import { test } from 'node:test'
import assert from 'node:assert/strict'
import { state } from '../server/state.js'
import {
  hasStudyAccess,
  isStudyUserCompleted,
  getAccessibleStudySlugs,
  markStudyCompletedIfDone,
  scheduleReengagementEmails,
} from '../server/study-helpers.js'

function setup() {
  state.cachedSiteContent = {
    studies: [{ slug: 'mini', sections: [{ id: 'a' }, { id: 'b' }] }, { slug: 'other', sections: [{ id: 'x' }] }],
  }
}

test('completing every lesson marks the study completed and keeps access after leaving', () => {
  setup()
  const user = { id: 'u1', enrolledStudySlugs: ['mini'] }
  assert.equal(markStudyCompletedIfDone(user, 'mini', ['a']), false)
  assert.equal(markStudyCompletedIfDone(user, 'mini', ['a', 'b']), true)
  assert.ok(isStudyUserCompleted(user, 'mini'))

  user.enrolledStudySlugs = [] // student leaves
  assert.ok(hasStudyAccess(user, 'mini'))
  assert.ok(!hasStudyAccess(user, 'other'))
  assert.deepEqual(getAccessibleStudySlugs(user), ['mini'])
})

test('completion is sticky when a lesson is added later, and not marked twice', () => {
  setup()
  const user = { id: 'u2', enrolledStudySlugs: ['mini'] }
  markStudyCompletedIfDone(user, 'mini', ['a', 'b'])
  state.cachedSiteContent.studies[0].sections.push({ id: 'c' })
  assert.equal(markStudyCompletedIfDone(user, 'mini', ['a', 'b']), false)
  assert.ok(isStudyUserCompleted(user, 'mini'))
  assert.deepEqual(user.completedStudySlugs, ['mini'])
})

test('unknown or empty studies are never marked completed', () => {
  setup()
  const user = { id: 'u3', enrolledStudySlugs: [] }
  assert.equal(markStudyCompletedIfDone(user, 'nope', ['a']), false)
  state.cachedSiteContent.studies.push({ slug: 'empty', sections: [] })
  assert.equal(markStudyCompletedIfDone(user, 'empty', []), false)
})

test('re-engagement emails skip students whose only study is finished', async () => {
  setup()
  const sent = []
  state.studyUsers = [{
    id: 'u4', username: 'a@b.co', studyRemindersEnabled: true, lastLoginAt: new Date(Date.now() - 40 * 864e5).toISOString(),
    enrolledStudySlugs: ['mini'], completedStudySlugs: ['mini'], reengagementSentAt: {},
  }, {
    id: 'u5', username: 'c@d.co', studyRemindersEnabled: true, lastLoginAt: new Date(Date.now() - 40 * 864e5).toISOString(),
    enrolledStudySlugs: ['mini'], reengagementSentAt: {},
  }]
  await scheduleReengagementEmails(async (email) => { sent.push(email) })
  assert.deepEqual(sent, ['c@d.co'])
})