-- | Parse the command-line options, and display help text if
--   necessary.
--
module CommandLine (
  get_args )
where

-- System imports.
import System.Console.CmdArgs (
  (&=),
  args,
  cmdArgs,
  def,
  details,
  help,
  program,
  summary,
  typ,
  typFile )
import Paths_htsn_import ( version ) -- These let us get the
import Data.Version ( showVersion )  -- version from Cabal.

-- Local imports.
import OptionalConfiguration ( OptionalConfiguration(..) )


-- | The description of the program, displayed as part of the help.
description :: String
description = "Import XML files from The Sports Network into an RDBMS."


-- | The name of this program.
program_name :: String
program_name = "htsn-import"


-- | A summary string output as part of the help.
my_summary :: String
my_summary = program_name ++ "-" ++ (showVersion version)


-- | A description of the "backend" option.
backend_help :: String
backend_help =
  "Database choice, either \"Sqlite\" or \"Postgres\"."


-- | A description of the "connection_string" option.
connection_string_help :: String
connection_string_help =
  "A database-specific connection string (depends on the backend)."


-- | A description of the "log_file" option.
log_file_help :: String
log_file_help =
  "Log to the given file."


-- | A description of the "log_level" option.
log_level_help :: String
log_level_help =
  "How verbose should the logs be? One of INFO, WARNING, ERROR."


-- | A description of the "remove" option.
remove_help :: String
remove_help =
  "Remove files that have been successfully imported."


-- | A description of the "syslog" option.
syslog_help :: String
syslog_help =
  "Enable logging to syslog."


-- | A data structure representing the possible command-line
--   options. The CmdArgs library is doing heavy magic beneath the
--   hood here.
--
arg_spec :: OptionalConfiguration
arg_spec =
  OptionalConfiguration {
    backend           = def &= typ "BACKEND"  &= help backend_help,
    connection_string = def &= typ "STRING"   &= help connection_string_help,
    log_file          = def &= typFile        &= help log_file_help,
    log_level         = def &= typ "LEVEL"    &= help log_level_help,
    remove            = def &= typ "BOOL"     &= help remove_help,
    syslog            = def &= typ "BOOL"     &= help syslog_help,
    xml_files         = def &= typ "XMLFILES" &= args }
  &= program program_name
  &= summary my_summary
  &= details [description]


-- | A convenience function; our only export. Meant to be used in
--   'main' to retrieve the command-line arguments.
--
get_args :: IO OptionalConfiguration
get_args = cmdArgs arg_spec