import { requireAuth } from '~/server/utils/auth'
import { canvases } from '~/server/utils/db'
import type { CanvasData } from '~/server/utils/db'

export default defineEventHandler(async (event) => {
  const user = requireAuth(event)
  const id = getRouterParam(event, 'id')

  if (!id) {
    throw createError({ statusCode: 400, message: 'Canvas ID is required' })
  }

  const original = canvases.get(id)
  if (!original) {
    throw createError({ statusCode: 404, message: 'Canvas not found' })
  }

  // Check permissions
  if (original.ownerId !== user.id && !original.isPublic) {
    throw createError({ statusCode: 403, message: 'Access denied' })
  }

  const newId = `canvas-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`
  const duplicate: CanvasData = {
    ...original,
    id: newId,
    name: `${original.name} (Copy)`,
    ownerId: user.id,
    groupId: undefined, // Duplicates are personal
    isPublic: false,
    createdAt: new Date().toISOString(),
    updatedAt: new Date().toISOString(),
    nodes: original.nodes.map(node => ({
      ...node,
      id: `${node.id}-copy-${Date.now()}`
    })),
    edges: original.edges.map(edge => ({
      ...edge,
      id: `${edge.id}-copy-${Date.now()}`
    }))
  }

  canvases.set(newId, duplicate)

  return { canvas: duplicate }
})