import { Button, Input, Space, Switch, Tabs, Typography, Radio, Select } from '@arco-design/web-react'
import { useEffect, useMemo, useState } from 'react'

export interface CronInputProps {
  value?: string
  onChange?: (value: string) => void
}

const DEFAULT_CRON = '* * * * *'

type CronPart = 'minute' | 'hour' | 'day' | 'month' | 'week'

interface CronState {
  minute: string
  hour: string
  day: string
  month: string
  week: string
}

// 常用预设
const PRESETS = [
  { label: '每天 02:00', value: '0 2 * * *' },
  { label: '每天 00:00', value: '0 0 * * *' },
  { label: '每 6 小时', value: '0 */6 * * *' },
  { label: '每 12 小时', value: '0 */12 * * *' },
  { label: '每周日 03:00', value: '0 3 * * 0' },
  { label: '每月 1 日 02:00', value: '0 2 1 * *' },
  { label: '每 30 分钟', value: '*/30 * * * *' },
  { label: '每小时', value: '0 * * * *' },
]

function parseCron(expr: string): CronState {
  const parts = (expr || DEFAULT_CRON).trim().split(/\s+/)
  return {
    minute: parts[0] || '*',
    hour: parts[1] || '*',
    day: parts[2] || '*',
    month: parts[3] || '*',
    week: parts[4] || '*',
  }
}

function stringifyCron(state: CronState): string {
  return `${state.minute} ${state.hour} ${state.day} ${state.month} ${state.week}`
}

// 将 cron 表达式转为中文可读描述
function describeCron(expr: string): string {
  const parts = expr.trim().split(/\s+/)
  if (parts.length !== 5) return ''
  const [minute, hour, day, month, week] = parts

  const segments: string[] = []

  // 月
  if (month !== '*') segments.push(`${month} 月`)
  // 日
  if (day !== '*') segments.push(`${day} 日`)
  // 周
  if (week !== '*') {
    const weekNames: Record<string, string> = { '0': '日', '1': '一', '2': '二', '3': '三', '4': '四', '5': '五', '6': '六', '7': '日' }
    const weekDesc = week.split(',').map((w) => weekNames[w] || w).join('、')
    segments.push(`星期${weekDesc}`)
  }
  // 小时
  if (hour.includes('/')) {
    segments.push(`每 ${hour.split('/')[1]} 小时`)
  } else if (hour !== '*') {
    segments.push(`${hour.padStart(2, '0')} 时`)
  }
  // 分钟
  if (minute.includes('/')) {
    segments.push(`每 ${minute.split('/')[1]} 分钟`)
  } else if (minute !== '*') {
    segments.push(`${minute.padStart(2, '0')} 分`)
  } else if (hour !== '*' && !hour.includes('/')) {
    segments.push('00 分')
  }

  if (segments.length === 0) return '每分钟执行'
  return segments.join(' ') + ' 执行'
}

function generateOptions(min: number, max: number) {
  return Array.from({ length: max - min + 1 }, (_, i) => ({
    label: String(i + min),
    value: String(i + min),
  }))
}

const MINUTES_OPTIONS = generateOptions(0, 59)
const HOURS_OPTIONS = generateOptions(0, 23)
const DAYS_OPTIONS = generateOptions(1, 31)
const MONTHS_OPTIONS = generateOptions(1, 12)
const WEEKS_OPTIONS = [
  { label: '星期日', value: '0' },
  { label: '星期一', value: '1' },
  { label: '星期二', value: '2' },
  { label: '星期三', value: '3' },
  { label: '星期四', value: '4' },
  { label: '星期五', value: '5' },
  { label: '星期六', value: '6' },
]

export function CronInput({ value, onChange }: CronInputProps) {
  const [internalValue, setInternalValue] = useState(value || DEFAULT_CRON)
  const [isAdvanced, setIsAdvanced] = useState(false)
  const [state, setState] = useState<CronState>(parseCron(internalValue))

