import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
import { ref } from 'vue'
import { enableAutoUnmount, flushPromises, mount, type VueWrapper } from '@vue/test-utils'
import ReorderBranch from '../../src/components/reorder/ReorderBranch.vue'
import { REORDER_PAGE, type ReorderPage } from '../../src/components/reorder/context'
import { applyDrop, applyMove, buildTree, canDrop, canMove, flatten, type TreeNode } from '../../src/components/reorder/tree'
import { setSettings } from '../../src/state/useSettings'
import ReorderView from '../../src/views/ReorderView.vue'
import { toasts } from '../../src/state/useToasts'
import { clone, companionsFormSchemaFixture, listFixture, listSchemaFixture } from '../fixtures/typed'
import { API, keydown, mountApp, queryOf, requestsTo, resetState, wait, type Reply, type Route } from '../helpers'

// Phase 17 plan 02 smoke specs for the tree reorder page (D-09), the list's
// Reorder button and the singleton form (D-11). Plan 06 completes them.
const BASE = `${API}/acme/companions/links`
const REORDER = `${BASE}/reorder`

function tree(): Reply {
  return {
    body: {
      data: {
        title: 'Reorder links',
        partition: {
          label: 'Group',
          value: 5,
          options: [
            { value: 5, label: 'Main' },
            { value: 6, label: 'Footer' },
          ],
        },
        nodes: [
          { id: 1, name: 'Home', parent_id: null, sort_order: 1 },
          { id: 2, name: 'Blog', parent_id: null, sort_order: 2 },
          { id: 3, name: 'News', parent_id: 2, sort_order: 3 },
          { id: 4, name: '', parent_id: null, sort_order: 4 },
        ],
      },
      meta: {},
    },
  }
}

/** The tree as "name(children)" strings, in display order. */
function shape(wrapper: VueWrapper): string {
  const read = (list: Element): string =>
    Array.from(list.children)
      .map((item) => {
        const name = item.querySelector(':scope > [data-reorder-node] > span.min-w-0')?.textContent?.trim() ?? '?'
        const children = item.querySelector(':scope > ul')
        return children ? `${name}(${read(children)})` : name
      })
      .join(' ')
  return read(wrapper.find('[data-reorder-tree]').element)
}

const handle = (wrapper: VueWrapper, id: number) => wrapper.find(`[data-reorder-handle="${id}"]`)

beforeEach(() => {
  resetState()
})

afterEach(() => {
  document.body.innerHTML = ''
})

enableAutoUnmount(afterEach)

describe('ReorderView', () => {
  it('ReorderView tracer: a keyboard move sends one debounced POST with the full node set', async () => {
    let body: unknown = null
    const { wrapper, calls } = await mountApp(
      '/acme/companions/links/reorder',
      {
        [`GET ${REORDER}`]: tree(),
        [`POST ${REORDER}`]: async (request) => {
          body = await request.json()
          return tree()
        },
      },
      { attach: true },
    )
    expect(wrapper.find('h1').text()).toBe('Reorder links')
    expect(wrapper.find('[data-reorder-tree]').attributes('aria-label')).toBe('Kolejność rekordów')
    expect(shape(wrapper)).toBe('Home Blog(News) Bez tytułu (#4)')
    expect(wrapper.find<HTMLSelectElement>('[data-reorder-partition]').element.value).toBe('5')
    // First row: up, indent and outdent are impossible.
    const first = wrapper.find('[data-reorder-node="1"]')
    expect(first.find('[data-action="reorder-up"]').attributes('disabled')).toBeDefined()
    expect(first.find('[data-action="reorder-indent"]').attributes('disabled')).toBeDefined()
    expect(first.find('[data-action="reorder-outdent"]').attributes('disabled')).toBeDefined()

