import "reflect-metadata"
import {
    createTestingConnections,
    closeTestingConnections,
    reloadTestingDatabases,
} from "../../utils/test-utils"
import { DataSource } from "../../../src/data-source/DataSource"
import { expect } from "chai"
import { Post } from "./entity/Post"

describe("github issues > #7146 Lazy relations resolve to 'undefined' instead of 'null'", () => {
    let connections: DataSource[]
    before(
        async () =>
            (connections = await createTestingConnections({
                entities: [__dirname + "/entity/*{.js,.ts}"],
                schemaCreate: true,
                dropSchema: true,
            })),
    )
    beforeEach(() => reloadTestingDatabases(connections))
    after(() => closeTestingConnections(connections))

    async function prepareData(connection: DataSource) {
        const savedPost = new Post()
        await connection.manager.save(savedPost)
    }

    // The following 3 tests hilight the reported issue.
    // The remaining 6 tests were already succeeding before, but are included for completeness sake.

    describe("lazy-loaded relations", () => {
        it("should return null if ManyToOne relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneByOrFail(
                        Post,
                        { id: 1 },
                    )
                    expect(await post.lazyManyToOne).to.be.null
                }),
            ))

        it("should return null if OneToOne+JoinColumn relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneByOrFail(
                        Post,
                        { id: 1 },
                    )
                    expect(await post.lazyOneToOneOwner).to.be.null
                }),
            ))

        it("should return null if OneToOne relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneByOrFail(
                        Post,
                        { id: 1 },
                    )
                    expect(await post.lazyOneToOne).to.be.null
                }),
            ))
    })

    describe("lazy-loaded relations included in 'relations' find option", () => {
        it("should return null if ManyToOne relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneOrFail(Post, {
                        where: {
                            id: 1,
                        },
                        relations: {
                            lazyManyToOne: true,
                        },
                    })
                    expect(await post.lazyManyToOne).to.be.null
                }),
            ))

        it("should return null if OneToOne+JoinColumn relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneOrFail(Post, {
                        where: {
                            id: 1,
                        },
                        relations: {
                            lazyOneToOneOwner: true,
                        },
                    })
                    expect(await post.lazyOneToOneOwner).to.be.null
                }),
            ))

        it("should return null if OneToOne relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneOrFail(Post, {
                        where: {
                            id: 1,
                        },
                        relations: {
                            lazyOneToOne: true,
                        },
                    })
                    expect(await post.lazyOneToOne).to.be.null
                }),
            ))
    })

    describe("eager-loaded relations", () => {
        it("should return null if ManyToOne relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneByOrFail(
                        Post,
                        { id: 1 },
                    )
                    expect(post.eagerManyToOne).to.be.null
                }),
            ))

        it("should return null if OneToOne+JoinColumn relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneByOrFail(
                        Post,
                        { id: 1 },
                    )
                    expect(post.eagerOneToOneOwner).to.be.null
                }),
            ))

        it("should return null if OneToOne relation has NULL in database", () =>
            Promise.all(
                connections.map(async (connection) => {
                    await prepareData(connection)
                    const post = await connection.manager.findOneByOrFail(
                        Post,
                        { id: 1 },
                    )
                    expect(post.eagerOneToOne).to.be.null
                }),
            ))
    })
})