import type { Page, TestInfo } from '@stablyai/playwright-test'
import { randomUUID } from 'node:crypto'
import { rmSync, writeFileSync } from 'node:fs'
import path from 'node:path'
import { test, expect } from './helpers/orca-app'
import {
  ensureTerminalVisible,
  getActiveWorktreeId,
  getAllWorktreeIds,
  switchToWorktree,
  waitForActiveWorktree,
  waitForSessionReady
} from './helpers/store'
import {
  getTerminalContent,
  sendToTerminal,
  splitActiveTerminalPane,
  waitForActivePanePtyId,
  waitForActiveTerminalManager,
  waitForPaneIdentitySnapshot,
  waitForTerminalOutput
} from './helpers/terminal'

type TerminalLoadPane = {
  paneKey: string
  ptyId: string
}

type TypingMeasurement = {
  latencies: number[]
  medianLatencyMs: number
  worstLatencyMs: number
  maxTimerDriftMs: number
  frameCount: number
}

type SyntheticOpenCodeWindow = Window & {
  __terminalPtyDataInjection?: {
    inject: (paneKey: string, data: string) => boolean
  }
  __terminalPtyOutputDebug?: {
    reset: () => void
    snapshot: () => TerminalPtyOutputDebugSnapshot
  }
  __terminalOutputSchedulerDebug?: {
    reset: () => void
    snapshot: () => TerminalOutputSchedulerDebugSnapshot
  }
}

type TerminalPtyOutputDebugSnapshot = {
  hiddenRendererSkipCount: number
  hiddenRendererSkippedChars: number
  hiddenRendererMode2031ReplyCount: number
}

type TerminalOutputSchedulerDebugSnapshot = {
  backgroundEnqueueCount: number
  deferredForegroundEnqueueCount: number
  foregroundWriteCount: number
  backgroundWriteCount: number
  deferredForegroundWriteCount: number
  flushWriteCount: number
  scheduledDrainCount: number
  drainWrites: number[]
}

const KEY_LATENCY_SAMPLES = 'abcdefghijklmnop'
const DEFAULT_SAME_WORKSPACE_PANES = 5
const DEFAULT_CROSS_WORKSPACE_PANES_PER_WORKTREE = 3
const DEFAULT_FRAME_COUNT = 180
const DEFAULT_FRAME_INTERVAL_MS = 6
const TIMER_SAMPLE_MS = 16
const MAX_MEDIAN_KEY_LATENCY_MS = 300
const MAX_WORST_KEY_LATENCY_MS = 1_200
const MAX_TIMER_DRIFT_MS = 300

function readPositiveInt(name: string, fallback: number): number {
  const raw = process.env[name]
  if (!raw) {
    return fallback
  }
  const value = Number(raw)
  return Number.isInteger(value) && value > 0 ? value : fallback
}

const SAME_WORKSPACE_PANES = readPositiveInt(
  'ORCA_E2E_OPENCODE_SAME_WORKSPACE_PANES',
  DEFAULT_SAME_WORKSPACE_PANES
)
const CROSS_WORKSPACE_PANES_PER_WORKTREE = readPositiveInt(
  'ORCA_E2E_OPENCODE_CROSS_WORKSPACE_PANES',
  DEFAULT_CROSS_WORKSPACE_PANES_PER_WORKTREE
)
const FRAME_COUNT = readPositiveInt('ORCA_E2E_OPENCODE_FRAME_COUNT', DEFAULT_FRAME_COUNT)
const FRAME_INTERVAL_MS = readPositiveInt(
  'ORCA_E2E_OPENCODE_FRAME_INTERVAL_MS',
  DEFAULT_FRAME_INTERVAL_MS
)