    // Three quick moves by keyboard on the handles.
    keydown(handle(wrapper, 1).element, 'ArrowDown')
    await flushPromises()
    expect(shape(wrapper)).toBe('Blog(News) Home Bez tytułu (#4)')
    expect(document.activeElement).toBe(handle(wrapper, 1).element)
    keydown(handle(wrapper, 1).element, 'ArrowRight')
    await flushPromises()
    expect(shape(wrapper)).toBe('Blog(News Home) Bez tytułu (#4)')
    keydown(handle(wrapper, 4).element, 'ArrowUp')
    await flushPromises()
    expect(shape(wrapper)).toBe('Bez tytułu (#4) Blog(News Home)')
    expect(document.activeElement).toBe(handle(wrapper, 4).element)
    expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(0)

    await vi.waitFor(() => {
      expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(1)
    })
    expect(body).toEqual({
      partition: 5,
      nodes: [
        { id: 4, parent_id: null, sort_order: 1 },
        { id: 2, parent_id: null, sort_order: 2 },
        { id: 3, parent_id: 2, sort_order: 3 },
        { id: 1, parent_id: 2, sort_order: 4 },
      ],
    })
    await vi.waitFor(() => {
      expect(wrapper.find('[data-reorder-status]').text()).toBe('Zapisano kolejność')
    })
    expect(wrapper.find('[data-reorder-live]').text()).toBe('Przeniesiono Bez tytułu (#4) na pozycję 1 z 2.')
    await wait(500)
    expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(1)
  })

  it('restores the saved tree when a save fails and reloads on a stale set', async () => {
    let status = 500
    const { wrapper, calls } = await mountApp(
      '/acme/companions/links/reorder',
      {
        [`GET ${REORDER}`]: tree(),
        [`POST ${REORDER}`]: () => ({ status, body: { error: { code: status === 409 ? 'reorder_stale' : 'x', message: 'x', details: {} } } }),
      },
      { attach: true },
    )
    await wrapper.find('[data-reorder-node="1"] [data-action="reorder-down"]').trigger('click')
    expect(shape(wrapper)).toBe('Blog(News) Home Bez tytułu (#4)')
    await vi.waitFor(() => {
      expect(toasts.value[0]).toMatchObject({ text: 'Nie udało się zapisać nowej kolejności. Przywrócono poprzednią.', tone: 'danger' })
    })
    expect(shape(wrapper)).toBe('Home Blog(News) Bez tytułu (#4)')

    status = 409
    await wrapper.find('[data-reorder-node="2"] [data-action="reorder-outdent"]').trigger('click')
    await wrapper.find('[data-reorder-node="3"] [data-action="reorder-outdent"]').trigger('click')
    await vi.waitFor(() => {
      expect(toasts.value[0]).toMatchObject({ text: 'Rekordy zmieniły się w międzyczasie. Lista została wczytana ponownie.', tone: 'danger' })
    })
    await flushPromises()
    expect(requestsTo(calls, 'GET', REORDER)).toHaveLength(2)
    expect(shape(wrapper)).toBe('Home Blog(News) Bez tytułu (#4)')
  })

  it('shows the empty state and the 403 alert', async () => {
    const empty = tree()
    ;(empty.body as { data: { nodes: unknown[] } }).data.nodes = []
    const { wrapper } = await mountApp('/acme/companions/links/reorder', { [`GET ${REORDER}`]: empty })
    expect(wrapper.find('[data-reorder-empty]').text()).toContain('Nie ma jeszcze czego porządkować')
    wrapper.unmount()

    const forbidden = await mountApp('/acme/companions/links/reorder', {
      [`GET ${REORDER}`]: { status: 403, body: { error: { code: 'forbidden', message: 'x', details: {} } } },
    })
    expect(forbidden.wrapper.find('[role="alert"]').text()).toContain('Nie masz uprawnień')
  })
})

