import { NextRequest, NextResponse } from "next/server"
import { getServerSession } from "next-auth"
import { authOptions } from "@/lib/auth"
import { prisma } from "@/lib/prisma"
import { checkPermission } from "@/lib/permissions"
import { Role } from "@prisma/client"
import { recordMemberHistory } from "@/lib/member-history"
import { recalculateGenerations, isRootMember, hasChildren, findNewRootMember } from "@/lib/generation-utils"

// 获取单个成员
export async function GET(
  req: NextRequest,
  { params }: { params: Promise<{ treeId: string; memberId: string }> }
) {
  try {
    const session = await getServerSession(authOptions)
    
    if (!session?.user?.id) {
      return NextResponse.json({ error: "未授权" }, { status: 401 })
    }

    const { treeId, memberId } = await params

    // 检查权限
    const { hasPermission } = await checkPermission(session.user.id, treeId)
    if (!hasPermission) {
      return NextResponse.json({ error: "无权访问此家族树" }, { status: 403 })
    }

    const member = await prisma.familyMember.findFirst({
      where: {
        id: memberId,
        treeId,
      }
    })

    if (!member) {
      return NextResponse.json({ error: "成员不存在" }, { status: 404 })
    }

    return NextResponse.json({ member })
  } catch (error) {
    console.error("获取成员失败:", error)
    return NextResponse.json(
      { error: "获取成员失败" },
      { status: 500 }
    )
  }
}

// 更新成员
export async function PATCH(
  req: NextRequest,
  { params }: { params: Promise<{ treeId: string; memberId: string }> }
) {
  try {
    const session = await getServerSession(authOptions)
    
    if (!session?.user?.id) {
      return NextResponse.json({ error: "未授权" }, { status: 401 })
    }

    const { treeId, memberId } = await params

    // 检查权限（需要 EDITOR 权限）
    const { hasPermission } = await checkPermission(session.user.id, treeId, Role.EDITOR)
    if (!hasPermission) {
      return NextResponse.json({ error: "无权限修改成员" }, { status: 403 })
    }

    const body = await req.json()

    // 检查成员是否存在
    const existingMember = await prisma.familyMember.findFirst({
      where: {
        id: memberId,
        treeId,
      }
    })

    if (!existingMember) {
      return NextResponse.json({ error: "成员不存在" }, { status: 404 })
    }

    const member = await prisma.familyMember.update({
      where: { id: memberId },
      data: {
        ...body,
        updatedAt: new Date(),
      }
    })

    // 维护配偶双向关系
    if (body.spouseIds !== undefined) {
      const newSpouseIds = body.spouseIds || []
      const oldSpouseIds = existingMember.spouseIds || []
      
      // 添加新配偶的反向关系
      for (const spouseId of newSpouseIds) {
        if (!oldSpouseIds.includes(spouseId)) {
          const spouse = await prisma.familyMember.findUnique({
            where: { id: spouseId }
          })
          
          if (spouse && !spouse.spouseIds.includes(memberId)) {
            await prisma.familyMember.update({
              where: { id: spouseId },
              data: {
                spouseIds: [...spouse.spouseIds, memberId]
              }
            })
          }
        }
      }
      
      // 移除旧配偶的反向关系
      for (const oldSpouseId of oldSpouseIds) {
        if (!newSpouseIds.includes(oldSpouseId)) {
          const spouse = await prisma.familyMember.findUnique({
            where: { id: oldSpouseId }
          })
          
          if (spouse && spouse.spouseIds.includes(memberId)) {
            await prisma.familyMember.update({
              where: { id: oldSpouseId },
              data: {
                spouseIds: spouse.spouseIds.filter(id => id !== memberId)
              }
            })
          }
        }
      }
    }

    // 维护父母-子女双向关系
    // 1. 处理父亲关系变化
    if (body.fatherId !== undefined) {
      const oldFatherId = existingMember.fatherId
      const newFatherId = body.fatherId
      
      // 从旧父亲的子女列表中移除
      if (oldFatherId && oldFatherId !== newFatherId) {
        const oldFather = await prisma.familyMember.findUnique({
          where: { id: oldFatherId }
        })
        if (oldFather && oldFather.childrenIds.includes(memberId)) {
          await prisma.familyMember.update({
            where: { id: oldFatherId },
            data: {
              childrenIds: oldFather.childrenIds.filter(id => id !== memberId)
            }
          })
        }
      }
      
      // 添加到新父亲的子女列表
      if (newFatherId && newFatherId !== oldFatherId) {
        const newFather = await prisma.familyMember.findUnique({
          where: { id: newFatherId }
        })
        if (newFather && !newFather.childrenIds.includes(memberId)) {
          await prisma.familyMember.update({
            where: { id: newFatherId },
            data: {
              childrenIds: [...newFather.childrenIds, memberId]
            }
          })
        }
      }
    }

