Online play (#156)

* new options, and hot keys and readme clean up

* oooooooooooh bazinga

src/link/CodeEntry.lua

@@ -0,0 +1,44 @@
+-- Shared 6-slot room-code entry widget: the digit-scrub interaction
+-- LinkState's own `ipDigits`/`addrPos` already uses for IP entry, over the
+-- Crockford-32-style alphabet pokeserver room/tournament codes are drawn
+-- from (23456789ABCDEFGHJKMNPQRSTUVWXYZ -- no 0/O/1/I/L, so a code read
+-- aloud or handwritten never has to be checked twice).
+
+local CodeEntry = {}
+
+CodeEntry.CHARSET = "23456789ABCDEFGHJKMNPQRSTUVWXYZ"
+CodeEntry.LENGTH = 6
+
+function CodeEntry.new()
+  local chars = {}
+  for i = 1, CodeEntry.LENGTH do chars[i] = 1 end -- index into CHARSET, 1-based
+  return { chars = chars, pos = 1 }
+end
+
+local N = #CodeEntry.CHARSET
+
+function CodeEntry.up(state)
+  state.chars[state.pos] = state.chars[state.pos] % N + 1
+end
+
+function CodeEntry.down(state)
+  state.chars[state.pos] = (state.chars[state.pos] - 2) % N + 1
+end
+
+function CodeEntry.left(state)
+  state.pos = math.max(1, state.pos - 1)
+end
+
+function CodeEntry.right(state)
+  state.pos = math.min(CodeEntry.LENGTH, state.pos + 1)
+end
+
+function CodeEntry.text(state)
+  local out = {}
+  for i = 1, CodeEntry.LENGTH do
+    out[i] = CodeEntry.CHARSET:sub(state.chars[i], state.chars[i])
+  end
+  return table.concat(out)
+end
+
+return CodeEntry

src/link/Handshake.lua

@@ -67,6 +67,17 @@ function Handshake.linkModified(game)
   return false
 end
 
+-- online play (the relay-based online match / tournament flows in
+-- LinkState/Tournament) meets strangers, not a coordinating friend, so it
+-- skips the LAN path's per-peer compatibility negotiation entirely and
+-- just requires vanilla on both ends: no mod-added Pokemon, no surprises.
+-- Mods only ever get baked in at boot (Loader:load), so this is a gate on
+-- attempting to go online, not a live mod toggle -- the player disables
+-- mods via the mod manager and relaunches.
+function Handshake.onlineAllowed(game)
+  return #Handshake.mods(game) == 0
+end
+
 -- mode is nil on the guest: it pairs and announces itself before the host
 -- has picked, and compatibility is decided from the two hellos, not the mode
 function Handshake.hello(game, mode)

src/link/LinkBattle.lua

@@ -15,6 +15,7 @@
 -- them in link battles).
 
 local Fingerprint = require("src.link.Fingerprint")
+local Font = require("src.render.Font")
 local Handshake = require("src.link.Handshake")
 local Logger = require("src.core.Logger")
 local Protocol = require("src.link.Protocol")
@@ -45,6 +46,38 @@ local function mkBattler(data, mon, isPlayer)
   return BattleState.makeBattler(data, mon, isPlayer, nil)
 end
 
+-- shared by LinkBattle.new (myParty/theirParty) and LinkBattle.newSpectator
+-- (hostParty/guestParty): pack->unpack clamp so every perspective watching
+-- a given match holds identical mon copies. errFmt(packedMon, why) builds
+-- the message shown when strict mode refuses an unrebuildable mon.
+local function unpackParty(game, packed, unpackOpts, errFmt)
+  local out = {}
+  for _, p in ipairs(packed or {}) do
+    local mon, why = Protocol.unpackMon(game.data, p, unpackOpts)
+    if mon then
+      table.insert(out, mon)
+    elseif unpackOpts.strict then
+      return nil, errFmt(p, why)
+    end
+  end
+  return out
+end
+
+-- decode a wire action message against whichever battler it belongs to
+-- (the opponent's, from a real participant's perspective; either side's,
+-- from a spectator's)
+local function decodeWireAction(s, msg, battler)
+  if msg.kind == "move" then
+    local slot = math.max(1, math.min(#battler.curMoves, math.floor(msg.slot or 1)))
+    return battler.curMoves[slot]
+  elseif msg.kind == "struggle" then
+    return { id = "STRUGGLE", pp = 1, struggle = true }
+  elseif msg.kind == "locked" then
+    return s:lockedAction(battler)
+  end
+  return nil
+end
+
 -- canonical (host-side-first) state hash, unchanged since v1: it stays on
 -- the wire as `value` so a pre-mod peer still compares something it agrees
 -- with, while the components below carry the real coverage
@@ -150,25 +183,14 @@ function LinkBattle.new(game, net, opts)
   -- both parties pass through the same pack->unpack clamp on both
   -- machines, so the copies are identical everywhere
   local unpackOpts = { strict = opts.strict or false }
-  local myParty, theirParty = {}, {}
-  for _, p in ipairs(opts.myParty or {}) do
-    local mon = Protocol.unpackMon(game.data, p, unpackOpts)
-    if mon then
-      table.insert(myParty, mon)
-    elseif unpackOpts.strict then
-      return nil, ("Your %s can't\nbattle on the\nother game."):format(
-        tostring(p.species))
-    end
-  end
-  for _, p in ipairs(opts.theirParty or {}) do
-    local mon, why = Protocol.unpackMon(game.data, p, unpackOpts)
-    if mon then
-      table.insert(theirParty, mon)
-    elseif unpackOpts.strict then
-      return nil, ("Their %s isn't\nin this game.\n(%s)"):format(
-        tostring(p.species), tostring(why))
-    end
-  end
+  local myParty, myErr = unpackParty(game, opts.myParty, unpackOpts, function(p)
+    return ("Your %s can't\nbattle on the\nother game."):format(tostring(p.species))
+  end)
+  if not myParty then return nil, myErr end
+  local theirParty, theirErr = unpackParty(game, opts.theirParty, unpackOpts, function(p, why)
+    return ("Their %s isn't\nin this game.\n(%s)"):format(tostring(p.species), tostring(why))
+  end)
+  if not theirParty then return nil, theirErr end
   if #myParty == 0 or #theirParty == 0 then
     Logger.warn("link: empty party on one side")
   end
@@ -227,6 +249,17 @@ function LinkBattle.new(game, net, opts)
     if text then s:say(text) end
   end
 