describe('list Reorder button', () => {
  it('links to the reorder page with the filtered partition', async () => {
    const schema = clone(listSchemaFixture)
    schema.data.toolbarButtons = ['create', 'reorder']
    schema.data.reorder = { title: 'Reorder links', partition: { column: 'group_id', label: 'Group' } }
    schema.data.filters = [...schema.data.filters, { ...schema.data.filters[0]!, name: 'group', label: 'Group', column: 'group_id' }]
    const routes: Record<string, Route> = {
      [`GET ${BASE}/schema/list`]: { body: schema },
      [`GET ${BASE}`]: { body: listFixture },
    }
    const { wrapper } = await mountApp('/acme/companions/links?filter[group]=6', routes)
    const buttons = wrapper.findAll('header [data-action]').map((button) => button.attributes('data-action'))
    expect(buttons).toEqual(['reorder', 'create'])
    const reorder = wrapper.find('[data-action="reorder"]')
    expect(reorder.text()).toBe('Zmień kolejność rekordów')
    expect(reorder.attributes('href')).toBe('/acme/companions/links/reorder?partition=6')
  })
})

describe('singleton form', () => {
  it('opens the one record from settings, without Delete, and returns to the settings index', async () => {
    setSettings([
      {
        code: 'profile',
        label: 'Site profile',
        description: '',
        icon: 'settings',
        category: 'CMS',
        keywords: [],
        model: '',
        controller: 'acme.companions.profiles',
        order: 1,
      },
    ])
    const schema = clone(companionsFormSchemaFixture)
    schema.data.singleton = true
    schema.data.fields = schema.data.fields.filter((field) => field.name === 'title')
    const PROFILES = `${API}/acme/companions/profiles`
    const { wrapper, router, calls } = await mountApp(
      '/settings',
      {
        [`GET ${PROFILES}/singleton`]: { body: { data: { id: 9 }, meta: {} } },
        [`GET ${PROFILES}/schema/form`]: { body: schema },
        [`GET ${PROFILES}/9`]: { body: { data: { id: 9, title: 'Main site' }, meta: {} } },
      },
      { attach: true },
    )
    await wrapper.find('[data-settings="profile"]').trigger('click', { button: 0 })
    await flushPromises()
    expect(requestsTo(calls, 'GET', `${PROFILES}/singleton`)).toHaveLength(1)
    expect(router.currentRoute.value.path).toBe('/acme/companions/profiles/9')
    expect(wrapper.find('[data-action="delete"]').exists()).toBe(false)
    expect(wrapper.find('[data-action="back"]').attributes('aria-label')).toBe('Wróć do ustawień')

    await wrapper.find('[data-action="cancel"]').trigger('click')
    await flushPromises()
    expect(router.currentRoute.value.path).toBe('/settings')
  })
})

// Plan 06 coverage: announcements per keyboard move, children moving with
// their parent, loading and load failure, the partition switch flushing a
// pending save, and the tree rules (no drop into the own subtree).
describe('ReorderView moves', () => {
  it('announces every keyboard move and moves children with their parent', async () => {
    let body: { nodes: unknown[] } | null = null
    const { wrapper, calls } = await mountApp(
      '/acme/companions/links/reorder',
      {
        [`GET ${REORDER}`]: tree(),
        [`POST ${REORDER}`]: async (request) => {
          body = (await request.json()) as { nodes: unknown[] }
          return tree()
        },
      },
      { attach: true },
    )
    const live = () => wrapper.find('[data-reorder-live]').text()

    keydown(handle(wrapper, 2).element, 'ArrowUp')
    await flushPromises()
    expect(shape(wrapper)).toBe('Blog(News) Home Bez tytułu (#4)')
    await vi.waitFor(() => expect(live()).toBe('Przeniesiono Blog na pozycję 1 z 3.'))

    keydown(handle(wrapper, 1).element, 'ArrowRight')
    await flushPromises()
    expect(shape(wrapper)).toBe('Blog(News Home) Bez tytułu (#4)')
    await vi.waitFor(() => expect(live()).toBe('Home jest teraz wewnątrz Blog.'))

