demo_email = 'demo@localhost'

User.transaction do
  break if User.find_by(email: demo_email)

  demo = User.create! email: demo_email, password: 'demo123', status: :active do |user|
    user.skip_confirmation!
    print "Creating demo account '#{user.email}' with password '#{user.password}'..."
  end
  puts "done."

  # --- Units ---
  u = {}
  u[:kg]  = demo.units.create! symbol: 'kg',  description: 'kilogram'
  u[:g]   = demo.units.create! symbol: 'g',   description: 'gram',       base: u[:kg], multiplier: 1e-3
  u[:cm]  = demo.units.create! symbol: 'cm',  description: 'centimetre'
  u[:bpm] = demo.units.create! symbol: 'bpm', description: 'beats per minute'
  u[:pct] = demo.units.create! symbol: '%',   description: 'percent'
  u[:h]   = demo.units.create! symbol: 'h',   description: 'hour'
  u[:min] = demo.units.create! symbol: 'min', description: 'minute',     base: u[:h], multiplier: (1.0/60).round(10)
  u[:kcal]= demo.units.create! symbol: 'kcal',description: 'kilocalorie'
  u[:mg]  = demo.units.create! symbol: 'mg',  description: 'milligram',  base: u[:kg], multiplier: 1e-6
  u[:mmhg]= demo.units.create! symbol: 'mmHg',description: 'millimetre of mercury'

  # --- Quantities ---
  body      = demo.quantities.create! name: 'Body'
  weight    = demo.quantities.create! name: 'Weight',        parent: body
  height    = demo.quantities.create! name: 'Height',        parent: body
  fat       = demo.quantities.create! name: 'Body fat',      parent: body

  cardio    = demo.quantities.create! name: 'Cardiovascular'
  hr_rest   = demo.quantities.create! name: 'Resting HR',    parent: cardio
  hr_peak   = demo.quantities.create! name: 'Peak HR',       parent: cardio
  bp_sys    = demo.quantities.create! name: 'BP systolic',   parent: cardio
  bp_dia    = demo.quantities.create! name: 'BP diastolic',  parent: cardio

  activity  = demo.quantities.create! name: 'Activity'
  sleep_dur = demo.quantities.create! name: 'Sleep',         parent: activity
  calories  = demo.quantities.create! name: 'Calories out',  parent: activity

  nutrition = demo.quantities.create! name: 'Nutrition'
  cal_in    = demo.quantities.create! name: 'Calories in',   parent: nutrition
  caffeine  = demo.quantities.create! name: 'Caffeine',      parent: nutrition

  # --- Readouts (60 days of daily-ish data) ---
  base_time = 60.days.ago.beginning_of_day
  rng = Random.new(42)

  weight_val  = 82.4
  fat_val     = 21.5
  hr_rest_val = 62.0

  60.times do |i|
    t = base_time + i.days + rng.rand(3600 * 2)

    weight_val  += rng.rand(-0.3..0.3)
    fat_val     += rng.rand(-0.15..0.15)
    hr_rest_val += rng.rand(-1.5..1.5)
    hr_rest_val  = hr_rest_val.clamp(52, 72)

    demo.readouts.create! quantity: weight,   unit: u[:kg],  value: weight_val.round(1),  created_at: t
    demo.readouts.create! quantity: fat,      unit: u[:pct], value: fat_val.round(1),     created_at: t
    demo.readouts.create! quantity: hr_rest,  unit: u[:bpm], value: hr_rest_val.round,    created_at: t

    if i % 2 == 0
      demo.readouts.create! quantity: bp_sys,  unit: u[:mmhg], value: (115 + rng.rand(-8..8)).round, created_at: t
      demo.readouts.create! quantity: bp_dia,  unit: u[:mmhg], value: (75  + rng.rand(-5..5)).round,  created_at: t
    end

    if i % 3 == 0
      demo.readouts.create! quantity: hr_peak, unit: u[:bpm], value: (155 + rng.rand(-10..10)).round, created_at: t
    end

    demo.readouts.create! quantity: sleep_dur, unit: u[:h],   value: (6.5 + rng.rand(-1.5..1.5)).round(1), created_at: t
    demo.readouts.create! quantity: calories,  unit: u[:kcal],value: (2100 + rng.rand(-300..300)).round,    created_at: t
    demo.readouts.create! quantity: cal_in,    unit: u[:kcal],value: (1900 + rng.rand(-400..400)).round,    created_at: t

    if i % 4 == 0
      demo.readouts.create! quantity: caffeine, unit: u[:mg], value: (200 + rng.rand(-80..80)).round, created_at: t
    end
  end

  # height is stable — record once
  demo.readouts.create! quantity: height, unit: u[:cm], value: 178.0, created_at: base_time

  puts "  Created #{demo.units.count} units, #{demo.quantities.count} quantities, #{demo.readouts.count} readouts."
end