export const TRAVEL_PLANNING_ACTION_GENERATE = 'generate_travel_application_plan'
export const TRAVEL_PLANNING_ACTION_SKIP = 'skip_travel_application_plan'

function normalizeText(value) {
  return String(value || '').trim()
}

function isTravelApplication(applicationType = '') {
  return /差旅|出差/.test(normalizeText(applicationType))
}

function extractDateParts(timeText = '') {
  const dates = normalizeText(timeText).match(/20\d{2}[-/.]\d{1,2}[-/.]\d{1,2}/g) || []
  return {
    startDate: dates[0] || '',
    endDate: dates[dates.length - 1] || dates[0] || ''
  }
}

function resolveTravelPlanningContext(preview = {}, draftPayload = {}) {
  const fields = preview?.fields && typeof preview.fields === 'object' ? preview.fields : {}
  const applicationType = normalizeText(fields.applicationType)
  if (!isTravelApplication(applicationType)) {
    return null
  }

  const location = normalizeText(fields.location)
  const time = normalizeText(fields.time)
  if (!location || !time) {
    return null
  }

  const dates = extractDateParts(time)
  return {
    applicationType,
    location,
    time,
    startDate: dates.startDate,
    endDate: dates.endDate,
    days: normalizeText(fields.days),
    transportMode: normalizeText(fields.transportMode),
    reason: normalizeText(fields.reason),
    claimNo: normalizeText(draftPayload?.claim_no || draftPayload?.claimNo)
  }
}

export function buildTravelPlanningNudgeMessage(preview = {}, draftPayload = {}) {
  const context = resolveTravelPlanningContext(preview, draftPayload)
  if (!context) {
    return ''
  }

  const timeCopy = context.startDate && context.endDate && context.startDate !== context.endDate
    ? `${context.startDate} 至 ${context.endDate}`
    : context.time
  const transportCopy = context.transportMode ? `、${context.transportMode}时间窗口` : '、交通方式比选'
  return [
    `本次${context.location}差旅申请已经提交。`,
    `如果您愿意，我可以继续按 ${timeCopy} 帮您整理一版行程规划，包括出发/返程${transportCopy}、酒店区域建议，以及还需要确认的事项。`
  ].join('\n')
}

export function buildTravelPlanningSuggestedActions(preview = {}, draftPayload = {}) {
  const context = resolveTravelPlanningContext(preview, draftPayload)
  if (!context) {
    return []
  }

  return [
    {
      label: '生成行程规划',
      action_type: TRAVEL_PLANNING_ACTION_GENERATE,
      description: '按本次申请的地点和时间给出交通、酒店和待确认事项。',
      icon: 'mdi mdi-map-clock-outline',
      emphasis: 'primary',
      payload: {
        context
      }
    },
    {
      label: '暂不需要',
      action_type: TRAVEL_PLANNING_ACTION_SKIP,
      description: '保留申请结果，不继续生成规划。',
      icon: 'mdi mdi-check-outline',
      payload: {
        context
      }
    }
  ]
}

export function buildTravelPlanningRecommendation(preview = {}, draftPayload = {}) {
  const context = resolveTravelPlanningContext(preview, draftPayload)
  if (!context) {
    return ''
  }

  const outboundDate = context.startDate || '出发当天'
  const returnDate = context.endDate || '返回当天'
  const transport = context.transportMode || '火车/飞机'
  const reasonLine = context.reason ? `业务安排：${context.reason}` : '业务安排：以申请事由为准，出发前再确认具体到场时间。'
  const hotelArea = `${context.location}核心办公区、客户现场周边或交通枢纽 30 分钟通勤范围内`
  const claimLine = context.claimNo ? `关联申请单：${context.claimNo}` : ''

  return [
    '可以，先给您一版轻量行程规划，后续您可以继续补充偏好。',
    '',
    claimLine,
    `行程时间：${context.time}${context.days ? `（${context.days}）` : ''}`,
    reasonLine,
    '',
    `交通建议：${outboundDate} 优先看上午到中午抵达 ${context.location} 的${transport}班次，预留到达后 1.5 小时交通和现场准备时间；${returnDate} 优先看下午或晚间返程，避免压缩最后一天工作安排。`,
    `酒店建议：优先选择${hotelArea}，同时关注可开发票、可取消、早餐和离现场距离。`,
    '需要确认：出发城市、客户现场地址、是否需要同行人、是否有指定住宿协议酒店、是否需要提前准备会议室或网络环境。',
    '',
    '您也可以继续告诉我出发城市、偏好的交通方式或预算，我再把规划细化成更具体的时间段。'
  ].filter(Boolean).join('\n')
}