{-# LANGUAGE CPP #-}
{-# LANGUAGE DuplicateRecordFields #-}
{-# LANGUAGE LambdaCase #-}
{-# LANGUAGE NamedFieldPuns #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE QuasiQuotes #-}
{-# LANGUAGE TupleSections #-}
{-# LANGUAGE TypeOperators #-}

module Simplex.Chat.Store.Badges
  ( BadgeStash (..),
    BadgeStashRef (..),
    UserBadgePurchase (..),
    getUserBadgePurchase,
    getBadgePurchase,
    userHasBadge,
    setBadgeAlertAcked,
    setBadgeIssueError,
    setBadgeNextWake,
    clearShownBadge,
    getBadgeCodeRedemption,
    createBadgeCodeRedemption,
    StoreReceipt (..),
    StoreReceiptStatus (..),
    HeldStoreReceipt (..),
    holdStoreReceipt,
    createBadgeStoreReceipt,
    getOpenStorePurchases,
    getNextDueStoreReceipt,
    recordStoreReceiptFailure,
    refuseStoreReceipt,
    deleteUnfundedStoreReceipts,
    deleteBadgeCodeRedemption,
    createStashBadgePurchase,
    getStashBadgePurchase,
    storeBadgeIssuance,
    getLatestIssuedCredential,
    storeBadgeStatement,
    getBadgeLedgerLastEntry,
    getBadgeLedger,
    getBadgeLedgerEntryId,
  )
where

import Control.Concurrent.STM (TVar, atomically)
import Control.Monad (forM, forM_, join)
import Crypto.Random (ChaChaDRG)
import qualified Data.Aeson as J
import Data.ByteString.Char8 (ByteString)
import qualified Data.ByteString.Lazy.Char8 as LB
import Data.Int (Int64)
import Data.List (find)
import Data.Maybe (isJust, mapMaybe)
import Data.Set (Set)
import qualified Data.Set as S
import Data.Text (Text)
import Data.Time.Clock (UTCTime)
import Simplex.Chat.Badges
import Simplex.Chat.Badges.Ledger
import Simplex.Chat.Badges.Service (StatementCreditType (..), StatementDebitType (..), StatementEntry (..), StatementEntryType (..))
import Simplex.Chat.Badges.Types (BadgeAlertKind, BadgeIssueError (..), BadgeIssueFailure, BadgePurchaseStatus (..), OpenStorePurchase (..))
import Simplex.Chat.PaymentService (ServicePayment)
import Simplex.Chat.PaymentService.Types (StoreTransactionRef (..))
import Simplex.Chat.Store.Shared (StoreError, insertedRowId)
import Simplex.Chat.Types
import Simplex.Messaging.Agent.Protocol (UserId)
import Simplex.Messaging.Agent.Store.DB (Binary (..), BoolInt (..))
import qualified Simplex.Messaging.Agent.Store.DB as DB
import qualified Simplex.Messaging.Crypto as C
import Simplex.Messaging.Encoding.String (strEncode)
import Simplex.Messaging.Util (decodeJSON, maybeFirstRow, maybeFirstRow', safeDecodeUtf8)

#if defined(dbPostgres)
import Database.PostgreSQL.Simple (Only (..), (:.) (..))
import Database.PostgreSQL.Simple.SqlQQ (sql)
#else
import Database.SQLite.Simple (Only (..), (:.) (..))
import Database.SQLite.Simple.QQ (sql)
#endif

