local s = require 'say'
local pretty = require 'pl.pretty'

local colors

if package.config:sub(1,1) == '\\' and not os.getenv("ANSICON") then
  -- Disable colors on Windows.
  colors = setmetatable({}, {__index = function() return function(s) return s end end})
else
  colors = require 'term.colors'
end

return function(options)
  local busted = require 'busted'
  local handler = require 'busted.outputHandlers.base'()

  local successDot = colors.green('●')
  local failureDot = colors.red('◼')
  local errorDot   = colors.magenta('✱')
  local pendingDot = colors.yellow('◌')

  local pendingDescription = function(pending)
    local name = pending.name

    local string = colors.yellow(s('output.pending')) .. ' → ' ..
      colors.cyan(pending.trace.short_src) .. ' @ ' ..
      colors.cyan(pending.trace.currentline)  ..
      '\n' .. colors.bright(name)

    if type(pending.message) == 'string' then
      string = string .. '\n' .. pending.message
    elseif pending.message ~= nil then
      string = string .. '\n' .. pretty.write(pending.message)
    end

    return string
  end

  local failureMessage = function(failure)
    local string = failure.randomseed and ('Random seed: ' .. failure.randomseed .. '\n') or ''
    if type(failure.message) == 'string' then
      string = string .. failure.message
    elseif failure.message == nil then
      string = string .. 'Nil error'
    else
      string = string .. pretty.write(failure.message)
    end

    return string
  end

  local failureDescription = function(failure, isError)
    local string = colors.red(s('output.failure')) .. ' → '
    if isError then
      string = colors.magenta(s('output.error')) .. ' → '
    end

    if not failure.element.trace or not failure.element.trace.short_src then
      string = string ..
        colors.cyan(failureMessage(failure)) .. '\n' ..
        colors.bright(failure.name)
    else
      string = string ..
        colors.cyan(failure.element.trace.short_src) .. ' @ ' ..
        colors.cyan(failure.element.trace.currentline) .. '\n' ..
        colors.bright(failure.name) .. '\n' ..
        failureMessage(failure)
    end

    if options.verbose and failure.trace and failure.trace.traceback then
      string = string .. '\n' .. failure.trace.traceback
    end

    return string
  end

  local statusString = function()
    local successString = s('output.success_plural')
    local failureString = s('output.failure_plural')
    local pendingString = s('output.pending_plural')
    local errorString = s('output.error_plural')

    local sec = handler.getDuration()
    local successes = handler.successesCount
    local pendings = handler.pendingsCount
    local failures = handler.failuresCount
    local errors = handler.errorsCount

    if successes == 0 then
      successString = s('output.success_zero')
    elseif successes == 1 then
      successString = s('output.success_single')
    end

    if failures == 0 then
      failureString = s('output.failure_zero')
    elseif failures == 1 then
      failureString = s('output.failure_single')
    end

    if pendings == 0 then
      pendingString = s('output.pending_zero')
    elseif pendings == 1 then
      pendingString = s('output.pending_single')
    end

    if errors == 0 then
      errorString = s('output.error_zero')
    elseif errors == 1 then
      errorString = s('output.error_single')
    end

    local formattedTime = ('%.6f'):format(sec):gsub('([0-9])0+$', '%1')

    return colors.green(successes) .. ' ' .. successString .. ' / ' ..
      colors.red(failures) .. ' ' .. failureString .. ' / ' ..
      colors.magenta(errors) .. ' ' .. errorString .. ' / ' ..
      colors.yellow(pendings) .. ' ' .. pendingString .. ' : ' ..
      colors.bright(formattedTime) .. ' ' .. s('output.seconds')
  end

  handler.testEnd = function(element, parent, status, debug)
    if not options.deferPrint then
      local string = successDot

      if status == 'pending' then
        string = pendingDot
      elseif status == 'failure' then
        string = failureDot
      elseif status == 'error' then
        string = errorDot
      end

      io.write(string)
      io.flush()
    end

    return nil, true
  end

  handler.suiteStart = function(suite, count, total)
    local runString = (total > 1 and '\nRepeating all tests (run %u of %u) . . .\n\n' or '')
    io.write(runString:format(count, total))
    io.flush()

    return nil, true
  end

  handler.suiteEnd = function(suite, count, total)
    print('')
    print(statusString())

    for i, pending in pairs(handler.pendings) do
      print('')
      print(pendingDescription(pending))
    end

    for i, err in pairs(handler.failures) do
      print('')
      print(failureDescription(err))
    end

    for i, err in pairs(handler.errors) do
      print('')
      print(failureDescription(err, true))
    end

    return nil, true
  end

  handler.error = function(element, parent, message, debug)
    io.write(errorDot)
    io.flush()

    return nil, true
  end

  busted.subscribe({ 'test', 'end' }, handler.testEnd, { predicate = handler.cancelOnPending })
  busted.subscribe({ 'suite', 'start' }, handler.suiteStart)
  busted.subscribe({ 'suite', 'end' }, handler.suiteEnd)
  busted.subscribe({ 'error', 'file' }, handler.error)
  busted.subscribe({ 'failure', 'file' }, handler.error)
  busted.subscribe({ 'error', 'describe' }, handler.error)
  busted.subscribe({ 'failure', 'describe' }, handler.error)

  return handler
end