{-# LANGUAGE OverloadedStrings #-}

module Model.Payment
  ( PaymentId
  , Payment(..)
  , find
  , list
  , listMonthly
  , create
  , createMany
  , editOwn
  , deleteOwn
  , modifiedDuring
  ) where

import Data.Int (Int64)
import Data.Maybe (listToMaybe)
import Data.Text (Text)
import Data.Time (UTCTime)
import Data.Time.Calendar (Day)
import Data.Time.Clock (getCurrentTime)
import Database.SQLite.Simple (Only(Only), FromRow(fromRow), ToRow)
import Database.SQLite.Simple.ToField (ToField(toField))
import Prelude hiding (id)
import qualified Database.SQLite.Simple as SQLite

import Model.Frequency
import Model.Query (Query(Query))
import Model.User (UserId)
import Resource (Resource, resourceCreatedAt, resourceEditedAt, resourceDeletedAt)

type PaymentId = Int64

data Payment = Payment
  { id :: PaymentId
  , userId :: UserId
  , name :: Text
  , cost :: Int
  , date :: Day
  , frequency :: Frequency
  , createdAt :: UTCTime
  , editedAt :: Maybe UTCTime
  , deletedAt :: Maybe UTCTime
  } deriving Show

instance Resource Payment where
  resourceCreatedAt = createdAt
  resourceEditedAt = editedAt
  resourceDeletedAt = deletedAt

instance FromRow Payment where
  fromRow = Payment <$>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field <*>
    SQLite.field

instance ToRow Payment where
  toRow p =
    [ toField (userId p)
    , toField (name p)
    , toField (cost p)
    , toField (date p)
    , toField (frequency p)
    , toField (createdAt p)
    , toField (createdAt p)
    ]

find :: PaymentId -> Query (Maybe Payment)
find paymentId =
  Query (\conn -> listToMaybe <$>
    SQLite.query conn "SELECT * FROM payment WHERE id = ?" (Only paymentId)
  )

list :: Query [Payment]
list =
  Query (\conn ->
    SQLite.query_ conn "SELECT * FROM payment WHERE deleted_at IS NULL"
  )

listMonthly :: Query [Payment]
listMonthly =
  Query (\conn ->
    SQLite.query
      conn
      "SELECT * FROM payment WHERE deleted_at IS NULL AND frequency = ? ORDER BY name DESC"
      (Only Monthly)
  )

create :: UserId -> Text -> Int -> Day -> Frequency -> Query PaymentId
create paymentUserId paymentName paymentCost paymentDate paymentFrequency =
  Query (\conn -> do
    now <- getCurrentTime
    SQLite.execute
      conn
      "INSERT INTO payment (user_id, name, cost, date, frequency, created_at) VALUES (?, ?, ?, ?, ?, ?)"
      (paymentUserId, paymentName, paymentCost, paymentDate, paymentFrequency, now)
    SQLite.lastInsertRowId conn
  )

createMany :: [Payment] -> Query ()
createMany payments =
  Query (\conn ->
    SQLite.executeMany
      conn
      "INSERT INTO payment (user_id, name, cost, date, frequency, created_at) VALUES (?, ?, ?, ?, ?, ?)"
      payments
  )

editOwn :: UserId -> PaymentId -> Text -> Int -> Day -> Frequency -> Query Bool
editOwn paymentUserId paymentId paymentName paymentCost paymentDate paymentFrequency =
  Query (\conn -> do
    mbPayment <- listToMaybe <$>
      SQLite.query conn "SELECT * FROM payment WHERE id = ?" (Only paymentId)
    case mbPayment of
      Just payment ->
        if userId payment == paymentUserId
          then do
            now <- getCurrentTime
            SQLite.execute
              conn
              "UPDATE payment SET edited_at = ?, name = ?, cost = ?, date = ?, frequency = ? WHERE id = ?"
              (now, paymentName, paymentCost, paymentDate, paymentFrequency, paymentId)
            return True
          else
            return False
      Nothing ->
        return False
  )

deleteOwn :: UserId -> PaymentId -> Query Bool
deleteOwn paymentUserId paymentId =
  Query (\conn -> do
    mbPayment <- listToMaybe <$>
      SQLite.query conn "SELECT * FROM payment WHERE id = ?" (Only paymentId)
    case mbPayment of
      Just payment ->
        if userId payment == paymentUserId
          then do
            now <- getCurrentTime
            SQLite.execute
              conn
              "UPDATE payment SET deleted_at = ? WHERE id = ?"
              (now, paymentId)
            return True
          else
            return False
      Nothing ->
        return False
  )

modifiedDuring :: UTCTime -> UTCTime -> Query [Payment]
modifiedDuring start end =
  Query (\conn ->
    SQLite.query
      conn
      "SELECT * FROM payment WHERE (created_at >= ? AND created_at <= ?) OR (edited_at >= ? AND edited_at <= ?) OR (deleted_at >= ? AND deleted_at <= ?)"
      (start, end, start, end, start, end)
  )