-- | The keys one attempt to fund a badge is signed with, stashed before the request is sent so that
-- a retry reaches the service as the same signer and is answered with the credential already issued.
data BadgeStash = BadgeStash
  { stashRef :: BadgeStashRef,
    purchaseKey :: C.PublicKeyEd25519,
    purchasePrivKey :: C.PrivateKeyEd25519,
    masterKey :: BadgeMasterKey
  }

data BadgeStashRef = BSRCodeRedemption Int64 | BSRStoreReceipt Int64

getBadgeCodeRedemption :: DB.Connection -> User -> Text -> IO (Maybe BadgeStash)
getBadgeCodeRedemption db User {userId} code =
  maybeFirstRow (toBadgeStash BSRCodeRedemption) $
    DB.query
      db
      [sql|
        SELECT badge_code_redemption_id, purchase_key, purchase_priv_key, master_key
        FROM badge_code_redemptions
        WHERE user_id = ? AND code = ?
      |]
      (userId, code)

createBadgeCodeRedemption :: DB.Connection -> TVar ChaChaDRG -> User -> Text -> UTCTime -> IO BadgeStash
createBadgeCodeRedemption db g User {userId} code now = do
  (purchaseKey, purchasePrivKey) <- atomically $ C.generateKeyPair g
  masterKey@(BadgeMasterKey mk) <- generateMasterKey g
  DB.execute
    db
    [sql|
      INSERT INTO badge_code_redemptions (user_id, code, purchase_key, purchase_priv_key, master_key, created_at)
      VALUES (?,?,?,?,?,?)
    |]
    (userId, code, purchaseKey, purchasePrivKey, Binary mk, now)
  redemptionId <- insertedRowId db
  pure BadgeStash {stashRef = BSRCodeRedemption redemptionId, purchaseKey, purchasePrivKey, masterKey}

-- | A store receipt as the record has it: held until the service credits or refuses it.
data StoreReceipt = StoreReceipt
  { receiptId :: Int64,
    ownerId :: UserId,
    status :: StoreReceiptStatus
  }

data StoreReceiptStatus
  = RSHeld
  | RSCredited {badgePurchaseId :: Int64}
  | RSRefused {refusal :: Maybe BadgeIssueFailure}

-- | A store transaction belongs to the store account, not to a profile, so it is found across profiles and
-- stays with the record whose keys the service may have credited. A new one goes to the record created when
-- Buy was tapped, or else to the presenting profile. 'True' when this hand-over is the one that held it.
holdStoreReceipt :: DB.Connection -> TVar ChaChaDRG -> User -> Maybe Text -> StoreTransactionRef -> ServicePayment -> UTCTime -> IO (Maybe (StoreReceipt, Bool))
holdStoreReceipt db g User {userId} invoiceId_ txRef@StoreTransactionRef {provider, transactionRef} payment now =
  getStoreReceipt db txRef >>= \case
    Just r@StoreReceipt {receiptId} -> do
      -- a settled record stays settled, so a hand-over landing just after its credit cannot hold it again
      DB.execute db "UPDATE badge_store_receipts SET payment = ? WHERE badge_store_receipt_id = ? AND payment IS NOT NULL" (paymentJSON, receiptId)
      pure $ Just (r, False)
    Nothing -> do
      forM_ invoiceId_ $ \invoiceId ->
        DB.execute
          db
          "UPDATE badge_store_receipts SET provider = ?, transaction_ref = ?, payment = ? WHERE invoice_id = ? AND transaction_ref IS NULL"
          (provider, transactionRef, paymentJSON, invoiceId)
      getStoreReceipt db txRef >>= \case
        Just r -> pure $ Just (r, True)
        Nothing -> do
          insertReceipt
          -- read back rather than trusted: a concurrent hand-over of the same transaction may have inserted first
          fmap (,True) <$> getStoreReceipt db txRef
  where
    paymentJSON = safeDecodeUtf8 . LB.toStrict $ J.encode payment
    insertReceipt = do
      (purchaseKey, purchasePrivKey) <- atomically (C.generateKeyPair g) :: IO C.KeyPairEd25519
      BadgeMasterKey mk <- generateMasterKey g
      -- an invoice id another record holds is not repeated: this record is then keyed by its transaction alone
      invoiceId' <- fmap join . forM invoiceId_ $ \invoiceId -> do
        taken <- DB.query db "SELECT badge_store_receipt_id FROM badge_store_receipts WHERE invoice_id = ?" (Only invoiceId) :: IO [Only Int64]
        pure $ if null taken then Just invoiceId else Nothing
      DB.execute
        db
        [sql|
          INSERT INTO badge_store_receipts
            (user_id, invoice_id, provider, transaction_ref, payment, purchase_key, purchase_priv_key, master_key, created_at)
          VALUES (?,?,?,?,?,?,?,?,?)
          ON CONFLICT DO NOTHING
        |]
        ((userId, invoiceId', provider, transactionRef, paymentJSON) :. (purchaseKey, purchasePrivKey, Binary mk, now))