+  -- a tournament shot clock (opts.turnLimit) costs the slow player
+  -- specifically, unlike RUN or a desync -- both of which stay a draw --
+  -- so it needs its own result rather than reusing endAsDraw
+  local function endWithResult(s, result, text)
+    if s.linkEnded then return end
+    s.result = result
+    s.afterQueue = "finish"
+    s.phase = "messages"
+    if text then s:say(text) end
+  end
+
   local function orderMove(action)
     if action and action.id then return game.data.moves[action.id] end
     return nil
@@ -271,15 +304,7 @@ function LinkBattle.new(game, net, opts)
 
   -- decode a remote action message against the enemy battler
   local function decodeTheirAction(s, msg)
-    if msg.kind == "move" then
-      local slot = math.max(1, math.min(#s.enemy.curMoves, math.floor(msg.slot or 1)))
-      return s.enemy.curMoves[slot]
-    elseif msg.kind == "struggle" then
-      return { id = "STRUGGLE", pp = 1, struggle = true }
-    elseif msg.kind == "locked" then
-      return s:lockedAction(s.enemy)
-    end
-    return nil
+    return decodeWireAction(s, msg, s.enemy)
   end
 
   -- with the handshake guaranteeing both games share a link surface, a
@@ -520,6 +545,19 @@ function LinkBattle.new(game, net, opts)
         if not s.result then
           endAsDraw(s, ("%s left the\nbattle."):format(theirName))
         end
+      elseif msg.type == "forfeit" then
+        -- the peer's own shot clock ran out; unlike a mutual RUN/desync
+        -- draw, this has a definite winner (us)
+        if not s.result then
+          endWithResult(s, "win", ("%s ran out of\ntime!"):format(theirName))
+        end
+      else
+        -- a tournament control message (bracket_update, the next
+        -- match_start, ...) can arrive while this match is still
+        -- finishing up; Tournament.lua drains this once it regains the
+        -- stack top rather than losing it to this poll loop
+        s.pendingTournamentMessages = s.pendingTournamentMessages or {}
+        table.insert(s.pendingTournamentMessages, msg)
       end
     end
     if net.closed and not s.linkEnded and not s.result then
@@ -535,16 +573,48 @@ function LinkBattle.new(game, net, opts)
       end
       return
     end
+    if opts.turnLimit and s.phase == "menu" then
+      if not s.turnClockActive then
+        s.turnClockActive = true
+        s.turnClock = opts.turnLimit
+      end
+      s.turnClock = s.turnClock - dt
+      if s.turnClock <= 0 then
+        s.turnClockActive = false
+        send({ type = "forfeit" })
+        endWithResult(s, "lose", "Time's up! You\nforfeit the match.")
+      end
+    elseif opts.turnLimit then
+      s.turnClockActive = false
+    end
     baseUpdate(s, dt)
   end
 
+  if opts.turnLimit then
+    local baseDraw = self.draw
+    self.draw = function(s, ...)
+      baseDraw(s, ...)
+      if s.phase == "menu" and s.turnClockActive then
+        love.graphics.setColor(1, 1, 1, 1)
+        Font.draw(tostring(math.max(0, math.ceil(s.turnClock))), 144, 4)
+      end
+    end
+  end
+
   local baseFinish = self.finish
   self.finish = function(s)
     if not s.linkEnded then
       s.linkEnded = true
       send({ type = "bye" })
     end
-    net:close()
+    -- opts.keepNetOpen: a tournament match's `net` is the caller's
+    -- long-lived tournament connection (still needed for the next round,
+    -- spectating, bracket updates, ...), not a dedicated match socket --
+    -- closing it here the way a plain 1v1 link battle does would sever
+    -- the whole tournament, not just this match.
+    if not opts.keepNetOpen then
+      net:close()
+    end
     if game.linkNet == net then game.linkNet = nil end
     baseFinish(s)
   end
@@ -552,6 +622,244 @@ function LinkBattle.new(game, net, opts)
   return self
 end
 
