import assert from 'node:assert/strict'
import test from 'node:test'
import { readFileSync } from 'node:fs'
import { parse } from '@vue/compiler-sfc'
import ts from 'typescript'
import { computed, ref, watch } from 'vue'

const source = parse(
  readFileSync(new URL('../src/views/m/pl/plan-cert/CertDetail.vue', import.meta.url), 'utf8')
).descriptor.scriptSetup!.content

// Execute production navigation declarations and lifecycle registrations. Only geometry,
// time and animation scheduling are controlled: no browser or mirrored scroll algorithm.
function harness() {
  const start = source.indexOf('  const detailTabs =')
  const code = source.slice(start, source.indexOf('  const showFeedback =', start))
  const mounts: Array<() => void> = [],
    unmounts: Array<() => void> = []
  const listeners = new Map<string, () => void>(),
    frames = new Map<number, () => void>()
  const timers = new Map<number, { due: number; callback: () => void }>()
  const scrolls: any[] = []
  let timerId = 0
  let frameId = 0,
    now = 1000,
    headerHeight = 66
  const state: Record<string, boolean> = { disposed: false, recordInvalidated: false }
  const plan = ref<any>({ id: 'A' }),
    loading = ref(false),
    props = { planId: 'A' }
  const tops: Record<string, number> = {
    'cert-sec-base': 122,
    'cert-sec-transport': 700,
    'cert-sec-attachments': 1300
  }
  const viewport = {
    scrollY: 0,
    innerHeight: 600,
    addEventListener: (name: string, fn: () => void) => listeners.set(name, fn),
    removeEventListener: (name: string, fn: () => void) => {
      assert.equal(listeners.get(name), fn)
      listeners.delete(name)
    },
    requestAnimationFrame: (fn: () => void) => {
      frames.set(++frameId, fn)
      return frameId
    },
    cancelAnimationFrame: (id: number) => frames.delete(id),
    setTimeout: (callback: () => void, delay: number) => {
      timers.set(++timerId, { due: now + delay, callback })
      return timerId
    },
    clearTimeout: (id: number) => timers.delete(id)
  }
  const document = {
    scrollingElement: { scrollHeight: 1600 },
    querySelector: () => ({ getBoundingClientRect: () => ({ height: headerHeight }) }),
    getElementById: (id: string) =>
      id in tops
        ? {
            getBoundingClientRect: () => ({ top: tops[id] - viewport.scrollY }),
            scrollIntoView: (options: any) => scrolls.push({ id, options })
          }
        : null
  }
  const bindings = {
    ref,
    computed,
    watch,
    stops: ref({ deliveries: [] }),
    plan,
    props,
    loading,
    window: viewport,
    document,
    Date: { now: () => now },
    onMounted: (fn: () => void) => mounts.push(fn),
    onUnmounted: (fn: () => void) => unmounts.push(fn)
  }
  const execute = new Function(
    'state',
    ...Object.keys(bindings),
    `with (state) {
    ${ts.transpile(code, { target: ts.ScriptTarget.ESNext })}
    return { activeTab, stickyOffset, onAnchorTab,
      sync: typeof syncActiveTabFromScroll === 'function' ? syncActiveTabFromScroll : () => {},
      margin: () => typeof scrollMargin !== 'undefined' ? scrollMargin.value : undefined }
  }`
  )
  const nav = execute(state, ...Object.values(bindings))
  return {
    ...nav,
    state,
    plan,
    props,
    loading,
    viewport,
    document,
    tops,
    scrolls,
    listeners,
    frames,
    timers,
    mount: () => mounts.forEach((fn) => fn()),
    unmount: () => unmounts.forEach((fn) => fn()),
    tick: (ms: number) => {
      now += ms
      for (const [id, timer] of [...timers]) {
        if (timer.due > now) continue
        timers.delete(id)
        timer.callback()
      }
    },
    resize: (height: number) => {
      headerHeight = height
      listeners.get('resize')?.()
    },
    flushFrame: () => {
      const pending = [...frames.values()]
      frames.clear()
      pending.forEach((fn) => fn())
    }
  }
}

