# Copyright (c) 2018 Yegor Bugayenko
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the 'Software'), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

require 'time'
require 'csv'
require_relative 'atomic_file'
require_relative 'log'
require_relative 'wallet'

# The list of copies.
# Author:: Yegor Bugayenko (yegor256@gmail.com)
# Copyright:: Copyright (c) 2018 Yegor Bugayenko
# License:: MIT
module Zold
  # All copies
  class Copies
    def initialize(dir, log: Log::Quiet.new)
      raise 'Dir can\'t be nil' if dir.nil?
      @dir = dir
      raise 'Log can\'t be nil' if log.nil?
      @log = log
      @mutex = Mutex.new
    end

    def root
      File.join(@dir, '..')
    end

    def to_s
      File.basename(@dir)
    end

    def clean
      @mutex.synchronize do
        list = load
        list.reject! { |s| s[:time] < Time.now - 24 * 60 * 60 }
        save(list)
        deleted = 0
        Dir.new(@dir).select { |f| File.basename(f, Wallet::EXTENSION) =~ /^[0-9]+$/ }.each do |f|
          next unless list.find { |s| s[:name] == File.basename(f, Wallet::EXTENSION) }.nil?
          file = File.join(@dir, f)
          size = File.size(file)
          File.delete(file)
          @log.debug("Copy ##{f} deleted: #{size}b")
          deleted += 1
        end
        deleted
      end
    end

    def remove(host, port)
      @mutex.synchronize do
        save(load.reject { |s| s[:host] == host && s[:port] == port })
      end
    end

    # Returns the name of the copy
    def add(content, host, port, score, time = Time.now)
      raise "Content can't be empty" if content.empty?
      raise 'TCP port must be of type Integer' unless port.is_a?(Integer)
      raise "TCP port can't be negative: #{port}" if port < 0
      raise 'Time must be of type Time' unless time.is_a?(Time)
      raise "Time must be in the past: #{time}" if time > Time.now
      raise 'Score must be Integer' unless score.is_a?(Integer)
      raise "Score can't be negative: #{score}" if score < 0
      @mutex.synchronize do
        FileUtils.mkdir_p(@dir)
        list = load
        target = list.find do |s|
          f = File.join(@dir, "#{s[:name]}#{Wallet::EXTENSION}")
          File.exist?(f) && AtomicFile.new(f).read == content
        end
        if target.nil?
          max = Dir.new(@dir)
            .select { |f| File.basename(f, Wallet::EXTENSION) =~ /^[0-9]+$/ }
            .map(&:to_i)
            .max
          max = 0 if max.nil?
          name = (max + 1).to_s
          AtomicFile.new(File.join(@dir, "#{name}#{Wallet::EXTENSION}")).write(content)
        else
          name = target[:name]
        end
        list.reject! { |s| s[:host] == host && s[:port] == port }
        list << {
          name: name,
          host: host,
          port: port,
          score: score,
          time: time
        }
        save(list)
        name
      end
    end

    def all
      @mutex.synchronize do
        load.group_by { |s| s[:name] }.map do |name, scores|
          {
            name: name,
            path: File.join(@dir, "#{name}#{Wallet::EXTENSION}"),
            score: scores.select { |s| s[:time] > Time.now - 24 * 60 * 60 }
              .map { |s| s[:score] }
              .inject(&:+) || 0
          }
        end.select { |c| File.exist?(c[:path]) }.sort_by { |c| c[:score] }.reverse
      end
    end

    private

    def load
      FileUtils.mkdir_p(File.dirname(file))
      FileUtils.touch(file)
      CSV.read(file).map do |s|
        {
          name: s[0],
          host: s[1],
          port: s[2].to_i,
          score: s[3].to_i,
          time: Time.parse(s[4])
        }
      end
    end

    def save(list)
      AtomicFile.new(file).write(
        list.map do |r|
          [
            r[:name], r[:host],
            r[:port], r[:score],
            r[:time].utc.iso8601
          ].join(',')
        end.join("\n")
      )
    end

    def file
      File.join(@dir, "scores#{Wallet::EXTENSION}")
    end
  end
end