-- | held is a CASE because in Postgres a comparison is boolean, which BoolInt rejects.
getStoreReceipt :: DB.Connection -> StoreTransactionRef -> IO (Maybe StoreReceipt)
getStoreReceipt db StoreTransactionRef {provider, transactionRef} =
  maybeFirstRow toStoreReceipt $
    DB.query
      db
      [sql|
        SELECT r.badge_store_receipt_id, r.user_id, (CASE WHEN r.payment IS NULL THEN 0 ELSE 1 END), p.badge_purchase_id, r.credit_error
        FROM badge_store_receipts r
        LEFT JOIN badge_purchases p ON p.badge_store_receipt_id = r.badge_store_receipt_id
        WHERE r.provider = ? AND r.transaction_ref = ?
      |]
      (provider, transactionRef)
  where
    toStoreReceipt (receiptId, ownerId, BI held, purchaseId_, refusal) =
      StoreReceipt {receiptId, ownerId, status = if held then RSHeld else maybe (RSRefused refusal) RSCredited purchaseId_}

-- | The record made when Buy is tapped, before any receipt: the store echoes its invoice id.
createBadgeStoreReceipt :: DB.Connection -> TVar ChaChaDRG -> User -> Text -> UTCTime -> IO ()
createBadgeStoreReceipt db g User {userId} invoiceId now = do
  (purchaseKey, purchasePrivKey) <- atomically (C.generateKeyPair g) :: IO C.KeyPairEd25519
  BadgeMasterKey mk <- generateMasterKey g
  DB.execute
    db
    [sql|
      INSERT INTO badge_store_receipts (user_id, invoice_id, purchase_key, purchase_priv_key, master_key, created_at)
      VALUES (?,?,?,?,?,?)
    |]
    (userId, invoiceId, purchaseKey, purchasePrivKey, Binary mk, now)

-- | No receipt yet, or one held: a credited or refused record is settled and not listed.
getOpenStorePurchases :: DB.Connection -> User -> IO [OpenStorePurchase]
getOpenStorePurchases db User {userId} =
  map toOpenStorePurchase
    <$> DB.query
      db
      [sql|
        SELECT invoice_id, transaction_ref, credit_error
        FROM badge_store_receipts
        WHERE user_id = ? AND (transaction_ref IS NULL OR payment IS NOT NULL)
        ORDER BY badge_store_receipt_id
      |]
      (Only userId)
  where
    toOpenStorePurchase (invoiceId, transactionRef, creditError) = OpenStorePurchase {invoiceId, transactionRef, creditError}

data HeldStoreReceipt = HeldStoreReceipt
  { receiptId :: Int64,
    stash :: BadgeStash,
    payment :: Text,
    retryDelay :: Maybe Int64
  }

getNextDueStoreReceipt :: DB.Connection -> UserId -> Set Int64 -> IO (Either StoreError (Maybe HeldStoreReceipt))
getNextDueStoreReceipt db userId parked =
  Right . find notParked . map toHeld
    <$> DB.query
      db
      [sql|
        SELECT r.badge_store_receipt_id, r.purchase_key, r.purchase_priv_key, r.master_key, r.payment, r.retry_delay
        FROM badge_store_receipts r
        JOIN users u ON u.user_id = r.user_id
        WHERE r.user_id = ? AND r.payment IS NOT NULL AND u.shown_badge_id IS NULL
        ORDER BY r.badge_store_receipt_id
      |]
      (Only userId)
  where
    notParked HeldStoreReceipt {receiptId} = receiptId `S.notMember` parked
    toHeld (stashRow@(receiptId, _, _, _) :. (payment, retryDelay)) =
      HeldStoreReceipt {receiptId, stash = toBadgeStash BSRStoreReceipt stashRow, payment, retryDelay}

