import {describe, expect, it, vi, beforeEach} from 'vitest';

const connection = {
	query: vi.fn(),
	execute: vi.fn(),
	beginTransaction: vi.fn(),
	commit: vi.fn(),
	rollback: vi.fn(),
	end: vi.fn()
};

vi.mock('../../src/models/calendar/Calendar.db.js', () => ({
	NachklangCalendarDB: {getConnection: vi.fn(async () => connection)}
}));

vi.mock('../../src/models/admin/users/users.admin.service.js', () => ({
	findDisplayNames: vi.fn()
}));

import {NachklangCalendarDB} from '../../src/models/calendar/Calendar.db.js';
import * as AdminUsersService from '../../src/models/admin/users/users.admin.service.js';
import * as EventService from '../../src/models/calendar/events/events.service.js';

/**
 * Step 3 of docs/calendar-auth-migration.md. The property under test is that
 * an event's creator resolves from whichever of its three possible sources is
 * strongest - the live admin name, then the snapshot from migration 002, then
 * the legacy join - and that a failure to reach the admin database costs a name
 * rather than the whole response: the public calendar is read anonymously by
 * the website and has never depended on the admin database being up.
 */

// One row of the shape the shared SELECT produces.
const row = (over: Record<string, unknown> = {}) => ({
	event_id: 1,
	calendar_id: 1,
	uuid: 'uuid-1',
	name: 'Konzert',
	description: '',
	start_datetime: new Date('2026-04-18T19:00:00Z'),
	end_datetime: new Date('2026-04-18T21:00:00Z'),
	created_date: new Date('2026-01-01T00:00:00Z'),
	version_created_at: new Date('2026-01-02T00:00:00Z'),
	location: '',
	created_by_id: 7,
	created_by_user_id: null,
	created_by_name: null,
	legacy_created_by_name: 'Legacy Person',
	version_created_by_id: 7,
	version_created_by_user_id: null,
	version_created_by_name: null,
	legacy_last_modified_by_name: 'Legacy Person',
	url: '',
	whole_day: 0,
	repeat_frequency: '',
	status: 'PUBLIC',
	...over
});

/** getAllEvents runs the calendars lookup first, then the events query. */
const givenEvents = (...rows: unknown[]) => {
	connection.query.mockReset();
	connection.query
		.mockResolvedValueOnce([{calendar_id: 1, includes_calendars: '[]'}])
		.mockResolvedValueOnce(rows);
};

beforeEach(() => {
	vi.clearAllMocks();
	connection.end.mockResolvedValue(undefined);
	(NachklangCalendarDB.getConnection as any).mockResolvedValue(connection);
});

describe('creator names', () => {
	it('uses the legacy join when the row has no admin id', async () => {
		givenEvents(row());

		const events = await EventService.getAllEvents(1);

		expect(events[0].createdBy).toBe('Legacy Person');
		expect(events[0].createdById).toBe(7);
		expect(events[0].createdByUserId).toBeNull();
		// Nothing to resolve, so the admin database is not touched at all.
		expect(AdminUsersService.findDisplayNames).not.toHaveBeenCalled();
	});

	it('prefers the admin name when the row carries an admin id', async () => {
		givenEvents(row({
			created_by_user_id: 'admin-1',
			version_created_by_user_id: 'admin-2'
		}));
		(AdminUsersService.findDisplayNames as any).mockResolvedValue(
			new Map([['admin-1', 'Neue Person'], ['admin-2', 'Andere Person']])
		);

		const events = await EventService.getAllEvents(1);

		expect(events[0].createdBy).toBe('Neue Person');
		expect(events[0].lastModifiedBy).toBe('Andere Person');
		// The legacy id is still reported during the transition.
		expect(events[0].createdById).toBe(7);
		expect(events[0].createdByUserId).toBe('admin-1');
	});

	it('prefers the snapshot over the legacy join', async () => {
		givenEvents(row({
			created_by_name: 'Archived Person',
			version_created_by_name: 'Archived Person'
		}));

		const events = await EventService.getAllEvents(1);

		expect(events[0].createdBy).toBe('Archived Person');
		expect(events[0].lastModifiedBy).toBe('Archived Person');
	});

	it('prefers the live admin name over the snapshot', async () => {
		// A renamed account has to win over an archive that was correct when it
		// was taken - otherwise renaming someone would leave stale names behind.
		givenEvents(row({created_by_user_id: 'admin-1', created_by_name: 'Archived Person'}));
		(AdminUsersService.findDisplayNames as any).mockResolvedValue(new Map([['admin-1', 'Neue Person']]));

		const events = await EventService.getAllEvents(1);

		expect(events[0].createdBy).toBe('Neue Person');
	});

	it('keeps the snapshot when step 5 has removed the legacy join', async () => {
		// What a post-step-5 row looks like: no legacy id, no join, snapshot only.
		givenEvents(row({
			created_by_id: null,
			legacy_created_by_name: undefined,
			legacy_last_modified_by_name: undefined,
			created_by_name: 'Archived Person',
			version_created_by_name: 'Archived Person'
		}));

		const events = await EventService.getAllEvents(1);

		expect(events[0].createdBy).toBe('Archived Person');
		expect(events[0].lastModifiedBy).toBe('Archived Person');
	});

	it('falls back to the legacy name when the admin account is gone', async () => {
		givenEvents(row({created_by_user_id: 'deleted'}));
		(AdminUsersService.findDisplayNames as any).mockResolvedValue(new Map());

		const events = await EventService.getAllEvents(1);

		expect(events[0].createdBy).toBe('Legacy Person');
	});

	it('resolves a mixed result set in a single lookup', async () => {
		givenEvents(
			row({event_id: 1}),
			row({event_id: 2, created_by_user_id: 'admin-1', version_created_by_user_id: 'admin-1'}),
			row({event_id: 3, created_by_user_id: 'admin-1', version_created_by_user_id: 'admin-1'})
		);
		(AdminUsersService.findDisplayNames as any).mockResolvedValue(new Map([['admin-1', 'Neue Person']]));

		const events = await EventService.getAllEvents(1);

		expect(events.map(e => e.createdBy)).toEqual(['Legacy Person', 'Neue Person', 'Neue Person']);
		expect(AdminUsersService.findDisplayNames).toHaveBeenCalledTimes(1);
	});

	it('still returns the events when the admin database is unreachable', async () => {
		givenEvents(row({created_by_user_id: 'admin-1'}));
		(AdminUsersService.findDisplayNames as any).mockRejectedValue(new Error('ECONNREFUSED'));

		const events = await EventService.getAllEvents(1);

		expect(events).toHaveLength(1);
		expect(events[0].name).toBe('Konzert');
		// Degrades to the legacy name rather than failing the request.
		expect(events[0].createdBy).toBe('Legacy Person');
	});
});

describe('status', () => {
	it('is omitted from the public listing and present in the admin one', async () => {
		givenEvents(row());
		const publicEvents = await EventService.getAllEvents(1);
		expect(publicEvents[0].status).toBeUndefined();

		connection.query.mockReset();
		connection.query.mockResolvedValueOnce([row()]);
		const adminEvents = await EventService.getAllEventsAdmin(1);
		expect(adminEvents[0].status).toBe('PUBLIC');
	});
});