class ICalPal::Options

def initialize
  # prologue
  @op = OptionParser.new
  @op.summary_width = 23
  @op.banner += ' [-c] COMMAND'
  @op.version = VERSION
  @op.accept(RDT) { |s| RDT.conv(s) }
  # head
  @op.on_head("\nCOMMAND must be one of the following:\n\n")
  @op.on('%s%s %sPrint events' % pad('events'))
  @op.on('%s%s %sPrint tasks' % pad('tasks'))
  @op.on('%s%s %sPrint calendars' % pad('calendars'))
  @op.on('%s%s %sPrint accounts' % pad('accounts'))
  @op.separator('')
  @op.on('%s%s %sPrint events occurring today' % pad('eventsToday'))
  @op.on('%s%s %sPrint events occurring between today and NUM days into the future' % pad('eventsToday+NUM'))
  @op.on('%s%s %sPrint events occurring at present time' % pad('eventsNow'))
  @op.on('%s%s %sPrint tasks with a due date' % pad('datedTasks'))
  @op.on('%s%s %sPrint tasks with no due date' % pad('undatedTasks'))
  # global
  @op.separator("\nGlobal options:\n\n")
  @op.on('-c=COMMAND', '--cmd=COMMAND', COMMANDS, 'Command to run')
  @op.on('--db=DB', 'Use DB file instead of Calendar',
         "(default: #{$defaults[:common][:db]}",
         'For the tasks commands this should be a directory containing .sqlite files',
         "(default: #{$defaults[:tasks][:db]})")
  @op.on('--cf=FILE', "Set config file path (default: #{$defaults[:common][:cf]})")
  @op.on('--norc', 'Ignore ICALPAL and ICALPAL_CONFIG environment variables')
  @op.on('-o', '--output=FORMAT', OUTFORMATS,
         "Print as FORMAT (default: #{$defaults[:common][:output]})", "[#{OUTFORMATS.join(', ')}]")
  # include/exclude
  @op.separator("\nIncluding/excluding accounts, calendars, items:\n\n")
  @op.on('--is=ACCOUNTS', Array, 'List of accounts to include')
  @op.on('--es=ACCOUNTS', Array, 'List of accounts to exclude')
  @op.separator('')
  @op.on('--it=TYPES', Array, 'List of calendar types to include')
  @op.on('--et=TYPES', Array, 'List of calendar types to exclude',
         "[#{EventKit::EKSourceType.map { |i| i[:name] }.join(', ')}]")
  @op.separator('')
  @op.on('--ic=CALENDARS', Array, 'List of calendars to include')
  @op.on('--ec=CALENDARS', Array, 'List of calendars to exclude')
  @op.separator('')
  @op.on('--il=LISTS', Array, 'List of reminder lists to include')
  @op.on('--el=LISTS', Array, 'List of reminder lists to exclude')
  @op.separator('')
  @op.on('--match=FIELD=REGEXP', String, 'Include only items whose FIELD matches REGEXP (ignoring case)')
  # dates
  @op.separator("\nChoosing dates:\n\n")
  @op.on('--from=DATE', RDT, 'List events starting on or after DATE')
  @op.on('--to=DATE', RDT, 'List events starting on or before DATE',
         'DATE can be yesterday, today, tomorrow, +N, -N, or anything accepted by DateTime.parse()',
         'See https://ruby-doc.org/stdlib-2.6.1/libdoc/date/rdoc/DateTime.html#method-c-parse')
  @op.separator('')
  @op.on('-n', 'Include only events from now on')
  @op.on('--days=N',  OptionParser::DecimalInteger,
         'Show N days of events, including start date')
  @op.on('--sed', 'Show empty dates with --sd')
  @op.on('--ia', 'Include only all-day events')
  @op.on('--ea', 'Exclude all-day events')
  # properties
  @op.separator("\nChoose properties to include in the output:\n\n")
  @op.on('--iep=PROPERTIES', Array, 'List of properties to include')
  @op.on('--eep=PROPERTIES', Array, 'List of properties to exclude')
