X-Git-Url: http://gitweb.michael.orlitzky.com/?p=mailbox-count.git;a=blobdiff_plain;f=src%2FMain.hs;h=af0911394cc8c84f260a48de5a0dae9d870d4c4e;hp=d6f7c8fdbf0d3656a49d09c59abc7c2886d0289f;hb=72482968102ebd7ad0abeef958fed2a02a126dd2;hpb=65ec33ab24068e50612e72e69d893ecac9079cdc

diff --git a/src/Main.hs b/src/Main.hs
index d6f7c8f..af09113 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -1,6 +1,212 @@
+{-# LANGUAGE PatternGuards #-}
+
 module Main
 where
 
+import Data.List ( foldl' )
+import qualified Data.Map as Map ( Map, alter, empty )
+import Data.Maybe ( catMaybes )
+import Data.Monoid ( (<>) )
+import Database.HDBC (
+  IConnection,
+  SqlValue,
+  disconnect,
+  safeFromSql,
+  quickQuery )
+import Database.HDBC.PostgreSQL ( connectPostgreSQL )
+import System.Console.CmdArgs ( def )
+
+import CommandLine ( get_args )
+import Configuration ( Configuration(..), merge_optional )
+import qualified OptionalConfiguration as OC ( from_rc )
+
+type Domain = String
+type Username = String
+type Count = Int
+
+-- | A wrapper around a (domain, count) pair to keep things type-safe.
+data DomainCount = DomainCount Domain Count
+
+instance Show DomainCount where
+  -- | Display a DomainCount in the form \"domain: count\".
+  --
+  --   Examples:
+  --
+  --   >>> let dc = DomainCount "example.com" 100
+  --   >>> show dc
+  --   "example.com: 100"
+  --
+  show (DomainCount domain count) = domain ++ ": " ++ (show count)
+
+
+-- | A wrapper around a (domain, user) pair to keep things type-safe.
+data DomainUser =
+  DomainUser Domain Username
+  deriving (Show)
+
+
+-- | In the detailed report, we store the usernames as a map from a
+--   domain name to a list of usernames. This type synonym is the type
+--   of that map.
+type DomainUserMap = Map.Map Domain [Username]
+
+
+-- | Convert a list of [SqlByteString, SqlInt32] to 'DomainCount's. If
+--   the conversion doesn't work for some reason (bad data, not enough
+--   columns, etc.), we return 'Nothing'.
+--
+--   Examples:
+--
+--   >>> import Database.HDBC ( iToSql, toSql )
+--
+--   >>> list_to_domain_count [toSql "example.com", iToSql 100]
+--   Just example.com: 100
+--
+--   >>> list_to_domain_count [toSql "example.com"]
+--   Nothing
+--
+--   >>> list_to_domain_count [toSql "example.com", toSql "example.com"]
+--   Nothing
+--
+list_to_domain_count :: [SqlValue] -> Maybe DomainCount
+list_to_domain_count (domain:count:_)
+  | Right d <- safeFromSql domain,
+    Right c <- safeFromSql count = Just $ DomainCount d c
+list_to_domain_count _ =
+  Nothing
+
+
+-- | Convert a list of [SqlByteString, SqlByteString] to 'DomainUser's. If
+--   the conversion doesn't work for some reason (bad data, not enough
+--   columns, etc.), we return 'Nothing'.