    keydown(handle(wrapper, 3).element, 'ArrowLeft')
    await flushPromises()
    expect(shape(wrapper)).toBe('Blog(Home) News Bez tytułu (#4)')
    await vi.waitFor(() => expect(live()).toBe('Przeniesiono News na poziom 1.'))
    expect(document.activeElement).toBe(handle(wrapper, 3).element)

    // A move that cannot run changes and announces nothing.
    const before = live()
    keydown(handle(wrapper, 2).element, 'ArrowUp')
    await flushPromises()
    expect(shape(wrapper)).toBe('Blog(Home) News Bez tytułu (#4)')
    expect(live()).toBe(before)

    await vi.waitFor(() => expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(1))
    expect(body!.nodes).toEqual([
      { id: 2, parent_id: null, sort_order: 1 },
      { id: 1, parent_id: 2, sort_order: 2 },
      { id: 3, parent_id: null, sort_order: 3 },
      { id: 4, parent_id: null, sort_order: 4 },
    ])
  })

  it('shows the loading skeleton, then the load failure alert', async () => {
    let release: (reply: Reply) => void = () => undefined
    const pending = new Promise<Reply>((resolve) => {
      release = resolve
    })
    const { wrapper } = await mountApp('/acme/companions/links/reorder', { [`GET ${REORDER}`]: () => pending })
    expect(wrapper.find('[data-reorder-card]').attributes('aria-busy')).toBe('true')
    expect(wrapper.findAll('[data-reorder-skeleton]')).toHaveLength(5)
    release({ status: 500, body: { error: { code: 'x', message: 'x', details: {} } } })
    await flushPromises()
    expect(wrapper.find('[role="alert"]').text()).toContain('Nie udało się wczytać rekordów.')
    expect(wrapper.find('[data-reorder-card]').exists()).toBe(false)
  })

  it('a partition switch sends the pending save first, then loads the chosen partition', async () => {
    const order: string[] = []
    const { wrapper, router, calls } = await mountApp(
      '/acme/companions/links/reorder',
      {
        [`GET ${REORDER}`]: (request) => {
          order.push(`GET ${queryOf(request).get('partition') ?? '-'}`)
          return tree()
        },
        [`POST ${REORDER}`]: async (request) => {
          const sent = (await request.json()) as { partition: number }
          order.push(`POST ${sent.partition}`)
          return tree()
        },
      },
      { attach: true },
    )
    keydown(handle(wrapper, 1).element, 'ArrowDown')
    await flushPromises()
    await wrapper.find('[data-reorder-partition]').setValue('6')
    await flushPromises()
    expect(router.currentRoute.value.query.partition).toBe('6')
    expect(order).toEqual(['GET -', 'POST 5', 'GET 6'])
    await wait(500)
    expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(1)
  })
})

// WR-02: one save in flight at a time, later moves sent after it settles,
// and a failure that a waiting save supersedes does not throw moves away.
describe('ReorderView save ordering', () => {
  it('sends a move made during a save after that save, with the latest tree', async () => {
    const bodies: { nodes: { id: number }[] }[] = []
    const releases: ((reply: Reply) => void)[] = []
    const { wrapper, calls } = await mountApp(
      '/acme/companions/links/reorder',
      {
        [`GET ${REORDER}`]: tree(),
        [`POST ${REORDER}`]: async (request) => {
          bodies.push((await request.json()) as { nodes: { id: number }[] })
          return new Promise<Reply>((resolve) => releases.push(resolve))
        },
      },
      { attach: true },
    )
    keydown(handle(wrapper, 1).element, 'ArrowDown')
    await flushPromises()
    await vi.waitFor(() => expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(1))

    // A second move while the first save is in flight waits for it.
    keydown(handle(wrapper, 4).element, 'ArrowUp')
    await flushPromises()
    await wait(500)
    expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(1)

