// @vitest-environment jsdom
/**
 * test/tabs.test.ts — frontend TabApp unit tests.
 *
 * Mocks TerminalSession + the launcher so we test TabApp's tab lifecycle in
 * isolation: the v0.5 "close last tab → launcher" invariant and that addEntry
 * builds a real (non-null) session before pushing the entry (Phase 1#5 — the
 * `null as unknown as TerminalSession` hole is gone).
 */

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

// ── Mock TerminalSession ──────────────────────────────────────────────────────
let constructed = 0
class FakeTerminalSession {
  el: HTMLDivElement
  id: string | null
  status = 'connecting'
  claudeStatus = 'unknown'
  cwd: string | null = null
  pendingApproval = false
  connect = vi.fn()
  dispose = vi.fn()
  show = vi.fn()
  hide = vi.fn()
  applyTheme = vi.fn()
  refit = vi.fn()
  send = vi.fn()
  approve = vi.fn()
  reject = vi.fn()
  findNext = vi.fn()
  findPrevious = vi.fn()
  clearSearch = vi.fn()
  // Captured callbacks so tests can drive status/title/activity events.
  cbs: {
    onClaudeStatus?: (s: string, d?: string) => void
    onStatus?: (s: string) => void
    onActivity?: () => void
    onTitle?: (t: string) => void
  }
  static instances: FakeTerminalSession[] = []
  constructor(opts: {
    sessionId: string | null
    onClaudeStatus?: (s: string, d?: string) => void
    onStatus?: (s: string) => void
    onActivity?: () => void
    onTitle?: (t: string) => void
  }) {
    constructed += 1
    this.id = opts.sessionId
    this.el = document.createElement('div')
    this.cbs = opts
    FakeTerminalSession.instances.push(this)
  }
}

vi.mock('../public/terminal-session.js', () => ({ TerminalSession: FakeTerminalSession }))

// ── Mock the launcher (records visibility) ────────────────────────────────────
const launcherVisible = { value: false }
const mountLauncher = vi.fn(() => ({
  setVisible: (v: boolean) => {
    launcherVisible.value = v
  },
  refresh: vi.fn(),
}))
vi.mock('../public/launcher.js', () => ({ mountLauncher }))

// settings.js is light but imports nothing heavy; let it load for real.

const { TabApp } = await import('../public/tabs.js')

function makeHosts(): { paneHost: HTMLElement; tabBar: HTMLElement } {
  const paneHost = document.createElement('div')
  const tabBar = document.createElement('div')
  document.body.append(paneHost, tabBar)
  return { paneHost, tabBar }
}

beforeEach(() => {
  constructed = 0
  FakeTerminalSession.instances = []
  launcherVisible.value = false
  document.body.replaceChildren()
  localStorage.clear()
})

describe('TabApp — v0.5 launcher chooser', () => {
  it('starts with NO auto-created tab and shows the launcher', () => {
    const { paneHost, tabBar } = makeHosts()
    new TabApp(paneHost, tabBar)
    // No TerminalSession constructed on boot (no auto tab).
    expect(constructed).toBe(0)
    expect(launcherVisible.value).toBe(true)
  })

  it('newTab() creates a tab and hides the launcher', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    expect(constructed).toBe(1)
    expect(launcherVisible.value).toBe(false)
  })

  it('closing the last tab returns to the launcher (no auto-blank tab)', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    expect(launcherVisible.value).toBe(false)
    app.closeTab(0)
    // Back to the chooser, and no new tab was auto-created.
    expect(launcherVisible.value).toBe(true)
    expect(constructed).toBe(1)
  })
})

describe('TabApp — addEntry has no null-session hole (Phase 1#5)', () => {
  it('the constructed session is real and used immediately (connect called)', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    // The entry's session must be the constructed FakeTerminalSession with connect() called.
    const snap = app.snapshot()
    expect(snap).toHaveLength(1)
    // sendToActive routes to a real session (would throw if session were null).
    expect(() => app.sendToActive('x')).not.toThrow()
  })

  it('openSession joins by id and focuses it', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.openSession('11111111-1111-4111-8111-111111111111')
    expect(constructed).toBe(1)
    expect(app.activeSessionId()).toBe('11111111-1111-4111-8111-111111111111')
  })

  it('openSession re-focuses an already-open session instead of duplicating', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    const id = '22222222-2222-4222-8222-222222222222'
    app.openSession(id)
    app.openSession(id)
    expect(constructed).toBe(1) // not duplicated
  })
})

describe('TabApp — multi-tab lifecycle', () => {
  it('renders a tab bar with one .tab per tab plus the add button', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    expect(tabBar.querySelectorAll('.tab')).toHaveLength(2)
    expect(tabBar.querySelector('.tab-add')).not.toBeNull()
  })

  it('activate() switches the active tab (show/hide on sessions)', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    app.activate(0)
    const snap = app.snapshot()
    expect(snap.find((t) => t.active)?.idx).toBe(0)
  })

  it('closeTab on a middle tab keeps the others and re-activates a neighbor', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    app.newTab()
    app.closeTab(1)
    expect(app.snapshot()).toHaveLength(2)
  })

  it('applySettings re-themes every tab without throwing', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    expect(() => app.applySettings({ theme: 'dark', fontSize: 15 })).not.toThrow()
  })

