import type { APIContext } from 'astro'
import { init, createId } from '@paralleldrive/cuid2'
import { createHash } from 'node:crypto'

export async function GET({ cookies }: APIContext) {
    const generateId = init({ length: 40 })

    const googleOauthState = createId()

    cookies.set('google_oauth_state', googleOauthState, {
        path: '/',
    })

    const googleCodeChallenge = generateId()
    const codeChallenge = createHash('sha256').update(googleCodeChallenge).digest('base64url')

    cookies.set('google_code_challenge', googleCodeChallenge, {
        path: '/',
    })

    const authorizationUrl = new URL('https://accounts.google.com/o/oauth2/v2/auth')
    authorizationUrl.search = new URLSearchParams({
        access_type: 'offline',
        scope: 'openid email profile',
        prompt: 'consent',
        response_type: 'code',
        client_id: import.meta.env.OAUTH_GOOGLE_CLIENT_ID,
        redirect_uri: import.meta.env.OAUTH_GOOGLE_CALLBACK_URL,
        state: googleOauthState,
        code_challenge: codeChallenge,
        code_challenge_method: 'S256',
    }).toString()

    return new Response(null, {
        status: 302,
        headers: {
            Location: authorizationUrl.toString(),
        },
    })
}