{-# LANGUAGE DeriveAnyClass #-}
{-# LANGUAGE DerivingStrategies #-}
{-# LANGUAGE DerivingVia #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE StrictData #-}

-- | Type definitions, note that all fields are strict
module Web.Telegraph.Types where

import Control.Exception
import Data.Aeson hiding (Result (..))
import Data.Maybe
import Data.Text (Text, unpack)
import Deriving.Aeson
import Deriving.Aeson.Stock
import Generic.Data.Surgery

-- | A Telegraph account
data Account = Account
  { -- | Account name, helps users with several accounts remember which they are currently using
    --
    -- Displayed to the user above the "Edit/Publish" button on Telegra.ph, other users don't see this name
    shortName :: {-# UNPACK #-} Text,
    -- | Default author name used when creating new articles
    authorName :: {-# UNPACK #-} Text,
    -- | Profile link, opened when users click on the author's name below the title
    --
    -- Can be any link, not necessarily to a Telegram profile or channel
    authorUrl :: {-# UNPACK #-} Text,
    -- | Access token of the Telegraph account
    accessToken :: Maybe Text,
    -- | URL to authorize a browser on telegra.ph and connect it to a Telegraph account
    --
    -- This URL is valid for only one use and for 5 minutes only
    authUrl :: Maybe Text,
    -- | Number of pages belonging to the Telegraph account
    pageCount :: Maybe Int
  }
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via CustomJSON '[FieldLabelModifier CamelToSnake, OmitNothingFields] Account

-- | A list of Telegraph articles belonging to an account
--
-- Most recently created articles first
data PageList = PageList
  { -- | Total number of pages belonging to the target Telegraph account
    totalCount :: {-# UNPACK #-} Int,
    -- | Requested pages of the target Telegraph account
    pages :: [Page]
  }
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via Snake PageList

-- | A page on Telegraph
data Page = Page
  { -- | Path to the page
    path :: {-# UNPACK #-} Text,
    -- | URL of the page
    url :: {-# UNPACK #-} Text,
    -- | Title of the page
    title :: {-# UNPACK #-} Text,
    -- | Description of the page
    description :: {-# UNPACK #-} Text,
    -- | Name of the author, displayed below the title
    authorName :: Maybe Text,
    -- | rofile link, opened when users click on the author's name below the title
    --
    -- Can be any link, not necessarily to a Telegram profile or channel
    authorUrl :: Maybe Text,
    -- | Image URL of the page
    imageUrl :: Maybe Text,
    -- | Content of the page
    content :: Maybe [Node],
    -- | Number of page views for the page
    views :: {-# UNPACK #-} Int,
    -- | True, if the target Telegraph account can edit the page
    canEdit :: Maybe Bool
  }
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via CustomJSON '[FieldLabelModifier CamelToSnake, OmitNothingFields] Page

-- | The number of page views for a Telegraph article
newtype PageViews = PageViews {views :: Int}
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via Vanilla PageViews

-- | A DOM Node
data Node
  = Content {-# UNPACK #-} Text
  | Element {-# UNPACK #-} NodeElement
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via CustomJSON '[SumUntaggedValue] Node

-- | A DOM elemen node
data NodeElement = NodeElement
  { -- | Name of the DOM element
    --
    -- Available tags: @a@, @aside@, @b@, @blockquote@, @br@, @code@, @em@, @figcaption@, @figure@,
    -- @h3@, @h4@, @hr@, @i@, @iframe@, @img@, @li@, @ol@, @p@, @pre@, @s@, @strong@, @u@, @ul@, @video@
    tag :: {-# UNPACK #-} Text,
    -- | Attributes of the DOM element
    --
    -- Key of object represents name of attribute, value represents value of attribute
    --
    -- Available attributes: @href@, @src@
    attrs :: [(Text, [Text])],
    -- | List of child nodes for the DOM element
    children :: [Node]
  }
  deriving (Show, Eq, Generic)
  deriving (ToJSON) via Vanilla NodeElement

instance FromJSON NodeElement where
  parseJSON =
    fmap
      ( fromORLazy
          . modifyRField @"attrs" (fromMaybe [])
          . modifyRField @"children" (fromMaybe [])
          . toOR'
      )
      . genericParseJSON defaultOptions

-- | The result of an API call
data Result a
  = Error {-# UNPACK #-} Text
  | Result a
  deriving (Show, Eq, Generic)

instance FromJSON a => FromJSON (Result a) where
  parseJSON = withObject "telegra.ph api call result" $ \o -> do
    ok <- o .: "ok"
    if ok
      then Result <$> o .: "result"
      else Error <$> o .: "error"

-- | An image uploaded to Telegraph
newtype Image = Image
  { -- | The path to the image
    src :: Text
  }
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via Vanilla Image

-- | The result of an image upload
data UploadResult
  = UploadError {error :: {-# UNPACK #-} Text}
  | Sources [Image]
  deriving (Show, Eq, Generic)
  deriving (FromJSON, ToJSON) via CustomJSON '[SumUntaggedValue] UploadResult

newtype TelegraphError
  = -- | An api call has failed, we cannot distinguish between minor errors (such as illformed author urls)
    -- and much serious errors, such as invalid accessTokens, so we always throw exceptions
    APICallFailure Text
  deriving newtype (Eq)
  deriving anyclass (Exception)

instance Show TelegraphError where
  show (APICallFailure e) = "API call failed with error: " ++ unpack e