More retreats.

2 files changed, 303 insertions, 44 deletions

diff --git a/play.js b/play.js
index 89a5413..75290bb 100644
--- a/play.js
+++ b/play.js
@@ -601,6 +601,11 @@ function on_update() {
 	action_button("rommel", "Rommel")
 	action_button("stop", "Stop")
 
+	action_button("retreat", "Retreat")
+	action_button("partial_retreat", "Partial retreat")
+	action_button("full_retreat", "Full retreat")
+	action_button("probe_combat", "Probe combat")
+
 	action_button("group", "Group")
 	action_button("regroup", "Regroup")
 
diff --git a/rules.js b/rules.js
index 2d75589..691461e 100644
--- a/rules.js
+++ b/rules.js
@@ -222,6 +222,10 @@ function is_unit_supplied(u) {
 	return ((game.units[u] & UNIT_SUPPLY_MASK) >> UNIT_SUPPLY_SHIFT) !== 0
 }
 
+function is_unit_unsupplied(u) {
+	return ((game.units[u] & UNIT_SUPPLY_MASK) >> UNIT_SUPPLY_SHIFT) === 0
+}
+
 function unit_supply(u) {
 	let src = (game.units[u] & UNIT_SUPPLY_MASK) >> UNIT_SUPPLY_SHIFT
 	return hex_from_supply_source[src]
@@ -557,6 +561,14 @@ function for_each_undisrupted_enemy_unit_in_hex(x, fn) {
 			fn(u)
 }
 
+function count_battle_hexes() {
+	let n = 0
+	for (let x of all_hexes)
+		if (is_battle_hex(x))
+			++n
+	return n
+}
+
 function count_normal_steps_in_battle() {
 	let steps = [ 0, 0, 0, 0 ]
 	for_each_undisrupted_enemy_unit_in_hex(game.battle, u => {
@@ -1242,7 +1254,7 @@ function goto_initial_supply_check() {
 		if (snet[x]) {
 			set_unit_supply(u, ssrc)
 			if (is_unit_disrupted(u) && set_has(game.recover, u) && !is_battle_hex(x)) {
-				log(`${unit_name(u)} recovered in ${hex_name[x]}`)
+				log(`${unit_name(u)} recovered at ${hex_name[x]}`)
 				set_delete(game.recover, u)
 				clear_unit_disrupted(u)
 			}
@@ -1475,17 +1487,21 @@ function goto_move_who() {
 	game.state = 'move_who'
 }
 
-function gen_group_move_who(from) {
+function gen_group_move_who(may_retreat, from) {
+	if (may_retreat !== is_battle_hex(from))
+		return
 	for_each_undisrupted_friendly_unit_in_hex(from, u => {
 		if (!is_unit_moved(u))
 			gen_action_unit(u)
 	})
 }
 
-function gen_regroup_move_who(command_point, destination, rommel) {
+function gen_regroup_move_who(may_retreat, command_point, destination, rommel) {
 	search_move(destination, 0, 4)
 	for_each_hex_and_adjacent_hex(command_point, x => {
 		if (x !== destination) {
+			if (may_retreat !== is_battle_hex(x))
+				return
 			for_each_undisrupted_friendly_unit_in_hex(x, u => {
 				if (!is_unit_moved(u) && can_move_from(x, 4, unit_speed(u) + rommel))
 					gen_action_unit(u)
@@ -1500,17 +1516,17 @@ states.move_who = {
 		view.prompt = `Move: Select unit to move.`
 		if (game.from1) {
 			if (game.to1)
-				gen_regroup_move_who(game.from1, game.to1, game.rommel === 1 ? 1 : 0)
+				gen_regroup_move_who(false, game.from1, game.to1, game.rommel === 1 ? 1 : 0)
 			else
-				gen_group_move_who(game.from1)
+				gen_group_move_who(false, game.from1)
 		}
 		if (game.from2) {
 			if (game.to2)
-				gen_regroup_move_who(game.from2, game.to2, game.rommel === 2 ? 1 : 0)
+				gen_regroup_move_who(false, game.from2, game.to2, game.rommel === 2 ? 1 : 0)
 			else
-				gen_group_move_who(game.from2)
+				gen_group_move_who(false, game.from2)
 		}
-		// TODO: retreat
+		// TODO: only retreat if possible
 		gen_action('retreat')
 		gen_action('end_move')
 	},
@@ -1521,16 +1537,24 @@ states.move_who = {
 		game.move_used = 0
 		game.move_road = 4
 	},
+	retreat() {
+		push_undo()
+		game.state = 'retreat_select_from'
+	},
 	end_move() {
 		clear_undo()
-		game.side_limit = {}
-		game.rommel = 0
-		game.from1 = game.from2 = game.to1 = game.to2 = 0
-		// TODO: forced marches
-		goto_refuse_battle()
+		end_move_phase()
 	}
 }
 