recordStoreReceiptFailure :: DB.Connection -> Int64 -> Int64 -> BadgeIssueFailure -> IO ()
recordStoreReceiptFailure db receiptId retryDelay failure =
  DB.execute
    db
    "UPDATE badge_store_receipts SET retry_delay = ?, credit_error = ? WHERE badge_store_receipt_id = ? AND payment IS NOT NULL"
    (retryDelay, failure, receiptId)

-- | Kept rather than deleted, so that a later hand-over of the same transaction is answered from the record.
refuseStoreReceipt :: DB.Connection -> Int64 -> BadgeIssueFailure -> IO ()
refuseStoreReceipt db receiptId refusal =
  DB.execute db "UPDATE badge_store_receipts SET payment = NULL, retry_delay = NULL, credit_error = ? WHERE badge_store_receipt_id = ?" (refusal, receiptId)

-- | A held record is paid for and a credited one is referenced by its purchase, so neither is deleted.
deleteUnfundedStoreReceipts :: DB.Connection -> UTCTime -> IO ()
deleteUnfundedStoreReceipts db createdBefore =
  DB.execute
    db
    [sql|
      DELETE FROM badge_store_receipts
      WHERE payment IS NULL AND created_at < ?
        AND NOT EXISTS (SELECT 1 FROM badge_purchases p WHERE p.badge_store_receipt_id = badge_store_receipts.badge_store_receipt_id)
    |]
    (Only createdBefore)

toBadgeStash :: (Int64 -> BadgeStashRef) -> (Int64, C.PublicKeyEd25519, C.PrivateKeyEd25519, Binary ByteString) -> BadgeStash
toBadgeStash ref (stashId, purchaseKey, purchasePrivKey, Binary mk) =
  BadgeStash {stashRef = ref stashId, purchaseKey, purchasePrivKey, masterKey = BadgeMasterKey mk}

-- | Drop the keys stashed for a code the service refused for good, unless a purchase already came
-- from them - badge_purchases references their row.
deleteBadgeCodeRedemption :: DB.Connection -> User -> Text -> IO ()
deleteBadgeCodeRedemption db User {userId} code =
  DB.execute
    db
    [sql|
      DELETE FROM badge_code_redemptions
      WHERE user_id = ? AND code = ?
        AND NOT EXISTS (SELECT 1 FROM badge_purchases p WHERE p.badge_code_redemption_id = badge_code_redemptions.badge_code_redemption_id)
    |]
    (userId, code)

-- | 'False' when the stash already funded a purchase here: the service replays the credential it
-- issued, and that must add no purchase and leave the shown badge alone.
createStashBadgePurchase :: DB.Connection -> User -> BadgeStash -> BadgeCredential -> UTCTime -> IO (Int64, Bool)
createStashBadgePurchase db User {userId} stash credential now = do
  -- the credit settles a held receipt in the transaction that stores its purchase, a replay included
  forM_ storeReceiptId_ $ \storeReceiptId -> DB.execute db "UPDATE badge_store_receipts SET payment = NULL, retry_delay = NULL WHERE badge_store_receipt_id = ?" (Only storeReceiptId)
  getStashBadgePurchase db stash >>= \case
    Just purchaseId -> pure (purchaseId, False)
    Nothing -> do
      DB.execute
        db
        [sql|
          INSERT INTO badge_purchases
            (user_id, purchase_key, purchase_priv_key, master_key, initial_badge_type, current_badge_type, status,
             badge_code_redemption_id, badge_store_receipt_id, created_at, updated_at)
          VALUES (?,?,?,?,?,?,?,?,?,?,?)
        |]
        ((userId, purchaseKey, purchasePrivKey, Binary mk, badgeType, badgeType) :. (PSIssued, redemptionId_, storeReceiptId_, now, now))
      purchaseId <- insertedRowId db
      DB.execute db "UPDATE users SET shown_badge_id = ? WHERE user_id = ?" (purchaseId, userId)
      pure (purchaseId, True)
  where
    BadgeStash {stashRef, purchaseKey, purchasePrivKey, masterKey = BadgeMasterKey mk} = stash
    BadgeCredential {badgeInfo = BadgeInfo {badgeType}} = credential
    (redemptionId_, storeReceiptId_) = case stashRef of
      BSRCodeRedemption redemptionId -> (Just redemptionId, Nothing)
      BSRStoreReceipt storeReceiptId -> (Nothing, Just storeReceiptId)

