import { NextRequest, NextResponse } from "next/server";
import { exchangeCodeForTokens } from "@/lib/tiktok";
import { prisma } from "@/lib/prisma";

const baseUrl = process.env.NEXTAUTH_URL || "https://marouette.fun";

export async function GET(request: NextRequest) {
    const { searchParams } = new URL(request.url);
    const code = searchParams.get("code");
    const state = searchParams.get("state");
    const error = searchParams.get("error");

    if (error || !code || !state) {
        return NextResponse.redirect(`${baseUrl}/tiktok?error=access_denied`);
    }

    try {
        const pkceRecord = await prisma.tikTokPKCE.findUnique({ where: { state } });
        if (!pkceRecord) {
            return NextResponse.redirect(`${baseUrl}/tiktok?error=missing_verifier`);
        }

        await prisma.tikTokPKCE.delete({ where: { state } });

        const { userId, codeVerifier } = pkceRecord;

        console.log("[TikTok callback] codeVerifier from DB:", codeVerifier);
        console.log("[TikTok callback] code from TikTok:", code);

        const tokens = await exchangeCodeForTokens(code, codeVerifier);
        const expiresAt = new Date(Date.now() + tokens.expires_in * 1000);

        // Upsert sur userId — plusieurs users peuvent partager le même compte TikTok
        await prisma.tikTokToken.upsert({
            where: { userId },
            update: {
                openId: tokens.open_id,
                accessToken: tokens.access_token,
                refreshToken: tokens.refresh_token,
                expiresAt,
            },
            create: {
                userId,
                openId: tokens.open_id,
                accessToken: tokens.access_token,
                refreshToken: tokens.refresh_token,
                expiresAt,
            },
        });

        // TrackedAccount : update si existe, sinon create
        const existing = await prisma.trackedAccount.findFirst({
            where: { userId, platform: "tiktok" },
        });

        if (existing) {
            await prisma.trackedAccount.update({
                where: { id: existing.id },
                data: { username: tokens.open_id, accountId: tokens.open_id },
            });
        } else {
            await prisma.trackedAccount.create({
                data: {
                    userId,
                    platform: "tiktok",
                    username: tokens.open_id,
                    accountId: tokens.open_id,
                },
            });
        }

        return NextResponse.redirect(`${baseUrl}/tiktok?connected=1`);
    } catch (err) {
        console.error("[TikTok callback error]", err);
        return NextResponse.redirect(`${baseUrl}/tiktok?error=token_exchange`);
    }
}