{-# LANGUAGE FlexibleInstances    #-}
{-# LANGUAGE OverlappingInstances #-}
{-# LANGUAGE TypeSynonymInstances #-}
module DCB.Structures where

import           Data.Array.Repa as A hiding ((++))
import           Data.Int
import           Util


-- | a one-dimensional array
type Vector r e = Array r DIM1 e
-- | a two-dimensional array
type Matrix r e = Array r DIM2 e

-- | A 'Matrix' of attribute values assigned to a graph’s nodes.
--   Each row contains the corresponding node’s attribute values.
type Attr  = Matrix A.U Double
-- | Adjacency-Matrix
type Adj   = Matrix A.U Int8

-- | Matrix storing the extent of a 'Graph'’s constraints fulfillment.
--   It stores the minimum (zeroth column) and maximum (first column) value of all
--   the 'Graph'’s nodes per attribute.
--   The 'Vector' stores values of @1@ if the bounds are within the allowed range
--   ragarding the corresponding attribute, or @0@ if not.
type Constraints = (Vector A.U Int, Matrix A.U Double)
-- | A 'Vector' of weights indicating how much divergence is allowed in which dimension.
--   Each dimension represents an attribute.
type MaxDivergence = Vector A.U Double
-- | A graph’s density.
type Density = Double

-- | consists of a 'Vector' denoting which columns of the 'Matrix' represents which originating
--   column in the global adjancency-matrix, a 'Matrix' of 'Constraints' and a scalar denoting the graph’s 'Density'
type Graph = (Vector A.U Int, Constraints, Density)

-- | inverse sorting on graphs.
--
--   "smallest" graph has max number of Nodes
--
--   If Nodecount is identical we prioritize the number of fulfilled Constraints
instance Ord Graph where
        (nodes, (const,_), _) `compare` (nodes', (const',_), _) = 
                let 
                        s1 = (A.size $ A.extent nodes')
                        s2 = (A.size $ A.extent nodes)
                in
                        if s1 == s2 then
                                (A.sumAllS const') `compare` (A.sumAllS const)
                        else
                                s1 `compare` s2