{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE OverloadedStrings #-}

-- |
-- Module: Aws.General
-- Copyright: Copyright © 2014 AlephCloud Systems, Inc.
-- License: BSD3
-- Maintainer: Lars Kuhtz <lars@alephcloud.com>
-- Stability: experimental
--
-- Bindings for AWS General Reference
--
-- /API Version: 1.0/
--
-- <http://docs.aws.amazon.com/general/latest/gr/>
--
module Aws.General
( AwsType(..)

-- * AWS General Version
, GeneralVersion(..)
, generalVersionToText
, parseGeneralVersion

-- * SignatureVersion
, SignatureVersion(..)
, signatureVersionToText
, parseSignatureVersion

-- * SignatureMethod
, SignatureMethod(..)
, signatureMethodToText
, parseSignatureMethod

-- * AWS Region
, Region(..)
, regionToText
, parseRegion

-- * AWS Account ID
, AccountId(..)
, accountIdToText
, parseAccountId

-- * AWS Canonical User ID
, CanonicalUserId(..)
, canonicalUserIdToText
, parseCanonicalUserId

-- * AWS Service Namespace
, ServiceNamespace(..)
, serviceNamespaceToText
, parseServiceNamespace

-- * AWS ARN
, Arn(..)
, arnToText
, parseArn
) where

import Control.Applicative
import Control.Monad

import Data.Aeson (ToJSON(..), FromJSON(..), withText)
import qualified Data.Attoparsec.Text as AP
import Data.Hashable (Hashable, hashWithSalt, hashUsing)
import Data.Monoid
import Data.String
import qualified Data.Text as T
import Data.Typeable

import qualified Test.QuickCheck as Q
import Test.QuickCheck.Instances ()

import qualified Text.Parser.Char as P
import qualified Text.Parser.Combinators as P
import Text.Parser.Combinators ((<?>))
import Text.Printf

-- -------------------------------------------------------------------------- --
-- AWS Type

class AwsType a where
    toText :: (IsString b, Monoid b) => a -> b
    parse :: (Monad m,  P.CharParsing m) => m a

    fromText :: T.Text -> Either String a
    fromText = AP.parseOnly $ parse <* P.eof

-- -------------------------------------------------------------------------- --
-- General API Version

data GeneralVersion
    = GeneralVersion_1_0
    deriving (Show, Read, Eq, Ord, Enum, Bounded, Typeable)

generalVersionToText :: (IsString a) => GeneralVersion -> a
generalVersionToText GeneralVersion_1_0 = "1.0"

parseGeneralVersion :: P.CharParsing m => m GeneralVersion
parseGeneralVersion = GeneralVersion_1_0 <$ P.text "1.0"
    <?> "General Version"

instance AwsType GeneralVersion where
    toText = generalVersionToText
    parse = parseGeneralVersion

instance Q.Arbitrary GeneralVersion where
    arbitrary = Q.elements [minBound..maxBound]

-- -------------------------------------------------------------------------- --
-- Signature Version

data SignatureVersion
    = SignatureVersion2
    | SignatureVersion4
    deriving (Show, Read, Eq, Ord, Enum, Bounded, Typeable)

signatureVersionToText :: IsString a => SignatureVersion -> a
signatureVersionToText SignatureVersion2 = "2"
signatureVersionToText SignatureVersion4 = "4"

parseSignatureVersion :: P.CharParsing m => m SignatureVersion
parseSignatureVersion =
    SignatureVersion2 <$ P.text "2"
    <|> SignatureVersion4 <$ P.text "4"
    <?> "SignatureVersion"

instance AwsType SignatureVersion where
    toText = signatureVersionToText
    parse = parseSignatureVersion

instance Q.Arbitrary SignatureVersion where
    arbitrary = Q.elements [minBound..maxBound]

-- -------------------------------------------------------------------------- --
-- Signature Method

data SignatureMethod
    = SignatureMethodSha1
    | SignatureMethodSha256
    deriving (Show, Read, Eq, Ord, Enum, Bounded, Typeable)

signatureMethodToText :: IsString a => SignatureMethod -> a
signatureMethodToText SignatureMethodSha1 = "HmacSHA1"
signatureMethodToText SignatureMethodSha256 = "HmacSHA256"

parseSignatureMethod :: P.CharParsing m => m SignatureMethod
parseSignatureMethod =
    SignatureMethodSha1 <$ P.text "HmacSHA1"
    <|> SignatureMethodSha256 <$ P.text "HmacSHA256"
    <?> "SignatureMethod"

instance AwsType SignatureMethod where
    toText = signatureMethodToText
    parse = parseSignatureMethod

instance Q.Arbitrary SignatureMethod where
    arbitrary = Q.elements [minBound..maxBound]