function interactivePromptScript(runId: string): string {
  return `
process.stdin.setEncoding('utf8')
if (process.stdin.isTTY) process.stdin.setRawMode(true)
process.stdin.resume()
let seq = 0
const interrupt = String.fromCharCode(3)
process.stdout.write('\\x1b]0;OpenCode load typing benchmark\\x07')
process.stdout.write('OPENCODE_TYPING_READY_${runId}\\n')
process.stdin.on('data', (chunk) => {
  if (chunk.includes(interrupt)) {
    process.exit(0)
  }
  for (const char of chunk) {
    if (char === '\\r' || char === '\\n') continue
    seq += 1
    process.stdout.write('\\r\\x1b[2KOpenCode load prompt ' + seq + ': ' + char + ' OPENCODE_TYPING_KEY_${runId}_' + seq + '\\n')
  }
})
`
}

async function focusActiveTerminalInput(page: Page): Promise<void> {
  await page.evaluate(() => {
    const store = window.__store
    const state = store?.getState()
    const worktreeId = state?.activeWorktreeId
    const tabId =
      state?.activeTabType === 'terminal'
        ? state.activeTabId
        : worktreeId
          ? (state?.activeTabIdByWorktree?.[worktreeId] ?? null)
          : null
    const manager = tabId ? window.__paneManagers?.get(tabId) : null
    const pane = manager?.getActivePane?.() ?? manager?.getPanes?.()[0] ?? null
    const textarea = pane?.container.querySelector<HTMLTextAreaElement>('.xterm-helper-textarea')
    if (!pane || !textarea) {
      throw new Error('Active terminal input is unavailable')
    }
    pane.terminal.focus()
    textarea.focus()
  })
}

async function focusPane(page: Page, paneKey: string): Promise<void> {
  const separator = paneKey.indexOf(':')
  const tabId = paneKey.slice(0, separator)
  const leafId = paneKey.slice(separator + 1)
  await page.evaluate(
    ({ tabId, leafId }) => {
      const manager = window.__paneManagers?.get(tabId)
      const pane = manager?.getPanes?.().find((candidate) => candidate.leafId === leafId)
      if (!manager || !pane) {
        throw new Error(`Unable to focus pane ${tabId}:${leafId}`)
      }
      manager.setActivePane?.(pane.id, { focus: true })
    },
    { tabId, leafId }
  )
}

async function ensureActiveWorktreePaneLoad(
  page: Page,
  paneCount: number
): Promise<TerminalLoadPane[]> {
  await ensureTerminalVisible(page)
  await waitForActiveTerminalManager(page, 30_000)
  let snapshot = await waitForPaneIdentitySnapshot(page, 1)
  while (snapshot.panes.length < paneCount) {
    await splitActiveTerminalPane(page, snapshot.panes.length % 2 === 0 ? 'horizontal' : 'vertical')
    snapshot = await waitForPaneIdentitySnapshot(page, snapshot.panes.length + 1)
  }
  return snapshot.panes.slice(0, paneCount).map((pane) => ({
    paneKey: `${snapshot.tabId}:${pane.leafId}`,
    ptyId: pane.ptyId ?? ''
  }))
}

async function waitForMarkerLatency(
  page: Page,
  marker: string,
  timeoutMs: number
): Promise<number> {
  const start = performance.now()
  while (performance.now() - start < timeoutMs) {
    if ((await getTerminalContent(page, 12_000)).includes(marker)) {
      return performance.now() - start
    }
    await page.waitForTimeout(5)
  }
  throw new Error(`Timed out waiting for terminal marker ${marker}`)
}

function median(values: number[]): number {
  const sorted = [...values].sort((a, b) => a - b)
  return sorted[Math.floor(sorted.length / 2)] ?? 0
}

async function startSyntheticOpenCodeInjection(
  page: Page,
  paneKeys: string[]
): Promise<{ stop: () => Promise<void> }> {
  await page.evaluate(
    ({ paneKeys, frameCount, intervalMs }) => {
      const target = window as SyntheticOpenCodeWindow & {
        __syntheticOpenCodeLoadTimer?: number
      }
      const injector = target.__terminalPtyDataInjection
      if (!injector) {
        throw new Error('terminal PTY data injection API is unavailable')
      }
      let frameIndex = 0
      target.__syntheticOpenCodeLoadTimer = window.setInterval(() => {
        for (const [paneIndex, paneKey] of paneKeys.entries()) {
          const injected = injector.inject(
            paneKey,
            syntheticOpenCodeFrameSource(paneIndex, frameIndex)
          )
          if (!injected) {
            throw new Error(`no PTY data injector registered for pane key ${paneKey}`)
          }
        }
        frameIndex += 1
        if (frameIndex >= frameCount && target.__syntheticOpenCodeLoadTimer != null) {
          window.clearInterval(target.__syntheticOpenCodeLoadTimer)
          delete target.__syntheticOpenCodeLoadTimer
        }
      }, intervalMs)

