{-# LANGUAGE OverloadedStrings #-}

module GitHub.Types.Events where


import Control.Applicative
import Control.Monad

import Data.Aeson
import Data.Aeson.Types
import Data.Text

import GitHub.Types.Base
import GitHub.Types.Repository



-- | All events which can be produced by GitHub.
--
-- See https://developer.github.com/v3/activity/events/types/
data Event
    = CommitCommentEventType    CommitCommentEvent
    | DeploymentEventType       DeploymentEvent
    | DeploymentStatusEventType DeploymentStatusEvent
    deriving (Eq, Show)


-- | Since the event type is included through different means (X-GitHub-Event
-- header, or inline in the JSON object), it's not possible to make 'Event'
-- an instance of 'FromJSON'. But if you know the type, you can use this
-- parser.
eventParser :: Text -> Value -> Parser Event
eventParser "commit_comment"    x = CommitCommentEventType    <$> parseJSON x
eventParser "deployment"        x = DeploymentEventType       <$> parseJSON x
eventParser "deployment_status" x = DeploymentStatusEventType <$> parseJSON x
eventParser _                   _ = mzero



------------------------------------------------------------------------------
-- CommitCommentEvent

data CommitCommentEvent = CommitCommentEvent
    { commitCommentEventRepository :: Repository
    } deriving (Eq, Show)

instance FromJSON CommitCommentEvent where
    parseJSON (Object x) = CommitCommentEvent
        <$> x .: "repository"

    parseJSON _ = mzero


------------------------------------------------------------------------------
-- DeploymentEvent

data DeploymentEvent = DeploymentEvent
    { deploymentEventDeployment  :: Deployment
      -- ^ The deployment.
    , deploymentEventRepository  :: Repository
      -- ^ The repository for which the deployment was created (UNDOCUMENTED).
    } deriving (Eq, Show)

instance FromJSON DeploymentEvent where
    parseJSON (Object x) = DeploymentEvent
        <$> x .: "deployment"
        <*> x .: "repository"

    parseJSON _ = mzero


------------------------------------------------------------------------------
-- DeploymentStatusEvent

data DeploymentStatusEvent = DeploymentStatusEvent
    { deploymentStatusEventDeploymentStatus :: DeploymentStatus
      -- ^ The deployment status.
    , deploymentStatusEventDeployment       :: Deployment
      -- ^ The deployment which the status affects.
    , deploymentStatusEventRepository       :: Repository
      -- ^ The repository for which the deployment was created (UNDOCUMENTED).
    } deriving (Eq, Show)

instance FromJSON DeploymentStatusEvent where
    parseJSON (Object x) = DeploymentStatusEvent
        <$> x .: "deployment_status"
        <*> x .: "deployment"
        <*> x .: "repository"

    parseJSON _ = mzero