module Waterfall.Internal.Edges
( edgeEndpoints
, edgeValue
, wireEndpoints
, allWireEndpoints
, allWires
, allEdges
, wireEdges
, wireTangentStart
, buildEdgeCurve3D
, reverseEdge
, reverseWire
, intersperseLines
, joinWires
, splitWires
, edgeToWire
) where

import qualified OpenCascade.TopoDS as TopoDS
import qualified OpenCascade.TopoDS.Shape as TopoDS.Shape
import qualified OpenCascade.BRep.Tool as BRep.Tool
import qualified OpenCascade.Geom.Curve as Geom.Curve
import qualified OpenCascade.BRepTools.WireExplorer as WireExplorer
import qualified OpenCascade.TopExp.Explorer as Explorer 
import qualified OpenCascade.TopAbs.ShapeEnum as ShapeEnum
import qualified OpenCascade.TopTools.ShapeMapHasher as TopTools.ShapeMapHasher
import qualified OpenCascade.BRepBuilderAPI.MakeEdge as MakeEdge
import qualified OpenCascade.BRepLib as BRepLib
import OpenCascade.GeomAbs.Shape as GeomAbs.Shape
import Waterfall.Internal.FromOpenCascade (gpPntToV3, gpVecToV3)
import Data.Acquire
import Control.Monad.IO.Class (liftIO)
import Linear (V3 (..), distance, normalize, nearZero)
import Foreign.Ptr
import qualified OpenCascade.BRepBuilderAPI.MakeWire as MakeWire
import Control.Monad (when)
import Waterfall.Internal.ToOpenCascade (v3ToPnt)
import Data.Foldable (traverse_)
import OpenCascade.Inheritance (upcast, unsafeDowncast)

edgeEndpoints :: Ptr TopoDS.Edge -> IO (V3 Double, V3 Double)
edgeEndpoints edge = (`with` pure) $ do
    curve <- BRep.Tool.curve edge
    p1 <- liftIO . BRep.Tool.curveParamFirst $ edge
    p2 <- liftIO . BRep.Tool.curveParamLast $ edge
    s <- (liftIO . gpPntToV3) =<< Geom.Curve.value curve p1
    e <- (liftIO . gpPntToV3) =<< Geom.Curve.value curve p2
    return (s, e)

edgeValue :: Ptr TopoDS.Edge -> Double -> IO (V3 Double)
edgeValue edge v = (`with` pure) $ do
    curve <- BRep.Tool.curve edge
    p1 <- liftIO . BRep.Tool.curveParamFirst $ edge
    p2 <- liftIO . BRep.Tool.curveParamLast $ edge
    let p' = (1-v) * p1 + v * p2
    (liftIO . gpPntToV3) =<< Geom.Curve.value curve p'

allWireEndpoints :: Ptr TopoDS.Wire -> IO [(V3 Double, V3 Double)]
allWireEndpoints wire = with (WireExplorer.fromWire wire) $ \explorer -> do
    let runToEnd = do
            edge <- WireExplorer.current explorer
            points <- edgeEndpoints edge
            WireExplorer.next explorer
            more <- WireExplorer.more explorer
            if more 
                then (points:) <$> runToEnd
                else pure [points]
    runToEnd

allSubShapes :: ShapeEnum.ShapeEnum -> Ptr TopoDS.Shape -> Acquire [Ptr TopoDS.Shape]
allSubShapes t s = do 
    explorer <- Explorer.new s t
    let go visited = do
            isMore <- liftIO $ Explorer.more explorer
            if isMore 
                then do
                    v <- liftIO $ Explorer.value explorer
                    hash <- liftIO $ TopTools.ShapeMapHasher.hash v
                    let add = if hash `elem` visited then id else (v:) 
                    liftIO $ Explorer.next explorer
                    add <$> go visited
                else return []
    go []

    
allSubShapesWithCopy :: ShapeEnum.ShapeEnum -> Ptr TopoDS.Shape -> Acquire [Ptr TopoDS.Shape]
allSubShapesWithCopy t s = do 
    explorer <- Explorer.new s t
    let go visited = do
            isMore <- liftIO $ Explorer.more explorer
            if isMore 
                then do
                    v <- liftIO $ Explorer.value explorer
                    hash <- liftIO $ TopTools.ShapeMapHasher.hash v
                    add <- if hash `elem` visited 
                        then pure id 
                        else do
                            v' <- TopoDS.Shape.copy v
                            return (v':) 
                    liftIO $ Explorer.next explorer
                    add <$> go visited
                else return []
    go []


allEdges :: Ptr TopoDS.Shape -> Acquire [Ptr TopoDS.Edge]
allEdges s = traverse (liftIO . unsafeDowncast) =<< allSubShapesWithCopy ShapeEnum.Edge s 

allWires :: Ptr TopoDS.Shape -> Acquire [Ptr TopoDS.Wire]
allWires s = traverse (liftIO . unsafeDowncast) =<< allSubShapes ShapeEnum.Wire s 
    
wireEndpoints :: Ptr TopoDS.Wire -> IO (V3 Double, V3 Double)
wireEndpoints wire = with (WireExplorer.fromWire wire) $ \explorer -> do
    v1 <- WireExplorer.current explorer
    (s, _) <- edgeEndpoints v1
    let runToEnd = do
            edge <- WireExplorer.current explorer
            (_s, e') <- edgeEndpoints edge
            WireExplorer.next explorer
            more <- WireExplorer.more explorer
            if more 
                then runToEnd
                else pure e'
    e <- runToEnd
    return (s, e)

edgeTangentStart :: Ptr TopoDS.Edge -> IO (V3 Double)
edgeTangentStart e = (`with` pure) $ do
    curve <- BRep.Tool.curve e
    p1 <- liftIO . BRep.Tool.curveParamFirst $ e
    liftIO . gpVecToV3 =<< Geom.Curve.dn curve p1 1

