{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}

module PGExtras.Queries.RecordsRank (recordsRankSQL, displayRecordsRank) where

import PGExtras.Helpers (maybeText, maybeInt)
import Database.PostgreSQL.Simple
import Text.RawString.QQ
import qualified Data.Text as Text
import Control.Monad (forM_)
import Data.List (intercalate)

recordsRankSQL :: Query
recordsRankSQL :: Query
recordsRankSQL = [r|SELECT
  relname AS name,
  n_live_tup AS estimated_count
FROM
  pg_stat_user_tables
ORDER BY
  n_live_tup DESC;|]

displayRecordsRank :: [(Maybe Text.Text, Maybe Int)] -> IO ()
displayRecordsRank :: [(Maybe Text, Maybe Int)] -> IO ()
displayRecordsRank rows :: [(Maybe Text, Maybe Int)]
rows = do
  String -> IO ()
putStrLn (String -> IO ()) -> String -> IO ()
forall a b. (a -> b) -> a -> b
$ String
description
  String -> IO ()
putStrLn (String -> IO ()) -> String -> IO ()
forall a b. (a -> b) -> a -> b
$ String -> [String] -> String
forall a. [a] -> [[a]] -> [a]
intercalate " | " [String]
tableHeaders
  [(Maybe Text, Maybe Int)]
-> ((Maybe Text, Maybe Int) -> IO ()) -> IO ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
t a -> (a -> m b) -> m ()
forM_ [(Maybe Text, Maybe Int)]
rows (((Maybe Text, Maybe Int) -> IO ()) -> IO ())
-> ((Maybe Text, Maybe Int) -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \(arg1 :: Maybe Text
arg1, arg2 :: Maybe Int
arg2) ->
    String -> IO ()
putStrLn (String -> IO ()) -> String -> IO ()
forall a b. (a -> b) -> a -> b
$ Maybe Text -> String
maybeText(Maybe Text
arg1) String -> String -> String
forall a. [a] -> [a] -> [a]
++ " | " String -> String -> String
forall a. [a] -> [a] -> [a]
++ Maybe Int -> String
maybeInt(Maybe Int
arg2)

description :: [Char]
description :: String
description = "All tables and the number of rows in each ordered by number of rows descending"

tableHeaders :: [[Char]]
tableHeaders :: [String]
tableHeaders = ["name", "estimated_count"]