# frozen_string_literal: true

module Bridgetown
  # TODO: to be retired once the Resource engine is made official
  class DataReader
    attr_reader :site, :content

    def initialize(site)
      @site = site
      @content = {}
      @entry_filter = EntryFilter.new(site)
    end

    # Read all the files in <dir> and adds them to @content
    #
    # dir - The String relative path of the directory to read.
    #
    # Returns @content, a Hash of the .yaml, .yml,
    # .json, and .csv files in the base directory
    def read
      base = site.in_source_dir(site.config.data_dir)
      read_data_to(base, @content)
      merge_environment_specific_metadata!
      @content = @content.with_dot_access
    end

    # Read and parse all .yaml, .yml, .json, .csv and .tsv
    # files under <dir> and add them to the <data> variable.
    #
    # dir - The string absolute path of the directory to read.
    # data - The variable to which data will be added.
    #
    # Returns nothing
    def read_data_to(dir, data)
      return unless File.directory?(dir)

      entries = Dir.chdir(dir) do
        Dir["*.{yaml,yml,json,csv,tsv}"] + Dir["*"].select { |fn| File.directory?(fn) }
      end

      entries.each do |entry|
        path = @site.in_source_dir(dir, entry)

        if File.directory?(path)
          read_data_to(
            path,
            data[sanitize_filename(entry)] = {}
          )
        else
          key = sanitize_filename(File.basename(entry, ".*"))
          data[key] = read_data_file(path)
        end
      end
    end

    # Determines how to read a data file.
    #
    # Returns the contents of the data file.
    def read_data_file(path)
      case File.extname(path).downcase
      when ".csv"
        CSV.read(path,
                 headers: true,
                 encoding: site.config["encoding"]).map(&:to_hash)
      when ".tsv"
        CSV.read(path,
                 col_sep: "\t",
                 headers: true,
                 encoding: site.config["encoding"]).map(&:to_hash)
      else
        YAMLParser.load_file(path)
      end
    end

    def merge_environment_specific_metadata!
      if @content["site_metadata"]
        @content["site_metadata"][Bridgetown.environment]&.each_key do |k|
          @content["site_metadata"][k] = @content["site_metadata"][Bridgetown.environment][k]
        end
        @content["site_metadata"].delete(Bridgetown.environment)
      end
    end

    def sanitize_filename(name)
      name.gsub(%r![^\w\s-]+|(?<=^|\b\s)\s+(?=$|\s?\b)!, "")
        .gsub(%r!\s+!, "_")
    end
  end
end