+function end_move_phase() {
+	game.side_limit = {}
+	game.rommel = 0
+	game.from1 = game.from2 = game.to1 = game.to2 = 0
+	// TODO: forced marches
+	goto_refuse_battle()
+}
+
 function print_path(who, from, to, road) {
 	let p = [ hex_name[to] ]
 	while (to && to !== from) {
@@ -1758,6 +1782,183 @@ function stop_move(who) {
 	game.state = 'move_who'
 }
 
+// === RETREAT ===
+
+function can_select_retreat_hex() {
+	let result = false
+	if (game.from1) {
+		if (game.to1) {
+			for_each_hex_and_adjacent_hex(game.from1, x => {
+				if (is_battle_hex(x) && !set_has(game.partial_retreats, x))
+					result = true
+			})
+		} else {
+			if (is_battle_hex(game.from1) && !set_has(game.partial_retreats, game.from1))
+				result = true
+		}
+	}
+	if (game.from2) {
+		if (game.to2) {
+			for_each_hex_and_adjacent_hex(game.from2, x => {
+				if (is_battle_hex(x) && !set_has(game.partial_retreats, x))
+					result = true
+			})
+		} else {
+			if (is_battle_hex(game.from2) && !set_has(game.partial_retreats, game.from2))
+				result = true
+		}
+	}
+	return result
+}
+
+states.retreat_select_from = {
+	prompt() {
+		view.prompt = `Retreat: Select hex to retreat from.`
+		if (game.from1) {
+			if (game.to1) {
+				for_each_hex_and_adjacent_hex(game.from1, x => {
+					if (is_battle_hex(x) && !set_has(game.partial_retreats, x))
+						gen_action_hex(x)
+				})
+			} else {
+				if (is_battle_hex(game.from1) && !set_has(game.partial_retreats, game.from1))
+					gen_action_hex(game.from1)
+			}
+		}
+		if (game.from2) {
+			if (game.to2) {
+				for_each_hex_and_adjacent_hex(game.from2, x => {
+					if (is_battle_hex(x) && !set_has(game.partial_retreats, x))
+						gen_action_hex(x)
+				})
+			} else {
+				if (is_battle_hex(game.from2) && !set_has(game.partial_retreats, game.from2))
+					gen_action_hex(game.from2)
+			}
+		}
+	},
+	hex(x) {
+		push_undo()
+		game.retreat = x
+		game.state = 'retreat_select_who'
+	}
+}
+
+states.retreat_select_who = {
+	prompt() {
+		view.prompt = `Retreat: Select unit to move.`
+		let full_retreat = true
+		for_each_undisrupted_friendly_unit_in_hex(game.retreat, u => {
+			if (!set_has(game.selected, u))
+				full_retreat = false
+			gen_action_unit(u)
+		})
+		// No Partial Retreat allowed for Pass turn option.
+		if (game.turn_option !== 'pass' && game.selected.length > 0)
+			gen_action('partial_retreat')
+		gen_action('full_retreat')
+	},
+	unit(u) {
+		console.log("set toggle", u)
+		set_toggle(game.selected, u)
+	},
+	full_retreat() {
+		clear_undo()
+		for_each_undisrupted_friendly_unit_in_hex(game.retreat, u => {
+			set_add(game.selected, u)
+		})
+		game.retreat_units = game.selected
+		game.selected = []
+		goto_pursuit_fire(game.retreat)
+	},
+	partial_retreat() {
+		clear_undo()
+		set_add(game.partial_retreats, game.retreat)
+		set_passive_player()
+		game.state = 'provoke_probe_combat'
+	},
+}
+
+states.provoke_probe_combat = {
+	prompt() {
+		view.prompt = `Retreat: You may provoke probe combat at ${hex_name[game.retreat]}.`
+		gen_action('probe_combat')
+		gen_action('pass')
+	},
+	// TODO: probe_combat
+	pass() {
+		set_active_player()
+		game.retreat_units = game.selected
+		game.selected = []
+		let shielded = false
+		for_each_undisrupted_friendly_unit_in_hex(game.retreat, u => {
+			if (!set_has(game.retreat_units, u))
+				shielded = true
+		})
+		if (shielded)
+			goto_retreat_who()
+		else
+			goto_pursuit_fire(game.retreat)
+	},
+}
+
+function goto_retreat_who() {
+	set_active_player()
+	game.state = 'retreat_who'
+}
+
+states.retreat_who = {
+	prompt() {
+		view.prompt = `Retreat: Select unit to move.`
+		let done = true
+		for (let u of game.retreat_units) {
+			if (unit_hex(u) === game.retreat) {
+				gen_action_unit(u)
+				done = false
+			}
+		}
+		if (done)
+			gen_action('end_retreat')
+	},
+	unit(who) {
+		push_undo()
+		game.selected = [ who ]
+		game.state = 'retreat_to'
+	},
+	end_retreat() {
+		clear_undo()
+		if (can_select_retreat_hex())
+			game.state = 'retreat_select_from'
+		else
+			end_move_phase()
+	}
+}
+
+states.retreat_to = {
+	prompt() {
+		view.prompt = `Retreat: Select destination.`
+		let who = game.selected[0]
+		gen_action_unit(who)
+		//if (game.turn_option === 'pass') {
+		{
+			search_withdraw(game.retreat, true)
+			// TODO: regroup
+			gen_withdraw_group_move(who, game.retreat)
+		}
+	},
+	unit(who) {
+		pop_undo()
+	},
+	hex(to) {
+		push_undo()
+		let who = game.selected[0]
+		set_unit_hex(who, to)
+		set_unit_disrupted(who)
+		game.selected = []
+		game.state = 'retreat_who'
+	},
+}
+
 // === REFUSE BATTLE ===
 