  @op.on('--aep=PROPERTIES', Array, 'List of properties to include in addition to the default list')
  @op.separator('')
  @op.on('--itp=PROPERTIES', Array, 'List of task properties to include')
  @op.on('--etp=PROPERTIES', Array, 'List of task properties to exclude')
  @op.on('--atp=PROPERTIES', Array, 'List of task properties to include in addition to the default list',
         'Included for backwards compatability, these are aliases for --iep, --eep, and --aep')
  @op.separator('')
  @op.on('--uid', 'Show event UIDs')
  @op.on('--eed', 'Exclude end datetimes')
  @op.separator('')
  @op.on('--nc', 'No calendar names')
  @op.on('--npn', 'No property names')
  @op.on('--nrd', 'No relative dates')
  @op.separator('')
  @op.separator("#{@op.summary_indent}Properties are listed in the order specified")
  @op.separator('')
  @op.separator("#{@op.summary_indent}Use 'all' for PROPERTIES to include all available properties (except any listed in --eep)")
  @op.separator("#{@op.summary_indent}Use 'list' for PROPERTIES to list all available properties and exit")
  # formatting
  @op.separator("\nFormatting the output:\n\n")
  @op.on('--li=N', OptionParser::DecimalInteger, 'Show at most N items (default: 0 for no limit)')
  @op.separator('')
  @op.on('--sc', 'Separate by calendar')
  @op.on('--sd', 'Separate by date')
  @op.on('--sp', 'Separate by priority')
  @op.on('--sep=PROPERTY', 'Separate by PROPERTY')
  @op.separator('')
  @op.on('--sort=PROPERTY', 'Sort by PROPERTY')
  @op.on('--std', 'Sort tasks by due date (same as --sort=due_date)')
  @op.on('--stda', 'Sort tasks by due date (ascending) (same as --sort=due_date -r)')
  @op.on('-r', '--reverse', 'Sort in reverse')
  @op.separator('')
  @op.on('--ps=SEPARATORS', Array, 'List of property separators')
  @op.on('--ss=SEPARATOR', String, 'Set section separator')
  @op.separator('')
  @op.on('--df=FORMAT', String, 'Set date format')
  @op.on('--tf=FORMAT', String, 'Set time format',
         'See https://ruby-doc.org/stdlib-2.6.1/libdoc/date/rdoc/DateTime.html#method-i-strftime for details')
  @op.separator('')
  @op.on('-b', '--bullet=STRING', String, 'Use STRING for bullets')
  @op.on('--ab=STRING', String, 'Use STRING for alert bullets')
  @op.on('--nb', 'Do not use bullets')
  @op.on('--nnr=SEPARATOR', String, 'Set replacement for newlines within notes')
  @op.separator('')
  @op.on('-f', 'Format output using standard ANSI colors')
  @op.on('--color', 'Format output using a larger color palette')
  # help
  @op.separator("\nHelp:\n\n")
  @op.on('-h', '--help', 'Show this message') { @op.abort(@op.help) }
  @op.on('-V', '-v', '--version', "Show version and exit (#{@op.version})") { @op.abort(@op.version) }
  @op.on('-d', '--debug=LEVEL', /#{Regexp.union(Logger::SEV_LABEL[0..-2]).source}/i,
         "Set the logging level (default: #{Logger::SEV_LABEL[$defaults[:common][:debug]].downcase})",
         "[#{Logger::SEV_LABEL[0..-2].join(', ').downcase}]")
  # environment variables
  @op.on_tail("\nEnvironment variables:\n\n")
  @op.on_tail('%s%s %sAdditional arguments' % pad('ICALPAL'))
  @op.on_tail('%s%s %sAdditional arguments from a file' % pad('ICALPAL_CONFIG'))
  @op.on_tail("%s%s %s(default: #{$defaults[:common][:cf]})" % pad(''))
  @op.on_tail('')
  note = 'Do not quote or escape values.'
  note += '  Options set in ICALPAL override ICALPAL_CONFIG.'
  note += '  Options on the command line override ICALPAL.'
