Battle of Midway VS Edits

;;==========================================================
;; BATTLE OF MIDWAY  -  Agent-Based Model
;; INTA-6742  |  Group 28
;;
;; WORLD  :  100 x 100 patches  (wrapping OFF in View settings)
;;           1 patch = 10 nautical miles
;; TIME   :  1 tick  = 15 minutes
;;
;; DESIGN PRINCIPLE:
;;   Carriers hold roughly fixed positions (historically accurate -
;;   carriers launched aircraft while steaming slowly).
;;   Only RECON and STRIKE PLANES move meaningfully across the map.
;;   This avoids all boundary / oscillation problems.
;;
;; STARTING POSITIONS:
;;   US   carriers  x=+30, spread vertically  (NE of Midway)
;;   Japan carriers  x=-30, spread vertically  (NW of Midway)
;;   Midway Atoll    x=0, y=0
;;   Distance between fleets ~ 60 patches = 600 nm
;;
;; SPEEDS (patches / tick):
;;   Recon   2.0   (~120 kts PBY Catalina)
;;   Strike  4.0   (~240 kts SBD Dauntless)
;;   Carrier 0.2   (slow drift only)
;;
;; HISTORICAL MECHANISMS:
;;   1. US INTEL  -  US recon sectors cover 170-310 deg (NW arc)
;;                   where Japan is known to approach.
;;   2. TONE DELAY - Japan recon planes 0-1 delayed 4 ticks
;;                   (Tone catapult malfunction, ~1 hr late).
;;   3. JAPAN REARM - When Japan first detects US fleet,
;;                    all Japan carriers enter REARM for 8 ticks:
;;                    yellow colour, no launches, 2x bomb damage.
;;   4. WAVES      - Strike planes return, refuel, and relaunch
;;                    continuously until their carrier sinks.
;;
;; SLIDERS (create in Interface tab, do NOT add to globals):
;;   num-us-recon     0-36   default 18
;;   num-japan-recon  0-28   default 14
;;
;; MONITORS (create in Interface tab):
;;   us-carriers-alive    japan-carriers-alive
;;   avg-us-health        avg-japan-health
;;   ticks                first-hit-tick
;;   rearm-ticker         contacts
;;==========================================================

breed [ carriers  one-carrier ]
breed [ recons    one-recon   ]
breed [ strikers  one-striker ]

carriers-own [
  fside          ;; "US" or "JAPAN"
  cname
  hp             ;; 0-100; sinks at 0
  cstate         ;; "active" "rearm" "sunk"
  rearm-timer    ;; countdown ticks for REARM state
]

recons-own [
  fside
  rstate         ;; "out" "home" "refuel" "dead"
  rfuel
  smax-fuel
  route          ;; outbound compass heading for this plane
  late-start     ;; Tone delay: ticks before this plane can fly
  spotted?       ;; has found enemy fleet
  base-x
  base-y
]

strikers-own [
  fside
  sstate         ;; "deck" "flying" "returning" "dead"
  sfuel
  smax-fuel
  home-ship      ;; home carrier agent
  target-ship    ;; current attack target
]

;; Only internal state here - slider names must NOT be listed
globals [
  us-found?        ;; US has located Japan fleet
  japan-found?     ;; Japan has located US fleet
  message-queue    ;; List of pending detection messages
  japan-in-rearm?
  rearm-length
  first-hit-tick
  contacts
]

;;==========================================================
;; SETUP
;;==========================================================

to setup
  clear-all

  set us-found?       false
  set japan-found?    false
  set japan-in-rearm? false
  set rearm-length    8
  set first-hit-tick  -1
  set contacts        0
  set message-queue []
  set recon-max-detect recon-max-detect
  set comm-delay comm-delay

  ;; Large world so agents have room to maneuver
  resize-world -50 50 -50 50
  set-patch-size 5

