import type { APIContext } from 'astro'

import {
    checkUserExists,
    createLoginLog,
    createSession,
    createUser,
    saveOauthToken,
    updateOauthToken,
} from '../../../../lib/auth'

export async function GET({ request, clientAddress, cookies }: APIContext) {
    const code = new URL(request.url).searchParams?.get('code')
    const state = new URL(request.url).searchParams?.get('state')

    const storedState = cookies.get('google_oauth_state')?.value
    const codeVerifier = cookies.get('google_code_challenge')?.value

    if (storedState !== state || !codeVerifier || !code) {
        cookies.delete('google_oauth_state', { path: '/' })
        cookies.delete('google_code_challenge', { path: '/' })

        console.log('state mismatch')

        return new Response(null, {
            status: 302,
            headers: {
                Location: '/login?error=Server+Error',
            },
        })
    }

    try {
        const tokenUrl = 'https://www.googleapis.com/oauth2/v4/token'

        const formData = new URLSearchParams()
        formData.append('grant_type', 'authorization_code')
        formData.append('client_id', import.meta.env.OAUTH_GOOGLE_CLIENT_ID)
        formData.append('client_secret', import.meta.env.OAUTH_GOOGLE_CLIENT_SECRET)
        formData.append('redirect_uri', import.meta.env.OAUTH_GOOGLE_CALLBACK_URL)
        formData.append('code', code)
        formData.append('code_verifier', codeVerifier)

        console.log('fetching token', formData)

        const fetchToken = await fetch(tokenUrl, {
            method: 'POST',
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded',
            },
            body: formData,
        })

        const fetchTokenRes = await fetchToken.json()

        console.log('fetchTokenRes', fetchTokenRes)

        const fetchUser = await fetch('https://www.googleapis.com/oauth2/v2/userinfo', {
            headers: { Authorization: `Bearer ${fetchTokenRes.access_token}` },
        })

        const fetchUserRes = await fetchUser.json()

        console.log('fetchUserRes', fetchUserRes)

        const userExists = await checkUserExists({
            email: fetchUserRes.email,
            strategy: 'google',
        })

        console.log('userExists', userExists)

        if (!userExists) {
            const { userId } = await createUser({
                email: fetchUserRes.email,
                fullName: fetchUserRes.name,
                profilePhoto: fetchUserRes.picture,
                userName: fetchUserRes.email.split('@')[0],
            })

            await saveOauthToken({
                userId: userId,
                strategy: 'google',
                accessToken: fetchTokenRes.access_token,
                refreshToken: fetchTokenRes.refresh_token,
            })

            const { sessionId } = await createSession({
                userId: userId,
            })

            // log
            await createLoginLog({
                sessionId,
                userAgent: request.headers.get('user-agent'),
                userId: userId,
                ip: clientAddress ?? 'dev',
            })

            cookies.delete('google_oauth_state', { path: '/' })
            cookies.delete('google_code_challenge', { path: '/' })

            cookies.set('app_auth_token', sessionId, {
                path: '/',
                httpOnly: true,
                sameSite: 'lax',
                secure: import.meta.env.PROD,
            })

            return new Response(null, {
                status: 302,
                headers: {
                    Location: '/profile',
                },
            })
        } else {
            if (userExists.oauthTokens.length > 0) {
                // oauth strategy exists
                // update token

                await updateOauthToken({
                    userId: userExists.id,
                    strategy: 'google',
                    accessToken: fetchTokenRes.access_token,
                    refreshToken: fetchTokenRes.refresh_token,
                })
            } else {
                await saveOauthToken({
                    userId: userExists.id,
                    strategy: 'google',
                    accessToken: fetchTokenRes.access_token,
                    refreshToken: fetchTokenRes.refresh_token,
                })
            }

            const { sessionId } = await createSession({
                userId: userExists.id,
            })

            await createLoginLog({
                sessionId,
                userAgent: request.headers.get('user-agent'),
                userId: userExists.id,
                ip: clientAddress ?? 'dev',
            })

            cookies.delete('google_oauth_state', { path: '/' })
            cookies.delete('google_code_challenge', { path: '/' })

            cookies.set('app_auth_token', sessionId, {
                path: '/',
                httpOnly: true,
                sameSite: 'lax',
                secure: import.meta.env.PROD,
            })

            return new Response(null, {
                status: 302,
                headers: {
                    Location: '/',
                },
            })
        }
    } catch (error) {
        cookies.delete('google_oauth_state', { path: '/' })
        cookies.delete('google_code_challenge', { path: '/' })

        console.error(error)

        return new Response(null, {
            status: 302,
            headers: {
                Location: '/login?error=Server+Error',
            },
        })
    }
}