edgeTangentEnd :: Ptr TopoDS.Edge -> IO (V3 Double)
edgeTangentEnd e = (`with` pure) $ do
    curve <- BRep.Tool.curve e
    p1 <- liftIO . BRep.Tool.curveParamLast $ e
    liftIO . gpVecToV3 =<< Geom.Curve.dn curve p1 1

wireTangentStart :: Ptr TopoDS.Wire -> IO (V3 Double)
wireTangentStart wire = with (WireExplorer.fromWire wire) $ \explorer -> do
    v1 <- WireExplorer.current explorer
    edgeTangentStart v1

reverseEdge :: Ptr TopoDS.Edge -> Acquire (Ptr TopoDS.Edge)
reverseEdge e = do
    curve <- BRep.Tool.curve e 
    firstP <- liftIO $ BRep.Tool.curveParamFirst e
    lastP <- liftIO $ BRep.Tool.curveParamLast e
    firstP' <- liftIO $ Geom.Curve.reversedParameter curve firstP
    lastP' <- liftIO $ Geom.Curve.reversedParameter curve lastP
    curve' <- Geom.Curve.reversed curve
    MakeEdge.fromCurveAndParameters curve' lastP' firstP' 

wireEdges :: Ptr TopoDS.Wire -> Acquire [Ptr TopoDS.Edge]
wireEdges wire = do
    explorer <- WireExplorer.fromWire wire
    let runToEnd = do
            edge <- liftIO $ WireExplorer.current explorer
            edge' <- (liftIO . unsafeDowncast) =<< TopoDS.Shape.copy (upcast edge)
            liftIO $ WireExplorer.next explorer
            more <- liftIO $ WireExplorer.more explorer
            if more 
                then (edge' :) <$> runToEnd
                else pure [edge']
    runToEnd

reverseWire :: Ptr TopoDS.Wire -> Acquire (Ptr TopoDS.Wire) 
reverseWire wire = do
    explorer <- WireExplorer.fromWire wire
    makeWire <- MakeWire.new
    let runToEnd = do
            edge <- liftIO $ WireExplorer.current explorer
            edge' <- reverseEdge edge
            liftIO $ WireExplorer.next explorer
            more <- liftIO $ WireExplorer.more explorer
            when more runToEnd
            liftIO $ MakeWire.addEdge makeWire edge'
    runToEnd
    MakeWire.wire makeWire

line' :: V3 Double -> V3 Double -> Acquire (Ptr TopoDS.Wire)
line' s e = do
    builder <- MakeWire.new
    pt1 <- v3ToPnt s
    pt2 <- v3ToPnt e
    edge <- MakeEdge.fromPnts pt1 pt2
    liftIO $ MakeWire.addEdge builder edge
    MakeWire.wire builder
    
intersperseLines :: [Ptr TopoDS.Wire] -> Acquire [Ptr TopoDS.Wire]
intersperseLines [] = pure []
intersperseLines [x] = pure [x]
intersperseLines (a:b:xs) = do
    (_, ea) <- liftIO $ wireEndpoints a
    (sb, _) <- liftIO $ wireEndpoints b
    if distance ea sb < 1e-6
            then (a :) <$> intersperseLines (b:xs)
            else (a :) <$> ((:) <$> line' ea sb <*> intersperseLines (b:xs))

joinWires :: [Ptr TopoDS.Wire] -> Acquire (Ptr TopoDS.Wire)
joinWires wires = do
    builder <- MakeWire.new
    let addWire wire = do 
            explorer <- WireExplorer.fromWire wire
            let runToEnd = do
                    edge <- liftIO $ WireExplorer.current explorer
                    liftIO $ MakeWire.addEdge builder edge
                    liftIO $ WireExplorer.next explorer
                    more <- liftIO $ WireExplorer.more explorer
                    when more runToEnd
            runToEnd
    traverse_ addWire $ wires
    MakeWire.wire builder

    
edgeToWire :: Ptr TopoDS.Edge -> Acquire (Ptr TopoDS.Wire)
edgeToWire edge = do
    builder <- MakeWire.new
    liftIO $ MakeWire.addEdge builder edge
    MakeWire.wire builder

splitWires :: Ptr TopoDS.Wire -> Acquire [Ptr TopoDS.Wire]
splitWires wire = do
    explorer <- WireExplorer.fromWire wire
    let makeSegment = do
            builder <- MakeWire.new
            let addOneWire lastDelta = do
                    edge <- liftIO $ WireExplorer.current explorer
                    s' <- normalize <$> edgeTangentStart edge
                    e' <- normalize <$> edgeTangentEnd edge
                    let startIsTangent = maybe True (nearZero . (s' -)) lastDelta
                    when startIsTangent $ do
                            liftIO $ MakeWire.addEdge builder edge
                            liftIO $ WireExplorer.next explorer
                            more <- liftIO $ WireExplorer.more explorer
                            when more (addOneWire (Just e'))
            liftIO $ addOneWire Nothing
            thisWire <- MakeWire.wire builder
            more <- liftIO $ WireExplorer.more explorer
            rest <- if more
                then makeSegment 
                else return []
            return $ thisWire : rest 
    makeSegment

buildEdgeCurve3D :: Ptr TopoDS.Edge -> Acquire (Ptr TopoDS.Edge)
buildEdgeCurve3D edge = do 
    edge' <- (liftIO . unsafeDowncast) =<< TopoDS.Shape.copy (upcast edge)
    _ <- liftIO $ BRepLib.buildCurve3d edge' 1e-5 GeomAbs.Shape.C1 14 0
    return edge'