    // The first save fails: the later moves stay on screen, and the waiting
    // save sends them.
    releases[0]!({ status: 500, body: { error: { code: 'x', message: 'x', details: {} } } })
    await vi.waitFor(() => expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(2))
    expect(shape(wrapper)).toBe('Blog(News) Bez tytułu (#4) Home')
    expect(toasts.value).toHaveLength(0)
    expect(bodies[1]!.nodes.map((node) => node.id)).toEqual([2, 3, 4, 1])
    releases[1]!(tree())
    await vi.waitFor(() => {
      expect(wrapper.find('[data-reorder-status]').text()).toBe('Zapisano kolejność')
    })
    expect(shape(wrapper)).toBe('Blog(News) Bez tytułu (#4) Home')
    await wait(500)
    expect(requestsTo(calls, 'POST', REORDER)).toHaveLength(2)
  })

  it('ignores a save response that arrives after the partition changed', async () => {
    let releaseFirst: (reply: Reply) => void = () => undefined
    let posts = 0
    const footer = tree()
    ;(footer.body as { data: { nodes: unknown[] } }).data.nodes = [
      { id: 7, name: 'Imprint', parent_id: null, sort_order: 1 },
      { id: 8, name: 'Privacy', parent_id: null, sort_order: 2 },
    ]
    const { wrapper } = await mountApp(
      '/acme/companions/links/reorder',
      {
        [`GET ${REORDER}`]: (request) => (queryOf(request).get('partition') === '6' ? footer : tree()),
        [`POST ${REORDER}`]: () => {
          posts++
          if (posts === 1) {
            return new Promise<Reply>((resolve) => {
              releaseFirst = resolve
            })
          }
          return { status: 500, body: { error: { code: 'x', message: 'x', details: {} } } }
        },
      },
      { attach: true },
    )
    keydown(handle(wrapper, 1).element, 'ArrowDown')
    await flushPromises()
    await wrapper.find('[data-reorder-partition]').setValue('6')
    await flushPromises()
    await vi.waitFor(() => expect(shape(wrapper)).toBe('Imprint Privacy'))

    // The first partition's save succeeds late: the second partition's
    // screen and its last saved tree are not touched.
    releaseFirst(tree())
    await flushPromises()
    expect(shape(wrapper)).toBe('Imprint Privacy')

    // A failed save on the second partition restores its own tree.
    keydown(handle(wrapper, 7).element, 'ArrowDown')
    await flushPromises()
    expect(shape(wrapper)).toBe('Privacy Imprint')
    await vi.waitFor(() => expect(toasts.value.length).toBeGreaterThan(0))
    expect(shape(wrapper)).toBe('Imprint Privacy')
  })
})

describe('reorder tree rules', () => {
  // The OpenAPI document types parent_id as a number although the wire
  // carries null at the top (17-02 deferred item 3), hence the cast.
  type Wire = Parameters<typeof buildTree>[0]
  const nodes = [
    { id: 1, name: 'Home', parent_id: null, sort_order: 2 },
    { id: 2, name: 'Blog', parent_id: null, sort_order: 1 },
    { id: 3, name: 'News', parent_id: 2, sort_order: 1 },
    { id: 4, name: 'Deep', parent_id: 3, sort_order: 1 },
    { id: 5, name: 'Orphan', parent_id: 99, sort_order: 3 },
  ] as unknown as Wire
  const names = (list: TreeNode[]): string => list.map((node) => (node.children.length ? `${node.name}(${names(node.children)})` : node.name)).join(' ')

  it('builds the tree by sort order and puts unknown parents and cycles at the top', () => {
    expect(names(buildTree(nodes))).toBe('Blog(News(Deep)) Home Orphan')
    const cycle = buildTree([
      { id: 1, name: 'A', parent_id: 2, sort_order: 1 },
      { id: 2, name: 'B', parent_id: 1, sort_order: 2 },
      { id: 3, name: 'C', parent_id: null, sort_order: 3 },
    ] as unknown as Wire)
    expect(names(cycle).split(' ').sort()).toEqual(['A(B)', 'C'].sort())
  })

