import React from 'react'
import { describe, it, expect, vi, beforeEach } from 'vitest'
import { render, screen, fireEvent, waitFor } from '@testing-library/react'
import { MemoryRouter, Routes, Route } from 'react-router-dom'

// §8.12 Option B — asking-while-reading on the canonical `main` view. The AI
// "Ask" affordance (selection tooltip + prompt bar) has no chat surface on
// main (RFCDiscussionPanel renders there, not ChatPanel). These tests cover the
// transparent branch-cut: Ask on main cuts an edit branch, navigates to it, and
// runs the question there; Ask on a branch is unchanged; a rejected cut degrades
// gracefully; Flag on main still opens a discussion thread.

const getRFC = vi.fn()
const getRFCMain = vi.fn()
const getBranch = vi.fn()
const listModels = vi.fn()
const getCollection = vi.fn()
const getThreadMessages = vi.fn()
const promoteToBranch = vi.fn()
const startEditBranch = vi.fn()
const streamChatTurn = vi.fn()
const createThread = vi.fn()

vi.mock('../api', () => ({
  getRFC: (...a) => getRFC(...a),
  getRFCMain: (...a) => getRFCMain(...a),
  getBranch: (...a) => getBranch(...a),
  listModels: (...a) => listModels(...a),
  getCollection: (...a) => getCollection(...a),
  getThreadMessages: (...a) => getThreadMessages(...a),
  promoteToBranch: (...a) => promoteToBranch(...a),
  startEditBranch: (...a) => startEditBranch(...a),
  streamChatTurn: (...a) => streamChatTurn(...a),
  createThread: (...a) => createThread(...a),
  acceptChange: vi.fn(), declineChange: vi.fn(), editMetadata: vi.fn(),
  manualFlush: vi.fn(), reaskChange: vi.fn(), resolveThread: vi.fn(),
  setBranchVisibility: vi.fn(), claimOwnership: vi.fn(),
  retireRFC: vi.fn(), unretireRFC: vi.fn(),
}))

vi.mock('../lib/entryPaths', () => ({
  entryPath: () => '/p/ohm/c/rfc-app/e/the-entry',
  entryPrPath: () => '/pr',
  useProjectId: () => 'ohm',
  useCollectionId: () => 'rfc-app',
}))
vi.mock('../lib/analytics', () => ({ EVENTS: { RFC_VIEWED: 'rfc_viewed' }, track: vi.fn() }))

// Stub the heavy children; expose just the callbacks/data the flow needs.
vi.mock('./MarkdownSourceEditor.jsx', () => ({ default: () => null }))
vi.mock('./MarkdownPreview.jsx', () => ({ default: () => <div data-testid="preview" /> }))
vi.mock('./RFCDiscussionPanel.jsx', () => ({ default: () => <div data-testid="discussion-panel" /> }))
vi.mock('./ChatPanel.jsx', () => ({
  default: ({ messages }) => (
    <div data-testid="chat-panel">
      {(messages || []).map((m, i) => (
        <div key={i} data-role={m.role}>{m.text}</div>
      ))}
    </div>
  ),
}))
vi.mock('./SelectionTooltip.jsx', () => ({
  default: ({ onAsk, onFlag, disabled }) => (
    <div data-testid="tooltip">
      <button data-testid="tooltip-ask" disabled={disabled}
        onClick={() => onAsk('Why this approach?', 'the selected quote')}>ask</button>
      <button data-testid="tooltip-flag"
        onClick={() => onFlag('confusing', 'the selected quote')}>flag</button>
    </div>
  ),
}))
vi.mock('./PromptBar.jsx', () => ({
  default: ({ onSubmit, disabled }) => (
    <button data-testid="prompt-submit" disabled={disabled}
      onClick={() => onSubmit('Why this approach?', { text: 'the selected quote' })}>send</button>
  ),
}))
vi.mock('./ChangePanel.jsx', () => ({ default: () => null, diffWords: () => [] }))
vi.mock('./PRModal.jsx', () => ({ default: () => null }))
vi.mock('./GraduateDialog.jsx', () => ({ default: () => null }))
vi.mock('./InvitationsModal.jsx', () => ({ default: () => null }))
vi.mock('./MetadataFieldsPanel.jsx', () => ({ default: () => null }))

import RFCView from './RFCView.jsx'

const ACTIVE_ENTRY = {
  id: 'RFC-0001', title: 'The Entry', state: 'active',
  owners: [], meta: {}, proposed_use_case: '', tags: [],
}
const MAIN_VIEW = { slug: 'the-entry', branches: [], open_prs: [] }

function branchPayload(branch, { main_thread_id = 't-1' } = {}) {
  return {
    slug: 'the-entry', title: 'The Entry', branch_name: branch, body: '# Body\n',
    body_sha: 'abc', main_thread_id, threads: [], changes: [],
    visibility: {}, grants: [], creator: 'me',
    capabilities: { can_contribute: true, can_change_branch_settings: true },
  }
}

const VIEWER = { gitea_login: 'me', role: 'contributor' }

function renderView(viewer = VIEWER, initialBranch = null) {
  const path = initialBranch ? `/e/the-entry?branch=${initialBranch}` : '/e/the-entry'
  return render(
    <MemoryRouter initialEntries={[path]}>
      <Routes>
        <Route path="/e/:slug" element={<RFCView viewer={viewer} />} />
      </Routes>
    </MemoryRouter>,
  )
}

