import { test, expect, Page } from '@playwright/test'

/**
 * E2E tests for /stundenplan
 *
 * Backend calls go through /api/school/* (Next.js proxy → school-service).
 * For most tests we intercept those routes so the suite is hermetic and does
 * not depend on a populated database or a valid JWT.
 */

const MOCK_TEACHER_ID = '11111111-1111-1111-1111-111111111111'
const MOCK_SUBJECT_ID = '22222222-2222-2222-2222-222222222222'
const MOCK_CLASS_ID = '33333333-3333-3333-3333-333333333333'

interface MockClass {
  id: string
  name: string
  grade_level: number
  student_count: number
  notes?: string
  created_by_user_id: string
  created_at: string
}

interface MockOpts {
  classes?: MockClass[]
  teachers?: unknown[]
  subjects?: unknown[]
  rooms?: unknown[]
  periods?: unknown[]
  curriculum?: unknown[]
  assignments?: unknown[]
}

async function mockSchoolApi(page: Page, opts: MockOpts = {}) {
  const classes = opts.classes ?? []
  const teachers = opts.teachers ?? []
  const subjects = opts.subjects ?? []
  const rooms = opts.rooms ?? []
  const periods = opts.periods ?? []
  const curriculum = opts.curriculum ?? []
  const assignments = opts.assignments ?? []

  await page.route('**/api/school/timetable/classes', async (route) => {
    if (route.request().method() === 'GET') {
      return route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify(classes) })
    }
    if (route.request().method() === 'POST') {
      const body = JSON.parse(route.request().postData() || '{}')
      const created: MockClass = {
        id: 'new-class-id',
        name: body.name,
        grade_level: body.grade_level,
        student_count: body.student_count ?? 0,
        notes: body.notes,
        created_by_user_id: 'test-user',
        created_at: new Date().toISOString(),
      }
      classes.push(created)
      return route.fulfill({ status: 201, contentType: 'application/json', body: JSON.stringify(created) })
    }
    return route.fulfill({ status: 405 })
  })

  // Helper to mount a read-only endpoint with a static list.
  const staticList = (path: string, data: unknown) =>
    page.route(`**/api/school/timetable/${path}`, async (route) =>
      route.fulfill({ status: 200, contentType: 'application/json', body: JSON.stringify(data) }))

  await staticList('teachers', teachers)
  await staticList('subjects', subjects)
  await staticList('rooms', rooms)
  await staticList('periods', periods)
  await staticList('curriculum', curriculum)
  await staticList('assignments', assignments)

  // Constraint endpoints — all empty by default.
  for (const path of [
    'constraints/teacher/unavailable-day',
    'constraints/teacher/unavailable-window',
    'constraints/subject/max-consecutive',
    'constraints/subject/preferred-period',
  ]) {
    await staticList(path, [])
  }
}

test.describe('Stundenplan — Page Shell', () => {
  test.beforeEach(async ({ page }) => {
    await mockSchoolApi(page)
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
  })

  test('page loads with title and subtitle', async ({ page }) => {
    await expect(page.getByRole('heading', { name: 'Stundenplan' })).toBeVisible()
    await expect(page.getByText('Stammdaten und Regeln fuer den Solver')).toBeVisible()
  })

  test('shows all 8 tabs', async ({ page }) => {
    // Sidebar entries collide with tab labels for 'Lehrer' — scope to <main nav>.
    const tabs = page.locator('main nav')
    for (const label of ['Klassen', 'Lehrer', 'Faecher', 'Raeume', 'Zeitraster', 'Stundentafel', 'Lehrauftraege', 'Regeln (Constraints)']) {
      await expect(tabs.getByRole('button', { name: label, exact: true })).toBeVisible()
    }
  })

  test('Klassen tab is active by default', async ({ page }) => {
    await expect(page.getByTestId('klassen-manager')).toBeVisible()
  })

  test('JWT dev field exists and persists into localStorage', async ({ page }) => {
    await page.getByText('Dev: JWT-Token setzen').click()
    page.on('dialog', d => d.accept())
    await page.getByPlaceholder('Bearer-Token').fill('test-jwt-abc')
    await page.getByRole('button', { name: 'Speichern' }).click()
    const stored = await page.evaluate(() => localStorage.getItem('bp_stundenplan_jwt'))
    expect(stored).toBe('test-jwt-abc')
  })
})

test.describe('Stundenplan — Tab navigation', () => {
  test.beforeEach(async ({ page }) => {
    await mockSchoolApi(page)
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
  })