      function syntheticOpenCodeFrameSource(paneIndex: number, frame: number): string {
        const row = (frame % 18) + 4
        const spinner = ['|', '/', '-', '\\'][frame % 4]
        const body = `${'opencode '.repeat(10)}pane=${paneIndex} frame=${frame}`
        return [
          '\x1b[?2026h',
          '\x1b[?25l',
          `\x1b[1;2H\x1b[38;2;255;138;0m${spinner} OpenCode synthetic agent ${paneIndex}\x1b[0m`,
          `\x1b[${row};4H\x1b[38;2;231;237;247m${body.padEnd(118, '#')}\x1b[0m`,
          `\x1b[23;2H\x1b[38;2;106;169;255mstream ${String(frame).padStart(4, '0')} ${'#'.repeat(96)}\x1b[0m`,
          '\x1b[?2026l'
        ].join('')
      }
    },
    { paneKeys, frameCount: FRAME_COUNT, intervalMs: FRAME_INTERVAL_MS }
  )
  return {
    stop: async () => {
      await page.evaluate(() => {
        const target = window as SyntheticOpenCodeWindow & {
          __syntheticOpenCodeLoadTimer?: number
        }
        if (target.__syntheticOpenCodeLoadTimer != null) {
          window.clearInterval(target.__syntheticOpenCodeLoadTimer)
          delete target.__syntheticOpenCodeLoadTimer
        }
      })
    }
  }
}

async function measureTypingDuringLoad(
  page: Page,
  scriptPath: string,
  ptyId: string,
  runId: string
): Promise<TypingMeasurement> {
  await sendToTerminal(page, ptyId, `node ${JSON.stringify(scriptPath)}\r`)
  await waitForTerminalOutput(page, `OPENCODE_TYPING_READY_${runId}`, 10_000)
  await focusActiveTerminalInput(page)

  const eventLoop = await page.evaluateHandle((sampleMs) => {
    let maxTimerDriftMs = 0
    let lastTick = performance.now()
    const timer = window.setInterval(() => {
      const now = performance.now()
      maxTimerDriftMs = Math.max(maxTimerDriftMs, now - lastTick - sampleMs)
      lastTick = now
    }, sampleMs)
    return {
      stop: () => {
        window.clearInterval(timer)
        return maxTimerDriftMs
      }
    }
  }, TIMER_SAMPLE_MS)

  const latencies: number[] = []
  for (const [index, char] of [...KEY_LATENCY_SAMPLES].entries()) {
    const marker = `OPENCODE_TYPING_KEY_${runId}_${index + 1}`
    const start = performance.now()
    await page.keyboard.type(char)
    await waitForMarkerLatency(page, marker, MAX_WORST_KEY_LATENCY_MS)
    latencies.push(performance.now() - start)
  }

  const maxTimerDriftMs = await eventLoop.evaluate((watcher) => watcher.stop())
  await eventLoop.dispose()
  return {
    latencies,
    medianLatencyMs: median(latencies),
    worstLatencyMs: Math.max(...latencies),
    maxTimerDriftMs,
    frameCount: FRAME_COUNT
  }
}

async function resetTerminalPtyOutputDebug(page: Page): Promise<void> {
  await page.evaluate(() => {
    ;(window as SyntheticOpenCodeWindow).__terminalPtyOutputDebug?.reset()
    ;(window as SyntheticOpenCodeWindow).__terminalOutputSchedulerDebug?.reset()
  })
}