  ;; Ocean
  ask patches [ set pcolor 96 ]
  ;; Midway Atoll
  ask patches with [ distancexy 0 0 < 2 ] [ set pcolor 66 ]

  make-carriers
  make-recon
  make-strikers
  reset-ticks
end 

to make-carriers
  ;; US Task Force - NE of Midway, historical ambush position
  let us-names (list "Enterprise" "Hornet"   "Yorktown")
  let us-ys    (list  5            0          10       )
  let i 0
  repeat 3 [
    create-carriers 1 [
      set fside      "US"
      set cname      item i us-names
      set hp         100
      set cstate     "active"
      set rearm-timer 0
      setxy 30 (item i us-ys)
      set shape "airplane"  set color blue  set size 4
      set label cname  set label-color white
    ]
    set i i + 1
  ]

  ;; Japan Kido Butai - NW of Midway
  let jp-names (list "Akagi" "Kaga"  "Soryu" "Hiryu")
  let jp-ys    (list  8       2      14      -4     )
  set i 0
  repeat 4 [
    create-carriers 1 [
      set fside      "JAPAN"
      set cname      item i jp-names
      set hp         100
      set cstate     "active"
      set rearm-timer 0
      setxy -30 (item i jp-ys)
      set shape "airplane"  set color red  set size 4
      set label cname  set label-color white
    ]
    set i i + 1
  ]
end 

to make-recon
  ;; US PBY Catalinas - based at Midway (0,0)
  ;; Intel advantage: sectors biased 170-310 deg (NW arc toward Japan)
  if num-us-recon > 0 [
    let arc-step 140.0 / num-us-recon
    create-recons num-us-recon [
      let slot (who mod num-us-recon)
      set fside    "US"
      set rstate   "out"
      set smax-fuel 35
      set rfuel     smax-fuel
      set route     170 + (slot * arc-step)
      set late-start 0
      set spotted?  false
      set base-x    0
      set base-y    0
      setxy 0 0
      set shape "airplane"  set color 107  set size 2
    ]
  ]

  ;; Japan E13A floatplanes - launched from carriers
  if num-japan-recon > 0 [
    let arc-step 360.0 / num-japan-recon
    let jp-positions []
    ask carriers with [ fside = "JAPAN" ] [
      set jp-positions lput (list xcor ycor) jp-positions
    ]
    create-recons num-japan-recon [
      let slot (who mod num-japan-recon)
      let pos  item (slot mod length jp-positions) jp-positions
      set fside    "JAPAN"
      set rstate   "out"
      set smax-fuel 28
      set rfuel     smax-fuel
      set route     (slot * arc-step)
      ;; Tone catapult failure: first 2 planes wait 4 ticks
      set late-start ifelse-value (slot < 2) [4] [0]
      set spotted?  false
      set base-x    item 0 pos
      set base-y    item 1 pos
      setxy base-x base-y
      set shape "airplane"  set color 25  set size 2
    ]
  ]
end 

to make-strikers
  ;; Collect carrier info at observer level (create is observer-only)
  let cdata []
  ask carriers [ set cdata lput (list fside xcor ycor self) cdata ]

  foreach cdata [ row ->
    let s  item 0 row
    let cx item 1 row
    let cy item 2 row
    let c  item 3 row
    ;; 6 strike planes per carrier
    create-strikers 6 [
      set fside      s
      set sstate     "deck"
      set smax-fuel  20
      set sfuel      smax-fuel
      set home-ship  c
      set target-ship nobody
      setxy cx cy
      set shape "airplane"
      set color ifelse-value (s = "US") [97] [135]
      set size 1.5
    ]
  ]
end 

to process-messages
  let new-queue []

  foreach message-queue [ msg ->
    let side item 0 msg
    let delay item 1 msg - 1

    if delay <= 0 [
      if side = "US" [
        set us-found? true
      ]
      if side = "JAPAN" and not japan-found? [
        set japan-found? true
        start-rearm
      ]
    ]
    if delay > 0 [
      set new-queue lput (list side delay) new-queue
    ]
  ]

  set message-queue new-queue
end 

;;==========================================================
;; GO
;;==========================================================

