require 'tty/prompt'
require 'tty/progressbar'
require 'tty/progressbar/multi'
require 'string/builder'
require 'benchmark'

module Limeta
  class Table
    using String::Builder

    FIELDS = {
      Event:           {type: :string},
      Site:            {type: :string, size: 50},
      White:           {type: :string, size: 30},
      Black:           {type: :string, size: 30},
      Result:          {type: :string, size: 10},
      UTCDate:         {type: :date,   size: 15},
      UTCTime:         {type: :time,   size: 8},
      WhiteElo:        {type: :integer},
      BlackElo:        {type: :integer},
      WhiteRatingDiff: {type: :integer},
      BlackRatingDiff: {type: :integer},
      WhiteTitle:      {type: :string, size: 5},
      BlackTitle:      {type: :string, size: 5},
      ECO:             {type: :string, size: 3},
      Opening:         {type: :string},
      TimeControl:     {type: :string, size: 15},
      Termination:     {type: :string, size: 20},
      Variant:         {type: :string}
    }

    def initialize(name, database:)
      @name = name
      @database = database
      prepare
    end

    def populate!(files)
      progress = TTY::ProgressBar::Multi.new("\e[1mAll files\e[0m: [:bar] :percent", incomplete: "\e[90m=\e[0m", complete: "\e[32;1m=\e[0m")
      bars = {}

      files.each do |file|
        bars[file] = progress.register("#{file} [:bar] :percent (of :total bytes)", total: File.size(file), complete: "\e[32;2m=\e[0m")
      end

      puts
      progress.start

      bm = Benchmark.measure do
        files.each do |file|
          record = {}
          prev = ''

          File.open(file, 'r').each do |line|
            if prev =~ /\A\[.*\Z/ && line =~ /\A[\n\r].*\Z/
              @database[@name.to_sym].insert(**record)
              record = {}
              prev = line
              bars[file].advance(line.bytesize) # Increment
              next
            end
            if line =~ /\A([\n\r]|[0-9]).*\Z/
              prev = line
              bars[file].advance(line.bytesize) # Increment
              next
            end
            subbed = line.gsub(%r{[\r\n\[\]\"]},'')
            field, value = subbed.split(' ', 2)
            field = field.to_sym
            if FIELDS[field]
              record[field] = case FIELDS[field][:type]
              when :string  then value
              when :integer then value.to_i
              when :date    then Date.parse(value)
              when :time    then value
              end
            end
            prev = line
            bars[file].advance(line.bytesize) # Increment
          end
        end
      end

      bm_out = String.build("Finished in ") do |s|
        s << "#{bm.utime.round(4)}s (cpu), "
        s << "#{bm.stime.round(4)}s (system), "
        s << "#{bm.total.round(4)}s (total), "
        s << "#{bm.real.round(4)}s (real)"
      end

      puts
      puts bm_out

      @database.disconnect
    end

    def prepare
      prompt = TTY::Prompt.new
      if exist?
        if prompt.yes? "Overwrite table '\e[1m#{@name}\e[0m'?"
          if prompt.yes? "Are you sure? This action cannot be reverted."
            create force: true
          end
        end
      else
        create
      end
    end

    def exist?
      @database.table_exists? @name
    end

    def create(force: false)
      @database.send((force ? :create_table! : :create_table), @name) do
        primary_key :id
        FIELDS.each do |name, options|
          case options[:type]
          when :string  then String name, size: (options[:size] || 255)
          when :integer then Integer name
          when :date    then Date name
          when :time    then Time name, only_time: true
          end
        end
      end
    end
  end
end