import { prisma } from './prisma'
import { Action } from '@prisma/client'

/**
 * 记录成员历史版本
 */
export async function recordMemberHistory(params: {
  memberId: string
  treeId: string
  changedBy: string
  changeType: Action
  oldData?: any
  newData: any
}) {
  const { memberId, treeId, changedBy, changeType, oldData, newData } = params

  // 获取当前最大版本号
  const lastHistory = await prisma.memberHistory.findFirst({
    where: { memberId },
    orderBy: { version: 'desc' },
    select: { version: true }
  })

  const nextVersion = (lastHistory?.version || 0) + 1

  // 计算变更的字段
  let changes: Record<string, { old: any, new: any }> | undefined = undefined
  
  if (changeType === 'UPDATE' && oldData) {
    const tempChanges: Record<string, { old: any, new: any }> = {}
    const fieldsToTrack = [
      'fullName', 'surname', 'givenName', 'gender', 'birthDate', 'deathDate',
      'birthPlace', 'ancestralHome', 'generation', 'bio', 'phone', 'email',
      'address', 'photoIds', 'spouseIds', 'childrenIds', 'motherId', 'fatherId',
      'generationName', 'courtesyName', 'artName', 'posthumousName', 'rank',
      'isFounder', 'isLunarDate', 'burialPlace', 'telephone', 'tags',
      'avatarUrl', 'stories'
    ]

    for (const field of fieldsToTrack) {
      const oldValue = oldData[field]
      const newValue = newData[field]
      
      // 比较值是否真的变化了
      const isChanged = JSON.stringify(oldValue) !== JSON.stringify(newValue)
      if (isChanged) {
        tempChanges[field] = { old: oldValue, new: newValue }
      }
    }

    // 如果没有实际变更，不记录
    if (Object.keys(tempChanges).length === 0) {
      return null
    }
    
    changes = tempChanges
  }

  // 创建历史记录
  const history = await prisma.memberHistory.create({
    data: {
      memberId,
      treeId,
      version: nextVersion,
      snapshot: newData,
      changedBy,
      changeType,
      changes: changes || undefined,
    }
  })

  return history
}

/**
 * 获取成员的历史版本列表
 */
export async function getMemberHistory(memberId: string) {
  return await prisma.memberHistory.findMany({
    where: { memberId },
    orderBy: { version: 'desc' }
  })
}

/**
 * 获取两个版本之间的差异
 */
export function compareVersions(oldVersion: any, newVersion: any) {
  const changes: Record<string, { old: any, new: any }> = {}
  
  const allFields = new Set([
    ...Object.keys(oldVersion.snapshot),
    ...Object.keys(newVersion.snapshot)
  ])

  for (const field of allFields) {
    const oldValue = oldVersion.snapshot[field]
    const newValue = newVersion.snapshot[field]
    
    if (JSON.stringify(oldValue) !== JSON.stringify(newValue)) {
      changes[field] = { old: oldValue, new: newValue }
    }
  }

  return changes
}