# Copyright (c) 2020 Wojtek Grabski (mostlydev.com)
#
# 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 NONINFRINGEMENT. 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.

puts "PayPal to Wave-importable CSV converter"
puts "Copyright (c) 2020 Wojtek Grabski (mostlydev.com)"
puts "------"
puts ""

if ARGV[0].to_s.empty?
  puts "First argument should be PayPal CSV"
  puts "e.g.,   ruby make_wave.rb \"PayPal Data 2013-2018.csv\""
  puts ""
  abort
end

unless File.exist?(ARGV[0])
  puts "Input CSV file wasn't found at #{ARGV[0]}"
  puts ""
  abort
end

require "csv"
require 'os'

class WaveMaker
  attr_accessor :basename, :waves, :total_rows, :pay_pal_csv

  def initialize(pay_pal_csv)
    @waves = {}
    @total_rows = 0
    @pay_pal_csv = pay_pal_csv
    @basename = File.basename(@pay_pal_csv, ".csv")
  end

  def make_wave(currency)
    index = @waves[currency].count
    output_path = "#{basename}.#{currency.downcase}.#{index}.wave.csv"
    csv = CSV.open(output_path, "wb")
    csv << [ "Date", "Description", "Amount"]
    puts "... created #{output_path}"
    wave = { csv: csv, rows: 0 }

    @waves[currency] << wave
    wave
  end

  def get_wave(currency)
    @waves[currency] = [] unless @waves.has_key?(currency)
    wave = @waves[currency].last
    wave ||= make_wave(currency)
    wave = make_wave(currency) unless wave && wave[:rows] < 200
    wave
  end

  def make_waves!
    quote_chars = %w(" | ~ ^ & *)
    charset = detect_charset(@pay_pal_csv);
    csv = File.open(@pay_pal_csv).read
    if charset != "utf-8"
      csv = csv.encode("utf-8", invalid: :replace, undef: :replace)
    end
    charset = detect_charset(@pay_pal_csv);
    CSV.parse(csv, headers: :first_row,
                encoding: "utf-8",
                # quote_char: quote_chars.shift,
                liberal_parsing: true) do |row|
      @row = row
      if currency_value.nil?
        puts "ERROR: This is not a PayPal export!"
        break
      end

      currency = currency_value.downcase
      wave = get_wave(currency)

      date = row[0]
      name = name_value
      name = name ? name.gsub(/[^\w\ ]/, "") : nil
      description = [ name, type_value ].reject(&:nil?).join(" - ")
      amount = get_amount(gross_value)

      wave[:csv] << [ date, description.to_s, amount ]
      wave[:rows] += 1
      @total_rows += 1
      fee = get_amount(fee_value)
      unless fee == "0.00"
        wave[:csv] << [ date, "PayPal Fee", fee ]
        wave[:rows] += 1
        @total_rows += 1
      end
    end
    puts "... outputted #{@total_rows} rows"
  end

  def get_amount(value)
    return "0.00" if value.nil? || value == "0" || value == "$-"
    amount = value.delete(",").delete("$")
    amount = "-" + amount.delete("(").delete(")") if amount.start_with?("(")
    '%.2f' % amount.to_f
  end

  def find_header(name)
    return name if @row.key?(name)
    key = @row.headers.find { |k| k.strip == name }
    key
  end


  [ "Gross", "Fee", "Name", "Currency", "Type" ].each do |header|
    attribute = header.downcase

    self.define_method "#{attribute}_key" do
      current = eval "@#{attribute}_key"
      return current unless current.nil?
      header = find_header(header)
      return nil if header.nil?
      eval "@#{attribute}_key='#{header}'"
      header
    end

    self.define_method "#{attribute}_value" do
      key = eval "#{attribute}_key"
      @row[key]
    end
  end

  def detect_charset(file_path)
    charset = if OS.mac?
      `file -I #{file_path}`.strip.split('charset=').last
    elsif OS.linux?
      `file -i #{file_path}`.strip.split('charset=').last
    else
      nil
    end
  rescue => e
    Rails.logger.warn "Unable to determine charset of #{file_path}"
    Rails.logger.warn "Error: #{e.message}"
  end
end

maker = WaveMaker.new(ARGV[0])
maker.make_waves!