  @op.on_tail("#{@op.summary_indent}#{note}")
end

def pad(t)
  [ @op.summary_indent, t, ' ' * (@op.summary_width - t.length) ]
end

def parse_options
  begin
    cli = {}
    env = {}
    cf = {}
    # Load from CLI
    @op.parse!(into: cli)
    # Environment variable needs special parsing.
    # OptionParser.parse doesn't handle whitespace in a
    # comma-separated value.
    begin
      o = []
      ENV['ICALPAL'].gsub(/^-/, ' -').split(' -').each do |e|
        a = e.split(' ', 2)
        if a[0]
          o.push("-#{a[0]}")
          o.push(a[1]) if a[1]
        end
      end
      @op.parse!(o, into: env)
    end if ENV['ICALPAL'] && !cli[:norc]
    # Configuration file needs special parsing for the same reason
    begin
      o = []
      cli[:cf] ||= ENV['ICALPAL_CONFIG'] || $defaults[:common][:cf]
      File.read(File.expand_path(cli[:cf])).split("\n").each do |line|
        a = line.split(' ', 2)
        if a[0] && a[0][0] != '#'
          o.push(a[0])
          o.push(a[1]) if a[1]
        end
      end
      @op.parse!(o, into: cf)
    rescue StandardError
    end unless cli[:norc]
    cli[:cmd] ||= @op.default_argv[0]
    cli[:cmd] ||= env[:cmd] if env[:cmd]
    cli[:cmd] ||= cf[:cmd] if cf[:cmd]
    cli[:cmd] = 'stores' if cli[:cmd] == 'accounts'
    # Parse eventsNow and eventsToday commands
    cli[:cmd].match('events(Now|Today)(\+[0-9]+)?') do |m|
      cli[:now] = true if m[1] == 'Now'
      cli[:days] = (m[1] == 'Today')? m[2].to_i : 1
      cli[:from] = $today
      cli[:to] = $today + cli[:days] if cli[:days]
      cli[:days] = Integer(cli[:to] - cli[:from])
      cli[:cmd] = 'events'
    end if cli[:cmd]
    # Must have a valid command
    raise(OptionParser::MissingArgument, 'COMMAND is required') unless cli[:cmd]
    raise(OptionParser::InvalidArgument, "Unknown COMMAND #{cli[:cmd]}") unless (COMMANDS.any? cli[:cmd])
    # Merge options
    opts = $defaults[:common]
      .merge($defaults[cli[:cmd].to_sym])
      .merge(cf)
      .merge(env)
      .merge(cli)
    # datedTasks and undatedTasks
    opts[:cmd] = 'tasks' if opts[:cmd] == 'datedTasks'
    opts[:cmd] = 'tasks' if opts[:cmd] == 'undatedTasks'
    # Make sure opts[:db] and opts[:tasks] are Arrays
    opts[:db] = [ opts[:db] ] unless opts[:db].is_a?(Array)
    opts[:tasks] = [ opts[:tasks] ] unless opts[:db].is_a?(Array)
    # All kids love log!
    $log.level = opts[:debug]
    # For posterity
    opts[:ruby] = RUBY_VERSION
    opts[:version] = @op.version
    # From the Department of Redundancy Department
    opts[:iep] += opts[:itp] if opts[:itp]
    opts[:eep] += opts[:etp] if opts[:etp]
    opts[:aep] += opts[:atp] if opts[:atp]
    opts[:props] = (opts[:iep] + opts[:aep] - opts[:eep]).uniq
    # From, to, days
    if opts[:from]
      opts[:to] += 1 if opts[:to]
      opts[:to] ||= opts[:from] + 1 if opts[:from]
      opts[:to] = opts[:from] + opts[:days] if opts[:days]
      opts[:to] = RDT.new(*opts[:to].to_a[0..2] + [ 23, 59, 59 ])
      opts[:days] ||= Integer(opts[:to] - opts[:from])
      opts[:from] = $now if opts[:n]
    end
    # Sorting
    opts[:sort] = 'due_date' if opts[:std] || opts[:stda]
    opts[:reverse] = true if opts[:std]
    # Colors
    opts[:palette] = 8 if opts[:f]
    opts[:palette] = 24 if opts[:color]
    # Sections
    unless opts[:sep]
      opts[:sep] = 'calendar' if opts[:sc]
      opts[:sep] = 'sday' if opts[:sd]
      opts[:sep] = 'long_priority' if opts[:sp]
    end
    opts[:nc] = true if opts[:sc]
    # Sanity checks
    raise(OptionParser::InvalidArgument, '--li cannot be negative') if opts[:li].negative?
    raise(OptionParser::InvalidOption, 'Start date must be before end date') if opts[:from] && opts[:from] > opts[:to]
    raise(OptionParser::MissingArgument, 'No properties to display') if opts[:props].empty?
  rescue StandardError => e
    @op.abort("#{e}\n\n#{@op.help}\n#{e}")
  end
  opts.sort.to_h
end