+-- A tournament spectator: reconstructs the exact same lockstep battle a
+-- live match's two real participants are playing, from a copy of the
+-- traffic the relay fans out to onlookers (see pokeserver's `spectate`
+-- envelope). No local input drives anything here -- both sides' actions
+-- arrive over the wire, tagged by which real player sent them -- so it's
+-- a read-only replay, not a third participant: no hash/desync checking
+-- (a spectator has nothing to verify against), no shot clock (nothing to
+-- act on), and `finish` must NOT close `net`, since that's the caller's
+-- long-lived tournament connection, not a dedicated match socket.
+--
+-- opts: { hostParty = packed, guestParty = packed, hostName, guestName,
+-- seed, verdict, strict }. `self.player` is always the host's battler and
+-- `self.enemy` the guest's, which is what makes TurnOrder.firstMover's
+-- tie-break (below) land on the same result the host's own instance
+-- already computed with invertTie=false.
+function LinkBattle.newSpectator(game, net, opts)
+  local BattleState = require("src.battle.BattleState")
+  local hostName = opts.hostName or "HOST"
+  local guestName = opts.guestName or "GUEST"
+
+  if not Handshake.battleAllowed(opts.verdict) then
+    return nil, "Link battle needs\nthe same mods on\nboth games."
+  end
+
+  local unpackOpts = { strict = opts.strict or false }
+  local hostParty, hostErr = unpackParty(game, opts.hostParty, unpackOpts, function(p)
+    return ("%s's %s can't\nbattle on this\ngame."):format(hostName, tostring(p.species))
+  end)
+  if not hostParty then return nil, hostErr end
+  local guestParty, guestErr = unpackParty(game, opts.guestParty, unpackOpts, function(p, why)
+    return ("%s's %s can't\nbattle on this\ngame.\n(%s)"):format(
+      guestName, tostring(p.species), tostring(why))
+  end)
+  if not guestParty then return nil, guestErr end
+  if #hostParty == 0 or #guestParty == 0 then
+    Logger.warn("link: empty party on one side (spectator)")
+  end
+
+  local self = BattleState.newWild(game, guestParty[1] and guestParty[1].species
+                                         or "RATTATA", 5)
+  self.kind = "link" -- exact same visual treatment as a real link battle
+  self.spectating = true -- Tournament.lua's marker: don't report a result for this one
+  self.net = net
+  game.linkNet = net
+  self.rng = makeRng(opts.seed or 1)
+  self.player = mkBattler(game.data, hostParty[1], true)
+  self.enemy = mkBattler(game.data, guestParty[1], false)
+  self.enemyParty = guestParty
+  self.playerParty = hostParty
+  self.opponentName = guestName
+  self.introText = ("%s vs %s!"):format(hostName, guestName)
+
+  local function orderMove(action)
+    if action and action.id then return game.data.moves[action.id] end
+    return nil
+  end
+
+  local function endSpectate(s, text)
+    if s.linkEnded then return end
+    s.result = s.result or "ended"
+    s.afterQueue = "finish"
+    s.phase = "messages"
+    if text then s:say(text) end
+  end
+
+  local function sendOutHost(s, mon)
+    local previous = s.player
+    s.player = mkBattler(game.data, mon, true)
+    s:syncSides()
+    Runtime.emit("battle.battler_switched", {
+      battle = s, side = s.sides[1], battler = s.player, previous = previous,
+    })
+    s.sendingOut = true
+    s:sayNext(s:sendOutText(s.player.name))
+    s:animNext("POOF_ANIM", false)
+    s:actNext(function()
+      s.sendingOut = false
+      s:startGrowIn(s.player)
+      require("src.core.Sound").playCry(s.data, s.player.mon.species)
+    end)
+  end
+
+  local function sendOutGuest(s, mon)
+    local previous = s.enemy
+    s.enemy = mkBattler(game.data, mon, false)
+    s:syncSides()
+    Runtime.emit("battle.battler_switched", {
+      battle = s, side = s.sides[2], battler = s.enemy, previous = previous,
+    })
+    s.enemySendingOut = true
+    s:sayNext(("%s sent\nout %s!"):format(guestName, s.enemy.name))
+    s:actNext(function()
+      s.enemySendingOut = false
+      s:startGrowIn(s.enemy)
+      s:actNext(function()
+        require("src.core.Sound").playCry(s.data, s.enemy.mon.species)
+      end)
+    end)
+  end
+
+  local function resolveSpecTurn(s, hostMsg, guestMsg)
+    if hostMsg.kind == "run" or guestMsg.kind == "run" then
+      endSpectate(s, "The match ended.")
+      return
+    end
+    s.phase = "messages"
+    s.afterQueue = "linkNext"
+    s.turnCount = (s.turnCount or 0) + 1
+
+    if hostMsg.kind == "switch" then
+      local idx = hostMsg.index
+      s:act(function() sendOutHost(s, hostParty[idx]) end)
+    end
+    if guestMsg.kind == "switch" then
+      local idx = guestMsg.index
+      s:act(function() sendOutGuest(s, guestParty[idx]) end)
+    end
+
+    s:act(function()
+      local hostAction = hostMsg.kind ~= "switch" and hostMsg.kind ~= "run"
+                          and decodeWireAction(s, hostMsg, s.player) or nil
+      local guestAction = guestMsg.kind ~= "switch" and guestMsg.kind ~= "run"
+                          and decodeWireAction(s, guestMsg, s.enemy) or nil
+      Runtime.emit("battle.turn_started", {
+        battle = s, turn = s.turnCount,
+        playerAction = hostAction, enemyAction = guestAction,
+      })
+      if hostAction and guestAction then
+        local hostMove, guestMove = orderMove(hostAction), orderMove(guestAction)
+        local first
+        if Runtime.wantsHook("battle.turn_order") then
+          first = Runtime.call("battle.turn_order", function(a, aMove, b, bMove, c)
+            return TurnOrder.firstMover(a, aMove, b, bMove, c.rng, c.invertTie)
+          end, s.player, hostMove, s.enemy, guestMove, { rng = s.rng, invertTie = false })
+        else
+          first = TurnOrder.firstMover(s.player, hostMove, s.enemy, guestMove, s.rng, false)
+        end
+        local order
+        if first then
+          order = { { s.player, s.enemy, hostAction }, { s.enemy, s.player, guestAction } }
+        else
+          order = { { s.enemy, s.player, guestAction }, { s.player, s.enemy, hostAction } }
+        end
+        for _, entry in ipairs(order) do
+          s:act(function() s:executeAction(entry[1], entry[2], entry[3]) end)
+        end
+      elseif hostAction then
+        s:act(function() s:executeAction(s.player, s.enemy, hostAction) end)
+      elseif guestAction then
+        s:act(function() s:executeAction(s.enemy, s.player, guestAction) end)
+      end
+      s:act(function() s:endOfTurn() end)
+    end)
+  end
+
+  self.resolveTurn = function() end -- a spectator's own input never drives anything
+  self.resolveSwitch = function() end
+  self.tryRun = function() end
+  self.openParty = function(s) s.phase = "waitBoth" end
+
+  self.playerMonFainted = function(s)
+    for _, mon in ipairs(hostParty) do
+      if mon.hp > 0 then
+        s:act(function() sendOutHost(s, mon) end)
+        return
+      end
+    end
+    s:sayNext(("%s is out of\nPOKéMON!\f%s wins!"):format(hostName, guestName))
+    s.result = "guestWin"
+    s.afterQueue = "finish"
+  end
+
+  self.enemyMonFainted = function(s)
+    for _, mon in ipairs(guestParty) do
+      if mon.hp > 0 then
+        s:act(function() sendOutGuest(s, mon) end)
+        return
+      end
+    end
+    s:sayNext(("%s is out of\nPOKéMON!\f%s wins!"):format(guestName, hostName))
+    s.result = "hostWin"
+    s.afterQueue = "finish"
+  end
+
+  self.hostMsg, self.guestMsg = nil, nil
+  local baseUpdate = self.update
+  self.update = function(s, dt)
+    net:update()
+    for _, msg in ipairs(net:poll()) do
+      if msg.type == "spectate" then
+        local inner = msg.msg
+        if inner.type == "action" then
+          if msg.side == "host" then s.hostMsg = inner else s.guestMsg = inner end
+          if s.hostMsg and s.guestMsg then
+            local h, g = s.hostMsg, s.guestMsg
+            s.hostMsg, s.guestMsg = nil, nil
+            resolveSpecTurn(s, h, g)
+          end
+        elseif inner.type == "bye" or inner.type == "forfeit" then
+          if not s.result then endSpectate(s, "The match ended.") end
+        end
+        -- "hello"/"party"/"hash" ride along too (Tournament.lua already
+        -- consumed hello/party before building this battle); none of them
+        -- need any action here
+      else
+        -- same reasoning as the real-participant loop above: don't lose a
+        -- bracket_update/match_start_spectate that arrives mid-match
+        s.pendingTournamentMessages = s.pendingTournamentMessages or {}
+        table.insert(s.pendingTournamentMessages, msg)
+      end
+    end
+    if net.closed and not s.linkEnded and not s.result then
+      endSpectate(s)
+    end
+    if s.phase == "messages" and s.afterQueue == "linkNext" then
+      if not s:updateQueue() then
+        s.afterQueue = "waitBoth"
+        s.phase = "waitBoth"
+      end
+      return
+    end
+    if s.phase == "menu" or s.phase == "waitBoth" then
+      return -- frozen between resolved turns; never a real decision here
+    end
+    baseUpdate(s, dt)
+  end
+
+  local baseFinish = self.finish
+  self.finish = function(s)
+    s.linkEnded = true
+    if game.linkNet == net then game.linkNet = nil end
+    baseFinish(s) -- deliberately doesn't touch net: it's the caller's
+                  -- tournament connection, still needed after this match
+  end
+
+  return self
+end
+
 -- backwards-compatible entry points (LinkState passes role explicitly)
 function LinkBattle.newHost(game, net, opts)
   opts.role = "host"