-- | The period comes from the ledger, the expiry from the credential, which runs a week longer.
-- 'False' means no issuance row was written, which the caller reports rather than drop in silence.
-- A replayed statement names a month already issued, and one month has one issuance.
storeBadgeIssuance :: DB.Connection -> TVar ChaChaDRG -> Int64 -> Int64 -> BadgeCredential -> UTCTime -> IO Bool
storeBadgeIssuance db g badgePurchaseId entryId credential now =
  getIssuedPeriod db badgePurchaseId entryId >>= \case
    Nothing -> pure False
    Just (periodStart, periodEnd) -> do
      issuanceId <- safeDecodeUtf8 . strEncode <$> atomically (C.randomBytes 16 g)
      DB.execute
        db
        [sql|
          INSERT INTO badge_issuances (issuance_id, badge_purchase_id, entry_id, badge_type, period_start, period_end, expiry, credential, created_at)
          VALUES (?,?,?,?,?,?,?,?,?)
          ON CONFLICT (badge_purchase_id, entry_id) DO NOTHING
        |]
        ((issuanceId, badgePurchaseId, entryId, badgeType) :. (periodStart, periodEnd, badgeExpiry, Binary (LB.toStrict $ J.encode credential), now))
      -- a month stored ends the run of failures
      DB.execute
        db
        "UPDATE badge_purchases SET issue_failed_since = NULL, issue_error_at = NULL, issue_error = NULL WHERE badge_purchase_id = ?"
        (Only badgePurchaseId)
      pure True
  where
    BadgeCredential {badgeInfo = BadgeInfo {badgeType, badgeExpiry}} = credential

getLatestIssuedCredential :: DB.Connection -> Int64 -> IO (Maybe BadgeCredential)
getLatestIssuedCredential db badgePurchaseId = do
  rows <-
    DB.query
      db
      [sql|
        SELECT credential FROM badge_issuances
        WHERE badge_purchase_id = ?
        ORDER BY period_end DESC
        LIMIT 1
      |]
      (Only badgePurchaseId)
  pure $ case rows of
    [Only (Binary bs)] -> J.decodeStrict' bs
    _ -> Nothing

-- the start is read from the row before rather than by subtracting a month, which clips
getIssuedPeriod :: DB.Connection -> Int64 -> Int64 -> IO (Maybe (UTCTime, UTCTime))
getIssuedPeriod db badgePurchaseId entryId = do
  rows <-
    DB.query
      db
      [sql|
        SELECT
          (SELECT prev.balance_start_ts FROM badge_ledger prev
           WHERE prev.badge_purchase_id = issued.badge_purchase_id AND prev.entry_id < issued.entry_id
           ORDER BY prev.entry_id DESC LIMIT 1),
          issued.balance_start_ts
        FROM badge_ledger issued
        WHERE issued.badge_purchase_id = ? AND issued.entry_id = ?
      |]
      (badgePurchaseId, entryId)
  -- no preceding row means no credit was ever stored, so the period this row issued is unknown
  pure $ case rows of
    [(Just periodStart, periodEnd)] -> Just (periodStart, periodEnd)
    _ -> Nothing

