#!/usr/bin/env ruby -w

require 'date'
require 'json'
require 'pp'

def load_races
  # get data from json file and convert to ruby types
  all_races = JSON.parse(File.read('races.json'))["races"].map do |race|
    {
      :date => Date.parse(race["date"]),
      :priority => race["priority"],
      :name => race["name"]
    }
  end

  # select all non-zero priority races
  all_races.select { |r| r[:priority] > 0 }.sort_by { |r| r[:date] }
end

def load_plan
  # get data from json file
  JSON.parse(File.read('plan.json'))["weeks"]
end

def mondays(first,last)
  (first..last).map { |d| Date.commercial(d.year, d.cweek, 1) }.sort.uniq
end

def get_plan_week(start_date, test_date, plan)
  days_from_start = (test_date - start_date).to_i
  (days_from_start / 7) % plan.size
end

def score(start_date, plan, races)
  races.inject(0.0) do |sum, race|
    weeks_from_start = get_plan_week(start_date, race[:date], plan)
    week_value = plan[weeks_from_start]
    sum + (week_value * race[:priority].to_f)
  end
end

def dump(start_date, plan, races)
  puts "starting on #{start_date}"
  puts "in week #{get_plan_week(start_date, Date.today, plan)+1} as of today (#{Date.today})"
  races.each do |race|
    weeks_from_start = get_plan_week(start_date, race[:date], plan)
    week_value = plan[weeks_from_start]
    puts "week #{weeks_from_start+1} (#{week_value}) #{race[:date]} #{race[:priority]} #{race[:name]}"
  end
end

# load data
races = load_races
plan = load_plan

# find all the mondays from a few months before the first date, through the end
first_race_date = races[0][:date]
m = mondays(first_race_date - 180, first_race_date)

# score the plan beginning on each monday
scores = m.map do |monday|
  [score(monday,plan,races), monday]
end.sort.reverse

# output three best dates
3.times do |i|
  starting = scores[i][1]
  dump(starting, plan, races)
end