{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE OverloadedStrings #-}

-- |
-- Module      : Pinboard.Types
-- Copyright   : (c) Jon Schoning, 2015
-- Maintainer  : jonschoning@gmail.com
-- Stability   : experimental
-- Portability : POSIX
module Pinboard.ApiTypes where

import Prelude hiding      (words)
import Control.Applicative ((<$>), (<*>), (<|>))
import Data.Aeson          (FromJSON (parseJSON), Value (String, Object), ( .:))
import Data.Aeson.Types    (Parser)
import Data.HashMap.Strict (HashMap, member, toList)
import Data.Text           (Text, words, unpack)
import Data.Time           (UTCTime)
import Data.Time.Calendar  (Day)
import Data.Time.Format    (readTime)
import System.Locale       (defaultTimeLocale)
import qualified Data.HashMap.Strict as HM


-- * Posts

data Posts = Posts {
      postsDate         :: UTCTime
    , postsUser         :: Text
    , posts             :: [Post]
    } deriving (Show, Eq)

instance FromJSON Posts where
   parseJSON (Object o) =
       Posts <$> o .: "date"
             <*> o .: "user"
             <*> o .: "posts"
   parseJSON _ = error "bad parse"

data Post = Post {
      postHref         :: Text
    , postDescription  :: Text
    , postExtended     :: Text
    , postMeta         :: Text
    , postHash         :: Text
    , postTime         :: UTCTime
    , postShared       :: Bool
    , postToread       :: Bool
    , postTags         :: [Text]
    } deriving (Show, Eq)

instance FromJSON Post where
   parseJSON (Object o) =
       Post <$> o .: "href"
            <*> o .: "description"
            <*> o .: "extended"
            <*> o .: "meta"
            <*> o .: "hash"
            <*> o .: "time"
            <*> (boolFromYesNo <$> o .: "shared")
            <*> (boolFromYesNo <$> o .: "toread")
            <*> (words <$> o .: "tags")
   parseJSON _ = error "bad parse"

boolFromYesNo :: Text -> Bool
boolFromYesNo "yes" = True
boolFromYesNo _     = False

data PostDates = PostDates {
      postDatesUser     :: Text
    , postDatesTag      :: Text
    , postDatesCount    :: [DateCount]
    } deriving (Show, Eq)

instance FromJSON PostDates where
   parseJSON (Object o) =
     PostDates <$> o .: "user"
               <*> o .: "tag"
               <*> (parseDates <$> o .: "dates")
     where
       parseDates :: Value -> [DateCount]
       parseDates (Object o')= do
          (dateStr, String countStr) <- toList o'
          return (read (unpack dateStr), read (unpack countStr))
       parseDates _ = []
   parseJSON _ = error "bad parse"

type DateCount = (Day, Int)


-- * Notes

data NoteList = NoteList {
      noteListCount     :: Int
    , noteListItems     :: [NoteListItem]
    } deriving (Show, Eq)

instance FromJSON NoteList where
   parseJSON (Object o) =
       NoteList <$> o .: "count"
                <*> o .: "notes"
   parseJSON _ = error "bad parse"

data NoteListItem = NoteListItem {
      noteListItemId     :: Text
    , noteListItemHash   :: Text
    , noteListItemTitle  :: Text
    , noteListItemLength :: Int
    , noteListItemCreatedAt :: UTCTime
    , noteListItemUpdatedAt :: UTCTime
    } deriving (Show, Eq)

instance FromJSON NoteListItem where
   parseJSON (Object o) =
       NoteListItem <$> o .: "id"
                    <*> o .: "hash"
                    <*> o .: "title"
                    <*> (read <$> (o .: "length"))
                    <*> (readNoteTime <$> o .: "created_at")
                    <*> (readNoteTime <$> o .: "updated_at")
   parseJSON _ = error "bad parse"



data Note = Note {
      noteId     :: Text
    , noteHash   :: Text
    , noteTitle  :: Text
    , noteText   :: Text
    , noteLength :: Int
    , noteCreatedAt :: UTCTime
    , noteUpdatedAt :: UTCTime
    } deriving (Show, Eq)

instance FromJSON Note where
   parseJSON (Object o) =
       Note <$> o .: "id"
            <*> o .: "hash"
            <*> o .: "title"
            <*> o .: "text"
            <*> o .: "length"
            <*> (readNoteTime <$> o .: "created_at")
            <*> (readNoteTime <$> o .: "updated_at")
   parseJSON _ = error "bad parse"

readNoteTime :: String -> UTCTime
readNoteTime = readTime defaultTimeLocale "%F %T"


-- * Tags

type TagMap = HashMap Text Int

newtype JsonTagMap = ToJsonTagMap {fromJsonTagMap :: TagMap}
    deriving (Show, Eq)

instance FromJSON JsonTagMap where
  parseJSON = return . toTags
    where toTags (Object o) = ToJsonTagMap $ HM.map (\(String s)-> read (unpack s)) o
          toTags _ = error "bad parse"


data Suggested = Popular [Text]
               | Recommended [Text]
    deriving (Show, Eq)

instance FromJSON Suggested where
   parseJSON (Object o)
     | member "popular" o = Popular <$> (o .: "popular")
     | member "recommended" o = Recommended  <$> (o .: "recommended")
     | otherwise = error "bad parse"  
   parseJSON _ = error "bad parse"


-- * Scalars

newtype DoneResult = ToDoneResult {fromDoneResult :: ()}
    deriving (Show, Eq)

instance FromJSON DoneResult where
  parseJSON (Object o) = parseDone =<< (o .: "result" <|> o .: "result_code")
    where
      parseDone :: Text -> Parser DoneResult
      parseDone "done" = return $ ToDoneResult ()
      parseDone msg = ( fail . unpack ) msg
  parseJSON _ = error "bad parse"

newtype TextResult = ToTextResult {fromTextResult :: Text}
    deriving (Show, Eq)

instance FromJSON TextResult where
  parseJSON (Object o) = ToTextResult <$> (o .: "result")
  parseJSON _ = error "bad parse"

newtype UpdateTime = ToUpdateTime {fromUpdateTime :: UTCTime}
    deriving (Show, Eq)

instance FromJSON UpdateTime where
  parseJSON (Object o) = ToUpdateTime <$> (o .: "update_time")
  parseJSON _ = error "bad parse"

-- * Aliases

-- | as defined by RFC 3986. Allowed schemes are http, https, javascript, mailto, ftp and file. The Safari-specific feed scheme is allowed but will be treated as a synonym for http.
type Url = Text

-- | up to 255 characters long
type Description = Text 

-- | up to 65536 characters long. Any URLs will be auto-linkified when displayed.
type Extended = Text

-- | up to 255 characters. May not contain commas or whitespace.
type Tag = Text 
type Old = Tag
type New = Tag

type Count = Int
type NumResults = Int
type StartOffset = Int

type Shared = Bool
type Replace = Bool
type ToRead = Bool

-- | UTC date in this format: 2010-12-11. Same range as datetime above
type Date = Day

-- | UTC timestamp in this format: 2010-12-11T19:48:02Z. Valid date range is Jan 1, 1 AD to January 1, 2100 (but see note below about future timestamps).
type DateTime = UTCTime
type FromDateTime = DateTime
type ToDateTime = DateTime

type Meta = Int

type NoteId = Text