{-# LANGUAGE DoAndIfThenElse #-}
{-# LANGUAGE NoMonomorphismRestriction #-}
module Main
where
-- System imports.
import Control.Arrow ( (&&&), (>>^), arr, returnA )
import Control.Concurrent ( threadDelay )
import Control.Exception ( SomeException, catch )
import Control.Monad ( when )
import Database.Groundhog.Generic ( runDbConn )
import Database.Groundhog.Sqlite (
withSqliteConn )
import Database.Groundhog.Postgresql (
withPostgresqlConn )
import Data.Monoid ( (<>) )
import Network.Services.TSN.Logging ( init_logging )
import System.Console.CmdArgs ( def )
import System.Directory ( removeFile )
import System.Exit ( exitWith, ExitCode (ExitFailure) )
import System.IO.Error ( catchIOError )
import Text.XML.HXT.Core (
ArrowXml,
IOStateArrow,
SysConfigList,
XmlTree,
(>>>),
(/>),
getAttrl,
getText,
hasName,
readDocument,
runX,
unpickleDoc )
-- Local imports.
import Backend ( Backend(..) )
import CommandLine ( get_args )
import Configuration ( Configuration(..), merge_optional )
import ConnectionString ( ConnectionString(..) )
import ExitCodes ( exit_no_xml_files )
import qualified OptionalConfiguration as OC (
OptionalConfiguration ( xml_files ),
from_rc )
import Network.Services.TSN.Report (
report_info,
report_error )
import TSN.DbImport ( DbImport(..), ImportResult(..) )
import TSN.Parse ( format_parse_error )
import qualified TSN.XML.AutoRacingDriverList as AutoRacingDriverList (
dtd,
pickle_message )
import qualified TSN.XML.AutoRacingResults as AutoRacingResults (
dtd,
pickle_message )
import qualified TSN.XML.AutoRacingSchedule as AutoRacingSchedule (
dtd,
pickle_message )
import qualified TSN.XML.EarlyLine as EarlyLine (
dtd,
pickle_message )
import qualified TSN.XML.GameInfo as GameInfo ( dtds, parse_xml )
import qualified TSN.XML.Heartbeat as Heartbeat ( dtd, verify )
import qualified TSN.XML.Injuries as Injuries ( dtd, pickle_message )
import qualified TSN.XML.InjuriesDetail as InjuriesDetail (
dtd,
pickle_message )
import qualified TSN.XML.MLBEarlyLine as MLBEarlyLine (
dtd,
pickle_message )
import qualified TSN.XML.JFile as JFile ( dtd, pickle_message )
import qualified TSN.XML.News as News (
dtd,
has_only_single_sms,
pickle_message )
import qualified TSN.XML.Odds as Odds ( dtd, pickle_message )
import qualified TSN.XML.ScheduleChanges as ScheduleChanges (
dtd,
pickle_message )
import qualified TSN.XML.Scores as Scores ( dtd, pickle_message )
import qualified TSN.XML.SportInfo as SportInfo ( dtds, parse_xml )
import qualified TSN.XML.Weather as Weather (
dtd,
is_type1,
pickle_message,
teams_are_normal )
import Xml ( DtdName(..), parse_opts, parse_opts_novalidate )
-- | This is where most of the work happens. This function is called
-- on every file that we would like to import. It determines which
-- importer to use based on the DTD, attempts to process the file,
-- and then returns whether or not it was successful. If the file
-- was processed, 'True' is returned. Otherwise, 'False' is
-- returned.
--
-- The implementation is straightforward with one exception: since
-- we are already in arrow world with HXT, the @import_with_dtd@
-- function is lifted to an 'Arrow' as well with 'arr'. This
-- prevents us from having to do a bunch of unwrapping and
-- rewrapping with the associated error checking.
--
import_file :: Configuration -- ^ A configuration object needed for the
-- 'backend' and 'connection_string'.
-> FilePath -- ^ The path of the XML file to import.
