-- Copyright (c) 2016-present, Facebook, Inc.
-- All rights reserved.
--
-- This source code is licensed under the BSD-style license found in the
-- LICENSE file in the root directory of this source tree. An additional grant
-- of patent rights can be found in the PATENTS file in the same directory.


{-# LANGUAGE GADTs #-}
{-# LANGUAGE OverloadedStrings #-}

module Duckling.Ordinal.EN.Rules
  ( rules ) where

import Control.Monad (join)
import Data.HashMap.Strict ( HashMap)
import qualified Data.HashMap.Strict as HashMap
import Data.Text (Text)
import qualified Data.Text as Text
import Prelude
import Data.String

import Duckling.Dimensions.Types
import Duckling.Numeral.Helpers (parseInt)
import Duckling.Ordinal.Helpers
import Duckling.Regex.Types
import Duckling.Types

ordinalsMap :: HashMap Text Int
ordinalsMap = HashMap.fromList
  [ ( "first", 1 )
  , ( "second", 2 )
  , ( "third", 3 )
  , ( "fourth", 4 )
  , ( "fifth", 5 )
  , ( "sixth", 6 )
  , ( "seventh", 7 )
  , ( "eighth", 8 )
  , ( "ninth", 9 )
  , ( "tenth", 10 )
  , ( "eleventh", 11 )
  , ( "twelfth", 12 )
  , ( "thirteenth", 13 )
  , ( "fourteenth", 14 )
  , ( "fifteenth", 15 )
  , ( "sixteenth", 16 )
  , ( "seventeenth", 17 )
  , ( "eighteenth", 18 )
  , ( "nineteenth", 19 )
  , ( "twentieth", 20 )
  , ( "thirtieth", 30 )
  , ( "fortieth", 40 )
  , ( "fiftieth", 50 )
  , ( "sixtieth", 60 )
  , ( "seventieth", 70 )
  , ( "eightieth", 80 )
  , ( "ninetieth", 90 )
  ]

cardinalsMap :: HashMap Text Int
cardinalsMap = HashMap.fromList
  [ ( "twenty", 20 )
  , ( "thirty", 30 )
  , ( "forty", 40 )
  , ( "fifty", 50 )
  , ( "sixty", 60 )
  , ( "seventy", 70 )
  , ( "eighty", 80 )
  , ( "ninety", 90 )
  ]


ruleOrdinals :: Rule
ruleOrdinals = Rule
  { name = "ordinals (first..twentieth,thirtieth,...)"
  , pattern = [regex "(first|second|third|fourth|fifth|sixth|seventh|eighth|ninth|tenth|eleventh|twelfth|thirteenth|fourteenth|fifteenth|sixteenth|seventeenth|eighteenth|nineteenth|twentieth|thirtieth|fortieth|fiftieth|sixtieth|seventieth|eightieth|ninetieth)"]
  , prod = \tokens -> case tokens of
      (Token RegexMatch (GroupMatch (match:_)):_) ->
        ordinal <$> HashMap.lookup (Text.toLower match) ordinalsMap
      _ -> Nothing
    }

ruleCompositeOrdinals :: Rule
ruleCompositeOrdinals = Rule
  { name = "ordinals (composite, e.g., eighty-seven)"
  , pattern = [regex "(twenty|thirty|forty|fifty|sixty|seventy|eighty|ninety)\\-(first|second|third|fourth|fifth|sixth|seventh|eighth|ninth)"]
  , prod = \tokens -> case tokens of
      (Token RegexMatch (GroupMatch (tens:units:_)):_) -> do
        tt <- HashMap.lookup (Text.toLower tens) cardinalsMap
        uu <- HashMap.lookup (Text.toLower units) ordinalsMap
        Just (ordinal (tt + uu))
      _ -> Nothing
  }

ruleOrdinalDigits :: Rule
ruleOrdinalDigits = Rule
  { name = "ordinal (digits)"
  , pattern = [regex "0*(\\d+) ?(st|nd|rd|th)"]
  , prod = \tokens -> case tokens of
      (Token RegexMatch (GroupMatch (match:_)):_) -> ordinal <$> parseInt match
      _ -> Nothing
  }

rules :: [Rule]
rules =
  [ ruleOrdinals
  , ruleCompositeOrdinals
  , ruleOrdinalDigits
  ]