module Minitest::CoverageRunner

# File lib/minitest/coverage.rb, line 7
def self.coverage_baseline
  @@coverage_baseline
end

# File lib/minitest/coverage.rb, line 11
def self.coverage_baseline= o
  @@coverage_baseline = o
end

# File lib/minitest/coverage.rb, line 19
def self.coverage_data
  @@coverage_data
end

# File lib/minitest/coverage.rb, line 23
def self.coverage_data= o
  @@coverage_data = o
end

# File lib/minitest/coverage.rb, line 104
def output_coverage
  require "json"

  cleaned = coverage_data.reject { |path, lines|
    path.nil? or
      path.include? RbConfig::CONFIG["libdir"] or
      not path.start_with? PWD
  }

  File.open "coverage.json", "w" do |f|
    f.puts JSON.pretty_generate cleaned
  end

  warn "created coverage.json"
end

# File lib/minitest/coverage.rb, line 37
def clean_path path
  path[Dir.pwd.length+1..-1]
end

# File lib/minitest/coverage.rb, line 15
def coverage_baseline
  @@coverage_baseline
end

# File lib/minitest/coverage.rb, line 27
def coverage_data
  @@coverage_data
end

# File lib/minitest/coverage.rb, line 41
def coverage_diff test_name, new, old
  puts

  path, lines = find_path_and_lines(new, test_name)

  return unless path && lines

  old_lines = old[path] || lines.map { |x| x ? 0 : nil }

  print "  #{clean_path path}"
  a, b, max = pct(old_lines), pct(lines), max(lines)

  if (a - b).abs < 0.01 then
    puts ": no change at %.1f%% of %d lines" % [a, max]
  else
    puts ": from %.1f%% to %.1f%% of %d lines" % [a, b, max]
  end
end

# File lib/minitest/coverage.rb, line 62
def find_path_and_lines coverage, test_name
  impl_re = /\/#{impl_name test_name}$/

  coverage.sort.find { |path, lines| # sorting biases towards app and lib
    next unless path.start_with? PWD
    path =~ impl_re
  }
end

# File lib/minitest/coverage.rb, line 71
def impl_name test_name
  unless test_name then
    p :nil => [test_name, self.name]
    p caller
    abort
  end
  (test_name[/^([\w:]+?)Test/, 1] || # rails style
   test_name[/^Test([\w:]+)$/, 1] || # ruby style
   test_name).                       # give up
    gsub(/([a-z])([A-Z])/, '\1_\2').
    gsub(/::/, "/").
    downcase + "\\.rb"
rescue => e
  p e
  p test_name
  p test_name[/^([\w:]+?)Test(?:::)?/, 1]
  raise e
end

# File lib/minitest/coverage.rb, line 90
def max lines
  lines.compact.size
end

# File lib/minitest/coverage.rb, line 94
def merge_coverage new_coverage
  path, lines = find_path_and_lines new_coverage, self.name

  if path and lines then
    coverage_data[path] = lines
  else
    # warn "Bad mapping for #{self.name}. Skipping coverage." # TODO
  end
end

# File lib/minitest/coverage.rb, line 122
def pct lines
  max = max lines
  n   = max - lines.count(0)
  100.0*n/max
end

# File lib/minitest/coverage.rb, line 128
def run *args
  return if self.runnable_methods.empty?

  unless impl_name self.name then
    warn "BAD NAME: #{self.name} -- can't map to implementation. Skipping"
  end

  puts
  puts "#{self.name}:"

  super

  new_coverage = Coverage.peek_result

  coverage_diff(self.name, new_coverage, coverage_data)
  merge_coverage new_coverage

  if Coverage.respond_to? :result= then
    Coverage.result = coverage_baseline
  else
    @@coverage_warning ||= false
    unless @@coverage_warning then
      warn "Unable to reset coverage baseline. Numbers will be artificially high."
      @@coverage_warning = true
    end
  end
end