const MentionSendingService = require('../../../../../core/server/services/mentions/mention-sending-service');
const assert = require('node:assert/strict');
const nock = require('nock');
// non-standard to use externalRequest here, but this is required for the overrides in the libary, which we want to test for security reasons in combination with the package
const externalRequest = require('../../../../../core/server/lib/request-external.js');
const sinon = require('sinon');
const logging = require('@tryghost/logging');
const dnsPromises = require('node:dns').promises;
const {createModel} = require('./utils/index.js');

// mock up job service
let jobService = {
    async addJob(name, fn) {
        return fn();
    }
};

describe('MentionSendingService', function () {
    let errorLogStub;

    beforeEach(function () {
        nock.disableNetConnect();
        sinon.stub(logging, 'info');
        errorLogStub = sinon.stub(logging, 'error');
    });

    afterEach(function () {
        nock.cleanAll();
        sinon.restore();
    });

    after(function () {
        nock.cleanAll();
        nock.enableNetConnect();
    });

    describe('listen', function () {
        it('Called on all events we listen to', async function () {
            const service = new MentionSendingService({});
            const stub = sinon.stub(service, 'sendForPost').resolves();
            let callback;
            const events = {
                on: sinon.stub().callsFake((event, c) => {
                    callback = c;
                })
            };
            service.listen(events);
            sinon.assert.callCount(events.on, 6);
            await callback({});
            sinon.assert.calledOnce(stub);
        });
    });

    describe('sendForPost', function () {
        it('Ignores if disabled', async function () {
            const service = new MentionSendingService({
                isEnabled: () => false
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost({});
            sinon.assert.notCalled(stub);
        });

        it('Ignores if importing data', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            let options = {importing: true};
            await service.sendForPost({}, options);
            sinon.assert.notCalled(stub);
        });

        it('Ignores if internal context', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            let options = {context: {internal: true}};
            await service.sendForPost({}, options);
            sinon.assert.notCalled(stub);
        });

        it('Ignores draft posts', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'draft',
                html: 'changed',
                previous: {
                    status: 'draft',
                    html: ''
                }
            }));
            sinon.assert.notCalled(stub);
        });

        it('Ignores if html was not changed', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'published',
                html: 'same',
                previous: {
                    status: 'published',
                    html: 'same'
                }
            }));
            sinon.assert.notCalled(stub);
        });

        it('Ignores email only posts', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'send',
                html: 'changed',
                previous: {
                    status: 'draft',
                    html: 'same'
                }
            }));
            sinon.assert.notCalled(stub);
        });

        it('Sends on publish', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true,
                getPostUrl: () => 'https://site.com/post/',
                jobService: jobService
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'published',
                html: 'same',
                previous: {
                    status: 'draft',
                    html: 'same'
                }
            }));
            sinon.assert.calledOnce(stub);
            const firstCall = stub.getCall(0).args[0];
            assert.equal(firstCall.url.toString(), 'https://site.com/post/');
            assert.equal(firstCall.html, 'same');
            assert.equal(firstCall.previousHtml, null);
        });

        it('Sends on unpublish', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true,
                getPostUrl: () => 'https://site.com/post/',
                jobService: jobService
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'draft',
                html: 'same',
                previous: {
                    status: 'published',
                    html: 'same'
                }
            }));
            sinon.assert.calledOnce(stub);
            const firstCall = stub.getCall(0).args[0];
            assert.equal(firstCall.url.toString(), 'https://site.com/post/');
            assert.equal(firstCall.html, null);
            assert.equal(firstCall.previousHtml, 'same');
        });

        it('Sends on html change', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true,
                getPostUrl: () => 'https://site.com/post/',
                jobService: jobService
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'published',
                html: 'updated',
                previous: {
                    status: 'published',
                    html: 'same'
                }
            }));
            sinon.assert.calledOnce(stub);
            const firstCall = stub.getCall(0).args[0];
            assert.equal(firstCall.url.toString(), 'https://site.com/post/');
            assert.equal(firstCall.html, 'updated');
            assert.equal(firstCall.previousHtml, 'same');
        });

        it('Catches and logs errors', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true,
                getPostUrl: () => 'https://site.com/post/'
            });
            sinon.stub(service, 'sendForHTMLResource').rejects(new Error('Internal error test'));
            await service.sendForPost(createModel({
                status: 'published',
                html: 'same',
                previous: {
                    status: 'draft',
                    html: 'same'
                }
            }));
            sinon.assert.calledTwice(errorLogStub);
        });