to go
  if not any? carriers with [ fside = "US"    and hp > 0 ] [ stop ]
  if not any? carriers with [ fside = "JAPAN" and hp > 0 ] [ stop ]

  process-messages
  tick-carriers
  tick-recon
  tick-strikers
  draw
  tick
end 

;;==========================================================
;; CARRIERS
;; Carriers drift very slowly. Their main job is to exist as
;; targets and launch strike planes. They do NOT chase each other.
;;==========================================================

to tick-carriers
  ask carriers with [ hp > 0 ] [

    ;; REARM countdown
    if cstate = "rearm" [
      set rearm-timer rearm-timer - 1
      if rearm-timer <= 0 [
        set cstate "active"
        set japan-in-rearm? any? carriers with [
          fside = "JAPAN" and cstate = "rearm"
        ]
        ;; Rearm done - launch all deck planes immediately
        launch-all-deck-planes self
      ]
      ;; Slow drift while rearming
      clamp-drift 0.1
      stop
    ]

    ;; ACTIVE: slow drift toward enemy zone, launch strikes when enemy known
    ;; US holds NE position until Japan detected; then holds to launch ops
    ;; Japan advances toward Midway; turns to face US when detected
    ifelse fside = "US" [
      ;; US: hold position with tiny drift (historical - held launch position)
      set heading (270 + random 20 - 10) mod 360
      clamp-drift 0.1
      if us-found? [ launch-all-deck-planes self ]
    ] [
      ;; Japan: advance SE toward Midway until US detected
      ifelse not japan-found? [
        set heading (120 + random 20 - 10) mod 360
        clamp-drift 0.2
      ] [
        ;; Japan detected US - turn toward US fleet
        let us-fleet carriers with [ fside = "US" and hp > 0 ]
        if any? us-fleet [
          face min-one-of us-fleet [ distance myself ]
          set heading (heading + random 16 - 8) mod 360
        ]
        clamp-drift 0.2
        if cstate = "active" [ launch-all-deck-planes self ]
      ]
    ]

    ;; Direct visual detection: spot enemy fleet within 15 patches
    let enemy-side ifelse-value (fside = "US") ["JAPAN"] ["US"]
    let visible carriers in-radius 15 with [ fside = enemy-side and hp > 0 ]
    if any? visible [
      if fside = "US" [ set us-found? true ]
      if fside = "JAPAN" and not japan-found? [
        set japan-found? true
        start-rearm
      ]
    ]
  ]
end 

;; Move forward by step but never leave world bounds

to clamp-drift [ step ]
  forward step
  if xcor > 48 [ set xcor 48 ]
  if xcor < -48 [ set xcor -48 ]
  if ycor > 48 [ set ycor 48 ]
  if ycor < -48 [ set ycor -48 ]
end 

to launch-all-deck-planes [ carr ]
  let enemy-side ifelse-value ([fside] of carr = "US") ["JAPAN"] ["US"]
  let targets carriers with [ fside = enemy-side and hp > 0 ]
  if not any? targets [ stop ]
  ask strikers with [ home-ship = carr and sstate = "deck" ] [
    set target-ship min-one-of targets [ distance myself ]
    set sstate "flying"
    set sfuel smax-fuel
  ]
end 

to start-rearm
  set japan-in-rearm? true
  ask carriers with [ fside = "JAPAN" and cstate != "sunk" ] [
    set cstate     "rearm"
    set rearm-timer rearm-length
  ]
end 

to do-sink
  set cstate "sunk"
  set hp 0
  set shape "x"
  set size 5
  set color gray
  set label (word cname " SUNK")
  set label-color red
  ask strikers with [ home-ship = myself ] [
    set sstate "dead"
    set color  gray
  ]
end 

;;==========================================================
;; RECON
;;==========================================================

to tick-recon
  ask recons with [ rstate != "dead" ] [

    ;; Refueling on ground
    if rstate = "refuel" [
      set rfuel rfuel + 5
      if rfuel >= smax-fuel [
        set rfuel smax-fuel
        set spotted? false
        set rstate  "out"
        set color ifelse-value (fside = "US") [107] [25]
      ]
      stop
    ]

