diff --git a/config.lua b/config.lua
index b1f8bd4..5458694 100644
--- a/config.lua
+++ b/config.lua
@@ -9,7 +9,10 @@ Config = {
 
     -- love2d line drawing settings
     lineStyle = "smooth",
-    lineWidth = 5
+    lineWidth = 5,
+
+    -- drag sensivity, px
+    dragSensivity = 5
 }
 
 -- Colors table
@@ -19,3 +22,23 @@ Color = {
     green = { 0, 1, 0 },
     blue = { 0, 0, 1 }
 }
+
+-- Find key by value in table by predicate
+function tableFind( table, value, pred )
+    for key, innervalue in pairs( table ) do
+        if pred( value, innervalue ) then
+            return key
+        end
+    end
+    return nil
+end
+
+-- Find if value exists in table by predicate
+function tableHas( table, value, pred )
+    for key, innervalue in pairs( table ) do
+        if pred( value, innervalue ) then
+            return true
+        end
+    end
+    return false
+end
diff --git a/grid.lua b/grid.lua
index 2946120..3981712 100644
--- a/grid.lua
+++ b/grid.lua
@@ -34,3 +34,43 @@ function Grid:draw()
         end
     end
 end
+
+-- Check all lines and return one, which contains point (if any)
+function Grid:matchesLine( point, ignoreEnd )
+    local line = self.lines[tableFind( self.lines, point,
+        function( value, innervalue )
+            return innervalue:has( value )
+        end
+    )]
+    
+    if line ~= nil and not ignoreEnd then
+        if line.startpoint:equals( point ) then
+            line:clear()
+            line:push( line.startpoint )
+        end
+        if line.endpoint:equals( point ) then
+            line:clear()
+            line:reverse()
+            return line
+        end
+    end
+
+    -- Try to check endpoint
+    if line == nil and not ignoreEnd then
+        line = self.lines[tableFind( self.lines, point,
+        function( value, innervalue )
+            if innervalue.endpoint:equals( value ) then
+                innervalue:clear()
+                innervalue:reverse()
+                return true
+            end
+            return false
+        end
+        )]
+    end
+    return line
+end
+
+function Grid:inBounds( point )
+    return point.x <= self.size.x and point.y <= self.size.y
+end
diff --git a/line.lua b/line.lua
index 00447c4..d89e24b 100644
--- a/line.lua
+++ b/line.lua
@@ -38,7 +38,7 @@ function Line:draw()
     love.graphics.circle( "fill", sx, sy, Config.linePointRadius )
     local ex, ey = self.endpoint:globalCoords()
     love.graphics.circle( "fill", ex, ey, Config.linePointRadius )
-    if #self.points == 1 then
+    if #self.points <= 1 then
         love.graphics.setColor( Color.white )
         return
     end
@@ -52,3 +52,27 @@ function Line:draw()
     love.graphics.line( points )
     love.graphics.setColor( Color.white )
 end
+
+-- Clear points
+function Line:clear()
+    for k, _ in pairs( self.points ) do
+        self.points[k] = nil
+    end
+end
+
+-- Swap startpoint and endpoint
+function Line:reverse()
+    local swap = self.startpoint
+    self.startpoint = self.endpoint
+    self.endpoint = swap 
+    self:push( self.startpoint )
+end
+
+-- Check if line has the exact point
+function Line:has( point )
+    return tableHas( self.points, point,
+        function( value, innervalue )
+            return innervalue:equals( value )
+        end
+    )
+end
diff --git a/main.lua b/main.lua
index 894b240..2eda39e 100644
--- a/main.lua
+++ b/main.lua
@@ -13,29 +13,90 @@ function love.load()
         Color.red
     )
     gameGrid:push( line )
+    local line1 = Line:new(
+        GridPoint:new( 1, 5 ),
+        GridPoint:new( 5, 2 ),
+        Color.green
+    )
+    gameGrid:push( line1 )
+    local line2 = Line:new(
+        GridPoint:new( 2, 5 ),
+        GridPoint:new( 5, 3 ),
+        Color.blue
+    )
+    gameGrid:push( line2 )
+
     mouse = {
         x = 0,
         y = 0,
         pressed = false,
-        lastPressed = false
+        lastPressed = false,
+        startX = -1,
+        startY = -1,
+        dragged = false,
+        lastLine = nil,
+        lastPoint = nil,
+        point = Point:new( 0, 0 )
     }
 end
 
 -- TODO: move input interactions into module
+-- TODO: fix collision with other line's endpoint
 function love.update( dt )
     mouse.x, mouse.y = love.mouse.getPosition()
+    mouse.x = mouse.x + 1
+    mouse.y = mouse.y + 1
+    mouse.lastPoint = mouse.point
     mouse.lastPressed = pressed
     mouse.pressed = love.mouse.isDown( 1 )
+    mouse.point = snapCoords( Point:new( mouse.x, mouse.y ) )
+    if mouse.lastLine ~= nil then
+        local pointsLen = #mouse.lastLine.points
+        local lastLinePoint = mouse.lastLine.points[pointsLen]
+        if vectorLength( mouse.point, lastLinePoint ) == 1 
+            and gameGrid:inBounds( mouse.point )
+            and gameGrid:matchesLine( mouse.point, true ) == nil 
+            and not lastLinePoint:equals( mouse.lastLine.endpoint ) then
+            mouse.lastLine:push( mouse.point )
+        end
+    end
+    
+
+    mouse.dragged = mouse.pressed 
+        and mouse.startX > 0 
+        and vectorLength( 
+            Point:new( mouse.x, mouse.y ),
+            Point:new( mouse.startX, mouse.startY )
+        ) > Config.dragSensivity
+
+    if not mouse.pressed and mouse.startX > 0 then
+        mouse.startX = -1
+        mouse.startY = -1
+        mouse.lastLine = nil
+    end
+
+    if not mouse.lastPressed 
+        and mouse.pressed 
+        and mouse.startX < 0 then
+        mouse.startX = mouse.x
+        mouse.startY = mouse.y
+        mouse.lastLine = gameGrid:matchesLine( mouse.point, false ) 
+    end
 end
 
 function love.draw()
     gameGrid:draw()
 
-    if mouse.pressed then
-        local x, y = snapCoords( Point:new( mouse.x, mouse.y ) ):coords()
-        local text = string.format( "%d:%d global\n%d:%d local", mouse.x, mouse.y, x, y )
-        love.graphics.print( text, 64, 256 )
+    local text = string.format( "%d:%d global\n%d:%d local\n%d:%d from start", mouse.x, mouse.y, mouse.point.x, mouse.point.y, mouse.startX - mouse.x, mouse.startY - mouse.y )
+    love.graphics.print( text, 64, 256 )
+    
+    if mouse.dragged then
+        love.graphics.print( "drag", 64, 300 )    
     end
+    if mouse.lastLine ~= nil then
+            love.graphics.print( tostring( mouse.lastLine ), 128, 300 )
+    end
+
 end
 
 -- Returns local coords from global
@@ -44,3 +105,7 @@ function snapCoords( point )
     local y = math.ceil( point.y / Config.cellSize )
     return GridPoint:new( x, y )
 end
+
+function vectorLength( startpoint, endpoint )
+    return math.sqrt( ( startpoint.x - endpoint.x ) ^ 2 +  ( startpoint.y - endpoint.y ) ^ 2 )
+end