module Web.Controller.Api.V2.ApiConsumers where

import Web.Types
import Generated.Types
import IHP.Prelude
import IHP.ControllerPrelude
import Data.Aeson (Value, object, (.=))
import Network.Wai (requestMethod)
import Web.Controller.Api.V2.Auth
    ( requireApiConsumer, paginatedResponse, getPageParams
    , respondWithStatus, hashApiKey )
import qualified Data.ByteString.Base16 as Base16
import qualified Data.ByteString.Random as Random
import qualified Data.Text as T
import qualified Data.Text.Encoding as TE
import qualified Data.UUID as UUID

instance Controller ApiV2ApiConsumersController where

    action ApiV2IndexApiConsumersAction = do
        case requestMethod ?request of
            "GET"  -> listApiConsumers
            "POST" -> createApiConsumerRecord
            _      -> respondWithStatus 405 $ object ["error" .= ("Method not allowed" :: Text)]

    action ApiV2ShowApiConsumerAction { apiConsumerId } = do
        _consumer <- requireApiConsumer
        apiConsumer <- fetch apiConsumerId
        renderJson (apiConsumerToJson apiConsumer)

    action ApiV2CreateApiConsumerAction = createApiConsumerRecord

    action ApiV2CreateApiConsumerKeyAction { apiConsumerId } = do
        when (requestMethod ?request /= "POST") do
            respondWithStatus 405 $ object ["error" .= ("Method not allowed" :: Text)]
        createApiConsumerKey apiConsumerId

listApiConsumers :: (?context :: ControllerContext, ?modelContext :: ModelContext, ?respond :: Respond, ?request :: Request) => IO ()
listApiConsumers = do
    _consumer <- requireApiConsumer
    (page, perPage) <- getPageParams
    let pageOffset = (page - 1) * perPage
    total <- query @ApiConsumer |> fetchCount
    consumers <- query @ApiConsumer
        |> orderByDesc #createdAt
        |> limit perPage
        |> offset pageOffset
        |> fetch
    renderJson $ paginatedResponse (map apiConsumerToJson consumers) page perPage total

createApiConsumerRecord :: (?context :: ControllerContext, ?modelContext :: ModelContext, ?respond :: Respond, ?request :: Request) => IO ()
createApiConsumerRecord = do
    _consumer <- requireApiConsumer
    let name = paramOrNothing @Text "name"
        description = paramOrNothing @Text "description"
        rateLimit = fromMaybe 60 (paramOrNothing @Int "rateLimitPerMinute")
        quota = fromMaybe 10000 (paramOrNothing @Int "quotaPerDay")

    when (maybe True (== "") name) do
        respondWithStatus 422 $ object
            [ "error"   .= ("Missing required fields" :: Text)
            , "missing" .= (["name"] :: [Text])
            ]
    unless (positiveLimit rateLimit) do
        respondWithStatus 422 $ object
            [ "error" .= ("rateLimitPerMinute must be positive" :: Text)
            , "code"  .= ("invalid_rate_limit" :: Text)
            ]
    unless (positiveLimit quota) do
        respondWithStatus 422 $ object
            [ "error" .= ("quotaPerDay must be positive" :: Text)
            , "code"  .= ("invalid_quota" :: Text)
            ]

    mManifestId <- parseOptionalActiveManifestId
    let Just nameText = name
    apiConsumer <- newRecord @ApiConsumer
        |> set #name nameText
        |> set #description description
        |> set #hubCapabilityManifestId mManifestId
        |> set #rateLimitPerMinute rateLimit
        |> set #quotaPerDay quota
        |> createRecord
    respondWithStatus 201 (apiConsumerToJson apiConsumer)

