module GitAnalysis

# File lib/git_analysis.rb, line 35
def self.count_diff(number=0)
  repo = load_repo()
  count = Hash.new{|h,k| h[k] = Hash.new(0) }
  total = Hash.new(0)
  repo.walk(repo.last_commit).each do |commit|
    domain = commit.author[:email].gsub(/\A[a-zA-Z0-9\_\-\.\+ \,\@]+@/,"").rstrip
    diff = commit_diff(repo, commit)

    count[:"#{domain}"][:"addition"] += diff[1].to_i
    count[:"#{domain}"][:"deletion"] += diff[2].to_i

    total[:"addition"] += diff[1].to_i
    total[:"deletion"] += diff[2].to_i
  end
  if number.nil?
    # TODO more Faster! it takes 50 sec(10k / sec).
    sorted = count.sort_by{|a,b| -b[:"addition"] }
  else
    sorted = count.sort_by{|a,b| -b[:"addition"] }.first(number)
    sum = Hash.new(0)
    sorted.each{|c|
      sum["addition"] += c[1][:"addition"]
      sum["deletion"] += c[1][:"deletion"]
    }
    tmp = Hash.new(0)
    tmp[:"addition"] = total[:"addition"] - sum["addition"]
    tmp[:"deletion"] = total[:"deletion"] - sum["deletion"]
    sorted << [:"others",tmp]
  end
  result = Hash.new
  result[:'count'] = Hash.new
  result[:'count'] = Hash[sorted]
  result[:'infomation'] = get_info(repo,total)
  puts Oj.dump(result, :mode => :compat)
end

# File lib/git_analysis.rb, line 10
def self.count_domain(number=0)
  repo = load_repo()
  count = Hash.new(0)
  total = 0
  repo.walk(repo.last_commit).each do |commit|
    # TODO more Faster
    domain = commit.author[:email].gsub(/\A[a-zA-Z0-9\_\-\.\+ \,\@]+@/,"").rstrip
    count[:"#{domain}"] += 1
    total += 1
  end
  if number.nil?
    sorted = count.sort_by{|a,b| -b }
  else
    sorted = count.sort_by{|a,b| -b }.first(number)
    sum =0
    sorted.each{|c| sum += c[1] } 
    sorted << [:others, total - sum] 
  end
  result = Hash.new
  result[:'count'] = Hash.new
  result[:'count'] = Hash[sorted]
  result[:'infomation'] = get_info(repo,total)
  puts Oj.dump(result, :mode => :compat)
end

# File lib/git_analysis.rb, line 72
def self.export()
  repo = load_repo()
  commits = repo.walk(repo.last_commit).to_a
  list = Hash.new
  domain = Array.new
  commits.each do |c|
    log = Hash.new
    log[:sha] = c.oid
    log[:message] = c.message
    log[:time] =  c.time
    log[:name] = c.author[:name]
    log[:email] = c.author[:email]
    log[:domain] = c.author[:email].match(/([a-zA-Z0-9\_\-\.]+$)/)[1]
    list["#{c.oid}"] = log
  end
  puts Oj.dump(list, :mode => :compat)
end

# File lib/git_analysis.rb, line 100
def self.commit_diff(repo,commit)
  sha = String.new
  sha_parents = String.new
  diff_stat = Array.new

  sha = commit.oid
  unless commit.parents[0].nil?
    sha_parents = commit.parents[0].oid
    # Too Slow. More Faster
    diff_stat = repo.diff(sha_parents,sha).stat
  else
    tmp = commit.diff.stat
    diff_stat = [tmp[0], tmp[2], tmp[1]]
  end
  return diff_stat
end

# File lib/git_analysis.rb, line 117
def self.get_info(repo,total)
  info = Hash.new
  info[:'last_commit_oid'] = repo.last_commit.oid
  info[:'last_commit_date'] = repo.last_commit.time.to_s
  info[:'total_commit'] = total
  return info
end

# File lib/git_analysis.rb, line 93
def self.load_repo()
  repo ||= Rugged::Repository.new(Dir::pwd)
rescue Rugged::RepositoryError, Rugged::OSError
  p 'Rugged::RepositoryError or Rugged::OSError'
  exit 1
end