src/link/LinkState.lua

@@ -2,6 +2,7 @@
 -- the other joins by typing that address in.  Direct peer-to-peer over
 -- lua-enet (bundled with LÖVE),  no relay server.
 
+local CodeEntry = require("src.link.CodeEntry")
 local Font = require("src.render.Font")
 local Handshake = require("src.link.Handshake")
 local Net = require("src.link.Net")
@@ -16,6 +17,12 @@ LinkState.isOpaque = true
 
 local CURSOR = 0xED
 
+-- stages before any Net object is meaningfully "this session's link" --
+-- .net can still be a leftover failed attempt sitting on self, so error/
+-- closed checks below skip these rather than keying off self.net's
+-- presence alone
+local PRE_CONNECT_STAGES = { menu = true, lanMenu = true, onlineMenu = true }
+
 -- how long the host waits for a v2 hello before deciding the peer predates
 -- the handshake (a pre-mod guest sends nothing until it hears the mode)
 local HELLO_GRACE = 2
@@ -119,25 +126,54 @@ function LinkState:update(dt)
   local input = self.game.input
   if self.net then
     self.net:update()
-    if self.net.error and self.stage ~= "menu" then
+    if self.net.error and not PRE_CONNECT_STAGES[self.stage] then
       self:exitWith("Link error:\n" .. self.net.error:sub(1, 60))
       return
     end
     -- the peer vanished without a bye (only once the inbox is drained,
     -- so a final message travelling with the disconnect still counts)
     if self.net.closed and #self.net.inbox == 0
-       and self.stage ~= "menu" and self.stage ~= "addrEntry"
-       and self.stage ~= "notice" and self.stage ~= "battleRunning" then
+       and not PRE_CONNECT_STAGES[self.stage] and self.stage ~= "addrEntry"
+       and self.stage ~= "codeEntry" and self.stage ~= "notice"
+       and self.stage ~= "battleRunning" then
       self:exitWith("The link was\nbroken.")
       return
     end
   end
 
   if self.stage == "menu" then
+    if input:wasPressed("down") then
+      self.index = self.index % 3 + 1
+    elseif input:wasPressed("up") then
+      self.index = (self.index - 2) % 3 + 1
+    elseif input:wasPressed("b") then
+      self:exitWith(nil)
+    elseif input:wasPressed("a") then
+      if self.index == 1 then
+        self.stage = "lanMenu"
+        self.index = 1
+      elseif self.index == 2 or self.index == 3 then
+        if not Handshake.onlineAllowed(self.game) then
+          self:exitWith("Online play needs\nno mods enabled.\fDisable them in\nSTART > MODS.")
+          return
+        end
+        if self.index == 2 then
+          self.stage = "onlineMenu"
+        else
+          local Tournament = require("src.link.Tournament")
+          self.game.stack:pop()
+          self.game.stack:push(Tournament.new(self.game))
+        end
+        self.index = 1
+      end
+    end
+
+  elseif self.stage == "lanMenu" then
     if input:wasPressed("up") or input:wasPressed("down") then
       self.index = self.index == 1 and 2 or 1
     elseif input:wasPressed("b") then
-      self:exitWith(nil)
+      self.stage = "menu"
+      self.index = 1
     elseif input:wasPressed("a") then
       self.net = Net.new()
       if self.index == 1 then
@@ -151,6 +187,62 @@ function LinkState:update(dt)
       end
     end
 
+  elseif self.stage == "onlineMenu" then
+    if input:wasPressed("up") or input:wasPressed("down") then
+      self.index = self.index == 1 and 2 or 1
+    elseif input:wasPressed("b") then
+      self.stage = "menu"
+      self.index = 2
+    elseif input:wasPressed("a") then
+      if self.index == 1 then
+        self.net = Net.new()
+        if self.net:hostOnline() then
+          self.stage = "onlineHosting"
+        else
+          self:exitWith("Link error:\n" .. (self.net.error or "?"))
+        end
+      else
+        self.stage = "codeEntry"
+        self.codeEntry = CodeEntry.new()
+      end
+    end
+
+  elseif self.stage == "onlineHosting" then
+    if input:wasPressed("b") then self:exitWith(nil) return end
+    if self.net.paired then
+      self.stage = "modeSelect"
+      self.index = 1
+    end
+
+  elseif self.stage == "codeEntry" then
+    if input:wasPressed("b") then
+      self.stage = "onlineMenu"
+      self.index = 2
+    elseif input:wasPressed("up") then
+      CodeEntry.up(self.codeEntry)
+    elseif input:wasPressed("down") then
+      CodeEntry.down(self.codeEntry)
+    elseif input:wasPressed("left") then
+      CodeEntry.left(self.codeEntry)
+    elseif input:wasPressed("right") then
+      CodeEntry.right(self.codeEntry)
+    elseif input:wasPressed("a") then
+      local code = CodeEntry.text(self.codeEntry)
+      self.net = Net.new()
+      if self.net:joinOnline(nil, code) then
+        self.stage = "onlineJoining"
+      else
+        self:exitWith("Link error:\n" .. (self.net.error or "?"))
+      end
+    end
+
+  elseif self.stage == "onlineJoining" then
+    if input:wasPressed("b") then self:exitWith(nil) return end
+    if self.net.paired then
+      self.stage = "waitMode"
+      self:sendHello(nil) -- the host owns the mode; this is just who we are
+    end
+
   elseif self.stage == "hosting" then
     if input:wasPressed("b") then self:exitWith(nil) return end
     if self.net.paired then
@@ -389,12 +481,49 @@ end
 