  it('findInActive / clearActiveSearch route to the active session', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    expect(() => {
      app.findInActive('q', 'next')
      app.findInActive('q', 'prev')
      app.clearActiveSearch()
      app.refitActive()
    }).not.toThrow()
  })

  it('newTabForResume opens a tab seeded with a resume command', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTabForResume('/work', '33333333-3333-4333-8333-333333333333')
    expect(constructed).toBe(1)
    expect(app.snapshot()).toHaveLength(1)
  })

  it('snapshot reflects per-tab connection + claude status fields', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    const snap = app.snapshot()
    expect(snap[0]).toMatchObject({ idx: 0, conn: 'connecting', claude: 'unknown' })
  })
})

describe('TabApp — DOM interactions on the tab bar', () => {
  function pointerdown(elm: Element): void {
    elm.dispatchEvent(new MouseEvent('pointerdown', { bubbles: true }))
  }

  it('pointerdown on a tab activates it', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    const tabs = tabBar.querySelectorAll('.tab')
    pointerdown(tabs[0]!)
    expect(app.snapshot().find((t) => t.active)?.idx).toBe(0)
  })

  it('clicking the × close button closes that tab', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    const close = tabBar.querySelector('.tab-close') as HTMLButtonElement
    close.dispatchEvent(new MouseEvent('click', { bubbles: true }))
    expect(app.snapshot()).toHaveLength(1)
  })

  it('clicking the + add button opens a new tab', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    const add = tabBar.querySelector('.tab-add') as HTMLButtonElement
    add.click()
    expect(app.snapshot()).toHaveLength(1)
  })

  it('middle-click (auxclick button 1) closes a tab', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    const tab = tabBar.querySelector('.tab') as HTMLElement
    tab.dispatchEvent(new MouseEvent('auxclick', { bubbles: true, button: 1 }))
    expect(app.snapshot()).toHaveLength(1)
  })

  it('double-click the label enters rename mode, Enter commits a custom title', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    const label = tabBar.querySelector('.tab-label') as HTMLElement
    label.dispatchEvent(new MouseEvent('dblclick', { bubbles: true }))
    const input = tabBar.querySelector('input.tab-rename') as HTMLInputElement
    expect(input).not.toBeNull()
    input.value = 'My Tab'
    input.dispatchEvent(new KeyboardEvent('keydown', { key: 'Enter', bubbles: true }))
    expect(app.snapshot()[0]!.title).toBe('My Tab')
  })

  it('activate() out of range is ignored', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    expect(() => {
      app.activate(99)
      app.activate(-1)
      app.focusTab(0)
    }).not.toThrow()
  })

  it('sendToActive / clearActiveSearch with no active tab do not throw', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    // No tab open (launcher visible).
    expect(() => {
      app.sendToActive('x')
      app.clearActiveSearch()
      app.refitActive()
    }).not.toThrow()
    expect(app.activeSessionId()).toBeNull()
  })

  it('Escape in rename mode cancels without committing', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    const label = tabBar.querySelector('.tab-label') as HTMLElement
    label.dispatchEvent(new MouseEvent('dblclick', { bubbles: true }))
    const input = tabBar.querySelector('input.tab-rename') as HTMLInputElement
    input.value = 'discard me'
    input.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true }))
    // Title falls back to the auto/default, not the typed value.
    expect(app.snapshot()[0]!.title).not.toBe('discard me')
  })

  it('onTitle/onStatus/onActivity callbacks refresh the tab in place', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    const fake = FakeTerminalSession.instances[0]!
    // Drive the captured callbacks like the real TerminalSession would.
    expect(() => {
      fake.cbs.onTitle?.('myproj')
      fake.cbs.onStatus?.('connected')
      fake.cbs.onActivity?.()
    }).not.toThrow()
  })

  it('onClaudeStatus "waiting" on a background tab notifies (H2/H4)', () => {
    const NotificationMock = vi.fn()
    ;(NotificationMock as unknown as { permission: string }).permission = 'granted'
    vi.stubGlobal('Notification', NotificationMock)
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab() // tab 0 (active)
    app.newTab() // tab 1 (active now)
    // tab 0 is in the background; fire its onClaudeStatus 'waiting'.
    const bg = FakeTerminalSession.instances[0]!
    bg.claudeStatus = 'waiting'
    bg.cbs.onClaudeStatus?.('waiting')
    expect(NotificationMock).toHaveBeenCalled()
    vi.unstubAllGlobals()
  })

  it('drag-and-drop reorders tabs', () => {
    const { paneHost, tabBar } = makeHosts()
    const app = new TabApp(paneHost, tabBar)
    app.newTab()
    app.newTab()
    const tabs = tabBar.querySelectorAll('.tab')
    // jsdom has no DataTransfer; the handlers use optional chaining + this.dragIndex,
    // so plain drag events (no dataTransfer) still drive the reorder path.
    tabs[0]!.dispatchEvent(new Event('dragstart', { bubbles: true }))
    tabs[1]!.dispatchEvent(new Event('dragover', { bubbles: true }))
    tabs[1]!.dispatchEvent(new Event('drop', { bubbles: true }))
    tabs[0]!.dispatchEvent(new Event('dragend', { bubbles: true }))
    expect(app.snapshot()).toHaveLength(2)
  })
})