-- -------------------------------------------------------------------------- --
-- AWS Region

-- | Region
--
-- <http://docs.aws.amazon.com/general/1.0/gr/rande.html>
--
-- The relation between regions and service endpoints is not bijective for all
-- AWS services. Not all AWS services support all regions. Some services don't
-- use the concept of region at all.
--
data Region
    = ApNortheast1
    | ApSoutheast1
    | ApSoutheast2
    | EuWest1
    | SaEast1
    | UsEast1
    | UsWest1
    | UsWest2
    deriving (Show, Read, Eq, Ord, Enum, Bounded, Typeable)

regionToText :: IsString a => Region -> a
regionToText ApNortheast1 = "ap-northeast-1"
regionToText ApSoutheast1 = "ap-southeast-1"
regionToText ApSoutheast2 = "ap-southeast-2"
regionToText EuWest1 = "eu-west-1"
regionToText SaEast1 = "sa-east-1"
regionToText UsEast1 = "us-east-1"
regionToText UsWest1 = "us-west-1"
regionToText UsWest2 = "us-west-2"

parseRegion :: P.CharParsing m => m Region
parseRegion =
    ApNortheast1 <$ P.text "ap-northeast-1"
    <|> ApSoutheast1 <$ P.text "ap-southeast-1"
    <|> ApSoutheast2 <$ P.text "ap-southeast-2"
    <|> EuWest1 <$ P.text "eu-west-1"
    <|> SaEast1 <$ P.text "sa-east-1"
    <|> UsEast1 <$ P.text "us-east-1"
    <|> UsWest1 <$ P.text "us-west-1"
    <|> UsWest2 <$ P.text "us-west-2"
    <?> "Region"

instance AwsType Region where
    toText = regionToText
    parse = parseRegion

{-
instance FromJSON Ec2Region where
    parseJSON = withText "Ec2Region" $ either fail return ∘ readEither ∘ T.unpack

instance ToJSON Ec2Region where
    toJSON = toJSON ∘ show
-}

instance Hashable Region where
     hashWithSalt = hashUsing fromEnum

instance Q.Arbitrary Region where
    arbitrary = Q.elements [minBound..maxBound]

-- -------------------------------------------------------------------------- --
-- AWS Account Id

-- | AWS Account Id
--
-- <http://docs.aws.amazon.com/general/1.0/gr/acct-identifiers.html>.
--
-- This is actually a 12 digit number.
--
newtype AccountId = AccountId T.Text
    deriving (Show, Read, Eq, Ord, IsString, Typeable)

accountIdToText :: (IsString a) => AccountId -> a
accountIdToText (AccountId t) = fromString $ T.unpack t

parseAccountId :: P.CharParsing m => m AccountId
parseAccountId = AccountId . T.pack
    <$> P.count 12 P.digit
    <?> "Account ID"

instance AwsType AccountId where
    toText = accountIdToText
    parse = parseAccountId

instance Q.Arbitrary AccountId where
    arbitrary = AccountId . T.pack . printf "%012d" <$> Q.choose (0::Integer, 999999999999)

-- -------------------------------------------------------------------------- --
-- AWS Canonical User ID

-- | AWS Canonical User ID
--
-- <http://docs.aws.amazon.com/general/latest/gr/acct-identifiers.html>.
--
-- This is actually a long hexadecimal number
--
newtype CanonicalUserId = CanonicalUserId T.Text
    deriving (Show, Read, Eq, Ord, IsString, Typeable)

canonicalUserIdToText :: (IsString a) => CanonicalUserId -> a
canonicalUserIdToText (CanonicalUserId t) = fromString $ T.unpack t

parseCanonicalUserId :: P.CharParsing m => m CanonicalUserId
parseCanonicalUserId = CanonicalUserId . T.pack
    <$> some P.hexDigit
    <?> "Canonical User ID"

instance AwsType CanonicalUserId where
    toText = canonicalUserIdToText
    parse = parseCanonicalUserId

instance Q.Arbitrary CanonicalUserId where
    arbitrary = CanonicalUserId . T.pack <$> do
        i <- Q.choose (32,128)
        replicateM i (Q.elements $ ['0'..'9'] <> ['a'..'f'])

-- -------------------------------------------------------------------------- --
-- Service Namespace

