{-|
Module      : Gargantext.Viz.Phylo.Tools
Description : Phylomemy Tools to build/manage it
Copyright   : (c) CNRS, 2017-Present
License     : AGPL + CECILL v3
Maintainer  : team@gargantext.org
Stability   : experimental
Portability : POSIX


-}

{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE FlexibleContexts  #-}
{-# LANGUAGE OverloadedStrings #-}

module Gargantext.Viz.Phylo.Metrics.Clustering
  where

import Data.List        (last,head,union,concat,null,nub,(++),init,tail,elemIndex,groupBy,(!!))
import Data.Map         (Map,elems,adjust,unionWith,intersectionWith,fromList,mapKeys)
import Data.Set         (Set)
import Data.Tuple       (fst, snd)

import Data.Graph.Clustering.Louvain.CplusPlus

import Gargantext.Prelude             hiding (head)
import Gargantext.Viz.Phylo
import Gargantext.Viz.Phylo.Tools

import qualified Data.List   as List
import qualified Data.Map    as Map
import qualified Data.Set    as Set


-- | To apply the related components method to a PhyloGraph
-- curr = the current PhyloGroup 
-- (nodes,edges) = the initial PhyloGraph minus the current PhyloGroup
-- next = the next PhyloGroups to be added in the cluster  
-- memo = the memory of the allready created clusters
relatedComp :: Int -> PhyloGroup -> PhyloGraph -> [PhyloGroup] -> [[PhyloGroup]] -> [[PhyloGroup]]
relatedComp idx curr (nodes,edges) next memo
  | null nodes' && null next' = memo'
  | (not . null) next'        = relatedComp idx (head next') (nodes',edges) (tail next') memo'
  | otherwise                 = relatedComp (idx + 1) (head nodes') (tail nodes',edges) [] memo'
  where
    --------------------------------------
    memo' :: [[PhyloGroup]]
    memo' 
      | null memo                  = [[curr]]
      | idx == ((length memo) - 1) = (init memo) ++ [(last memo) ++ [curr]]
      | otherwise                  = memo ++ [[curr]]
    --------------------------------------
    next' :: [PhyloGroup]
    next' = filter (\x -> not $ elem x $ concat memo) $ nub $ next ++ (getNeighbours False curr edges)
    --------------------------------------
    nodes' :: [PhyloGroup]
    nodes' = filter (\x -> not $ elem x next') nodes
    --------------------------------------


{-
louvain :: (PhyloNodes,PhyloEdges) -> [Cluster]
louvain (nodes,edges) = undefined 
-} 


louvain :: (PhyloNodes,PhyloEdges) -> IO [[PhyloGroup]]
louvain (nodes,edges) = map (\community -> map (\node -> nodes !! (l_node_id node)) community)
                      <$> groupBy (\a b -> (l_community_id a) == (l_community_id b))
                      <$> (cLouvain $ mapKeys (\(x,y) -> (idx x, idx y)) $ fromList edges)
  where
    -------------------------------------- 
    idx :: PhyloGroup -> Int
    idx e = case elemIndex e nodes of
      Nothing -> panic "[ERR][Gargantext.Viz.Phylo.Metrics.Clustering] a node is missing"
      Just i  -> i
    --------------------------------------