        it('Sends no mentions for posts without html and previous html', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true,
                getPostUrl: () => 'https://site.com/post/',
                jobService: jobService
            });
            const stub = sinon.stub(service, 'sendForHTMLResource');
            await service.sendForPost(createModel({
                status: 'published',
                html: '',
                previous: {
                    status: 'draft',
                    html: ''
                }
            }));
            sinon.assert.notCalled(stub);
        });
    });

    describe('sendForHTMLResource', function () {
        it('Sends to all links', async function () {
            this.retries(1);
            let counter = 0;
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .reply(() => {
                    counter += 1;
                    return [202];
                });

            const service = new MentionSendingService({
                externalRequest,
                getSiteUrl: () => new URL('https://site.com'),
                discoveryService: {
                    getEndpoint: async () => new URL('https://example.org/webmentions-test')
                }
            });
            await service.sendForHTMLResource({url: new URL('https://site.com'),
                html: `
                    <html>
                        <body>
                            <a href="https://example.com">Example</a>
                            <a href="https://example.com">Example repeated</a>
                            <a href="https://example.org#fragment">Example</a>
                            <a href="http://example2.org">Example 2</a>
                        </body>
                    </html>
            `});
            assert.equal(scope.isDone(), true);
            assert.equal(counter, 3);
        });

        it('Catches and logs errors', async function () {
            this.retries(1);
            let counter = 0;
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .reply(() => {
                    counter += 1;
                    if (counter === 2) {
                        return [500];
                    }
                    return [202];
                });

            const service = new MentionSendingService({
                externalRequest,
                getSiteUrl: () => new URL('https://site.com'),
                discoveryService: {
                    getEndpoint: async () => new URL('https://example.org/webmentions-test')
                }
            });
            await service.sendForHTMLResource({url: new URL('https://site.com'),
                html: `
                    <html>
                        <body>
                            <a href="https://example.com">Example</a>
                            <a href="https://example.com">Example repeated</a>
                            <a href="https://example.org#fragment">Example</a>
                            <a href="http://example2.org">Example 2</a>
                        </body>
                    </html>
            `});
            assert.equal(scope.isDone(), true);
            assert.equal(counter, 3);
            sinon.assert.calledOnce(errorLogStub);
        });

        it('Sends to deleted links', async function () {
            this.retries(1);
            let counter = 0;
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .reply(() => {
                    counter += 1;
                    return [202];
                });

            const service = new MentionSendingService({
                externalRequest,
                getSiteUrl: () => new URL('https://site.com'),
                discoveryService: {
                    getEndpoint: async () => new URL('https://example.org/webmentions-test')
                },
                jobService: jobService
            });
            await service.sendForHTMLResource({url: new URL('https://site.com'),
                html: `<a href="https://example.com">Example</a>`,
                previousHtml: `<a href="https://typo.com">Example</a>`});
            assert.equal(scope.isDone(), true);
            assert.equal(counter, 2);
        });

        // cheerio must be served a string
        it('Does not evaluate links for an empty post', async function () {
            const service = new MentionSendingService({
                isEnabled: () => true
            });
            const linksStub = sinon.stub(service, 'getLinks');
            await service.sendForHTMLResource({html: ``,previousHtml: ``});
            sinon.assert.notCalled(linksStub);
        });
    });

    describe('getLinks', function () {
        it('Returns all unique links in a HTML-document', async function () {
            const service = new MentionSendingService({
                getSiteUrl: () => new URL('https://site.com')
            });
            const links = service.getLinks(`
                <html>
                    <body>
                        <a href="https://example.com">Example</a>
                        <a href="https://example.com">Example repeated</a>
                        <a href="https://example.org#fragment">Example</a>
                        <a href="http://example2.org">Example 2</a>
                    </body>
                </html>
            `);
            assert.deepEqual(links, [
                new URL('https://example.com'),
                new URL('https://example.org#fragment'),
                new URL('http://example2.org')
            ]);
        });

        it('Does not include invalid or local URLs', async function () {
            const service = new MentionSendingService({
                getSiteUrl: () => new URL('https://site.com')
            });
            const links = service.getLinks(`<a href="/">Example</a>`);
            assert.deepEqual(links, []);
        });

        it('Does not include non-http protocols', async function () {
            const service = new MentionSendingService({
                getSiteUrl: () => new URL('https://site.com')
            });
            const links = service.getLinks(`<a href="ftp://invalid.com">Example</a>`);
            assert.deepEqual(links, []);
        });