-- | AWS Service Namespaces
--
-- <http://docs.aws.amazon.com/general/1.0/gr/aws-arns-and-namespaces.html#genref-aws-service-namespaces>
--
data ServiceNamespace
    = ServiceNamespaceAwsPortal
    | ServiceNamespaceAutoscaling
    | ServiceNamespaceCloudformation
    | ServiceNamespaceCloudfront
    | ServiceNamespaceCloudwatch
    | ServiceNamespaceDynamodb
    | ServiceNamespaceEc2
    -- ^ Amazon EC2 and Amazon VPC
    | ServiceNamespaceElasticbeanstalk
    | ServiceNamespaceElasticloadbalancing
    | ServiceNamespaceElasticmapreduce
    | ServiceNamespaceElasticache
    | ServiceNamespaceGlacier
    | ServiceNamespaceIam
    | ServiceNamespaceKinesis
    | ServiceNamespaceAwsMarketplaceManagement
    | ServiceNamespaceOpsworks
    | ServiceNamespaceRds
    | ServiceNamespaceRedshift
    | ServiceNamespaceRoute53
    | ServiceNamespaceS3
    | ServiceNamespaceSes
    | ServiceNamespaceSdb
    | ServiceNamespaceSqs
    | ServiceNamespaceSns
    | ServiceNamespaceStoragegateway
    | ServiceNamespaceSts
    | ServiceNamespaceSupport
    | ServiceNamespaceSwf
    | ServiceNamespaceHost
    -- ^ For testing purposes (see <http://docs.aws.amazon.com/general/1.0/gr/signature-v4-test-suite.html>)
    deriving (Show, Read, Eq, Ord, Enum, Bounded, Typeable)

serviceNamespaceToText :: IsString a => ServiceNamespace -> a
serviceNamespaceToText ServiceNamespaceAwsPortal = "aws-portal"
serviceNamespaceToText ServiceNamespaceAutoscaling = "autoscaling"
serviceNamespaceToText ServiceNamespaceCloudformation = "cloudformation"
serviceNamespaceToText ServiceNamespaceCloudfront = "cloudfront"
serviceNamespaceToText ServiceNamespaceCloudwatch = "cloudwatch"
serviceNamespaceToText ServiceNamespaceDynamodb = "dynamodb"
serviceNamespaceToText ServiceNamespaceEc2 = "ec2"
serviceNamespaceToText ServiceNamespaceElasticbeanstalk = "elasticbeanstalk"
serviceNamespaceToText ServiceNamespaceElasticloadbalancing = "elasticloadbalancing"
serviceNamespaceToText ServiceNamespaceElasticmapreduce = "elasticmapreduce"
serviceNamespaceToText ServiceNamespaceElasticache = "elasticache"
serviceNamespaceToText ServiceNamespaceGlacier = "glacier"
serviceNamespaceToText ServiceNamespaceIam = "iam"
serviceNamespaceToText ServiceNamespaceKinesis = "kinesis"
serviceNamespaceToText ServiceNamespaceAwsMarketplaceManagement = "aws-marketplace-management"
serviceNamespaceToText ServiceNamespaceOpsworks = "opsworks"
serviceNamespaceToText ServiceNamespaceRds = "rds"
serviceNamespaceToText ServiceNamespaceRedshift = "redshift"
serviceNamespaceToText ServiceNamespaceRoute53 = "route53"
serviceNamespaceToText ServiceNamespaceS3 = "s3"
serviceNamespaceToText ServiceNamespaceSes = "ses"
serviceNamespaceToText ServiceNamespaceSdb = "sdb"
serviceNamespaceToText ServiceNamespaceSqs = "sqs"
serviceNamespaceToText ServiceNamespaceSns = "sns"
serviceNamespaceToText ServiceNamespaceStoragegateway = "storagegateway"
serviceNamespaceToText ServiceNamespaceSts = "sts"
serviceNamespaceToText ServiceNamespaceSupport = "support"
serviceNamespaceToText ServiceNamespaceSwf = "swf"
serviceNamespaceToText ServiceNamespaceHost = "host"

