module Utils where
import Debug.Trace

debug = False
debugLineSearch = False
debugObj = False -- turn on/off output in obj fn or constraint

-- used when sampling the inital state, make sure sizes satisfy subset constraints
subsetSizeDiff :: Floating a => a
subsetSizeDiff = 10.0

epsd :: Floating a => a -- to prevent 1/0 (infinity). put it in the denominator
epsd = 10 ** (-10)

halfDiagonal :: (Floating a) => a -> a
halfDiagonal side = 0.5 * dist (0, 0) (side, side)

labelName :: String -> String
labelName name = "Label_" ++ name


-- Some debugging functions. @@@
debugF :: (Show a) => a -> a
debugF x = if debug then traceShowId x else x
debugXY x1 x2 y1 y2 = if debug then trace (show x1 ++ " " ++ show x2 ++ " " ++ show y1 ++ " " ++ show y2 ++ "\n") else id

-- To send output to a file, do ./EXECUTABLE 2> FILE.txt
tr :: Show a => String -> a -> a
tr s x = if debug then trace "---" $ trace s $ traceShowId x else x -- prints in left to right order

trRaw :: Show a => String -> a -> a
trRaw s x = if debug then  trace "---" $ trace s $ trace (show x ++ "\n") x else x-- prints in left to right order

trStr :: String -> a -> a
trStr s x = if debug then trace "---" $ trace s x else x -- prints in left to right order

tr' :: Show a => String -> a -> a
tr' s x = if debugLineSearch then trace "---" $ trace s $ traceShowId x else x -- prints in left to right order

tro :: Show a => String -> a -> a
tro s x = if debugObj then trace "---" $ trace s $ traceShowId x else x -- prints in left to right order

---- Lists-as-vectors utility functions, TODO split out of file

-- define operator precedence: higher precedence = evaluated earlier
infixl 6 +., -.
infixl 7 *. -- .*, /.

-- assumes lists are of the same length
dotL :: Floating a => [a] -> [a] -> a
dotL u v = if not $ length u == length v
           then error $ "can't dot-prod different-len lists: " ++ (show $ length u) ++ " " ++ (show $ length v)
           else sum $ zipWith (*) u v

(+.) :: Floating a => [a] -> [a] -> [a] -- add two vectors
(+.) u v = if not $ length u == length v
           then error $ "can't add different-len lists: " ++ (show $ length u) ++ " " ++ (show $ length v)
           else zipWith (+) u v

(-.) :: Floating a => [a] -> [a] -> [a] -- subtract two vectors
(-.) u v = if not $ length u == length v
           then error $ "can't subtract different-len lists: " ++ (show $ length u) ++ " " ++ (show $ length v)
           else zipWith (-) u v

negL :: Floating a => [a] -> [a]
negL = map negate

(*.) :: Floating a => a -> [a] -> [a] -- multiply by a constant
(*.) c v = map ((*) c) v

norm :: Floating a => [a] -> a
norm = sqrt . sum . map (^ 2)

normsq :: Floating a => [a] -> a
normsq = sum . map (^ 2)

normalize :: Floating a => [a] -> [a]
normalize v = (1 / norm v) *. v

-- Find the angle between x-axis and a line passing points, reporting in radians
findAngle :: Floating a => (a, a) -> (a, a) -> a
findAngle (x1, y1) (x2, y2) = atan $ (y2 - y1) / (x2 - x1)

midpoint :: Floating a => (a, a) -> (a, a) -> (a, a) -- mid point
midpoint (x1, y1) (x2, y2) = ((x1 + x2) / 2, (y1 + y2) / 2)

dist :: Floating a => (a, a) -> (a, a) -> a -- distance
dist (x1, y1) (x2, y2) = sqrt ((x1 - x2)^2 + (y1 - y2)^2)

distsq :: Floating a => (a, a) -> (a, a) -> a -- distance
distsq (x1, y1) (x2, y2) = (x1 - x2)^2 + (y1 - y2)^2