+--
+--   Examples:
+--
+--   >>> import Database.HDBC ( toSql )
+--   >>>
+--   >>> list_to_domain_user [toSql "example.com", toSql "user1"]
+--   Just (DomainUser "example.com" "user1")
+--
+--   >>> list_to_domain_user [toSql "example.com"]
+--   Nothing
+--
+list_to_domain_user :: [SqlValue] -> Maybe DomainUser
+list_to_domain_user (domain:user:_)
+  | Right d <- safeFromSql domain,
+    Right u <- safeFromSql user = Just $ DomainUser d u
+list_to_domain_user _ =
+  Nothing
+
+
+report_summary :: IConnection a => a -> IO String
+report_summary conn = do
+  list_rows <- quickQuery conn query []
+  let maybe_domain_counts = map list_to_domain_count list_rows
+  let domain_counts = catMaybes maybe_domain_counts
+  return $ header ++ (concatMap show domain_counts)
+  where
+    header = "mailbox-count summary report" ++
+             "----------------------------"
+
+    query = "SELECT domain,COUNT(username) " ++
+            "FROM mailbox " ++
+            "GROUP BY domain "++
+            "ORDER BY domain;"
+
+
+-- | Construct a Domain -> [Username] (a DomainUserMap) map from a
+--   list of 'DomainUser's. We do this with a fold over the list of
+--   'DomainUser's, appending each new user to the list associated
+--   with the domain that the user is paired with.
+--
+--   The [Username] lists (the values stored in the map) are kept in
+--   the same order as they are given.
+--
+--   Examples:
+--
+--   >>> let du1 = DomainUser "example.com" "user1"
+--   >>> let du2 = DomainUser "example.com" "user2"
+--   >>> let du3 = DomainUser "example.net" "user3"
+--   >>> construct_domain_user_map [du1,du2,du3]
+--   fromList [("example.com",["user1","user2"]),("example.net",["user3"])]
+--
+--   >>> construct_domain_user_map [du2,du1,du3]
+--   fromList [("example.com",["user2","user1"]),("example.net",["user3"])]
+--
+construct_domain_user_map :: [DomainUser] -> DomainUserMap
+construct_domain_user_map dus =
+  foldl' append_this_du Map.empty dus
+  where
+    append_func :: Username -> (Maybe [Username]) -> (Maybe [Username])
+    append_func user maybe_userlist =
+      case maybe_userlist of
+        Just userlist -> Just (userlist ++ [user])
+        Nothing       -> Just [user]
+
+    append_this_du :: DomainUserMap -> DomainUser -> DomainUserMap
+    append_this_du du_map (DomainUser domain user) =
+      Map.alter (append_func user) domain du_map
+
+
+report_detail :: IConnection a => a -> IO String
+report_detail conn = do
+  list_rows <- quickQuery conn query []
+  let maybe_domain_users = map list_to_domain_user list_rows
+  let domain_users = catMaybes maybe_domain_users
+  let domain_users_map = construct_domain_user_map domain_users
+  return ""
+  where
+    query = "SELECT domain,username " ++
+            "FROM mailbox " ++
+            "ORDER BY domain;"
+
+
+report_both :: IConnection a => a -> IO String
+report_both conn = do
+  rs <- report_summary conn
+  rd <- report_detail conn
+  return (rs ++ rd)
+
+report :: IConnection a => a -> Bool -> Bool -> IO String
+report conn do_both do_detail =
+  if do_both
+  then (report_both conn)
+  else if do_detail then (report_detail conn) else (report_summary conn)
+
+
+connection_string :: Configuration -> String
+connection_string cfg =
+  "host=" ++ (host cfg) ++ " " ++
+  "port=" ++ (show $ port cfg) ++ " " ++
+  "user=" ++ (username cfg) ++ " " ++
+  "password=" ++ (password cfg) ++ " " ++
+  "dbname=" ++ (database cfg)
+
 main :: IO ()
 main = do
-  putStrLn "Hello, world!"
+  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
+
+  -- Check the optional config for missing required options.
+  --when (isNothing (OC.password opt_config)) $ do
+  --  report_error "No password supplied."
+  --  exitWith (ExitFailure exit_no_password)
+
+  --when (isNothing (OC.username opt_config)) $ do
+  --  report_error "No username supplied."
+  --exitWith (ExitFailure exit_no_username)
+
+  conn <- connectPostgreSQL (connection_string cfg)
+  r <- report conn (both cfg) (detail cfg)
+  putStrLn r
+  disconnect conn