import { NextRequest, NextResponse } from 'next/server'
import { auth } from '@/auth'
import { prisma } from '@/lib/prisma'

export async function GET(req: NextRequest) {
  try {
    const session = await auth()
    if (!session?.user?.id) {
      return NextResponse.json({ success: false, error: 'Unauthorized' }, { status: 401 })
    }

    const userId = session.user.id

    const [allNotes, labels, notebooks] = await Promise.all([
      prisma.note.findMany({
        where: { userId },
        orderBy: { createdAt: 'asc' },
      }),
      prisma.label.findMany({
        where: { userId },
        include: { notes: { select: { id: true } } },
      }),
      prisma.notebook.findMany({
        where: { userId },
        include: { notes: { select: { id: true } } },
      }),
    ])

    const noteLabelMap = new Map<string, string[]>()
    for (const label of labels) {
      for (const note of label.notes) {
        const arr = noteLabelMap.get(note.id) || []
        arr.push(label.id)
        noteLabelMap.set(note.id, arr)
      }
    }

    const exportData = {
      version: '2.0.0',
      exportDate: new Date().toISOString(),
      user: {
        id: userId,
        email: session.user.email ?? '',
        name: session.user.name ?? '',
      },
      data: {
        notebooks: notebooks.map(nb => ({
          id: nb.id,
          name: nb.name,
          icon: nb.icon,
          color: nb.color,
          order: nb.order,
          parentId: nb.parentId,
          trashedAt: nb.trashedAt?.toISOString() ?? null,
          createdAt: nb.createdAt.toISOString(),
          updatedAt: nb.updatedAt.toISOString(),
          noteIds: nb.notes.map(n => n.id),
        })),
        labels: labels.map(lb => ({
          id: lb.id,
          name: lb.name,
          color: lb.color,
          notebookId: lb.notebookId,
          type: lb.type,
          createdAt: lb.createdAt.toISOString(),
          updatedAt: lb.updatedAt.toISOString(),
          noteIds: lb.notes.map(n => n.id),
        })),
        notes: allNotes.map(n => ({
          id: n.id,
          title: n.title,
          content: n.content,
          color: n.color,
          isPinned: n.isPinned,
          isArchived: n.isArchived,
          type: n.type,
          order: n.order,
          isMarkdown: n.isMarkdown,
          size: n.size,
          autoGenerated: n.autoGenerated,
          historyEnabled: n.historyEnabled,
          checkItems: n.checkItems,
          images: n.images,
          links: n.links,
          trashedAt: n.trashedAt?.toISOString() ?? null,
          notebookId: n.notebookId,
          createdAt: n.createdAt.toISOString(),
          updatedAt: n.updatedAt.toISOString(),
          contentUpdatedAt: n.contentUpdatedAt?.toISOString() ?? null,
          labelIds: noteLabelMap.get(n.id) || [],
        })),
      },
    }

    const jsonString = JSON.stringify(exportData, null, 2)
    return new NextResponse(jsonString, {
      headers: {
        'Content-Type': 'application/json',
        'Content-Disposition': `attachment; filename="memento-export-${new Date().toISOString().split('T')[0]}.json"`,
      },
    })
  } catch (error) {
    console.error('Export error:', error)
    return NextResponse.json({ success: false, error: 'Failed to export notes' }, { status: 500 })
  }
}