require "sinatra/base"
require "sinatra/json"

module Maptool
  class App < Sinatra::Base
    set :public_folder, File.join(__dir__, "public")
    set :views, File.join(__dir__, "views")

    OFFLINE_PMTILES_PATH = File.join(__dir__, "data", "offline.pmtiles")

    get "/" do
      erb :index
    end

    get "/api/health" do
      json status: "ok"
    end

    get "/api/offline-tiles" do
      json available: File.exist?(OFFLINE_PMTILES_PATH)
    end

    # Served as a plain range-request-capable file, not decoded server-side:
    # pmtiles.js reads the archive's directory and fetches only the byte
    # ranges it needs for the tiles currently on screen.
    get "/tiles/offline.pmtiles" do
      halt 404 unless File.exist?(OFFLINE_PMTILES_PATH)

      send_file OFFLINE_PMTILES_PATH, type: "application/octet-stream"
    end
  end
end