    ;; Tone delay: Japan planes 0 and 1 sit on deck
    if late-start > 0 [
      set late-start late-start - 1
      stop
    ]

    set rfuel rfuel - 1
    if rfuel <= 0 [ set rstate "dead"  set color gray  stop ]
    let fuel-threshold smax-fuel * 0.35
    if rfuel < fuel-threshold and rstate = "out" [ set rstate "home" ]

    if rstate = "out"  [ recon-outbound ]
    if rstate = "home" [ recon-return   ]
  ]
end 

to recon-outbound
  set heading route
  ;; Simple wall bounce - only flip heading, small margin
  if xcor > 47 or xcor < -47 [
    set heading (360 - heading) mod 360
    set xcor clamp-coord xcor -47 47
  ]
  if ycor > 47 or ycor < -47 [
    set heading (180 - heading) mod 360
    set ycor clamp-coord ycor -47 47
  ]
  forward 2.0

  ;; Scan for enemy carriers within 12 patches
  if not spotted? [
    let opp ifelse-value (fside = "US") ["JAPAN"] ["US"]
    let found-carriers carriers in-radius 12 with [ fside = opp and hp > 0 ]
    if any? found-carriers [
      let tc one-of found-carriers
      ;; Detection probability: exponential decay with distance
      let d distance tc
      let p recon-max-detect * exp(-0.012 * d * 10)
      let delay comm-delay
      if random-float 1.0 < p [
        set spotted? true
        set color    green
        set rstate   "home"
        set contacts contacts + 1
        ;; Trigger detection for this faction
        set message-queue lput (list fside delay) message-queue
        ]
      ]
    ]
end 

to recon-return
  ;; Japan recon follows its carrier home
  if fside = "JAPAN" [
    let nearest-carrier min-one-of carriers with [
      fside = "JAPAN" and hp > 0
    ] [ distance myself ]
    if nearest-carrier != nobody [
      set base-x [xcor] of nearest-carrier
      set base-y [ycor] of nearest-carrier
    ]
  ]
  facexy base-x base-y
  forward 2.0
  if distancexy base-x base-y < 2 [
    set rstate "refuel"
    set color  gray
    setxy base-x base-y
  ]
end 

to-report clamp-coord [ val lo hi ]
  if val > hi [ report hi ]
  if val < lo [ report lo ]
  report val
end 

;;==========================================================
;; STRIKE PLANES
;; Simple three-state machine: deck -> flying -> returning
;; They fly DIRECTLY to target - no wall logic needed because
;; the target is always somewhere in the middle of the world.
;;==========================================================

to tick-strikers
  ask strikers with [ sstate != "dead" ] [

    ;; On deck: just sit on carrier
    if sstate = "deck" [
      if home-ship != nobody and [hp] of home-ship > 0 [
        setxy [xcor] of home-ship [ycor] of home-ship
      ]
      stop
    ]

    ;; Fuel burn while airborne
    set sfuel sfuel - 1
    let fuel-threshold smax-fuel * 0.35
    if sfuel <= 0 [ set sstate "dead" set color gray stop ]
    if sfuel < fuel-threshold and sstate = "flying" [ set sstate "returning" ]

    if sstate = "flying"    [ striker-fly    ]
    if sstate = "returning" [ striker-return ]
  ]
end 

to striker-fly
  ;; If target sank, find next nearest
  if target-ship = nobody or [hp] of target-ship <= 0 [
    let opp ifelse-value (fside = "US") ["JAPAN"] ["US"]
    let remaining carriers with [ fside = opp and hp > 0 ]
    ifelse any? remaining [
      set target-ship min-one-of remaining [ distance myself ]
    ] [
      set sstate "returning"
      stop
    ]
  ]

