Behavioural synchrony model

globals [ day ]

turtles-own [
  speed
  bspeed
  neighbor
  move-countdown
  rest-countdown
  movement
  sync
  energy
  reward
  shelters
  nearest-shelter ]


breed [ fishes fish ]

to setup
  clear-all
  reset-ticks
  set day 1

  ;;to randomly create food patches with given density
  ask patches [
    if random-normal 50 50 > (200 - (food-density)) [
        set pcolor green ] ]

  ;;set 5 brown shelters with yellow boundaries
  ask n-of 5 patches [ set pcolor brown
    ask neighbors [ set pcolor yellow ] ]

  ;;for spatial restriction of food to the corner
  ;ask patches [
  ;  if (pxcor > 40 * corner and pycor > 25 * corner) [
  ;    if random-normal (50 + (5 * corner)) 20 > 90 [
  ;      set pcolor green ] ] ]

  ;;create 10 agents with baseline average speed 2, assigned sync-factors, and variable values of initial move and rest times (with averages of 100), at random starting locations
  create-fishes 10 [
    set size 5
    set bspeed boldness1 + random-normal 0 0.1
    set speed bspeed
    set sync sync-factor
    set move-countdown 100 + random-normal 0 50
    set rest-countdown 100 + random-normal 0 50
    setxy random-xcor random-ycor ]
end 

to go

  if ticks > day * 400 [ set day day + 1 ]  ;;each day is 400 timesteps long

 ;;to alternate colour to represent day and night (daylength is 400, 200:200 day-night)
  ifelse ticks > (day * 400) - 200 and ticks < (day)  * 400
    [ ask patches [ if pcolor = 55 [ set pcolor 52 ] ] ]
    [ ask patches [ if pcolor = 52 [ set pcolor 55 ] ] ]

  ask turtles [

    set neighbor min-one-of other turtles [ distance myself ]  ;;Set the nearest agent as neighbor

    ;;Move with constant speed and variable direction, try to synchronize with neighbors, consume food, have a start-stop motion, and update synchrony factor according to reward.
    move
    synchronize
    eat-grass
    stop-start
    update-sync

    ;;Move towards shelter before dusk and restrict activity at dusk/dawn
    find-shelter
    if ticks = (day * 400) - 200 [ adjust-movement2 ]
    if ticks = (day * 400) [ adjust-movement1 ]

    ;;While moving, shoal with neighbors and bounce off walls; also check whether each individual is in motion or at rest at the end of the procedures
    if speed > 0 [
      interact
      bounce-off-walls ]

    check-move ]

  tick
end 



;;When agent is at half the maximum speed or greater (i.e. is starting motion or slowing down), move at the max speed with slightly variable direction

to move
  ifelse speed > 0.9 [
    rt random 10
    lt random 10
    fd 1 * bspeed ]
  [ fd 1 * speed ]
end 

;;Adjust the move-time and rest-time to synchronize with the neighbour

to synchronize
  if [ movement ] of neighbor = 0 and movement = 1
    [ set move-countdown move-countdown - sync ]
  if [ movement ] of neighbor = 0 and movement = 0
    [ set rest-countdown rest-countdown + sync ]
  if [ movement ] of neighbor = 1 and movement = 0
    [ set rest-countdown rest-countdown - sync ]
  if [ movement ] of neighbor = 1 and movement = 1
    [ set move-countdown move-countdown + sync ]
end 

;;Agent gets reward according to whether neighbor is moving

to eat-grass
  set reward 0

  if pcolor = 55 or pcolor = 52 [ ;;green patches during the day or night
    set pcolor black
    set energy energy + 1
    if [movement] of neighbor = 1 [
      set reward 1 ]
    if [movement] of neighbor = 0 [
      set reward 1 * comp-cost ] ]
end 

;;For cyclic start-stop motion

to stop-start
  ;;While fish is moving, move-time (move-countdown) ticks down, otherwise rest-time ticks down.
  ifelse movement = 1
    [ set move-countdown move-countdown - 1 ]
    [ set rest-countdown rest-countdown - 1 ]

  ;;Accelerate or decelerate (by 0.1) to initiate movement or come to rest when move-time or  ticks down to 0
  if move-countdown < 0 [ set speed speed - 0.1 ]
  if rest-countdown < 0 [ set speed speed + 0.1 ]

  ;;Reset move-time when agent comes to rest, reset rest-time when agent reaches half maximum speed
  if speed < 0 [
    set speed 0
    set move-countdown 200 + random-normal 0 50]
  if speed > 0.9 [
    set rest-countdown 200 + random-normal 0 50]
end 


;;Reinforcement learning of synchronous or asynchronous strategy

to update-sync
  ;;Increase or decrease sync-factor based on whether agent is synchronous or asynchronous with neighbour
  if reward > 0 [
    if movement = 1 and [movement] of neighbor = 1 [
      set sync sync + reward * 0.01 ]
    if movement = 1 and [movement] of neighbor = 0 [
      set sync sync - reward * 0.01 ] ]

  ;;Set maximum and minimum sync-factor as 0.9 and -0.9
  if sync > 0.9 [ set sync 0.9 ]
  if sync < -0.9 [ set sync -0.9 ]
end 



;;Move towards nearest unoccupied shelters 25 steps before dusk

to find-shelter
  if ticks > (day * 400) - 225 and ticks < (day * 400) - 175 [
      set shelters (patches with [pcolor = brown])
    let empty-shelters shelters with [pcolor = brown and not any? turtles-here ]
    set nearest-shelter min-one-of empty-shelters [distance myself]
    if any? empty-shelters [
        set heading towards nearest-shelter ] ]
end 

;;Adjust the move-time and rest-time of individuals at dawn and dusk

to adjust-movement1
  if movement = 1 [ set move-countdown move-countdown + restrict ]
  if movement = 0 [ set rest-countdown rest-countdown - restrict ]
end 

to adjust-movement2
  if movement = 1 [ set move-countdown move-countdown - restrict ]
  if movement = 0 [ set rest-countdown rest-countdown + restrict ]
end 


;;Shoaling rules

to interact
  if distance neighbor < 2
    [ set heading towards neighbor
      set heading heading + random-normal 180 10 ]
  if distance neighbor < 10 and distance neighbor > 2
    [ set heading [heading] of neighbor + random-normal 0 10 ]
  if distance neighbor > 10 and any? other turtles in-cone 15 60 [
    set heading towards neighbor
    set heading heading + random-normal 0 10 ]
end 

;;Bouncing off the walls

to bounce-off-walls
  if abs pxcor = max-pxcor [ set heading (heading + 90) ]
  if abs pycor = max-pycor [ set heading (heading + 90) ]
end 

;;Check whether each individual is moving

to check-move
  ifelse speed > 0
    [ set movement 1 ]
    [ set movement 0 ]
end 

;;Report the number of individuals moving at any given time

to-report active-fish
  report count turtles with [ movement = 1 ]
end 

;;Report the average sync-factor of the 10 individuals in the population

to-report avg-sync
  report mean [sync] of turtles
end