include "../crazy-rabbit/ud.lut"
include "../crazy-rabbit/moving-obstacle.lut"

node rabbit_speed (low, high:real) returns (Speed: real) =
   exist Delta, SpeedLow, SpeedHigh: real in
   let draw_params() =
      between(Delta, 0.5, 1.0) and
      between(SpeedLow, 0.0, low) and between(SpeedHigh, 1.0, high)
    in
    let keep_params() = 
       Delta = pre Delta and SpeedLow = pre SpeedLow and 
       SpeedHigh = pre SpeedHigh
    in
       {
          &> loop { draw_params() fby loop ~100: 10 { keep_params() } } 
          &> Speed = 1.0 fby 
             run Speed := up_and_down(pre SpeedLow, pre SpeedHigh, pre Delta) 
       }
extern sin(x:  real) : real
extern cos(x:  real) : real

-- extern printint(i:int):unit 

exception Pb

node rabbit (x_min, x_max, y_min, y_max : real)
returns(x, y, p1x, p1y, p2x, p2y, p3x, p3y, p4x, p4y:  real ; freeze:bool) =
   exist Speed, Alpha, Beta : real in
   let keep_position() = (x = pre x and y = pre y) in
   let draw_params() = between(Alpha, -3.14, 3.14) and between(Beta, -0.3, 0.3)
   in
   -- The beginning
   run Speed := rabbit_speed(5.0, 50.0) in
   run p1x,p1y, p2x,p2y, p3x,p3y, p4x,p4y := obstacle(x_min, x_max, y_min, y_max) in
   let line() =
     x = (pre x + Speed * cos(pre Alpha)) and
     y = (pre y + Speed * sin(pre Alpha)) and
     Alpha = pre Alpha and
    -- And he always avoids the obstacle
     not is_inside(x,y,p1x,p1y,p2x,p2y,p3x,p3y,p4x,p4y)
   in
   let escape () = 
      try
         between(x, pre x - 21.0, pre x + 21.) and
         between(y, pre y - 21.0, pre y + 21.) and
         not is_inside(x,y,p1x,p1y,p2x,p2y,p3x,p3y,p4x,p4y)
     do raise Pb 
   in
   let curve() =
     x = (pre x + Speed * cos(pre Alpha)) and
     y = (pre y + Speed * sin(pre Alpha)) and
     Alpha = pre Alpha - Beta and Beta = pre Beta and
     not is_inside(x,y,p1x,p1y,p2x,p2y,p3x,p3y,p4x,p4y)
   in
   let spiral() =
     x = (pre x + Speed * cos(pre Alpha)) and
     y = (pre y + Speed * sin(pre Alpha)) and
     Alpha = pre Alpha - Beta and Beta = pre Beta- 0.02 and
     not is_inside(x,y,p1x,p1y,p2x,p2y,p3x,p3y,p4x,p4y)
   in
   assert
       -- The rabbit always remains in its playground
        between(x, x_min, x_max) and
        between(y, y_min, y_max)
   in
   assert (freeze = is_inside(x,y,p1x,p1y,p2x,p2y,p3x,p3y,p4x,p4y)) in
      draw_params() fby
      try loop {
--         try
                { draw_params() &> escape() } fby
--                { draw_params() and keep_position() } fby
                {
                  |1: loop [0,40] line()  -- forward straigth ahead for a while
                  |3: loop [0,40] curve() -- forward by turning for a while
                  |3: loop [0,60] spiral() -- forward by turning for a while
                  
                }
--          do escape() 
        -- nb: if it is inside the obstacle, it keeps its position until it can move
     }