describe('RFCView — §8.12 main-view Ask (Option B)', () => {
  beforeEach(() => {
    vi.clearAllMocks()
    getRFC.mockResolvedValue(ACTIVE_ENTRY)
    getRFCMain.mockResolvedValue(MAIN_VIEW)
    listModels.mockResolvedValue({ models: [{ id: 'claude' }], default: 'claude' })
    getCollection.mockResolvedValue({ fields: null })
    getThreadMessages.mockResolvedValue({ messages: [] })
    getBranch.mockImplementation((_slug, branch) => Promise.resolve(branchPayload(branch)))
    promoteToBranch.mockResolvedValue({ branch_name: 'edit-me-1' })
    startEditBranch.mockResolvedValue({ branch_name: 'edit-the-entry' })
    createThread.mockResolvedValue({ thread_id: 1, message_id: 1 })
    streamChatTurn.mockImplementation(async (_slug, _branch, _threadId, { text, quote }, cb) => {
      cb.onChunk?.('Here is the answer.')
      cb.onChanges?.({ message_id: 42 })
      cb.onDone?.()
      return { assistantId: 42, userMsgId: 41 }
    })
  })

  it('cuts an edit branch and runs the question (with the quote) there', async () => {
    renderView()
    await screen.findByTestId('discussion-panel')   // we start on main

    fireEvent.click(screen.getByTestId('prompt-submit'))

    // The active-RFC dispatch is promote-to-branch.
    await waitFor(() => expect(promoteToBranch).toHaveBeenCalledWith('the-entry'))

    // Once the new branch view loads, the turn runs there — not on main —
    // with the selected quote intact.
    await waitFor(() => expect(streamChatTurn).toHaveBeenCalled())
    const [slug, branch, threadId, payload] = streamChatTurn.mock.calls[0]
    expect(slug).toBe('the-entry')
    expect(branch).toBe('edit-me-1')
    expect(threadId).toBe('t-1')
    expect(payload).toMatchObject({ text: 'Why this approach?', quote: 'the selected quote' })

    // The chat panel is now mounted (we left main) and shows the streamed answer.
    const panel = await screen.findByTestId('chat-panel')
    await waitFor(() => expect(panel).toHaveTextContent('Here is the answer.'))
  })

  it('uses start-edit-branch for a super-draft entry', async () => {
    getRFC.mockResolvedValue({ ...ACTIVE_ENTRY, state: 'super-draft' })
    getBranch.mockImplementation((_slug, branch) =>
      Promise.resolve(branchPayload(branch === 'main' ? 'main' : 'edit-the-entry')))
    renderView()
    await screen.findByTestId('discussion-panel')

    fireEvent.click(screen.getByTestId('tooltip-ask'))

    await waitFor(() => expect(startEditBranch).toHaveBeenCalledWith('the-entry'))
    expect(promoteToBranch).not.toHaveBeenCalled()
    await waitFor(() => expect(streamChatTurn).toHaveBeenCalled())
    expect(streamChatTurn.mock.calls[0][1]).toBe('edit-the-entry')
  })

  it('asking from an existing branch runs directly, without cutting a new one', async () => {
    renderView(VIEWER, 'edit-me-1')
    await screen.findByTestId('chat-panel')

    fireEvent.click(screen.getByTestId('prompt-submit'))

    await waitFor(() => expect(streamChatTurn).toHaveBeenCalled())
    expect(promoteToBranch).not.toHaveBeenCalled()
    expect(startEditBranch).not.toHaveBeenCalled()
    expect(streamChatTurn.mock.calls[0][1]).toBe('edit-me-1')
  })

  it('surfaces an error and does not chat when the branch cut is rejected', async () => {
    promoteToBranch.mockRejectedValue(new Error('not a contributor'))
    renderView()
    await screen.findByTestId('discussion-panel')

    fireEvent.click(screen.getByTestId('prompt-submit'))

    await waitFor(() => expect(promoteToBranch).toHaveBeenCalled())
    // Explicit error path — not a silent no-op — and no spurious chat turn.
    expect(await screen.findByText(/not a contributor/)).toBeInTheDocument()
    expect(streamChatTurn).not.toHaveBeenCalled()
  })

  it('Flag on the canonical view still creates a discussion thread (no branch cut)', async () => {
    renderView()
    await screen.findByTestId('discussion-panel')

    fireEvent.click(screen.getByTestId('tooltip-flag'))

    await waitFor(() => expect(createThread).toHaveBeenCalled())
    const [, branch, body] = createThread.mock.calls[0]
    expect(branch).toBe('main')
    expect(body).toMatchObject({ thread_kind: 'flag' })
    expect(promoteToBranch).not.toHaveBeenCalled()
    expect(streamChatTurn).not.toHaveBeenCalled()
  })

  it('signed-out viewer gets a read-only path on main — no prompt bar, Ask disabled, no cut', async () => {
    renderView(null)
    await screen.findByTestId('discussion-panel')

    expect(screen.queryByTestId('prompt-submit')).toBeNull()
    expect(screen.getByTestId('tooltip-ask')).toBeDisabled()
    expect(promoteToBranch).not.toHaveBeenCalled()
    expect(startEditBranch).not.toHaveBeenCalled()
  })
})