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

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(new URL("/tiktok?error=access_denied", request.url));
    }

    try {
        // userId stocké dans le record PKCE lors du /connect (pas besoin de session)
        const pkceRecord = await prisma.tikTokPKCE.findUnique({ where: { state } });
        if (!pkceRecord) {
            return NextResponse.redirect(new URL("/tiktok?error=missing_verifier", request.url));
        }

        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);

        await prisma.tikTokToken.upsert({
            where: { userId },
            create: { userId, openId: tokens.open_id, accessToken: tokens.access_token, refreshToken: tokens.refresh_token, expiresAt },
            update: { openId: tokens.open_id, accessToken: tokens.access_token, refreshToken: tokens.refresh_token, expiresAt },
        });

        const existing = await prisma.trackedAccount.findFirst({ where: { userId, platform: "tiktok" } });
        if (!existing) {
            await prisma.trackedAccount.create({
                data: { userId, platform: "tiktok", username: tokens.open_id, accountId: tokens.open_id },
            });
        }

        return NextResponse.redirect(new URL("/tiktok?connected=1", request.url));
    } catch (err) {
        console.error("[TikTok callback error]", err);
        return NextResponse.redirect(new URL("/tiktok?error=token_exchange", request.url));
    }
}