import { PrismaPg } from "@prisma/adapter-pg";
import { type Request } from "express";
import { PrismaClient } from "../../generated/prisma/client.js";
import type { UserModel } from "../../generated/prisma/models.js";
import { Injectable } from "../../infrastructure/di/injectable-decorator.js";

type ExtendedClient = ReturnType<typeof createExtendedClient>;

export type SafeClient = Omit<
    ExtendedClient,
    | "$connect"
    | "$disconnect"
    | "$on"
    | "$transaction"
    | "$executeRaw"
    | "$executeRawUnsafe"
    | "$queryRaw"
    | "$queryRawUnsafe"
    | "$extends"
>;

function createExtendedClient(client: PrismaClient) {
    return client.$extends({
        client: {
            async ensureUserKnown(userId: string): Promise<UserModel> {
                let user = await client.user.findUnique({
                    where: { id: userId },
                });
                if (user == null) {
                    user = await client.user.create({ data: { id: userId } });
                }
                return user;
            },
        },
    });
}

@Injectable()
export class DatabaseService {
    private readonly prismaClient: ExtendedClient;

    public constructor() {
        const dbUser = process.env["TKD_DB_USER"]!;
        const dbPassword = process.env["TKD_DB_PASSWORD"]!;
        const dbHost = process.env["TKD_DB_HOST"]!;

        const connectionString = `postgresql://${dbUser}:${dbPassword}@${dbHost}:5432/taekwondo?schema=public`;

        const adapter = new PrismaPg({ connectionString });
        this.prismaClient = createExtendedClient(new PrismaClient({ adapter }));
    }

    public async doRequest<T>(
        command: (prisma: SafeClient) => Promise<T>,
        request: Request | null,
    ): Promise<T> {
        const transaction: SafeClient | null = (request as any | null)
            ?.transaction;
        const effectiveClient = transaction ?? this.prismaClient;
        return await command(effectiveClient);
    }
}