test('manual scroll selects transport and Home restores base', () => {
  const h = harness()
  h.mount()
  h.viewport.scrollY = 650
  h.sync()
  assert.equal(h.activeTab.value, 'transport')
  h.viewport.scrollY = 0
  h.sync()
  assert.equal(h.activeTab.value, 'base')
})
test('bottom selects visible short final section', () => {
  const h = harness()
  h.mount()
  h.viewport.scrollY = 1000
  h.sync()
  assert.equal(h.activeTab.value, 'attachments')
})
for (const missing of [false, true])
  test(missing ? 'missing last section uses top probe' : 'short unscrolled page keeps base', () => {
    const h = harness()
    h.mount()
    if (missing) {
      delete h.tops['cert-sec-attachments']
      h.viewport.scrollY = 1000
    } else {
      h.document.scrollingElement.scrollHeight = 500
      h.tops['cert-sec-transport'] = 250
      h.tops['cert-sec-attachments'] = 400
    }
    h.sync()
    assert.equal(h.activeTab.value, missing ? 'transport' : 'base')
  })
test('final section below viewport does not win bottom override', () => {
  const h = harness()
  h.mount()
  h.viewport.scrollY = 1000
  h.tops['cert-sec-attachments'] = 1800
  h.sync()
  assert.equal(h.activeTab.value, 'transport')
})
test('anchor click locks selected tab for 700ms and uses smooth positioning', () => {
  const h = harness()
  h.mount()
  h.onAnchorTab({ name: 'attachments' })
  assert.equal(h.activeTab.value, 'attachments')
  assert.deepEqual(h.scrolls, [
    { id: 'cert-sec-attachments', options: { behavior: 'smooth', block: 'start' } }
  ])
  h.tick(699)
  h.sync()
  assert.equal(h.activeTab.value, 'attachments')
  h.tick(1)
  h.sync()
  assert.equal(h.activeTab.value, 'base')
})
for (const invalid of ['disposed', 'recordInvalidated', 'loading', 'mismatch', 'empty'])
  test(`${invalid} record never reads stale anchors or starts scrolling`, () => {
    const h = harness()
    h.mount()
    if (invalid === 'loading') h.loading.value = true
    else if (invalid === 'mismatch') h.props.planId = 'B'
    else if (invalid === 'empty') h.plan.value = null
    else h.state[invalid] = true
    h.document.getElementById = () => {
      assert.fail('stale DOM must not be read')
    }
    h.viewport.scrollY = 1000
    h.sync()
    h.onAnchorTab({ name: 'attachments' })
    assert.equal(h.activeTab.value, 'base')
    assert.deepEqual(h.scrolls, [])
  })
test('unknown or absent anchor cannot change active tab', () => {
  const h = harness()
  h.mount()
  h.onAnchorTab({ name: 'missing' })
  delete h.tops['cert-sec-attachments']
  h.onAnchorTab({ name: 'attachments' })
  assert.equal(h.activeTab.value, 'base')
  assert.deepEqual(h.scrolls, [])
})
test('mount measures header; resize recomputes header + nav + gap', () => {
  const h = harness()
  h.mount()
  assert.equal(h.stickyOffset.value, 66)
  assert.equal(h.margin(), 122)
  h.resize(78.3)
  assert.equal(h.stickyOffset.value, 79)
  assert.equal(h.margin(), 135)
})
test('scroll lifecycle coalesces frames and removes listeners and pending frame on unmount', () => {
  const h = harness()
  h.mount()
  assert.ok(h.listeners.has('scroll'))
  h.viewport.scrollY = 650
  h.listeners.get('scroll')!()
  h.listeners.get('scroll')!()
  assert.equal(h.frames.size, 1)
  h.flushFrame()
  assert.equal(h.activeTab.value, 'transport')
  h.listeners.get('scroll')!()
  h.unmount()
  assert.equal(h.frames.size, 0)
  assert.equal(h.listeners.size, 0)
})

test('Home during click lock resyncs once lock expires without another scroll event', () => {
  const h = harness()
  h.mount()
  h.onAnchorTab({ name: 'attachments' })
  h.viewport.scrollY = 1000
  h.tick(400)
  h.viewport.scrollY = 0
  h.listeners.get('scroll')!()
  h.flushFrame()
  assert.equal(h.activeTab.value, 'attachments')
  h.tick(300)
  assert.equal(h.activeTab.value, 'base')
  assert.equal(h.timers.size, 0)
})

test('consecutive anchor clicks replace the previous lock-expiry timer', () => {
  const h = harness()
  h.mount()
  h.onAnchorTab({ name: 'attachments' })
  h.tick(400)
  h.onAnchorTab({ name: 'transport' })
  assert.equal(h.timers.size, 1)
  h.tick(300)
  assert.equal(h.activeTab.value, 'transport')
  assert.equal(h.timers.size, 1)
  h.tick(400)
  assert.equal(h.activeTab.value, 'base')
  assert.equal(h.timers.size, 0)
})

test('unmount cancels pending lock-expiry timer', () => {
  const h = harness()
  h.mount()
  h.onAnchorTab({ name: 'attachments' })
  assert.equal(h.timers.size, 1)
  h.unmount()
  assert.equal(h.timers.size, 0)
  h.document.getElementById = () => {
    assert.fail('unmounted timer must not read DOM')
  }
  h.tick(700)
  assert.equal(h.activeTab.value, 'attachments')
})

test('lock expiry after record invalidation does not read stale sections', () => {
  const h = harness()
  h.mount()
  h.onAnchorTab({ name: 'attachments' })
  assert.equal(h.timers.size, 1)
  h.state.recordInvalidated = true
  h.document.getElementById = () => {
    assert.fail('invalidated timer must not read DOM')
  }
  h.tick(700)
  assert.equal(h.activeTab.value, 'attachments')
  assert.equal(h.timers.size, 0)
})