 function gen_withdraw_group_move(who, from) {
@@ -1788,7 +1989,6 @@ states.refuse_battle = {
 	hex(x) {
 		push_undo()
 		set_delete(game.active_battles, x)
-		game.pursuit = x
 		goto_pursuit_fire(x)
 	},
 	next() {
@@ -1850,18 +2050,17 @@ states.refuse_battle_to = {
 function goto_combat_phase() {
 	clear_undo()
 	set_active_player()
-	if (game.active_battles.length > 0)
-		return goto_select_battles()
-	for (let x of all_hexes)
-		if (is_battle_hex(x))
-			return goto_select_battles()
+	let n = count_battle_hexes()
+	if (n > 0) {
+		if (n > game.active_battles.length)
+			return game.state = 'select_active_battles'
+		if (game.turn_option === 'assault')
+			return game.state = 'select_assault_battles'
+		return goto_select_battle()
+	}
 	end_combat_phase()
 }
 
-function goto_select_battles() {
-	game.state = 'select_active_battles'
-}
-
 states.select_active_battles = {
 	inactive: "combat phase (select active battles)",
 	prompt() {
@@ -1910,6 +2109,18 @@ states.select_assault_battles = {
 	}
 }
 
+function goto_select_battle() {
+	if (game.active_battles.length > 0) {
+		if (game.active_battles.length > 1) {
+			game.state = 'select_battle'
+		} else {
+			goto_battle(game.active_battles[0])
+		}
+	} else {
+		end_combat_phase()
+	}
+}
+
 states.select_battle = {
 	inactive: "combat phase (select next battle)",
 	prompt() {
@@ -1920,12 +2131,25 @@ states.select_battle = {
 			gen_action_hex(x)
 	},
 	hex(x) {
-		clear_undo()
-		game.battle = x
-		goto_defensive_fire()
+		goto_battle(x)
 	},
 }
 
