index.ts

import { KVNamespace } from '@cloudflare/workers-types'

declare const TODOS: KVNamespace

async function handleGETRequests (request: Request) {
  const url = new URL(request.url)
  switch (url.pathname) {
    case '/status':
      return new Response(JSON.stringify({ hello: 'world' }))

    case '/todos': {
      const todos: any = await TODOS.get(url.searchParams.get('user'))

      return new Response(todos || '[]', {
        status: 200,
        headers: { 'Content-Type': 'application/json' }
      })
    }
  }

  return new Response(null, { status: 404 })
}

async function handlePOSTRequests (request: Request) {
  const url = new URL(request.url)
  switch (url.pathname) {
    case '/todos': {
      const payload = await request.json()
      const todos: any = (await TODOS.get(payload.user, 'json')) || []
      todos.push(payload.todo)
      await TODOS.put(payload.user, JSON.stringify(todos))

      return new Response(null, { status: 204 })
    }
  }

  return new Response(null, { status: 400 })
}

async function handleDELETERequests (request: Request) {
  const url = new URL(request.url)
  switch (url.pathname) {
    case '/todos': {
      const payload = await request.json()
      const todos = (await TODOS.get(payload.user, 'json')) || []
      const index = payload.index
      if (todos.length > 0 && index >= 0 && index < todos.length) {
        await TODOS.put(
          payload.user,
          JSON.stringify(todos.slice(0, index).concat(todos.slice(index + 1)))
        )
      }

      return new Response(null, { status: 204 })
    }
  }

  return new Response(null, { status: 400 })
}

async function handleRequest (request: Request) {
  if (request.method === 'POST') {
    return handlePOSTRequests(request)
  }
  if (request.method === 'DELETE') {
    return handleDELETERequests(request)
  }

  return handleGETRequests(request)
}

function handler (event: FetchEvent) {
  event.respondWith(handleRequest(event.request))
}

addEventListener('fetch', handler)