// entities.ts
import { EntitySchema } from 'typeorm';

interface DocumentRelation {
    documentRelationId: number;
    documentId: number;
    userId?: number;

    document?: Document;
}

interface Document {
    documentId: number;

    documentRelation?: DocumentRelation[];
}

interface User {
    userId: number;

    documents?: Document[];
}

export const userEntitySchema = new EntitySchema<User>({
    name: 'user',
    columns: {
        userId: { type: Number, primary: true, generated: 'increment', name: 'user_id' },
    },
    relations: {
        documents: {
            type: 'many-to-many',
            target: 'document',
            joinTable: {
                name: 'document_relation',
                joinColumn: {
                    name: 'user_id',
                    referencedColumnName: 'userId',
                },
                inverseJoinColumn: {
                    name: 'document_id',
                    referencedColumnName: 'documentId',
                },
            },
        },
    },
});

export const documentEntitySchema = new EntitySchema<Document>({
    name: 'document',
    columns: {
        documentId: { type: Number, primary: true, generated: 'increment', name: 'document_id' },
    },
    relations: {
        documentRelation: {
            type: 'one-to-many',
            target: 'document_relation',
            inverseSide: 'document',
            joinColumn: {
                name: 'document_id',
                referencedColumnName: 'documentId',
            },
        },
    },
});

export const documentRelationEntitySchema = new EntitySchema<DocumentRelation>({
    name: 'document_relation',
    columns: {
        documentRelationId: { type: Number, primary: true, generated: 'increment', name: 'document_relation_id' },
        documentId: { type: Number, name: 'document_id' },
        userId: { type: Number, name: 'user_id', nullable: true },
    },
    relations: {
        document: {
            type: 'many-to-one',
            target: 'document',
            inverseSide: 'documentRelation',
            onDelete: 'CASCADE',
            onUpdate: 'CASCADE',
            joinColumn: {
                name: 'document_id',
                referencedColumnName: 'documentId',
            },
        },
    },
});


// index.ts
import { DataSource } from 'typeorm';
import { documentRelationEntitySchema } from './entities';

async function run() {
    const dataSource = new DataSource({
        url: 'postgres://postgres:postgres@localhost:5432/db',
        entities: ['./entities.ts'],
        type: 'postgres',
        synchronize: false,
    });

    await dataSource.initialize();
    const repository = dataSource.manager.getRepository(documentRelationEntitySchema);

    console.log(repository.metadata.relations); // []
    await repository.find({ where: { userId: 2030 }, relations: ['document'] }); // throws EntityPropertyNotFoundError: Property "document" was not found in ""
}

run();