getStashBadgePurchase :: DB.Connection -> BadgeStash -> IO (Maybe Int64)
getStashBadgePurchase db BadgeStash {stashRef} =
  maybeFirstRow fromOnly $ case stashRef of
    BSRCodeRedemption redemptionId ->
      DB.query db "SELECT badge_purchase_id FROM badge_purchases WHERE badge_code_redemption_id = ?" (Only redemptionId)
    BSRStoreReceipt storeReceiptId ->
      DB.query db "SELECT badge_purchase_id FROM badge_purchases WHERE badge_store_receipt_id = ?" (Only storeReceiptId)

data UserBadgePurchase = UserBadgePurchase
  { badgePurchaseId :: Int64,
    purchaseKey :: C.PublicKeyEd25519,
    purchasePrivKey :: C.PrivateKeyEd25519,
    masterKey :: BadgeMasterKey,
    badgeType :: BadgeType,
    shown :: Bool,
    alertAcked :: Maybe (BadgeAlertKind, Text),
    alertSnoozeUntil :: Maybe UTCTime,
    issueError :: Maybe BadgeIssueError,
    nextWakeAt :: Maybe UTCTime
  }

-- | Newest, not the one shown_badge_id points at - retirement clears that, and the support ended
-- alert is recomputed from this purchase after the badge stops being shown.
getUserBadgePurchase :: DB.Connection -> User -> IO (Maybe UserBadgePurchase)
getUserBadgePurchase db User {userId} =
  maybeFirstRow fromOnly newestId >>= maybe (pure Nothing) (getBadgePurchase db)
  where
    newestId =
      DB.query
        db
        [sql|
          SELECT badge_purchase_id FROM badge_purchases
          WHERE user_id = ? AND purchase_priv_key IS NOT NULL
          ORDER BY badge_purchase_id DESC
          LIMIT 1
        |]
        (Only userId)

-- shown is a CASE because in Postgres a comparison is boolean, which BoolInt rejects.
getBadgePurchase :: DB.Connection -> Int64 -> IO (Maybe UserBadgePurchase)
getBadgePurchase db purchaseId =
  maybeFirstRow toPurchase $
    DB.query
      db
      [sql|
        SELECT p.badge_purchase_id, p.purchase_key, p.purchase_priv_key, p.master_key, p.current_badge_type,
               (CASE WHEN u.shown_badge_id = p.badge_purchase_id THEN 1 ELSE 0 END),
               p.alert_acked_kind, p.alert_acked_episode, p.alert_snooze_until,
               p.issue_failed_since, p.issue_error_at, p.issue_error, p.next_wake_at
        FROM badge_purchases p
        JOIN users u ON u.user_id = p.user_id
        WHERE p.badge_purchase_id = ? AND p.purchase_priv_key IS NOT NULL
      |]
      (Only purchaseId)
  where
    toPurchase ((badgePurchaseId, purchaseKey, purchasePrivKey, Binary mk, badgeType, shown_, ackedKind_, ackedEpisode_, alertSnoozeUntil) :. (failedSince_, lastAttemptAt_, reason_, nextWakeAt)) =
      UserBadgePurchase
        { badgePurchaseId,
          purchaseKey,
          purchasePrivKey,
          masterKey = BadgeMasterKey mk,
          badgeType,
          shown = unBI shown_,
          alertAcked = (,) <$> ackedKind_ <*> ackedEpisode_,
          alertSnoozeUntil,
          issueError = BadgeIssueError <$> failedSince_ <*> lastAttemptAt_ <*> reason_,
          nextWakeAt
        }