  // Sync prop to internal state
  useEffect(() => {
    if (value !== undefined && value !== internalValue) {
      setInternalValue(value || DEFAULT_CRON)
      if (!isAdvanced) {
        setState(parseCron(value || DEFAULT_CRON))
      }
    }
  }, [value, isAdvanced, internalValue])

  const description = useMemo(() => describeCron(internalValue), [internalValue])

  const notifyChange = (nextValue: string) => {
    setInternalValue(nextValue)
    if (onChange) {
      onChange(nextValue)
    }
  }

  const handleStateChange = (part: CronPart, val: string) => {
    const nextState = { ...state, [part]: val }
    setState(nextState)
    notifyChange(stringifyCron(nextState))
  }

  const handlePreset = (cronExpr: string) => {
    setInternalValue(cronExpr)
    setState(parseCron(cronExpr))
    if (onChange) onChange(cronExpr)
  }

  const renderPartTab = (
    part: CronPart,
    title: string,
    options: { label: string; value: string }[],
    allowAnyVal = '*',
  ) => {
    const currentVal = state[part]
    const isAny = currentVal === allowAnyVal || currentVal === '*' || currentVal === '?'
    const isSpecific = !isAny && !currentVal.includes('/') && !currentVal.includes('-')

    const type = isAny ? 'any' : 'specific'
    const specificValues = isSpecific ? currentVal.split(',') : []

    return (
      <div style={{ padding: '16px 0' }}>
        <Radio.Group
          direction="vertical"
          value={type}
          onChange={(val) => {
            if (val === 'any') {
              handleStateChange(part, allowAnyVal)
            } else {
              handleStateChange(part, options[0].value)
            }
          }}
        >
          <Radio value="any">
            <Typography.Text>通配 ({allowAnyVal}) - 任意{title}</Typography.Text>
          </Radio>
          <Radio value="specific">
            <Typography.Text>指定{title}</Typography.Text>
          </Radio>
        </Radio.Group>

        {type === 'specific' && (
          <div style={{ paddingLeft: 24, marginTop: 12 }}>
            <Select
              mode="multiple"
              placeholder={`请选择${title}`}
              value={specificValues}
              options={options}
              onChange={(vals: string[]) => {
                if (vals.length === 0) {
                  handleStateChange(part, allowAnyVal)
                } else {
                  const sorted = [...vals].sort((a, b) => Number(a) - Number(b))
                  handleStateChange(part, sorted.join(','))
                }
              }}
              style={{ width: '100%', maxWidth: 400 }}
              allowClear
            />
          </div>
        )}
      </div>
    )
  }

  return (
    <div className="cron-input-container">
      {/* 常用预设 */}
      <div style={{ marginBottom: 12 }}>
        <Typography.Text type="secondary" style={{ display: 'block', marginBottom: 8 }}>常用预设</Typography.Text>
        <Space wrap size="small">
          {PRESETS.map((preset) => (
            <Button
              key={preset.value}
              size="small"
              type={internalValue === preset.value ? 'primary' : 'secondary'}
              onClick={() => handlePreset(preset.value)}
            >
              {preset.label}
            </Button>
          ))}
        </Space>
      </div>

      {/* 表达式 + 可读描述 */}
      <div style={{ marginBottom: 12, display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
        <Input
          value={internalValue}
          onChange={(val) => {
            setInternalValue(val)
            if (isAdvanced && onChange) {
              onChange(val)
            }
          }}
          readOnly={!isAdvanced}
          style={{ width: 240, fontFamily: 'monospace' }}
          placeholder="* * * * *"
        />
        <Space>
          <Typography.Text type="secondary">高级模式</Typography.Text>
          <Switch
            checked={isAdvanced}
            onChange={(checked) => {
              setIsAdvanced(checked)
              if (!checked) {
                setState(parseCron(internalValue))
                notifyChange(stringifyCron(parseCron(internalValue)))
              }
            }}
          />
        </Space>
      </div>

      {/* 中文可读描述 */}
      {description && (
        <Typography.Paragraph type="secondary" style={{ marginBottom: 12, marginTop: 0 }}>
          {description}
        </Typography.Paragraph>
      )}

      {!isAdvanced && (
        <Tabs type="card-gutter" size="small">
          <Tabs.TabPane key="minute" title="分钟">
            {renderPartTab('minute', '分钟', MINUTES_OPTIONS, '*')}
          </Tabs.TabPane>
          <Tabs.TabPane key="hour" title="小时">
            {renderPartTab('hour', '小时', HOURS_OPTIONS, '*')}
          </Tabs.TabPane>
          <Tabs.TabPane key="day" title="日">
            {renderPartTab('day', '日', DAYS_OPTIONS, '*')}
          </Tabs.TabPane>
          <Tabs.TabPane key="month" title="月">
            {renderPartTab('month', '月', MONTHS_OPTIONS, '*')}
          </Tabs.TabPane>
          <Tabs.TabPane key="week" title="周">
            {renderPartTab('week', '周', WEEKS_OPTIONS, '*')}
          </Tabs.TabPane>
        </Tabs>
      )}
    </div>
  )
}