 function LinkState:draw()
   if self.stage == "menu" then
-    drawTitle("LINK CABLE CLUB")
+    drawTitle("BOIS CLUB LIVE")
+    Font.draw("LINK CABLE (LAN)", 32, 44)
+    Font.draw("ONLINE MATCH", 32, 60)
+    Font.draw("TOURNAMENT", 32, 76)
+    Font.drawCode(CURSOR, 24, 44 + (self.index - 1) * 16)
+
+  elseif self.stage == "lanMenu" then
+    drawTitle("LINK CABLE (LAN)")
     Font.draw("HOST A GAME", 32, 48)
     Font.draw("JOIN A GAME", 32, 68)
     Font.drawCode(CURSOR, 24, self.index == 1 and 48 or 68)
     Font.draw("UDP port " .. Net.defaultPort(), 8, 128)
 
+  elseif self.stage == "onlineMenu" then
+    drawTitle("ONLINE MATCH")
+    Font.draw("HOST ONLINE", 32, 48)
+    Font.draw("JOIN ONLINE", 32, 68)
+    Font.drawCode(CURSOR, 24, self.index == 1 and 48 or 68)
+
+  elseif self.stage == "onlineHosting" then
+    drawTitle("HOSTING ONLINE")
+    Font.draw("Tell your friend", 16, 40)
+    Font.draw("the code:", 16, 52)
+    Font.draw(self.net.code or "??????", 32, 68)
+    Font.draw("Waiting for join...", 8, 96)
+
+  elseif self.stage == "codeEntry" then
+    drawTitle("ENTER CODE")
+    for i = 1, CodeEntry.LENGTH do
+      local x = 16 + (i - 1) * 16
+      local ch = CodeEntry.CHARSET:sub(self.codeEntry.chars[i], self.codeEntry.chars[i])
+      Font.draw(ch, x, 64)
+      if i == self.codeEntry.pos then
+        Font.drawCode(0xEE, x, 76) -- ▼ under the active slot
+      end
+    end
+    Font.draw("A: connect  B: back", 8, 128)
+
+  elseif self.stage == "onlineJoining" then
+    drawTitle("CONNECTING...")
+    Font.draw("Calling...", 8, 56)
+    Font.draw(self.net.target or "", 8, 72)
+
   elseif self.stage == "hosting" then
     drawTitle("HOSTING")
     Font.draw("Friend joins at:", 16, 48)

src/link/Net.lua

@@ -14,6 +14,15 @@
 -- Plain luajit (headless tests) has no enet; Net.available() reports
 -- that, and Net.loopbackPair() returns two in-memory ends with the
 -- same API so the protocol/battle logic stays testable offline.
+--
+-- A second backend, alongside the ENet one above, talks plain TCP to a
+-- pokeserver relay instead of direct peer-to-peer: both sides dial out
+-- to a public server (works through NAT with no hole-punching), the host
+-- gets a 6-character room code instead of an IP, and the server forwards
+-- messages between them. Same newline-delimited JSON on the wire, same
+-- Net API (host/join/send/update/poll/.paired/.closed/.error) -- see
+-- Net:hostOnline/Net:joinOnline below. LinkState/LinkBattle/Protocol don't
+-- know or care which backend is in play.
 
 local Json = require("src.link.Json")
 local Logger = require("src.core.Logger")
@@ -21,10 +30,14 @@ local Logger = require("src.core.Logger")
 local hasEnet, enet = pcall(require, "enet")
 if not hasEnet then enet = nil end
 
+local hasSocket, socket = pcall(require, "socket")
+if not hasSocket then socket = nil end
+
 local Net = {}
 Net.__index = Net
 
 Net.DEFAULT_PORT = 7777
+Net.DEFAULT_RELAY_ADDRESS = "147.182.215.255:7778"
 
 function Net.available()
   return enet ~= nil
@@ -34,6 +47,10 @@ function Net.defaultPort()
   return tonumber(os.getenv("POKEPORT_LINK_PORT") or "") or Net.DEFAULT_PORT
 end
 
+function Net.defaultRelayAddress()
+  return os.getenv("POKEPORT_RELAY_ADDR") or Net.DEFAULT_RELAY_ADDRESS
+end
+
 -- monotonic-ish clock for the join timeout
 local function now()
   if love and love.timer and love.timer.getTime then
@@ -64,13 +81,17 @@ function Net.new()
     enetHost = nil, -- our enet host object (both ends have one)
     peer = nil,     -- the connected remote peer
     inbox = {},
-    outbox = {},    -- messages queued before pairing completes
+    outbox = {},    -- messages queued before pairing completes (enet only)
     paired = false,
     address = nil,  -- host: "ip:port" the other player types in
     error = nil,
     closed = false,
     mode = nil,
     joinTimeout = 10,
+    tcpSocket = nil, -- relay backend: the luasocket TCP connection
+    rxBuf = "",      -- relay backend: bytes read but not yet a full line
+    txBuf = "",      -- relay backend: bytes queued but not yet written
+    code = nil,      -- relay backend, hosting: the room/tournament code
   }, Net)
 end
 