parseServiceNamespace :: P.CharParsing m => m ServiceNamespace
parseServiceNamespace =
    ServiceNamespaceAwsPortal <$ P.text "aws-portal"
    <|> ServiceNamespaceAutoscaling <$ P.text "autoscaling"
    <|> ServiceNamespaceCloudformation <$ P.text "cloudformation"
    <|> ServiceNamespaceCloudfront <$ P.text "cloudfront"
    <|> ServiceNamespaceCloudwatch <$ P.text "cloudwatch"
    <|> ServiceNamespaceDynamodb <$ P.text "dynamodb"
    <|> ServiceNamespaceEc2 <$ P.text "ec2"
    <|> ServiceNamespaceElasticbeanstalk <$ P.text "elasticbeanstalk"
    <|> ServiceNamespaceElasticloadbalancing <$ P.text "elasticloadbalancing"
    <|> ServiceNamespaceElasticmapreduce <$ P.text "elasticmapreduce"
    <|> ServiceNamespaceElasticache <$ P.text "elasticache"
    <|> ServiceNamespaceGlacier <$ P.text "glacier"
    <|> ServiceNamespaceIam <$ P.text "iam"
    <|> ServiceNamespaceKinesis <$ P.text "kinesis"
    <|> ServiceNamespaceAwsMarketplaceManagement <$ P.text "aws-marketplace-management"
    <|> ServiceNamespaceOpsworks <$ P.text "opsworks"
    <|> ServiceNamespaceRds <$ P.text "rds"
    <|> ServiceNamespaceRedshift <$ P.text "redshift"
    <|> ServiceNamespaceRoute53 <$ P.text "route53"
    <|> ServiceNamespaceS3 <$ P.text "s3"
    <|> ServiceNamespaceSes <$ P.text "ses"
    <|> ServiceNamespaceSdb <$ P.text "sdb"
    <|> ServiceNamespaceSqs <$ P.text "sqs"
    <|> ServiceNamespaceSns <$ P.text "sns"
    <|> ServiceNamespaceStoragegateway <$ P.text "storagegateway"
    <|> ServiceNamespaceSts <$ P.text "sts"
    <|> ServiceNamespaceSupport <$ P.text "support"
    <|> ServiceNamespaceSwf <$ P.text "swf"
    <|> ServiceNamespaceHost <$ P.text "host"
    <?> "Service Namespace"

instance AwsType ServiceNamespace where
    toText = serviceNamespaceToText
    parse = parseServiceNamespace

instance Hashable ServiceNamespace where
     hashWithSalt = hashUsing fromEnum

instance Q.Arbitrary ServiceNamespace where
    arbitrary = Q.elements [minBound..maxBound]

-- -------------------------------------------------------------------------- --
-- ARN

-- | Amazon Resource Names
--
-- <http://docs.aws.amazon.com/general/1.0/gr/aws-arns-and-namespaces.html>
--
-- From the specification it is not clear if elements of 'arnResource'
-- can be empty. Though examples given in the specification do not inlcude
-- such a case, our parser allows it.
--
data Arn = Arn
    { arnService :: ServiceNamespace
    , arnRegion :: Maybe Region
    , arnAccount :: Maybe AccountId
    , arnResource :: [T.Text]
    -- ^ expected to be non-empty. Elements are separated by only @:@.
    -- @/@ is not treated specially.
    }
    deriving (Show, Read, Eq, Ord, Typeable)

arnToText :: (IsString a, Monoid a) => Arn -> a
arnToText arn = "arn:aws"
    <> ":" <> serviceNamespaceToText (arnService arn)
    <> ":" <> maybe "" regionToText (arnRegion arn)
    <> ":" <> maybe "" accountIdToText (arnAccount arn)
    <> ":" <> (fromString . T.unpack) (T.intercalate ":" (arnResource arn))

parseArn :: P.CharParsing m => m Arn
parseArn = P.text "arn:aws" *> p <?> "ARN"
  where
    p = Arn
        <$> (P.char ':' *> parseServiceNamespace)
        <*> (P.char ':' *> P.optional parseRegion)
        <*> (P.char ':' *> P.optional parseAccountId)
        <*> (P.char ':' *> P.sepBy1 (T.pack <$> many (P.notChar ':')) (P.char ':'))

instance AwsType Arn where
    toText = arnToText
    parse = parseArn

instance ToJSON Arn where
    toJSON = toJSON . (arnToText :: Arn -> T.Text)

instance FromJSON Arn where
    parseJSON = withText "Arn" $ either fail return . fromText

-- | This instance if for general testing of the syntax of ARNs. For service
-- specific ARNs you should use a newtype wrapper and define an 'Arbitrary'
-- instance the satisfies the constraints of that particular services.
--
instance Q.Arbitrary Arn where
    arbitrary = Arn
        <$> Q.arbitrary
        <*> Q.arbitrary
        <*> Q.arbitrary
        <*> (map (T.filter (/= ':')) . Q.getNonEmpty <$> Q.arbitrary)