// 自动评分：编译一次学生工程，每个检查项各启动一次程序，按步骤操作并核对结果。
// 检查大部分时间在等定时器，CPU 主要花在编译和启动程序上；2 核的服务器全站同时跑 GRADE_CONCURRENCY 个检查，其余排队。
import type { CheckResult, ControlNode, GradeResult } from '@iot/shared'
import { compileService } from '../compile-service'
import type { Check, Expectation, Step } from './checks'
import { ProgramDriver } from './driver'

const GRADE_CONCURRENCY = 6
/** 程序启动后多久内应该显示出窗体 */
const START_TIMEOUT = 10_000

const RELAY_NAMES = ['报警灯', '照明灯', '路灯', '插座 1', '插座 2']
const ZIGBEE_NAMES = ['ZigBee 节点 0', '照明灯 1']

// ---------- 并发限制 ----------
let running = 0
const waiting: (() => void)[] = []

async function withSlot<T>(task: () => Promise<T>): Promise<T> {
  if (running >= GRADE_CONCURRENCY) await new Promise<void>((resolve) => waiting.push(resolve))
  running++
  try {
    return await task()
  } finally {
    running--
    waiting.shift()?.()
  }
}

/** 给学生工程评分；dir 是已写好源文件的工程目录 */
export async function grade(dir: string, checks: Check[]): Promise<GradeResult> {
  const start = Date.now()
  const compiled = await compileService.compile(dir)
  if (!compiled.ok) {
    return {
      compiled: false,
      results: checks.map((c) => ({ title: c.title, passed: false, message: '编译没有通过，先改正编译错误' })),
      ms: Date.now() - start,
    }
  }
  const results = await Promise.all(checks.map((check) => withSlot(() => runCheck(dir, check))))
  return { compiled: true, results, ms: Date.now() - start }
}

class Failure extends Error {}

async function runCheck(dir: string, check: Check): Promise<CheckResult> {
  const driver = new ProgramDriver()
  try {
    driver.start(dir)
    if (!(await driver.waitFor(() => driver.forms.length > 0 || driver.exited, START_TIMEOUT)) || driver.forms.length === 0) {
      throw new Failure(driver.exceptions[0] ? `程序出错：${driver.exceptions[0]}` : '程序启动后没有显示窗体')
    }
    for (const step of check.steps) {
      await runStep(driver, step)
      if (driver.exceptions.length > 0) throw new Failure(`程序出错：${driver.exceptions[0]}`)
    }
    return { title: check.title, passed: true }
  } catch (error) {
    if (error instanceof Failure) return { title: check.title, passed: false, message: error.message }
    throw error
  } finally {
    driver.stop()
  }
}

function need(driver: ProgramDriver, name: string): ControlNode {
  const node = driver.find(name)
  if (!node) throw new Failure(`找不到名为 ${name} 的控件（书上规定的控件名，注意大小写）`)
  return node
}

async function runStep(driver: ProgramDriver, step: Step) {
  switch (step.kind) {
    case 'click': {
      const node = need(driver, step.control)
      if (node.props.Enabled === false) throw new Failure(`${step.control} 是灰色的（Enabled 为 false），点不了`)
      driver.act(node, { action: 'click' })
      await driver.settle()
      break
    }
    case 'text':
      driver.act(need(driver, step.control), { action: 'text', value: step.value })
      await driver.settle()
      break
    case 'select': {
      const node = need(driver, step.control)
      if (node.type !== 'ComboBox') throw new Failure(`${step.control} 不是下拉框`)
      // 和浏览器一样先展开（教材在下拉框的 Click 里填充串口列表），再选
      driver.act(node, { action: 'dropDown' })
      await driver.settle()
      const items = ((node.props.Items as unknown[] | undefined) ?? []).map(String)
      const index = items.indexOf(step.item)
      if (index < 0) {
        // 串口列表是空的：最常见的原因是没有填充
        const hint = items.length === 0 && /^COM\d+$/.test(step.item) ? '。串口列表要在窗体的 Load 事件或下拉框的 Click 事件里用 SerialPort.GetPortNames() 填充' : ''
        throw new Failure(`下拉框 ${step.control} 里没有"${step.item}"（现在的选项：${items.length ? items.join('、') : '空'}）${hint}`)
      }
      driver.act(node, { action: 'select', index })
      await driver.settle()
      break
    }
    case 'board':
      driver.setBoard(step)
      await driver.settle()
      break
    case 'wait':
      await Bun.sleep(step.ms)
      break
    case 'expect':
      await expectStep(driver, step)
      break
  }
}