  test('all 8 tabs render their manager', async ({ page }) => {
    const tabs = page.locator('main nav')
    const cases: { label: string; testId: string }[] = [
      { label: 'Lehrer', testId: 'lehrer-manager' },
      { label: 'Faecher', testId: 'faecher-manager' },
      { label: 'Raeume', testId: 'raeume-manager' },
      { label: 'Zeitraster', testId: 'periods-manager' },
      { label: 'Stundentafel', testId: 'curriculum-manager' },
      { label: 'Lehrauftraege', testId: 'assignments-manager' },
      { label: 'Regeln (Constraints)', testId: 'regeln-hub' },
    ]
    for (const c of cases) {
      await tabs.getByRole('button', { name: c.label, exact: true }).click()
      await expect(page.getByTestId(c.testId)).toBeVisible()
    }
  })
})

test.describe('Stundenplan — Klassen CRUD', () => {
  test('empty state shows when no classes', async ({ page }) => {
    await mockSchoolApi(page, { classes: [] })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await expect(page.getByText('Noch keine Klassen angelegt.')).toBeVisible()
  })

  test('renders classes returned by the backend', async ({ page }) => {
    await mockSchoolApi(page, {
      classes: [
        { id: 'c1', name: '5a', grade_level: 5, student_count: 24, created_by_user_id: 'u', created_at: '2026-05-21T10:00:00Z' },
        { id: 'c2', name: '5b', grade_level: 5, student_count: 23, created_by_user_id: 'u', created_at: '2026-05-21T10:00:00Z' },
      ],
    })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await expect(page.getByText('Klassen (2)')).toBeVisible()
    await expect(page.getByRole('cell', { name: '5a' })).toBeVisible()
    await expect(page.getByRole('cell', { name: '5b' })).toBeVisible()
  })

  test('+ Neue Klasse toggles the form', async ({ page }) => {
    await mockSchoolApi(page)
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')

    await expect(page.getByPlaceholder('z.B. 5a')).toHaveCount(0)
    await page.getByRole('button', { name: '+ Neue Klasse' }).click()
    await expect(page.getByPlaceholder('z.B. 5a')).toBeVisible()
    await page.getByRole('button', { name: 'Abbrechen' }).click()
    await expect(page.getByPlaceholder('z.B. 5a')).toHaveCount(0)
  })

  test('form submission appends a new class to the list', async ({ page }) => {
    await mockSchoolApi(page, { classes: [] })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')

    await page.getByRole('button', { name: '+ Neue Klasse' }).click()
    await page.getByPlaceholder('z.B. 5a').fill('7c')
    await page.locator('input[type=number]').first().fill('7')
    await page.getByRole('button', { name: 'Anlegen' }).click()

    await expect(page.getByText('Klassen (1)')).toBeVisible()
    await expect(page.getByRole('cell', { name: '7c' })).toBeVisible()
  })
})

test.describe('Stundenplan — Periods grid', () => {
  test('empty state shows when no periods', async ({ page }) => {
    await mockSchoolApi(page, { periods: [] })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Zeitraster', exact: true }).click()
    await expect(page.getByText('Noch kein Zeitraster definiert.')).toBeVisible()
  })

  test('renders weekday grid with period entries', async ({ page }) => {
    await mockSchoolApi(page, {
      periods: [
        { id: 'p1', day_of_week: 1, period_index: 1, start_time: '08:00', end_time: '08:45', is_break: false, created_by_user_id: 'u', created_at: '' },
        { id: 'p2', day_of_week: 2, period_index: 1, start_time: '08:00', end_time: '08:45', is_break: false, created_by_user_id: 'u', created_at: '' },
        { id: 'p3', day_of_week: 1, period_index: 2, start_time: '08:50', end_time: '09:35', is_break: false, created_by_user_id: 'u', created_at: '' },
      ],
    })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Zeitraster', exact: true }).click()
    await expect(page.getByText('Zeitraster (3)')).toBeVisible()
    // Header row contains weekday abbreviations Mo–So.
    for (const day of ['Mo', 'Di', 'Mi']) {
      await expect(page.getByRole('columnheader', { name: day, exact: true })).toBeVisible()
    }
    // Two distinct time labels should appear in the grid.
    await expect(page.getByText('08:00–08:45').first()).toBeVisible()
    await expect(page.getByText('08:50–09:35')).toBeVisible()
  })
})

test.describe('Stundenplan — Curriculum prerequisites', () => {
  test('shows warning when classes or subjects missing', async ({ page }) => {
    await mockSchoolApi(page, { classes: [], subjects: [] })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Stundentafel', exact: true }).click()
    await expect(page.getByText('Zuerst Klassen und Faecher anlegen.')).toBeVisible()
  })

  test('enables form when both classes and subjects exist', async ({ page }) => {
    await mockSchoolApi(page, {
      classes: [{ id: MOCK_CLASS_ID, name: '5a', grade_level: 5, student_count: 24, created_by_user_id: 'u', created_at: '' }],
      subjects: [{ id: MOCK_SUBJECT_ID, name: 'Mathematik', short_code: 'M', is_main_subject: true, created_by_user_id: 'u', created_at: '' }],
    })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Stundentafel', exact: true }).click()
    const btn = page.getByRole('button', { name: '+ Neuer Eintrag' })
    await expect(btn).toBeEnabled()
    await btn.click()
    await expect(page.getByRole('combobox').first().locator('option', { hasText: '5a' })).toHaveCount(1)
    await expect(page.locator('select').nth(1).locator('option', { hasText: 'Mathematik' })).toHaveCount(1)
  })
})