-- | Whether a badge is on the profile now: set when a redemption stores one, cleared when it is
-- retired. Read as the id rather than as a comparison, which in Postgres would be a boolean.
userHasBadge :: DB.Connection -> User -> IO Bool
userHasBadge db User {userId} =
  maybeFirstRow' False shownBadge $
    DB.query db "SELECT shown_badge_id FROM users WHERE user_id = ?" (Only userId)
  where
    shownBadge :: Only (Maybe Int64) -> Bool
    shownBadge = isJust . fromOnly

-- | An ack and a snooze both record the occurrence answered; a snooze also records how long it
-- holds, so that it silences that occurrence and not whichever one is derived next.
setBadgeAlertAcked :: DB.Connection -> User -> Int64 -> BadgeAlertKind -> Text -> Maybe UTCTime -> IO ()
setBadgeAlertAcked db User {userId} badgePurchaseId kind episode snoozeUntil =
  DB.execute
    db
    "UPDATE badge_purchases SET alert_acked_kind = ?, alert_acked_episode = ?, alert_snooze_until = ? WHERE badge_purchase_id = ? AND user_id = ?"
    (kind, episode, snoozeUntil, badgePurchaseId, userId)

-- | Record a renewal that ended without a credential. The COALESCE keeps the start of the current
-- run of failures, which is the alert's episode and must survive a restart.
setBadgeIssueError :: DB.Connection -> Int64 -> UTCTime -> BadgeIssueFailure -> IO ()
setBadgeIssueError db badgePurchaseId now failure =
  DB.execute
    db
    [sql|
      UPDATE badge_purchases
      SET issue_failed_since = COALESCE(issue_failed_since, ?), issue_error_at = ?, issue_error = ?
      WHERE badge_purchase_id = ?
    |]
    (now, now, failure, badgePurchaseId)

-- | The wake the worker is about to wait for, so the state the apps hold says when it will try again.
setBadgeNextWake :: DB.Connection -> Int64 -> Maybe UTCTime -> IO ()
setBadgeNextWake db badgePurchaseId at_ =
  DB.execute db "UPDATE badge_purchases SET next_wake_at = ? WHERE badge_purchase_id = ?" (at_, badgePurchaseId)

-- | Stop showing a badge that has expired unrenewed; the profile update is broadcast by the caller.
clearShownBadge :: DB.Connection -> User -> Int64 -> IO ()
clearShownBadge db User {userId} badgePurchaseId =
  DB.execute db "UPDATE users SET shown_badge_id = NULL WHERE user_id = ? AND shown_badge_id = ?" (userId, badgePurchaseId)

-- | Verbatim, entry_uuid and type included: the client authors no row, or the two sides stop
-- holding the same ledger. DO NOTHING makes a re-applied statement a no-op rather than a throw.
-- An entry whose balance does not follow from the one before it is stored and marked, not refused.
storeBadgeStatement :: DB.Connection -> Int64 -> BadgeType -> Maybe StatementEntry -> [StatementEntry] -> UTCTime -> IO ()
storeBadgeStatement db badgePurchaseId badgeType tip entries now =
  mapM_ storeEntry $ balanceChecked now badgeType tip entries
  where
    storeEntry (StatementEntry {entryId, changeMonths, balanceMonths, balanceStartTs, balanceAnchorTs, balanceBadgeType, wasPausedSince, createdAt, entryType}, checked) =
      DB.execute
        db
        [sql|
          INSERT INTO badge_ledger
            (entry_uuid, badge_purchase_id, change_months, balance_months, balance_start_ts, balance_anchor_ts, balance_badge_type,
             was_paused_since, service_created_at, created_at, entry_type, entry_credit_type, entry_debit_type,
             entry_type_unknown, entry_type_value, balance_checked)
          VALUES (?,?,?,?,?,?,?,?,?,?,?,?,?,?,?,?)
          ON CONFLICT (entry_uuid) DO NOTHING
        |]
        ( (entryId, badgePurchaseId, changeMonths, balanceMonths, balanceStartTs, balanceAnchorTs, balanceBadgeType, wasPausedSince)
            :. (createdAt, now, entryTypeT, creditType, debitType, BI typeUnknown, entryTypeValue, BI <$> checked)
        )
      where
        (entryTypeT, creditType, debitType) = entryTypeColumns entryType
        -- kept for every entry, not only for a type this version cannot decode: a tag alone does
        -- not rebuild the types that name an invoice, a charge or another purchase
        entryTypeValue = safeDecodeUtf8 . LB.toStrict $ case entryType of
          SECredit c -> J.encode c
          SEDebit d -> J.encode d
        typeUnknown = case entryType of
          SECredit SCUnknown {} -> True
          SEDebit SDUnknown {} -> True
          _ -> False