@@ -133,8 +154,56 @@ function Net:join(address)
   return true
 end
 
+-- opens a TCP connection to a pokeserver relay (blocking connect with a
+-- short timeout -- this runs once, from a single explicit user action, not
+-- from a per-frame poll, so blocking briefly is fine). Callers then send
+-- whatever control message starts their session ({type="host"},
+-- {type="join",...}, {type="host_tournament",...}, ...); every reply that
+-- isn't one of the four generic ones below lands in the normal inbox for
+-- the caller (LinkState, or Tournament.lua) to interpret.
+function Net:connectTCP(addr)
+  if not socket then
+    self.error = "online play needs luasocket (bundled with LOVE)"
+    return false
+  end
+  local host, port = addr:match("^(.-):(%d+)$")
+  host = host or addr
+  port = tonumber(port) or 7778
+  local tcp = socket.tcp()
+  tcp:settimeout(5)
+  local ok, err = tcp:connect(host, port)
+  if not ok then
+    self.error = ("can't reach relay %s:%d\n(%s)"):format(host, port, tostring(err))
+    return false
+  end
+  tcp:settimeout(0)
+  self.tcpSocket = tcp
+  self.rxBuf = ""
+  self.txBuf = ""
+  return true
+end
+
+function Net:hostOnline(addr)
+  if not self:connectTCP(addr or Net.defaultRelayAddress()) then return false end
+  self.mode = "onlineHosting"
+  self:send({ type = "host" })
+  return true
+end
+
+function Net:joinOnline(addr, code)
+  if not self:connectTCP(addr or Net.defaultRelayAddress()) then return false end
+  self.mode = "onlineJoining"
+  self.target = code
+  self:send({ type = "join", code = code })
+  return true
+end
+
 function Net:send(msg)
   if self.closed then return end
+  if self.tcpSocket then
+    self.txBuf = self.txBuf .. Json.encode(msg) .. "\n"
+    return
+  end
   if self.peerEnd then -- loopback: re-encode through json like the wire
     local decoded = Json.decode(Json.encode(msg))
     if decoded and not self.peerEnd.closed then
@@ -155,8 +224,102 @@ function Net:send(msg)
   end
 end
 
+-- one control message recognized on every relay connection, regardless of
+-- what it's being used for (a 1v1 room or a tournament): "peer_gone" only
+-- ever fires for a paired 1v1 room (tournaments signal disconnects through
+-- bracket_update/tournament_over instead), so it's unambiguous here.
+local function handleGenericRelayControl(self, msg)
+  if msg.type == "hosted" then
+    self.code = msg.code
+    return true
+  elseif msg.type == "paired" then
+    self.paired = true
+    return true
+  elseif msg.type == "join_error" then
+    self.error = ({
+      not_found = "That code wasn't\nfound.",
+      full = "That game already\nhas two players.",
+      expired = "That code has\nexpired.",
+    })[msg.reason] or ("Couldn't join:\n%s"):format(tostring(msg.reason))
+    self.closed = true
+    return true
+  elseif msg.type == "peer_gone" then
+    self.closed = true
+    return true
+  end
+  return false
+end
+
+function Net:handleTCPLine(line)
+  local msg = Json.decode(line)
+  if not msg then
+    Logger.warn("link: bad relay message %q", line:sub(1, 60))
+    return
+  end
+  if not handleGenericRelayControl(self, msg) then
+    table.insert(self.inbox, msg)
+  end
+end
+
+-- pulls every complete "\n"-terminated line out of rxBuf (leaving a
+-- trailing partial line, if any, for the next call to complete) and hands
+-- each to handleTCPLine. Pure buffer manipulation, no socket -- factored
+-- out of updateTCP so the framing logic is testable without a real
+-- connection (see the relay-path tests in tests/run_link_tests.lua).
+function Net:drainLines()
+  while true do
+    local nl = self.rxBuf:find("\n", 1, true)
+    if not nl then break end
+    local line = self.rxBuf:sub(1, nl - 1)
+    self.rxBuf = self.rxBuf:sub(nl + 1)
+    if #line > 0 then self:handleTCPLine(line) end
+  end
+end
+
+-- non-blocking pump for the relay TCP backend: flush queued writes, drain
+-- whatever's arrived into complete lines. Uses a byte-count receive
+-- (rather than the "*l" pattern) because luasocket's "*l" doesn't let a
+-- non-blocking caller recover the partial line across calls -- a
+-- byte-count read hands back whatever's available via the third return
+-- value on timeout, which we can buffer ourselves.
+function Net:updateTCP()
+  if self.closed then return end
+  local sock = self.tcpSocket
+  if #self.txBuf > 0 then
+    local sent, err, lastByte = sock:send(self.txBuf)
+    if sent then
+      self.txBuf = ""
+    elseif err == "timeout" then
+      self.txBuf = self.txBuf:sub((lastByte or 0) + 1)
+    else
+      self.error = "send failed: " .. tostring(err)
+      self.closed = true
+      return
+    end
+  end
+  while true do
+    local data, err, partial = sock:receive(8192)
+    local chunk = data or partial or ""
+    if #chunk > 0 then self.rxBuf = self.rxBuf .. chunk end
+    if err == "closed" then
+      self.closed = true
+      break
+    elseif err and err ~= "timeout" then
+      self.error = tostring(err)
+      self.closed = true
+      break
+    end
+    if not data then break end -- nothing more buffered this frame
+  end
+  self:drainLines()
+end
+
 -- pump enet events; decoded JSON messages are queued for poll()
 function Net:update()
+  if self.tcpSocket then
+    self:updateTCP()
+    return
+  end
   if self.peerEnd then return end -- loopback needs no pumping
   if not self.enetHost or self.closed then return end
   while true do
@@ -219,6 +382,12 @@ function Net:close()
     self.closed = true
     return
   end
+  if self.tcpSocket then
+    pcall(function() self.tcpSocket:close() end)
+    self.tcpSocket = nil
+    self.closed = true
+    return
+  end
   if self.enetHost then
     if self.peer and self.paired and not self.closed then
       -- graceful goodbye: disconnect_later delivers the queued