test.describe('Stundenplan — Assignments prerequisites', () => {
  test('warns when teachers/classes/subjects missing', async ({ page }) => {
    await mockSchoolApi(page)
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Lehrauftraege', exact: true }).click()
    await expect(page.getByText('Zuerst Klassen, Faecher und Lehrer anlegen.')).toBeVisible()
  })

  test('renders existing assignments with joined names', async ({ page }) => {
    await mockSchoolApi(page, {
      teachers: [{ id: MOCK_TEACHER_ID, first_name: 'Anna', last_name: 'Schmidt', short_code: 'SCH', employment_percentage: 100, max_hours_week: 28, created_by_user_id: 'u', created_at: '' }],
      classes: [{ id: MOCK_CLASS_ID, name: '5a', grade_level: 5, student_count: 24, created_by_user_id: 'u', created_at: '' }],
      subjects: [{ id: MOCK_SUBJECT_ID, name: 'Mathe', short_code: 'M', is_main_subject: true, created_by_user_id: 'u', created_at: '' }],
      assignments: [{
        id: 'a1', teacher_id: MOCK_TEACHER_ID, class_id: MOCK_CLASS_ID, subject_id: MOCK_SUBJECT_ID,
        teacher_name: 'Schmidt, Anna', class_name: '5a', subject_name: 'Mathe', created_at: '',
      }],
    })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Lehrauftraege', exact: true }).click()
    await expect(page.getByText('Lehrauftraege (1)')).toBeVisible()
    await expect(page.getByRole('cell', { name: 'Schmidt, Anna' })).toBeVisible()
    await expect(page.getByRole('cell', { name: 'Mathe' })).toBeVisible()
  })
})

test.describe('Stundenplan — Regeln Hub', () => {
  test.beforeEach(async ({ page }) => {
    await mockSchoolApi(page, {
      teachers: [{ id: MOCK_TEACHER_ID, first_name: 'Anna', last_name: 'Schmidt', short_code: 'SCH', employment_percentage: 100, max_hours_week: 28, created_by_user_id: 'u', created_at: '' }],
      subjects: [{ id: MOCK_SUBJECT_ID, name: 'Mathe', short_code: 'M', is_main_subject: true, created_by_user_id: 'u', created_at: '' }],
    })
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    await page.locator('main nav').getByRole('button', { name: 'Regeln (Constraints)' }).click()
  })

  test('shows all 4 rule groups in the sidebar', async ({ page }) => {
    for (const group of ['Lehrer', 'Fach', 'Klasse', 'Raum']) {
      await expect(page.getByTestId('regeln-hub').getByText(group, { exact: true })).toBeVisible()
    }
  })

  test('TeacherUnavailableDay editor is active by default', async ({ page }) => {
    await expect(page.getByTestId('teacher-unavailable-day-editor')).toBeVisible()
  })

  test('switching to UnavailableWindow editor swaps the right pane', async ({ page }) => {
    await page.getByRole('button', { name: 'Zeitfenster nicht verfuegbar' }).click()
    await expect(page.getByTestId('teacher-unavailable-window-editor')).toBeVisible()
    await expect(page.getByText('„Lehrer Z Dienstags 13:00–17:00 nicht".')).toBeVisible()
  })

  test('switching to SubjectMaxConsecutive editor works', async ({ page }) => {
    await page.getByRole('button', { name: 'Max. Stunden am Stueck' }).click()
    await expect(page.getByTestId('subject-max-consecutive-editor')).toBeVisible()
  })

  test('switching to SubjectPreferredPeriod editor works', async ({ page }) => {
    await page.getByRole('button', { name: 'Bevorzugter Stunden-Bereich' }).click()
    await expect(page.getByTestId('subject-preferred-period-editor')).toBeVisible()
  })

  test('unimplemented rules are disabled in the sidebar', async ({ page }) => {
    const soonBtn = page.getByRole('button', { name: /Min\. Tagesabstand/ })
    await expect(soonBtn).toBeDisabled()
    await expect(page.getByText('soon').first()).toBeVisible()
  })
})

test.describe('Stundenplan — Sidebar entry', () => {
  test('sidebar contains Stundenplan link', async ({ page }) => {
    await mockSchoolApi(page)
    await page.goto('/stundenplan')
    await page.waitForLoadState('networkidle')
    const sidebar = page.locator('aside').first()
    await expect(sidebar.getByText(/Stundenplan|Timetable/).first()).toBeVisible()
  })
})