const seconds = (ms: number) => `${Math.round(ms / 100) / 10} 秒`
const quote = (value: unknown) => (value === undefined || value === null || value === '' ? '空的' : `"${String(value)}"`)

async function expectStep(driver: ProgramDriver, step: Extract<Step, { kind: 'expect' }>) {
  const { expect: e, within } = step
  const wait = within > 2000 ? `${seconds(within)}内` : ''

  if (e.kind === 'unchanged') {
    const node = need(driver, e.control)
    const before = node.props.Text
    await Bun.sleep(e.ms)
    if (node.props.Text !== before) {
      throw new Failure(`期望 ${e.control} ${step.desc ?? `在 ${seconds(e.ms)}内保持不变`}，实际从${quote(before)}变成了${quote(node.props.Text)}`)
    }
    return
  }

  const ok = await driver.waitFor(() => satisfied(driver, e), within)
  if (!ok) throw new Failure(describeFailure(driver, e, step.desc, wait))
}

function satisfied(driver: ProgramDriver, e: Exclude<Expectation, { kind: 'unchanged' }>): boolean {
  const props = (name: string) => driver.find(name)?.props
  switch (e.kind) {
    case 'prop':
      return props(e.control)?.[e.prop] === e.value
    case 'contains':
      return String(props(e.control)?.Text ?? '').includes(e.text)
    case 'matches':
      return e.pattern.test(String(props(e.control)?.Text ?? ''))
    case 'led':
      return driver.board.state.ledText.includes(e.text)
    case 'relay':
      return driver.board.state.relays[e.index] === e.on
    case 'zigbee':
      return driver.board.state.zigbee[e.index] === e.on
    case 'messageBox':
      return driver.messageBoxes.some((box) => box.text.includes(e.text))
    case 'console':
      return driver.console.includes(e.text)
  }
}

function describeFailure(driver: ProgramDriver, e: Exclude<Expectation, { kind: 'unchanged' }>, desc: string | undefined, wait: string): string {
  const prefix = wait ? `${wait}` : ''
  const onOff = (on: boolean) => (on ? '打开' : '关闭')
  switch (e.kind) {
    case 'prop': {
      const actual = need(driver, e.control).props[e.prop]
      if (e.prop === 'Text' || e.prop === 'LedText') return `期望${prefix} ${e.control} ${desc ?? `显示"${e.value}"`}，实际是${quote(actual)}`
      if (e.prop === 'Enabled') return `期望${prefix} ${e.control} ${desc ?? (e.value ? '可用' : '变成灰色不可用')}，实际${actual === false ? '不可用' : '可用'}`
      if (e.prop === 'Checked') return `期望${prefix} ${e.control} ${desc ?? (e.value ? '被选中' : '没有被选中')}，实际${actual ? '被选中' : '没有被选中'}`
      if (e.prop === 'IsOn') return `期望${prefix}窗体上的 ${e.control} ${desc ?? (e.value ? '亮' : '灭')}，实际是${actual ? '亮' : '灭'}的`
      return `期望${prefix} ${e.control} 的 ${e.prop} 是 ${String(e.value)}，实际是 ${String(actual)}`
    }
    case 'contains':
      return `期望${prefix} ${e.control} ${desc ?? `的文字包含"${e.text}"`}，实际是${quote(need(driver, e.control).props.Text)}`
    case 'matches':
      return `期望${prefix} ${e.control} ${desc ?? `的文字符合 ${e.pattern}`}，实际是${quote(need(driver, e.control).props.Text)}`
    case 'led':
      return `期望${prefix}实训台 LED 屏${desc ?? `显示"${e.text}"`}，实际${driver.board.state.ledText ? `显示"${driver.board.state.ledText}"` : '什么也没显示'}`
    case 'relay':
      return `期望${prefix}实训台的${RELAY_NAMES[e.index] ?? `DO${e.index}`}（ADAM-4150 DO${e.index}）${desc ?? onOff(e.on)}，实际是${onOff(driver.board.state.relays[e.index])}的`
    case 'zigbee':
      return `期望${prefix}实训台的${ZIGBEE_NAMES[e.index] ?? `ZigBee 继电器 ${e.index}`}${desc ?? onOff(e.on)}，实际是${onOff(driver.board.state.zigbee[e.index])}的`
    case 'messageBox': {
      const shown = driver.messageBoxes.map((b) => `"${b.text}"`).join('、')
      return `期望${prefix}弹出${desc ?? `包含"${e.text}"的提示框`}，${shown ? `实际弹出的是 ${shown}` : '实际没有弹出提示框'}`
    }
    case 'console':
      return `期望${prefix}控制台${desc ?? `输出"${e.text}"`}，实际输出${quote(driver.console.trim())}`
  }
}