require 'csv'
require 'tempfile'

namespace :import do

    desc 'Import public bodies from CSV provided on standard input'
    task :import_csv => :environment do
        dryrun = ENV['DRYRUN'] != '0'
        if dryrun
            STDERR.puts "Only a dry run; public bodies will not be created"
        end

        tmp_csv = nil
        Tempfile.open('alaveteli') do |f|
            f.write STDIN.read
            tmp_csv = f
        end

        number_of_rows = 0

        STDERR.puts "Preliminary check for ambiguous names or slugs..."

        # Check that the name and slugified version of the name are
        # unique:
        url_part_count = Hash.new { 0 }
        name_count = Hash.new { 0 }
        reader = CSV.open tmp_csv.path, 'r'
        header_line = reader.shift
        headers = header_line.collect { |h| h.gsub /^#/, ''}

        reader.each do |row_array|
            row = Hash[headers.zip row_array]
            name = row['name']
            url_part = MySociety::Format::simplify_url_part name, "body"
            name_count[name] += 1
            url_part_count[url_part] += 1
            number_of_rows += 1
        end

        non_unique_error = false

        [[name_count, 'name'],
         [url_part_count, 'url_part']].each do |counter, field|
            counter.sort.map do |name, count|
                if count > 1
                    non_unique_error = true
                    STDERR.puts "The #{field} #{name} was found #{count} times."
                end
            end
        end

        next if non_unique_error

        STDERR.puts "Now importing the public bodies..."

        # Now it's (probably) safe to try to import:
        errors, notes = PublicBody.import_csv_from_file(tmp_csv.path,
                                                        tag='',
                                                        tag_behaviour='replace',
                                                        dryrun,
                                                        editor="#{ENV['USER']} (Unix user)",
                                                        I18n.available_locales) do |row_number, fields|
            percent_complete = (100 * row_number.to_f / number_of_rows).to_i
            STDERR.print "#{row_number} out of #{number_of_rows} "
            STDERR.puts "(#{percent_complete}% complete)"
        end

        if errors.length > 0
            STDERR.puts "Import failed, with the following errors:"
            errors.each do |error|
                STDERR.puts "  #{error}"
            end
        else
            STDERR.puts "Done."
        end

    end
end