Hash projection

# title: Hash projection
# category: Vibescript Showcase
# difficulty: Showcase
# summary: Remove, select, merge, and fetch fields from a hash.
# description: except removes private fields, slice selects public fields, and fetch_values fails when a required field is missing.
# tags: collections, hashes, projection
# vibe: 0.4

def public_view(record: hash) -> hash
  record.except(:password_hash, :ssn)
end

def summary(record: hash) -> hash
  record.slice(:id, :name, :plan)
end

def with_defaults(record: hash) -> hash
  { plan: "free", region: "us" }.merge(record)
end

def required_fields(record: hash) -> array
  record.fetch_values(:id, :email)
end

def run
  record = {
    id: 42,
    name: "Ada",
    email: "ada@vibe.dev",
    plan: "pro",
    password_hash: "x1y2z3",
    ssn: "000-00-0000"
  }

  {
    public_view: public_view(record),
    summary: summary(record),
    with_defaults: with_defaults({ id: 7, name: "Lin" }),
    required_fields: required_fields(record),
    contacts: record.values_at(:name, :email)
  }
end