-> IO Bool -- ^ True if we processed the file, False otherwise.
import_file cfg path = do
results <- parse_and_import `catch` exception_handler
case results of
[] -> do
-- One of the arrows returned "nothing."
report_error $ "Unable to determine DTD for file " ++ path ++ "."
return False
(ImportFailed errmsg:_) -> do
report_error $ errmsg ++ " (" ++ path ++ ")"
return False
(ImportSkipped infomsg:_) -> do
-- We processed the message but didn't import anything. Return
-- "success" so that the XML file is deleted.
report_info infomsg
return True
(ImportSucceeded:_) -> do
report_info $ "Successfully imported " ++ path ++ "."
return True
(ImportUnsupported infomsg:_) -> do
-- For now we return "success" for these too, since we know we don't
-- support a bunch of DTDs and we want them to get deleted.
report_info infomsg
return True
where
-- | This will catch *any* exception, even the ones thrown by
-- Haskell's 'error' (which should never occur under normal
-- circumstances).
exception_handler :: SomeException -> IO [ImportResult]
exception_handler e = do
report_error (show e)
let errdesc = "Failed to import file " ++ path ++ "."
-- Return a nonempty list so we don't claim incorrectly that
-- we couldn't parse the DTD.
return [ImportFailed errdesc]
-- | An arrow that reads a document into an 'XmlTree'. We take a
-- SysConfigList so our caller can decide whether or not to
-- e.g. validate the document against its DTD.
readA :: SysConfigList -> IOStateArrow s a XmlTree
readA scl = readDocument scl path
-- | An arrow which parses the doctype "SYSTEM" of an 'XmlTree'.
-- We use these to determine the parser to use.
dtdnameA :: ArrowXml a => a XmlTree DtdName
dtdnameA = getAttrl >>> hasName "doctype-SYSTEM" /> getText >>^ DtdName
-- | Combine the arrows above as well as the function below
-- (arrowized with 'arr') into an IO action that does everything
-- (parses and then runs the import on what was parsed).
--
-- The result of runX has type IO [IO ImportResult]. We thus use
-- bind (>>=) and sequence to combine all of the IOs into one
-- big one outside of the list.
--
-- Before we actually run the import, we check it against a list
-- of problem DTDs. These can produce weird errors, and we have
-- checks for them. But with DTD validation enabled, we can't
-- even look inside the document to see what's wrong -- parsing
-- will fail! So for those special document types, we proceed
-- using 'parse_opts_novalidate' instead of the default
-- 'parse_opts'.
--
parse_and_import :: IO [ImportResult]
parse_and_import = do
-- Get the DTD name without validating against it.
((DtdName dtd) : _) <- runX $ (readA parse_opts_novalidate) >>> dtdnameA
let problem_dtds = [ News.dtd, Weather.dtd ]
let opts = if dtd `elem` problem_dtds
then parse_opts_novalidate
else parse_opts
runX ((readA opts) >>> (dtdnameA &&& returnA) >>> (arr import_with_dtd))
>>= sequence
-- | Takes a ('DtdName', 'XmlTree') pair and uses the 'DtdName'
-- to determine which function to call on the 'XmlTree'.
import_with_dtd :: (DtdName, XmlTree) -> IO ImportResult
import_with_dtd (DtdName dtd,xml)
-- We special-case the heartbeat so it doesn't have to run in
-- the database monad.
| dtd == Heartbeat.dtd = Heartbeat.verify xml
| otherwise =
-- We need NoMonomorphismRestriction here.
if backend cfg == Postgres
then withPostgresqlConn cs $ runDbConn importer
else withSqliteConn cs $ runDbConn importer
where
-- | Pull the real connection String out of the configuration.
--
cs :: String
cs = get_connection_string $ connection_string cfg
-- | Convenience; we use this everywhere below in 'importer'.
--
migrate_and_import m = dbmigrate m >> dbimport m
-- | The error message we return if unpickling fails.
--
errmsg = "Could not unpickle " ++ dtd ++ "."
-- | Try to migrate and import using the given pickler @f@;
-- if it works, return the result. Otherwise, return an
-- 'ImportFailed' along with our error message.
--
go f = maybe
(return $ ImportFailed errmsg)
migrate_and_import
(unpickleDoc f xml)
importer
| dtd == AutoRacingDriverList.dtd =
go AutoRacingDriverList.pickle_message
| dtd == AutoRacingResults.dtd =
go AutoRacingResults.pickle_message
| dtd == AutoRacingSchedule.dtd =
go AutoRacingSchedule.pickle_message
| dtd == EarlyLine.dtd =
go EarlyLine.pickle_message
-- GameInfo and SportInfo appear last in the guards
| dtd == Injuries.dtd = go Injuries.pickle_message
| dtd == InjuriesDetail.dtd = go InjuriesDetail.pickle_message
| dtd == JFile.dtd = go JFile.pickle_message
| dtd == MLBEarlyLine.dtd = go MLBEarlyLine.pickle_message
| dtd == News.dtd =
-- Some of the newsxml docs are busted in predictable ways.