-- | The balance is the last row; nothing derives it by summing the history.
getBadgeLedgerLastEntry :: DB.Connection -> Int64 -> IO (Maybe StatementEntry)
getBadgeLedgerLastEntry db badgePurchaseId =
  maybeFirstRow' Nothing toStatementEntry $
    DB.query
      db
      [sql|
        SELECT entry_uuid, change_months, balance_months, balance_start_ts, balance_anchor_ts, balance_badge_type,
               was_paused_since, service_created_at, entry_type, entry_credit_type, entry_debit_type, entry_type_value
        FROM badge_ledger
        WHERE badge_purchase_id = ?
        ORDER BY entry_id DESC
        LIMIT 1
      |]
      (Only badgePurchaseId)

-- | Oldest first. A row whose type this version cannot rebuild is left out, as it is from the tip.
getBadgeLedger :: DB.Connection -> User -> Int64 -> IO [StatementEntry]
getBadgeLedger db User {userId} badgePurchaseId =
  mapMaybe toStatementEntry
    <$> DB.query
      db
      [sql|
        SELECT l.entry_uuid, l.change_months, l.balance_months, l.balance_start_ts, l.balance_anchor_ts, l.balance_badge_type,
               l.was_paused_since, l.service_created_at, l.entry_type, l.entry_credit_type, l.entry_debit_type, l.entry_type_value
        FROM badge_ledger l
        JOIN badge_purchases p ON p.badge_purchase_id = l.badge_purchase_id
        WHERE l.badge_purchase_id = ? AND p.user_id = ?
        ORDER BY l.entry_id
      |]
      (badgePurchaseId, userId)

toStatementEntry :: (Text, Int, Int, UTCTime, UTCTime, BadgeType) :. (Maybe UTCTime, UTCTime, Text, Maybe Text, Maybe Text, Maybe Text) -> Maybe StatementEntry
toStatementEntry ((entryId, changeMonths, balanceMonths, balanceStartTs, balanceAnchorTs, balanceBadgeType) :. (wasPausedSince, createdAt, entryType_, credit_, debit_, value_)) =
  (\entryType -> StatementEntry {entryId, changeMonths, balanceMonths, balanceStartTs, balanceAnchorTs, balanceBadgeType, wasPausedSince, createdAt, entryType})
    <$> maybe (entryTypeFromColumns Nothing entryType_ credit_ debit_) (entryTypeFromValue entryType_) value_

-- | Decodes the stored JSON rather than rebuilding from the tag, so a version that has since
-- learnt the type reads it with its fields, and one that has not still gets it back verbatim.
entryTypeFromValue :: Text -> Text -> Maybe StatementEntryType
entryTypeFromValue entryTypeT value_ = case entryTypeT of
  "credit" -> SECredit <$> decodeJSON value_
  "debit" -> SEDebit <$> decodeJSON value_
  _ -> Nothing

getBadgeLedgerEntryId :: DB.Connection -> Int64 -> Text -> IO (Maybe Int64)
getBadgeLedgerEntryId db badgePurchaseId entryUuid =
  maybeFirstRow fromOnly $
    DB.query db "SELECT entry_id FROM badge_ledger WHERE badge_purchase_id = ? AND entry_uuid = ?" (badgePurchaseId, entryUuid)