employees.csv

employees.rb

def print_hierarchy filename, *args
    # split the file by line break
    file = File.read(filename).split("\n")
    
    # remove the top row
    top_row = file.shift.split(",")
    
    # store column indices based on Column names passed as args
    name_col = top_row.index(args[0] || "Name")
    dept_col = top_row.index(args[1] || "Department")
    mgr_col = top_row.index(args[2] || "Manager")
    
    employees = []
    
    # add all employees to array
    file.each do |line|
        employees << line.split(",")
    end
    
    # push employees into last element of their respective managers' arrays
    employees.each do |e|
        e << employees.select { |x| x[mgr_col] == e[name_col] }
    end
    
    # run print_employee through managers and their employees
    employees.delete_if { |e| !e[mgr_col].empty? }.each do |e|
        print_employee e, 0, name_col, dept_col
    end
end

def print_employee employee, level, name_col, dept_col
    # add indentaion characters to line depending on level of employee
    indent = "" + (">> " * level)
    
    # if employee has no manager...
    dept = (employee[dept_col].empty?) ? "Manager" : employee[dept_col]
    
    puts indent + employee[name_col] + " (" + dept + ")"
    
    # call recursively if employee has any managed employees
    if (employee.last.is_a?(Array) && !employee.last.empty?)
        level += 1
        employee.last.each do |e|
            print_employee e, level, name_col, dept_col
        end
    end
end

print_hierarchy ARGV[0], "Name", "Department", "Manager"