-- We want them to "succeed" so that they're deleted.
-- We already know we can't parse them.
if News.has_only_single_sms xml
then go News.pickle_message
else do
let msg = "Unsupported newsxml.dtd with multiple SMS " ++
"(" ++ path ++ ")"
return $ ImportUnsupported msg
| dtd == Odds.dtd = go Odds.pickle_message
| dtd == ScheduleChanges.dtd = go ScheduleChanges.pickle_message
| dtd == Scores.dtd = go Scores.pickle_message
-- SportInfo and GameInfo appear last in the guards
| dtd == Weather.dtd =
-- Some of the weatherxml docs are busted in predictable ways.
-- We want them to "succeed" so that they're deleted.
-- We already know we can't parse them.
if Weather.is_type1 xml
then if Weather.teams_are_normal xml
then go Weather.pickle_message
else do
let msg = "Teams in reverse order in weatherxml.dtd" ++
" (" ++ path ++ ")"
return $ ImportUnsupported msg
else do
let msg = "Unsupported weatherxml.dtd type (" ++ path ++ ")"
return $ ImportUnsupported msg
| dtd `elem` GameInfo.dtds = do
let either_m = GameInfo.parse_xml dtd xml
case either_m of
-- This might give us a slightly better error
-- message than the default 'errmsg'.
Left err -> return $ ImportFailed (format_parse_error err)
Right m -> migrate_and_import m
| dtd `elem` SportInfo.dtds = do
let either_m = SportInfo.parse_xml dtd xml
case either_m of
-- This might give us a slightly better error
-- message than the default 'errmsg'.
Left err -> return $ ImportFailed (format_parse_error err)
Right m -> migrate_and_import m
| otherwise = do
let infomsg =
"Unrecognized DTD in " ++ path ++ ": " ++ dtd ++ "."
return $ ImportUnsupported infomsg
-- | Entry point of the program. It twiddles some knobs for
-- configuration options and then calls 'import_file' on each XML
-- file given on the command-line.
--
-- Any file successfully processed is then optionally removed, and
-- we're done.
--
main :: IO ()
main = do
rc_cfg <- OC.from_rc
cmd_cfg <- get_args
-- Merge the config file options with the command-line ones,
-- prefering the command-line ones.
let opt_config = rc_cfg <> cmd_cfg
-- Update a default config with any options that have been set in
-- either the config file or on the command-line. We initialize
-- logging before the missing parameter checks below so that we can
-- log the errors.
let cfg = (def :: Configuration) `merge_optional` opt_config
init_logging (log_level cfg) (log_file cfg) (syslog cfg)
-- Check the optional config for missing required options.
when (null $ OC.xml_files opt_config) $ do
report_error "No XML files given."
exitWith (ExitFailure exit_no_xml_files)
-- We don't do this in parallel (for now?) to keep the error
-- messages nice and linear.
results <- mapM (import_file cfg) (OC.xml_files opt_config)
-- Zip the results with the files list to find out which ones can be
-- deleted.
let result_pairs = zip (OC.xml_files opt_config) results
let victims = [ p | (p, True) <- result_pairs ]
let processed_count = length victims
report_info $ "Processed " ++ (show processed_count) ++ " document(s) total."
when (remove cfg) $ mapM_ (kill True) victims
where
-- | Wrap these two actions into one function so that we don't
-- report that the file was removed if the exception handler is
-- run.
remove_and_report path = do
removeFile path
report_info $ "Removed processed file " ++ path ++ "."
-- | Try to remove @path@ and potentially try again.
kill try_again path =
(remove_and_report path) `catchIOError` exception_handler
where
-- | A wrapper around threadDelay which takes seconds instead of
-- microseconds as its argument.
thread_sleep :: Int -> IO ()
thread_sleep seconds = do
let microseconds = seconds * (10 ^ (6 :: Int))
threadDelay microseconds
-- | If we can't remove the file, report that, and try once
-- more after waiting a few seconds.
exception_handler :: IOError -> IO ()
exception_handler e = do
report_error (show e)
report_error $ "Failed to remove imported file " ++ path ++ "."
if try_again then do
report_info "Waiting 5 seconds to attempt removal again..."
thread_sleep 5
kill False path
else
report_info $ "Giving up on " ++ path ++ "."