+function end_combat_phase() {
+	// TODO: blitz
+	// TODO: final supply check
+	// TODO: supply cards revealed
+	end_player_turn()
+}
+
+// === BATTLES ===
+
+function goto_battle(x) {
+	clear_undo()
+	game.battle = x
+	goto_defensive_fire()
+}
+
 function goto_defensive_fire() {
 	set_passive_player()
 	game.fired = []
@@ -2073,7 +2297,7 @@ const xxx_fire_hits = {
 		if (game.state === 'defensive_fire_hits') {
 			goto_offensive_fire()
 		} else {
-			end_combat()
+			end_battle()
 		}
 	},
 }
@@ -2127,7 +2351,7 @@ function goto_fire_hits() {
 	}
 }
 
-function end_combat() {
+function end_battle() {
 	clear_undo()
 	set_active_player()
 	set_delete(game.active_battles, game.battle)
@@ -2146,19 +2370,24 @@ states.offensive_fire_target = xxx_fire_target
 states.defensive_fire_hits = xxx_fire_hits
 states.offensive_fire_hits = xxx_fire_hits
 
-function end_combat_phase() {
-	// TODO: blitz
-	// TODO: final supply check
-	// TODO: supply cards revealed
-	end_player_turn()
-}
-
 // === PURSUIT FIRE ===
 
-function goto_pursuit_fire() {
+function goto_retreat_fire(where) {
+	clear_undo()
+	set_passive_player()
+	game.hits = 0
+	game.pursuit = where
+	if (can_pursuit_fire())
+		game.state = 'pursuit_fire'
+	else
+		goto_pursuit_hits()
+}
+
+function goto_pursuit_fire(where) {
 	clear_undo()
 	set_active_player()
 	game.hits = 0
+	game.pursuit = where
 	if (can_pursuit_fire())
 		game.state = 'pursuit_fire'
 	else
@@ -2187,10 +2416,19 @@ function can_pursuit_fire() {
 }
 
 function roll_pursuit_fire(n) {
-	for (let i = 0; i < n; ++i) {
-		let roll = random(6) + 1
-		log(`Pursuit fire ${roll}.`)
-		if (roll >= 4)
+	if (n === 2) {
+		let a = random(6) + 1
+		let b = random(6) + 1
+		log(`Pursuit fire ${a}, ${b}.`)
+		if (a >= 4)
+			game.hits++
+		if (b >= 4)
+			game.hits++
+	}
+	if (n === 1) {
+		let a = random(6) + 1
+		log(`Pursuit fire ${a}.`)
+		if (a >= 4)
 			game.hits++
 	}
 }
@@ -2207,7 +2445,7 @@ states.pursuit_fire = {
 		gen_action('next')
 	},
 	unit(who) {
-		let slowest = slowest_enemy_unit_speed(game.pursuit)
+		let slowest = slowest_undisrupted_enemy_unit_speed(game.pursuit)
 		if (unit_speed(who) > slowest)
 			roll_pursuit_fire(2)
 		else
@@ -2275,8 +2513,13 @@ states.pursuit_hits = {
 function end_pursuit_fire() {
 	game.from1 = game.pursuit
 	game.pursuit = 0
-	set_passive_player()
-	game.state = 'refuse_battle_who'
+	if (game.retreat) {
+		set_active_player()
+		game.state = 'retreat_who'
+	} else {
+		set_passive_player()
+		game.state = 'refuse_battle_who'
+	}
 }
 
 // === DEPLOYMENT ===
@@ -2860,8 +3103,12 @@ exports.setup = function (seed, scenario, options) {
 		move_used: 0,
 		move_road: 4,
 
-		// combat
+		// retreat
 		partial_retreats: [], // remember partial retreats to forbid initiating combat
+		retreat: 0,
+		retreat_units: null,
+
+		// combat
 		active_battles: [],
 		assault_battles: [],
 		pursuit: 0,
@@ -2986,6 +3233,13 @@ function set_clear(set) {
 	set.length = 0
 }
 
+function set_toggle(set, item) {
+	if (set_has(set, item))
+		set_delete(set, item)
+	else
+		set_add(set, item)
+}
+
 function remove_from_array(array, item) {
 	let i = array.indexOf(item)
 	if (i >= 0)