async function readTerminalPtyOutputDebug(
  page: Page
): Promise<TerminalPtyOutputDebugSnapshot | null> {
  return page.evaluate(() => {
    return (window as SyntheticOpenCodeWindow).__terminalPtyOutputDebug?.snapshot() ?? null
  })
}

async function readTerminalOutputSchedulerDebug(
  page: Page
): Promise<TerminalOutputSchedulerDebugSnapshot | null> {
  return page.evaluate(() => {
    return (window as SyntheticOpenCodeWindow).__terminalOutputSchedulerDebug?.snapshot() ?? null
  })
}

function annotateTypingMeasurement(
  testInfo: TestInfo,
  type: string,
  paneCount: number,
  measurement: TypingMeasurement,
  debug: TerminalPtyOutputDebugSnapshot | null = null,
  scheduler: TerminalOutputSchedulerDebugSnapshot | null = null
): void {
  const hiddenSkipSummary = debug
    ? ` hiddenSkips=${debug.hiddenRendererSkipCount} hiddenSkippedChars=${debug.hiddenRendererSkippedChars} mode2031Replies=${debug.hiddenRendererMode2031ReplyCount}`
    : ''
  const schedulerSummary = scheduler
    ? ` deferredForegroundEnqueue=${scheduler.deferredForegroundEnqueueCount} deferredForegroundWrite=${scheduler.deferredForegroundWriteCount} scheduledDrains=${scheduler.scheduledDrainCount}`
    : ''
  testInfo.annotations.push({
    type,
    description: `panes=${paneCount} frames=${measurement.frameCount} median=${measurement.medianLatencyMs.toFixed(
      1
    )}ms worst=${measurement.worstLatencyMs.toFixed(
      1
    )}ms maxTimerDrift=${measurement.maxTimerDriftMs.toFixed(1)}ms samples=${measurement.latencies
      .map((value) => value.toFixed(1))
      .join(',')}${hiddenSkipSummary}${schedulerSummary}`
  })
}

test.describe('Artificial OpenCode terminal load', () => {
  test.describe.configure({ mode: 'serial' })

  test('measures baseline typing responsiveness with one active terminal', async ({
    orcaPage,
    testRepoPath
  }, testInfo) => {
    await waitForSessionReady(orcaPage)
    await waitForActiveWorktree(orcaPage)
    await ensureTerminalVisible(orcaPage)
    await waitForActiveTerminalManager(orcaPage, 30_000)
    const typingPtyId = await waitForActivePanePtyId(orcaPage)

    const runId = randomUUID()
    const scriptPath = path.join(testRepoPath, `.orca-opencode-baseline-typing-${runId}.mjs`)
    writeFileSync(scriptPath, interactivePromptScript(runId))
    await resetTerminalPtyOutputDebug(orcaPage)
    try {
      const measurement = await measureTypingDuringLoad(orcaPage, scriptPath, typingPtyId, runId)
      const debug = await readTerminalPtyOutputDebug(orcaPage)
      const scheduler = await readTerminalOutputSchedulerDebug(orcaPage)
      annotateTypingMeasurement(
        testInfo,
        'opencode-baseline-typing',
        1,
        measurement,
        debug,
        scheduler
      )
      expect(measurement.medianLatencyMs).toBeLessThan(MAX_MEDIAN_KEY_LATENCY_MS)
      expect(measurement.worstLatencyMs).toBeLessThan(MAX_WORST_KEY_LATENCY_MS)
      expect(measurement.maxTimerDriftMs).toBeLessThan(MAX_TIMER_DRIFT_MS)
    } finally {
      await sendToTerminal(orcaPage, typingPtyId, '\x03').catch(() => undefined)
      rmSync(scriptPath, { force: true })
    }
  })

  test('keeps typing responsive while same-workspace panes redraw simultaneously', async ({
    orcaPage,
    testRepoPath
  }, testInfo) => {
    await waitForSessionReady(orcaPage)
    await waitForActiveWorktree(orcaPage)
    const panes = await ensureActiveWorktreePaneLoad(orcaPage, SAME_WORKSPACE_PANES)
    const [typingPane, ...loadPanes] = panes
    await focusPane(orcaPage, typingPane.paneKey)

