# SPDX-License-Identifier: AGPL-3.0-only
# SPDX-FileCopyrightText: 2023 Hugo Peixoto <hugo.peixoto@gmail.com>

require 'sinatra'

require './database.rb'
require './models.rb'

def h(bytes)
  if bytes < 2**10
    "#{bytes} bytes"
  elsif bytes < 2**20
    "%.2f KiB" % (1.0 * bytes / 2**10)
  elsif bytes < 2**30
    "%.2f MiB" % (1.0 * bytes / 2**20)
  elsif bytes < 2**40
    "%.2f GiB" % (1.0 * bytes / 2**30)
  else
    "%.2f TiB" % (1.0 * bytes / 2**40)
  end
end

def attempt(attempts, &block)
  begin
    block.call
  rescue
    if attempts > 1
      attempts -= 1
      retry
    else
      raise
    end
  end
end

set :public_folder, __dir__ + '/public'
get '/' do
  downloads = ActiveRecord::Base.connection.execute("
    SELECT
    COUNT(1) AS total,
    SUM(size) AS bytes
    FROM (select MAX(size) AS size from downloads group by video_id) as x;
  ")[0]

  videos = ActiveRecord::Base.connection.execute("select count(1) AS total from videos;")[0]
  users = ActiveRecord::Base.connection.execute("select count(distinct email) AS total from downloads;")[0]
  downloads_per_user = ActiveRecord::Base.connection.execute("select SUM(size) AS size, COUNT(1) AS total FROM (select email, video_id, MAX(size) as size from downloads group by email, video_id) x GROUP BY email ORDER BY 1 DESC;")

  stats = {
    videos_known: videos["total"].to_i,
    videos_downloaded: downloads["total"].to_i,

    bytes_downloaded: downloads["bytes"].to_i,

    downloads_per_user: downloads_per_user,

    users: users["total"],
  }

  ERB
    .new(File.read("index.html.erb"), trim_mode: "<>-")
    .result_with_hash(stats)
end

get '/videos.json' do
  content_type 'application/json'

  amount = params['amount'].to_i

  if amount > 100_000
    { error: "greedy" }.to_json
  else
    videos = Video
      .left_outer_joins(:downloads)
      .group("randname")
      .order("COUNT(downloads.video_id) ASC, RANDOM()")
      .limit(amount)
      .pluck(:randname)

    { videos: videos }.to_json
  end
end

post '/video' do
  content_type 'application/json'

  data = JSON.parse(request.body.read)

  attempt(10) do
    Download.create!(
      video: Video.find_by!(randname: data["video_id"]),
      size: data["size"],
      sha256: data["sha256"],
      email: data["email"],
    )
  end

  { status: 'ok' }.to_json
end

post '/check' do
  content_type 'application/json'

  ids = JSON.parse(request.body.read)

  videos = Video
    .left_outer_joins(:downloads)
    .where(randname: ids)
    .pluck(:randname, :sha256, :size)
    .map { |v| %w[randname sha256 size].zip(v).to_h }

  { videos: videos }.to_json
end


get '/config.json' do
  content_type 'application/json'
  {
    videos_url: "https://sapo.pxto.pt/videos.json",
    upload_url: "https://sapo.pxto.pt/video",
    check_url: "https://sapo.pxto.pt/check",
    max_amount: 100_000,
  }.to_json
end