    // 2. 处理母亲关系变化
    if (body.motherId !== undefined) {
      const oldMotherId = existingMember.motherId
      const newMotherId = body.motherId
      
      // 从旧母亲的子女列表中移除
      if (oldMotherId && oldMotherId !== newMotherId) {
        const oldMother = await prisma.familyMember.findUnique({
          where: { id: oldMotherId }
        })
        if (oldMother && oldMother.childrenIds.includes(memberId)) {
          await prisma.familyMember.update({
            where: { id: oldMotherId },
            data: {
              childrenIds: oldMother.childrenIds.filter(id => id !== memberId)
            }
          })
        }
      }
      
      // 添加到新母亲的子女列表
      if (newMotherId && newMotherId !== oldMotherId) {
        const newMother = await prisma.familyMember.findUnique({
          where: { id: newMotherId }
        })
        if (newMother && !newMother.childrenIds.includes(memberId)) {
          await prisma.familyMember.update({
            where: { id: newMotherId },
            data: {
              childrenIds: [...newMother.childrenIds, memberId]
            }
          })
        }
      }
    }

    // 3. 处理子女关系变化
    if (body.childrenIds !== undefined) {
      const newChildrenIds = body.childrenIds || []
      const oldChildrenIds = existingMember.childrenIds || []
      
      // 添加新子女的父母关系
      for (const childId of newChildrenIds) {
        if (!oldChildrenIds.includes(childId)) {
          const child = await prisma.familyMember.findUnique({
            where: { id: childId }
          })
          
          if (child) {
            // 根据当前成员的性别设置为父亲或母亲
            if (member.gender === 'MALE' && !child.fatherId) {
              await prisma.familyMember.update({
                where: { id: childId },
                data: { fatherId: memberId }
              })
            } else if (member.gender === 'FEMALE' && !child.motherId) {
              await prisma.familyMember.update({
                where: { id: childId },
                data: { motherId: memberId }
              })
            }
          }
        }
      }
      
      // 移除旧子女的父母关系
      for (const oldChildId of oldChildrenIds) {
        if (!newChildrenIds.includes(oldChildId)) {
          const child = await prisma.familyMember.findUnique({
            where: { id: oldChildId }
          })
          
          if (child) {
            // 根据当前成员的性别移除父亲或母亲
            if (member.gender === 'MALE' && child.fatherId === memberId) {
              await prisma.familyMember.update({
                where: { id: oldChildId },
                data: { fatherId: null }
              })
            } else if (member.gender === 'FEMALE' && child.motherId === memberId) {
              await prisma.familyMember.update({
                where: { id: oldChildId },
                data: { motherId: null }
              })
            }
          }
        }
      }
    }

    // 记录成员历史版本
    const historyRecord = await recordMemberHistory({
      memberId: member.id,
      treeId,
      changedBy: session.user.id,
      changeType: 'UPDATE',
      oldData: existingMember,
      newData: member
    })

    // 记录操作日志，使用历史记录中的详细变更信息
    await prisma.activityLog.create({
      data: {
        treeId,
        userId: session.user.id,
        action: 'UPDATE',
        entityType: 'MEMBER',
        entityId: member.id,
        entityName: member.fullName,
        changes: historyRecord?.changes || body,
      }
    })

    return NextResponse.json({ member })
  } catch (error) {
    console.error("更新成员失败:", error)
    return NextResponse.json(
      { error: "更新成员失败" },
      { status: 500 }
    )
  }
}

// 删除成员
export async function DELETE(
  req: NextRequest,
  { params }: { params: Promise<{ treeId: string; memberId: string }> }
) {
  try {
    const session = await getServerSession(authOptions)
    
    if (!session?.user?.id) {
      return NextResponse.json({ error: "未授权" }, { status: 401 })
    }

    const { treeId, memberId } = await params

    // 检查权限（需要 EDITOR 权限）
    const { hasPermission } = await checkPermission(session.user.id, treeId, Role.EDITOR)
    if (!hasPermission) {
      return NextResponse.json({ error: "无权限删除成员" }, { status: 403 })
    }

    // 检查成员是否存在
    const existingMember = await prisma.familyMember.findFirst({
      where: {
        id: memberId,
        treeId,
      }
    })

    if (!existingMember) {
      return NextResponse.json({ error: "成员不存在" }, { status: 404 })
    }

    // 获取家族树信息
    const tree = await prisma.familyTree.findUnique({
      where: { id: treeId },
      select: { rootMemberId: true }
    })

    // 检查是否删除的是根成员（始祖）
    const isDeletingRoot = await isRootMember(memberId)
    const memberHasChildren = await hasChildren(memberId)
    let needRecalculate = false
    let newRootId: string | null = null

    // 如果删除的是根成员且有子女，需要调整全族代数
    if (isDeletingRoot && memberHasChildren) {
      needRecalculate = true
    }