    const runId = randomUUID()
    const scriptPath = path.join(testRepoPath, `.orca-opencode-typing-${runId}.mjs`)
    writeFileSync(scriptPath, interactivePromptScript(runId))
    await resetTerminalPtyOutputDebug(orcaPage)
    const load = await startSyntheticOpenCodeInjection(
      orcaPage,
      loadPanes.map((pane) => pane.paneKey)
    )
    try {
      const measurement = await measureTypingDuringLoad(
        orcaPage,
        scriptPath,
        typingPane.ptyId,
        runId
      )
      annotateTypingMeasurement(
        testInfo,
        'opencode-same-workspace-typing',
        panes.length,
        measurement,
        await readTerminalPtyOutputDebug(orcaPage),
        await readTerminalOutputSchedulerDebug(orcaPage)
      )
      expect(measurement.medianLatencyMs).toBeLessThan(MAX_MEDIAN_KEY_LATENCY_MS)
      expect(measurement.worstLatencyMs).toBeLessThan(MAX_WORST_KEY_LATENCY_MS)
      expect(measurement.maxTimerDriftMs).toBeLessThan(MAX_TIMER_DRIFT_MS)
    } finally {
      await load.stop()
      await sendToTerminal(orcaPage, typingPane.ptyId, '\x03').catch(() => undefined)
      rmSync(scriptPath, { force: true })
    }
  })

  test('keeps typing responsive while another workspace streams OpenCode-style output', async ({
    orcaPage,
    testRepoPath
  }, testInfo) => {
    await waitForSessionReady(orcaPage)
    const firstWorktreeId = await waitForActiveWorktree(orcaPage)
    const allWorktreeIds = await getAllWorktreeIds(orcaPage)
    const secondWorktreeId = allWorktreeIds.find((id) => id !== firstWorktreeId)
    test.skip(
      !secondWorktreeId,
      'OpenCode cross-workspace load needs the seeded secondary worktree'
    )
    if (!secondWorktreeId) {
      return
    }

    await switchToWorktree(orcaPage, secondWorktreeId)
    const hiddenPanes = await ensureActiveWorktreePaneLoad(
      orcaPage,
      CROSS_WORKSPACE_PANES_PER_WORKTREE
    )

    await switchToWorktree(orcaPage, firstWorktreeId)
    await expect
      .poll(() => getActiveWorktreeId(orcaPage), { timeout: 10_000 })
      .toBe(firstWorktreeId)
    await ensureTerminalVisible(orcaPage)
    await waitForActiveTerminalManager(orcaPage, 30_000)
    const typingPtyId = await waitForActivePanePtyId(orcaPage)

    const runId = randomUUID()
    const scriptPath = path.join(testRepoPath, `.orca-opencode-cross-typing-${runId}.mjs`)
    writeFileSync(scriptPath, interactivePromptScript(runId))
    await resetTerminalPtyOutputDebug(orcaPage)
    const load = await startSyntheticOpenCodeInjection(
      orcaPage,
      hiddenPanes.map((pane) => pane.paneKey)
    )
    try {
      const measurement = await measureTypingDuringLoad(orcaPage, scriptPath, typingPtyId, runId)
      annotateTypingMeasurement(
        testInfo,
        'opencode-cross-workspace-typing',
        hiddenPanes.length + 1,
        measurement,
        await readTerminalPtyOutputDebug(orcaPage),
        await readTerminalOutputSchedulerDebug(orcaPage)
      )
      expect(measurement.medianLatencyMs).toBeLessThan(MAX_MEDIAN_KEY_LATENCY_MS)
      expect(measurement.worstLatencyMs).toBeLessThan(MAX_WORST_KEY_LATENCY_MS)
      expect(measurement.maxTimerDriftMs).toBeLessThan(MAX_TIMER_DRIFT_MS)
    } finally {
      await load.stop()
      await sendToTerminal(orcaPage, typingPtyId, '\x03').catch(() => undefined)
      rmSync(scriptPath, { force: true })
    }
  })
})