        it('Does not include invalid urls', async function () {
            const service = new MentionSendingService({
                getSiteUrl: () => new URL('https://site.com')
            });
            const links = service.getLinks(`<a href="()">Example</a>`);
            assert.deepEqual(links, []);
        });

        it('Does not include urls from site domain', async function () {
            const service = new MentionSendingService({
                getSiteUrl: () => new URL('https://site.com')
            });
            const links = service.getLinks(`<a href="http://site.com/test?123">Example</a>`);
            assert.deepEqual(links, []);
        });

        it('Ignores invalid site urls', async function () {
            const service = new MentionSendingService({
                getSiteUrl: () => new URL('invalid()')
            });
            const links = service.getLinks(`<a href="http://site.com/test?123">Example</a>`);
            assert.deepEqual(links, [
                new URL('http://site.com/test?123')
            ]);
        });
    });

    describe('send', function () {
        it('Can handle 202 accepted responses', async function () {
            this.retries(1);
            const source = new URL('https://example.com/source');
            const target = new URL('https://target.com/target');
            const endpoint = new URL('https://example.org/webmentions-test');
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test', `source=${encodeURIComponent('https://example.com/source')}&target=${encodeURIComponent('https://target.com/target')}&source_is_ghost=true`)
                .reply(202);

            const service = new MentionSendingService({externalRequest});
            await service.send({
                source: source,
                target: target,
                endpoint: endpoint
            });
            assert(scope.isDone());
        });

        it('Can handle 201 created responses', async function () {
            this.retries(1);
            const source = new URL('https://example.com/source');
            const target = new URL('https://target.com/target');
            const endpoint = new URL('https://example.org/webmentions-test');
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test', `source=${encodeURIComponent('https://example.com/source')}&target=${encodeURIComponent('https://target.com/target')}&source_is_ghost=true`)
                .reply(201);

            const service = new MentionSendingService({externalRequest});
            await service.send({
                source: source,
                target: target,
                endpoint: endpoint
            });
            assert(scope.isDone());
        });

        it('Can handle 400 responses', async function () {
            this.retries(1);
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .reply(400);

            const service = new MentionSendingService({externalRequest});
            await assert.rejects(service.send({
                source: new URL('https://example.com/source'),
                target: new URL('https://target.com/target'),
                endpoint: new URL('https://example.org/webmentions-test')
            }), /sending failed/);
            assert(scope.isDone());
        });

        it('Can handle 500 responses', async function () {
            this.retries(1);
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .reply(500);

            const service = new MentionSendingService({externalRequest});
            await assert.rejects(service.send({
                source: new URL('https://example.com/source'),
                target: new URL('https://target.com/target'),
                endpoint: new URL('https://example.org/webmentions-test')
            }), /sending failed/);
            assert(scope.isDone());
        });

        it('Can handle redirect responses', async function () {
            this.retries(1);
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .reply(302, '', {
                    Location: 'https://example.org/webmentions-test-2'
                });
            const scope2 = nock('https://example.org')
                .persist()
                .post('/webmentions-test-2')
                .reply(201);

            const service = new MentionSendingService({externalRequest});
            await service.send({
                source: new URL('https://example.com'),
                target: new URL('https://example.com'),
                endpoint: new URL('https://example.org/webmentions-test')
            });
            assert(scope.isDone());
            assert(scope2.isDone());
        });

        it('Can handle network errors', async function () {
            this.retries(1);
            const scope = nock('https://example.org')
                .persist()
                .post('/webmentions-test')
                .replyWithError('network error');

            const service = new MentionSendingService({externalRequest});
            await assert.rejects(service.send({
                source: new URL('https://example.com/source'),
                target: new URL('https://target.com/target'),
                endpoint: new URL('https://example.org/webmentions-test')
            }), /network error/);
            assert(scope.isDone());
        });

        it('Does not send to private IP behind DNS', async function () {
            // Stub DNS to return a private IP for the target domain
            dnsPromises.lookup.restore?.();
            const dnsStub = sinon.stub(dnsPromises, 'lookup').callsFake(() => {
                return Promise.resolve({address: '127.0.0.1', family: 4});
            });

            try {
                const service = new MentionSendingService({externalRequest});
                await assert.rejects(service.send({
                    source: new URL('https://example.com/source'),
                    target: new URL('https://target.com/target'),
                    endpoint: new URL('http://domaincontrol.com/webmentions')
                }), /non-permitted private IP/);
            } finally {
                dnsStub.restore();
            }
        });
    });
});