createApiConsumerKey :: (?context :: ControllerContext, ?modelContext :: ModelContext, ?respond :: Respond, ?request :: Request) => Id ApiConsumer -> IO ()
createApiConsumerKey apiConsumerId = do
    _requestingConsumer <- requireApiConsumer
    apiConsumer <- fetch apiConsumerId
    unless apiConsumer.isActive do
        respondWithStatus 422 $ object
            [ "error" .= ("API consumer is inactive" :: Text)
            , "code"  .= ("api_consumer_inactive" :: Text)
            ]
    let scopes = fromMaybe "" (paramOrNothing @Text "scopes")

    fullKey <- generateApiKeySecret
    let prefix = T.take 8 fullKey
        keyHash = hashApiKey fullKey
    apiKey <- newRecord @ApiKey
        |> set #apiConsumerId apiConsumer.id
        |> set #keyPrefix prefix
        |> set #keyHash keyHash
        |> set #scopes scopes
        |> set #tokenType "static"
        |> createRecord
    respondWithStatus 201 (apiKeyCreatedToJson apiKey fullKey)

parseOptionalActiveManifestId :: (?context :: ControllerContext, ?modelContext :: ModelContext, ?respond :: Respond, ?request :: Request) => IO (Maybe (Id HubCapabilityManifest))
parseOptionalActiveManifestId =
    case nonEmptyText =<< paramOrNothing @Text "hubCapabilityManifestId" of
        Nothing -> pure Nothing
        Just manifestIdRaw ->
            case UUID.fromText manifestIdRaw of
                Nothing -> respondWithStatus 422 $ object
                    ["error" .= ("hubCapabilityManifestId must be a valid UUID" :: Text)]
                Just rawId -> do
                    let manifestId = Id rawId :: Id HubCapabilityManifest
                    mManifest <- fetchOneOrNothing manifestId
                    case mManifest of
                        Nothing -> respondWithStatus 422 $ object
                            ["error" .= ("Hub capability manifest not found" :: Text)]
                        Just manifest -> do
                            unless (manifest.status == "active") do
                                respondWithStatus 422 $ object
                                    [ "error" .= ("Hub capability manifest must be active" :: Text)
                                    , "code"  .= ("manifest_not_active" :: Text)
                                    ]
                            pure (Just manifestId)

generateApiKeySecret :: IO Text
generateApiKeySecret = do
    rawBytes <- Random.random 32
    pure $ TE.decodeUtf8 (Base16.encode rawBytes)

apiConsumerToJson :: ApiConsumer -> Value
apiConsumerToJson apiConsumer = object
    [ "id" .= apiConsumer.id
    , "name" .= apiConsumer.name
    , "description" .= apiConsumer.description
    , "hubCapabilityManifestId" .= apiConsumer.hubCapabilityManifestId
    , "rateLimitPerMinute" .= apiConsumer.rateLimitPerMinute
    , "quotaPerDay" .= apiConsumer.quotaPerDay
    , "quotaResetsAt" .= apiConsumer.quotaResetsAt
    , "isActive" .= apiConsumer.isActive
    , "createdAt" .= apiConsumer.createdAt
    , "updatedAt" .= apiConsumer.updatedAt
    ]

apiKeyToJson :: ApiKey -> Value
apiKeyToJson apiKey = object
    [ "id" .= apiKey.id
    , "apiConsumerId" .= apiKey.apiConsumerId
    , "keyPrefix" .= apiKey.keyPrefix
    , "scopes" .= apiKey.scopes
    , "tokenType" .= apiKey.tokenType
    , "expiresAt" .= apiKey.expiresAt
    , "revokedAt" .= apiKey.revokedAt
    , "lastUsedAt" .= apiKey.lastUsedAt
    , "createdAt" .= apiKey.createdAt
    ]

apiKeyCreatedToJson :: ApiKey -> Text -> Value
apiKeyCreatedToJson apiKey fullKey = object
    [ "apiKey" .= apiKeyToJson apiKey
    , "fullKey" .= fullKey
    , "displayOnce" .= True
    ]

positiveLimit :: Int -> Bool
positiveLimit value = value > 0

nonEmptyText :: Text -> Maybe Text
nonEmptyText "" = Nothing
nonEmptyText value = Just value