require 'json'
require 'fileutils'

MAX_POINTS = 360
OUTPUT_FILE = File.join(__dir__, 'src', 'pernet_data.json')
NODES = ['VE9B0101', 'VE9B0103', 'VE9B0104', 'VE9B0107', 'VE9B010F', 'VE9B0118', 'VE9B011D', 'VE9B0129', 'VE9B0153', 'VE9B0165']

data = []
now = Time.now.to_f * 1000

base_vals = NODES.map { rand * 2.0 }

MAX_POINTS.times do |i|
  ts = (now - (MAX_POINTS - i) * 60 * 1000).to_i
  cells = base_vals.map { |bv| (bv + (rand - 0.5) * 0.1).round(4) }
  data << { 'time' => ts, 'cells' => cells }
end

FileUtils.mkdir_p(File.dirname(OUTPUT_FILE))
File.write(OUTPUT_FILE, JSON.generate(data))
puts "Demo data for Pernet generated: #{OUTPUT_FILE}"