  ;; Close on target - resolve attack when within 3 patches
  let dist-to-target distance target-ship
  if dist-to-target < 3 [
    resolve-attack
    stop
  ]

  face target-ship
  forward 4.0

  ;; If we overshot (moved past target), resolve attack
  if distance target-ship < 3 [
    resolve-attack
  ]
end 

to resolve-attack
  if target-ship = nobody or [hp] of target-ship <= 0 [
    set sstate "returning"
    stop
  ]

  ;; AA fire: carrier defense may shoot down attacker
  let aa ifelse-value ([fside] of target-ship = "US") [aa-fire-us] [aa-fire-japan]
  if random-float 1.0 < aa [
    set sstate "dead"
    set color  gray
    stop
  ]

  ;; Hit roll
  let hit ifelse-value (fside = "US") [hit-us] [hit-japan]
  if random-float 1.0 < hit [
    let dmg ifelse-value (fside = "US") [25] [35]

    ;; REARM VULNERABILITY: 2x damage when Japan carrier is rearming
    ;; Models Akagi/Kaga/Soryu caught with armed planes and fuel
    ;; hoses on deck - destroyed in the "fatal five minutes" 1020-1025
    if fside = "US" and [cstate] of target-ship = "rearm" [
      set dmg dmg * 2
    ]

    ask target-ship [
      set hp hp - dmg
      if hp < 0 [ set hp 0 ]
      if hp <= 0 [ do-sink ]
    ]
    if first-hit-tick = -1 [ set first-hit-tick ticks ]
  ]

  set sstate "returning"
end 

to striker-return
  if home-ship = nobody or [hp] of home-ship <= 0 [
    ;; Home carrier sunk - ditch at sea
    set sstate "dead"
    set color  gray
    stop
  ]

  face home-ship
  forward 4.0

  if distance home-ship < 2 [
    ;; Back on deck - rearm and relaunch immediately if enemy still exists
    set sfuel smax-fuel
    set sstate "deck"
    set target-ship nobody
    setxy [xcor] of home-ship [ycor] of home-ship

    let opp ifelse-value (fside = "US") ["JAPAN"] ["US"]
    let can-launch false
    if fside = "US" [ set can-launch us-found? ]
    if fside = "JAPAN" [
      set can-launch (japan-found? and [cstate] of home-ship = "active")
    ]
    if can-launch [
      let targets carriers with [ fside = opp and hp > 0 ]
      if any? targets [
        set target-ship min-one-of targets [ distance myself ]
        set sstate "flying"
      ]
    ]
  ]
end 

;;==========================================================
;; DISPLAY
;;==========================================================

to draw
  ask patches [ set pcolor 96 ]
  ask patches with [ distancexy 0 0 < 2 ] [ set pcolor 66 ]

  ask carriers with [ hp > 0 ] [
    if fside = "US" [
      set color ifelse-value (hp > 50) [blue] [
                ifelse-value (hp > 25) [105] [15]]
    ]
    if fside = "JAPAN" [
      set color ifelse-value (cstate = "rearm") [yellow] [
                ifelse-value (hp > 50) [red] [
                ifelse-value (hp > 25) [25] [15]]]
    ]
    set label (word cname "  " hp "hp")
  ]

  ask strikers [
    if sstate = "flying" [
      set color ifelse-value (fside = "US") [white] [yellow]
      set size 2
    ]
    if sstate = "deck" [ set size 1.2 ]
  ]
end 

;;==========================================================
;; MONITORS
;;==========================================================

to-report us-carriers-alive
  report count carriers with [ fside = "US" and hp > 0 ]
end 

to-report japan-carriers-alive
  report count carriers with [ fside = "JAPAN" and hp > 0 ]
end 

to-report avg-us-health
  let a carriers with [ fside = "US" and hp > 0 ]
  if not any? a [ report 0 ]
  report precision mean [hp] of a 1
end 

to-report avg-japan-health
  let a carriers with [ fside = "JAPAN" and hp > 0 ]
  if not any? a [ report 0 ]
  report precision mean [hp] of a 1
end 

to-report rearm-ticker
  let r carriers with [ fside = "JAPAN" and cstate = "rearm" ]
  if not any? r [ report 0 ]
  report max [rearm-timer] of r
end