    // 清理关系引用
    // 1. 清理配偶关系
    if (existingMember.spouseIds && existingMember.spouseIds.length > 0) {
      for (const spouseId of existingMember.spouseIds) {
        const spouse = await prisma.familyMember.findUnique({
          where: { id: spouseId }
        })
        if (spouse && spouse.spouseIds.includes(memberId)) {
          await prisma.familyMember.update({
            where: { id: spouseId },
            data: {
              spouseIds: spouse.spouseIds.filter(id => id !== memberId)
            }
          })
        }
      }
    }

    // 2. 清理父母的子女引用
    if (existingMember.fatherId) {
      const father = await prisma.familyMember.findUnique({
        where: { id: existingMember.fatherId }
      })
      if (father && father.childrenIds.includes(memberId)) {
        await prisma.familyMember.update({
          where: { id: existingMember.fatherId },
          data: {
            childrenIds: father.childrenIds.filter(id => id !== memberId)
          }
        })
      }
    }

    if (existingMember.motherId) {
      const mother = await prisma.familyMember.findUnique({
        where: { id: existingMember.motherId }
      })
      if (mother && mother.childrenIds.includes(memberId)) {
        await prisma.familyMember.update({
          where: { id: existingMember.motherId },
          data: {
            childrenIds: mother.childrenIds.filter(id => id !== memberId)
          }
        })
      }
    }

    // 3. 清理子女的父母引用
    if (existingMember.childrenIds && existingMember.childrenIds.length > 0) {
      for (const childId of existingMember.childrenIds) {
        const child = await prisma.familyMember.findUnique({
          where: { id: childId }
        })
        if (child) {
          const updates: any = {}
          if (child.fatherId === memberId) {
            updates.fatherId = null
          }
          if (child.motherId === memberId) {
            updates.motherId = null
          }
          if (Object.keys(updates).length > 0) {
            await prisma.familyMember.update({
              where: { id: childId },
              data: updates
            })
          }
        }
      }
    }

    // 删除成员
    await prisma.familyMember.delete({
      where: { id: memberId }
    })

    // 如果需要调整全族代数
    if (needRecalculate) {
      try {
        // 将所有成员的代数 -1
        await recalculateGenerations(treeId, -1)
        
        // 查找新的根成员
        newRootId = await findNewRootMember(treeId)
        
        if (newRootId) {
          // 更新家族树的 rootMemberId
          await prisma.familyTree.update({
            where: { id: treeId },
            data: { rootMemberId: newRootId }
          })
          
          // 将新根成员设为始祖
          await prisma.familyMember.update({
            where: { id: newRootId },
            data: { isFounder: true }
          })
        } else {
          // 如果没有找到新的根成员，清空 rootMemberId
          await prisma.familyTree.update({
            where: { id: treeId },
            data: { rootMemberId: null }
          })
        }
        
        // 记录全族代数调整的日志
        await prisma.activityLog.create({
          data: {
            treeId,
            userId: session.user.id,
            action: 'UPDATE',
            entityType: 'TREE',
            entityId: treeId,
            entityName: `全族代数调整（-1代）`,
            changes: {
              reason: '删除始祖',
              offset: -1,
              newRootMemberId: newRootId,
              deletedMemberId: memberId,
              deletedMemberName: existingMember.fullName
            }
          }
        })
      } catch (error) {
        console.error('调整全族代数失败:', error)
        // 注意：此时成员已被删除，无法回滚
        // 记录错误日志
        await prisma.activityLog.create({
          data: {
            treeId,
            userId: session.user.id,
            action: 'ERROR',
            entityType: 'TREE',
            entityId: treeId,
            entityName: '代数调整失败',
            changes: {
              error: '删除始祖后调整代数失败',
              deletedMemberId: memberId
            }
          }
        })
      }
    } else if (tree?.rootMemberId === memberId) {
      // 如果删除的是根成员但没有子女，需要更新 rootMemberId
      // 情况1: 有配偶，配偶成为新根
      if (existingMember.spouseIds && existingMember.spouseIds.length > 0) {
        const newRoot = existingMember.spouseIds[0]
        await prisma.familyTree.update({
          where: { id: treeId },
          data: { rootMemberId: newRoot }
        })
      } else {
        // 情况2: 无配偶无子女，清空 rootMemberId
        await prisma.familyTree.update({
          where: { id: treeId },
          data: { rootMemberId: null }
        })
      }
    }

    // 记录操作日志
    await prisma.activityLog.create({
      data: {
        treeId,
        userId: session.user.id,
        action: 'DELETE',
        entityType: 'MEMBER',
        entityId: memberId,
        entityName: existingMember.fullName,
      }
    })

    return NextResponse.json({ 
      success: true,
      generationRecalculated: needRecalculate,
      newRootMemberId: newRootId
    })
  } catch (error) {
    console.error("删除成员失败:", error)
    return NextResponse.json(
      { error: "删除成员失败" },
      { status: 500 }
    )
  }
}