module Unflatten

# File lib/flat_json_unflattener/unflatten.rb, line 16
def process(path, value, output_hash)
  # split path by / into each object
  ref = output_hash
  objects = path.split('/')
  objects.each_with_index do |object, index|
    # split by : to find the arrays
    arrays = object.split(':');
    object_name = arrays[0]
    array_index = arrays[1]
    if array_index == nil # if it's a part of the object tree, not a leaf node
      if ref[object_name] == nil # if it doesn't already exist in the tree we're building
        if index == objects.count-1 # if it's the last object
          ref[object_name] = value # then set the key and value
        else
          ref[object_name] = {} # else set it to an empty object (as a placeholder)
        end
      end
      ref = ref[object_name]
    else # handle arrays
      if ref[object_name] == nil
        ref[object_name] = []
        if index == objects.count-1
          ref[object_name][array_index.to_i] = value
        else
          ref[object_name][array_index.to_i] = {}
        end
      end
      if ref[object_name][array_index.to_i] == nil #if it's not already set
        if index == objects.count-1 # if it's the last object
          ref[object_name][array_index.to_i] = value # then set the key and value
        else
          ref[object_name][array_index.to_i] = {} # else set it to an empty object (as a placeholder)
        end
      end
      ref = ref[object_name][array_index.to_i]
    end
  end
  return ref
end

# File lib/flat_json_unflattener/unflatten.rb, line 5
def unflattener(input_flat_json)
  output_hash = {}
  input_hash = JSON.parse(input_flat_json)
  # each line of the hash is passed as 'path' and corresponding 'value'
  input_hash.each do |path, value|
    path = path.gsub("|", "/|") # regularises object finding with pipes
    process(path, value, output_hash)
  end
  return output_hash.to_json
end