv> {
    const app = new Hono<WebAppEnv>()

    app.use('*', logger())

    const corsOrigins = configuration.corsOrigins
    const corsOriginOption = corsOrigins.includes('*') ? '*' : corsOrigins
    const corsMiddleware = cors({
        origin: corsOriginOption,
        allowMethods: ['GET', 'POST', 'OPTIONS'],
        allowHeaders: ['authorization', 'content-type']
    })
    app.use('/api/*', corsMiddleware)
    app.use('/cli/*', corsMiddleware)

    app.route('/cli', createCliRoutes(options.getSyncEngine))

    app.route('/api', createAuthRoutes(options.jwtSecret))

    app.use('/api/*', createAuthMiddleware(options.jwtSecret))
    app.route('/api', createSessionsRoutes(options.getSyncEngine))
    app.route('/api', createMessagesRoutes(options.getSyncEngine))
    app.route('/api', createPermissionsRoutes(options.getSyncEngine))
    app.route('/api', createMachinesRoutes(options.getSyncEngine))

    const { distDir, indexHtmlPath } = findWebappDistDir()

    if (!existsSync(indexHtmlPath)) {
        app.get('/', (c) => {
            return c.text(
                'Mini App is not built.\n\nRun:\n  cd web\n  bun install\n  bun run build\n',
                503
            )
        })
        return app
    }

    app.use('/assets/*', serveStatic({ root: distDir }))

    app.use('*', async (c, next) => {
        if (c.req.path.startsWith('/api')) {
            await next()
            return
        }

        return await serveStatic({ root: distDir })(c, next)
    })

    app.get('*', async (c, next) => {
        if (c.req.path.startsWith('/api')) {
            await next()
            return
        }

        return await serveStatic({ root: distDir, path: 'index.html' })(c, next)
    })

    return app
}

export async function startWebServer(options: {
    getSyncEngine: () => SyncEngine | null
    jwtSecret: Uint8Array
    socketEngine: SocketEngine
}): Promise<BunServer<WebSocketData>> {
    const app = createWebApp({
        getSyncEngine: options.getSyncEngine,
        jwtSecret: options.jwtSecret
    })

    const socketHandler = options.socketEngine.handler()

    const server = Bun.serve({
        port: configuration.webappPort,
        idleTimeout: Math.max(30, socketHandler.idleTimeout),
        maxRequestBodySize: socketHandler.maxRequestBodySize,
        websocket: socketHandler.websocket,
        fetch: (req, server) => {
            const url = new URL(req.url)
            if (url.pathname.startsWith('/socket.io/')) {
                return socketHandler.fetch(req, server)
            }
            return app.fetch(req)
        }
    })

    console.log(`[Web] Mini App server listening on :${configuration.webappPort}`)
    console.log(`[Web] Mini App public URL: ${configuration.miniAppUrl}`)

    return server
}