  it('refuses a drop into the node itself or its own subtree and leaves the tree as it was', () => {
    const tree = buildTree(nodes)
    for (const target of [2, 3, 4]) {
      expect(canDrop(tree, 2, target)).toBe(false)
      for (const zone of ['before', 'after', 'inside'] as const) {
        expect(applyDrop(tree, 2, target, zone)).toBe(false)
      }
    }
    expect(names(tree)).toBe('Blog(News(Deep)) Home Orphan')
    expect(canDrop(tree, 4, 2)).toBe(true)
    expect(applyDrop(tree, 4, 1, 'inside')).toBe(true)
    expect(applyDrop(tree, 5, 2, 'before')).toBe(true)
    expect(applyDrop(tree, 3, 1, 'after')).toBe(true)
    expect(names(tree)).toBe('Orphan Blog Home(Deep) News')
  })

  it('moves only where a sibling or parent exists, and flattens pre-order from 1', () => {
    const tree = buildTree(nodes)
    expect(canMove(tree, 2, 'up')).toBe(false)
    expect(canMove(tree, 2, 'indent')).toBe(false)
    expect(canMove(tree, 2, 'outdent')).toBe(false)
    expect(canMove(tree, 5, 'down')).toBe(false)
    expect(canMove(tree, 99, 'down')).toBe(false)
    expect(applyMove(tree, 4, 'outdent')).toBe(true)
    expect(applyMove(tree, 1, 'indent')).toBe(true)
    expect(names(tree)).toBe('Blog(News Deep Home) Orphan')
    expect(flatten(tree)).toEqual([
      { id: 2, parent_id: null, sort_order: 1 },
      { id: 3, parent_id: 2, sort_order: 2 },
      { id: 4, parent_id: 2, sort_order: 3 },
      { id: 1, parent_id: 2, sort_order: 4 },
      { id: 5, parent_id: null, sort_order: 5 },
    ])
  })
})

// The reorder modules imported by path (T-10-25): the page the route renders,
// its tree level and the injection key they share.
describe('reorder modules', () => {
  it('the reorder route renders ReorderView with a ReorderBranch per tree level', async () => {
    const { wrapper } = await mountApp('/acme/companions/links/reorder', { [`GET ${REORDER}`]: tree() })
    expect(wrapper.findComponent(ReorderView).exists()).toBe(true)
    // Top level and Blog's children.
    expect(wrapper.findAllComponents(ReorderBranch).length).toBe(2)
  })

  it('ReorderBranch renders each node from the REORDER_PAGE context and moves through it', async () => {
    const move = vi.fn()
    const page: ReorderPage = {
      dragging: ref(null),
      dropTarget: ref(null),
      blocked: ref(null),
      nameOf: (node: TreeNode) => node.name,
      canMove: () => true,
      move,
      onHandleKeydown: vi.fn(),
      onDragStart: vi.fn(),
      onDragOver: vi.fn(),
      onDragLeave: vi.fn(),
      onDrop: vi.fn(),
      onDragEnd: vi.fn(),
    }
    const nodes: TreeNode[] = [
      { id: 7, name: 'First', children: [] },
      { id: 8, name: 'Second', children: [{ id: 9, name: 'Child', children: [] }] },
    ]
    const wrapper = mount(ReorderBranch, { props: { nodes, depth: 0 }, global: { provide: { [REORDER_PAGE as symbol]: page } } })
    const rows = wrapper.findAll('[data-reorder-node]')
    expect(rows.map((row) => row.attributes('data-reorder-node'))).toEqual(['7', '8', '9'])
    expect(rows.map((row) => row.find('span.min-w-0').text())).toEqual(['First', 'Second', 'Child'])
    await wrapper.find('[data-reorder-node="8"] [data-action="reorder-down"]').trigger('click')
    expect(move).toHaveBeenCalledWith(8, 'down')
  })
})