src/link/Tournament.lua

@@ -0,0 +1,577 @@
+-- Tournament play: host or join a bracket over the pokeserver relay.
+-- Single-elimination, server-managed (pokeserver's `tournaments` map).
+-- Matches run one at a time in bracket order; everyone not currently
+-- playing -- still waiting their turn, or already eliminated -- watches
+-- the live match play out via LinkBattle.newSpectator, reconstructed from
+-- a copy of the real traffic the server fans out. Battle mode only (no
+-- trade); vanilla only (Handshake.onlineAllowed already gated entry here
+-- from LinkState). Elite Four music (Music_IndigoPlateau) loops the whole
+-- time, uninterrupted by individual matches.
+
+local CodeEntry = require("src.link.CodeEntry")
+local Font = require("src.render.Font")
+local Handshake = require("src.link.Handshake")
+local LinkBattle = require("src.link.LinkBattle")
+local Net = require("src.link.Net")
+local Protocol = require("src.link.Protocol")
+local Runtime = require("src.mods.Runtime")
+local Sound = require("src.core.Sound")
+local TextBox = require("src.render.TextBox")
+
+local Tournament = {}
+Tournament.__index = Tournament
+Tournament.isOpaque = true
+
+local CURSOR = 0xED
+local MUSIC = "Music_IndigoPlateau"
+local TURN_LIMITS = { 3, 6, 9 }
+local PARTY_SIZES = { 1, 2, 3, 4, 5, 6 }
+local ANY = "ANY" -- sentinel: a leading *nil* array entry breaks ipairs
+                  -- (LuaJIT's # still reports the literal's full size, but
+                  -- ipairs stops dead at the hole), so level bounds use
+                  -- this string in self.settings instead of nil, converted
+                  -- to nil only on the wire
+local LEVEL_STEPS = { ANY, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65,
+                       70, 75, 80, 85, 90, 95, 100 }
+local SETTINGS_ROWS = 5 -- POKEMON, MIN LV, MAX LV, TIMER, PLAYING
+
+local function indexOf(list, value)
+  for i, v in ipairs(list) do
+    if v == value then return i end
+  end
+  return 1
+end
+
+-- accepts either the internal ANY sentinel or a raw wire value (nil means
+-- "any" there too, since the server never round-trips the sentinel string)
+local function levelLabel(v)
+  return (v == ANY or v == nil) and "ANY" or tostring(v)
+end
+
+local function levelForWire(v)
+  return v == ANY and nil or v
+end
+
+local function partyStats(party)
+  local size, minLevel, maxLevel = 0, nil, nil
+  for _, mon in ipairs(party or {}) do
+    size = size + 1
+    local lvl = mon.level or 1
+    minLevel = minLevel and math.min(minLevel, lvl) or lvl
+    maxLevel = maxLevel and math.max(maxLevel, lvl) or lvl
+  end
+  return size, minLevel or 0, maxLevel or 0
+end
+
+function Tournament.new(game)
+  local self = setmetatable({}, Tournament)
+  self.game = game
+  self.stage = "menu"
+  self.index = 1
+  self.settings = { turnLimit = 6, requiredPartySize = 3, minLevel = ANY, maxLevel = ANY,
+                    participating = true }
+  self.settingsIndex = 1
+  self.roster = {}
+  self.spectatorRoster = {}
+  Sound.startLoop(game.data, MUSIC)
+  return self
+end
+
+function Tournament:exitWith(message)
+  Sound.stopLoop(MUSIC)
+  Runtime.emit("link.ended", { reason = message and "error" or "bye" })
+  if self.net then self.net:close() end
+  self.game.stack:pop()
+  if message then
+    self.game.stack:push(TextBox.new(self.game, message))
+  end
+end
+
+-- -------------------------------------------------------------------
+-- host / join
+-- -------------------------------------------------------------------
+
+function Tournament:startHosting()
+  self.net = Net.new()
+  if not self.net:connectTCP(Net.defaultRelayAddress()) then
+    self:exitWith("Link error:\n" .. (self.net.error or "?"))
+    return
+  end
+  local size, minL, maxL = partyStats(self.game.save.party)
+  self.isCreator = true
+  self.participating = self.settings.participating
+  self.net:send({
+    type = "host_tournament",
+    turnLimit = self.settings.turnLimit,
+    requiredPartySize = self.settings.requiredPartySize,
+    minLevel = levelForWire(self.settings.minLevel),
+    maxLevel = levelForWire(self.settings.maxLevel),
+    participating = self.settings.participating,
+    name = self.game.save.player.name,
+    partySize = size, partyMinLevel = minL, partyMaxLevel = maxL,
+  })
+  self.stage = "registering"
+end
+
+function Tournament:startJoining(code)
+  self.net = Net.new()
+  if not self.net:connectTCP(Net.defaultRelayAddress()) then
+    self:exitWith("Link error:\n" .. (self.net.error or "?"))
+    return
+  end
+  local size, minL, maxL = partyStats(self.game.save.party)
+  self.isCreator = false
+  self.participating = true -- joining is always to compete; only hosting can opt out
+  self.code = code
+  self.net:send({
+    type = "join_tournament", code = code, name = self.game.save.player.name,
+    partySize = size, partyMinLevel = minL, partyMaxLevel = maxL,
+  })
+  self.stage = "registering"
+end
+
+-- -------------------------------------------------------------------
+-- message handling (shared between "registering"/"bracket" and drained
+-- again from a just-finished match's pendingTournamentMessages)
+-- -------------------------------------------------------------------
+
+local JOIN_ERROR_TEXT = {
+  not_found = "That code wasn't\nfound.",
+  already_started = "That tournament\nhas already begun.",
+  expired = "That code has\nexpired.",
+}
+
+function Tournament:handleMessage(msg)
+  if msg.type == "tournament_hosted" then
+    self.code = msg.code
+    self.settings.turnLimit = msg.turnLimit
+    self.participating = msg.participating
+    self.stage = "bracket"
+  elseif msg.type == "tournament_host_error" then
+    if msg.reason == "party_ineligible" then
+      self:exitWith(("Can't host:\nneed %d Pokemon\nLv %s-%s."):format(
+        msg.requiredPartySize, levelLabel(msg.minLevel), levelLabel(msg.maxLevel)))
+    else
+      self:exitWith("Couldn't host\nthat tournament.")
+    end
+  elseif msg.type == "tournament_join_error" then
+    if msg.reason == "party_ineligible" then
+      self:exitWith(("Your party needs\n%d Pokemon, Lv\n%s-%s."):format(
+        msg.requiredPartySize, levelLabel(msg.minLevel), levelLabel(msg.maxLevel)))
+    else
+      self:exitWith(JOIN_ERROR_TEXT[msg.reason] or "Couldn't join\nthat tournament.")
+    end
+  elseif msg.type == "tournament_roster" then
+    self.roster = msg.players
+    self.spectatorRoster = msg.spectators or {}
+    self.settings.turnLimit = msg.turnLimit
+    self.settings.requiredPartySize = msg.requiredPartySize
+    self.settings.minLevel = msg.minLevel == nil and ANY or msg.minLevel
+    self.settings.maxLevel = msg.maxLevel == nil and ANY or msg.maxLevel
+    self.stage = "bracket"
+  elseif msg.type == "bracket_update" then
+    self.bracket = msg.tournament
+    self.code = self.bracket.code
+    if self.stage == "registering" then self.stage = "bracket" end
+  elseif msg.type == "match_start" then
+    self:enterMatch(msg)
+  elseif msg.type == "match_start_spectate" then
+    self:enterSpectate(msg)
+  elseif msg.type == "tournament_bye" then
+    self.byeRound = msg.round
+  elseif msg.type == "tournament_over" then
+    self.champion = msg.champion
+    self.stage = "done"
+  end
+end
+
+-- -------------------------------------------------------------------
+-- entering a match: real participant
+-- -------------------------------------------------------------------
+
+function Tournament:sendHello(mode)
+  self.myHello = Handshake.hello(self.game, mode)
+  self.net:send(self.myHello)
+end
+
+function Tournament:pollHello()
+  local msgs = self.net:poll()
+  local keep, got = {}, false
+  for _, msg in ipairs(msgs) do
+    if msg.type == "hello" and not self.peerHello then
+      self.peerHello = msg
+      got = true
+    else
+      keep[#keep + 1] = msg
+    end
+  end
+  for i = #keep, 1, -1 do
+    table.insert(self.net.inbox, 1, keep[i])
+  end
+  return got
+end
+
+function Tournament:enterMatch(msg)
+  self.isHost = (msg.role == "host")
+  self.opponentName = msg.opponent
+  self.matchRound = msg.round
+  self.matchTurnLimit = msg.turnLimit
+  self.peerHello = nil
+  self:sendHello(self.isHost and "battle" or nil)
+  self.stage = "matchHello"
+end
+
+function Tournament:beginMatchBattle()
+  local verdict = Handshake.checkCompat(self.myHello, self.peerHello)
+  if not (verdict == "full" or verdict == "vanilla_peer") then
+    -- shouldn't happen (both sides already passed the online-play mods
+    -- gate), but a mismatched engine/build is still possible -- bail out
+    -- of just this match rather than crash the tournament
+    self:exitWith("Link error:\nversion mismatch\nwith opponent.")
+    return
+  end
+  self.linkSeed = self.isHost and love.math.random(1, 2 ^ 30) or nil
+  local opts = {
+    myParty = Protocol.packParty(self.game.save.party),
+    theirName = self.opponentName or "FOE",
+    seed = self.isHost and self.linkSeed or nil,
+    verdict = verdict,
+    strict = Handshake.strict(verdict),
+    turnLimit = self.matchTurnLimit,
+    keepNetOpen = true, -- this is the tournament's own connection, not a
+                        -- dedicated match socket -- don't let finish() close it
+  }
+  self.stage = "matchWaitParty"
+  self.pendingBattleOpts = opts
+  self.net:send({ type = "party",
+                  mons = Protocol.packParty(self.game.save.party),
+                  seed = self.linkSeed })
+end
+
+-- -------------------------------------------------------------------
+-- entering a match: spectator
+-- -------------------------------------------------------------------
+
+function Tournament:enterSpectate(msg)
+  self.matchRound = msg.round
+  self.spectate = {
+    hostName = msg.playerHost, guestName = msg.playerGuest,
+    hostParty = nil, guestParty = nil, seed = nil,
+  }
+  self.stage = "spectateWait"
+end
+
+-- -------------------------------------------------------------------
+-- update
+-- -------------------------------------------------------------------
+
+function Tournament:update(dt)
+  local input = self.game.input
+
+  if self.stage == "matchRunning" or self.stage == "spectateRunning" then
+    if self.game.stack:top() == self then
+      -- the battle popped; drain anything the network handed to it but it
+      -- didn't itself understand (a bracket_update, the next match...)
+      local battle = self.activeBattle
+      self.activeBattle = nil
+      if self.stage == "matchRunning" and battle and battle.result and self.net
+         and not self.net.closed then
+        -- a real participant reports its own outcome; the server resolves
+        -- the match once both sides have (or one disconnects)
+        self.net:send({ type = "tournament_result", result = battle.result })
+      end
+      if battle and battle.pendingTournamentMessages then
+        for _, msg in ipairs(battle.pendingTournamentMessages) do
+          self:handleMessage(msg)
+        end
+      end
+      if self.stage == "matchRunning" or self.stage == "spectateRunning" then
+        self.stage = "bracket"
+      end
+    end
+    return
+  end
+
+  if self.net then
+    self.net:update()
+    if self.net.error and self.stage ~= "menu" and self.stage ~= "hostSettings"
+       and self.stage ~= "codeEntry" then
+      self:exitWith("Link error:\n" .. self.net.error:sub(1, 60))
+      return
+    end
+    if self.net.closed and self.stage ~= "done" then
+      self:exitWith("The tournament\nconnection was\nlost.")
+      return
+    end
+  end
+
+  if self.stage == "matchHello" then
+    if input:wasPressed("b") then self:exitWith(nil) return end
+    self:pollHello()
+    if self.peerHello then self:beginMatchBattle() end
+    for _, msg in ipairs(self.net:poll()) do self:handleMessage(msg) end
+    return
+  elseif self.stage == "matchWaitParty" then
+    if input:wasPressed("b") then self:exitWith(nil) return end
+    local msgs = self.net:poll()
+    for i, msg in ipairs(msgs) do
+      if msg.type == "party" then
+        self.pendingBattleOpts.theirParty = msg.mons
+        if self.isHost then
+          self.pendingBattleOpts.seed = self.pendingBattleOpts.seed or self.linkSeed
+        else
+          self.pendingBattleOpts.seed = msg.seed
+        end
+        local battle, why = self.isHost
+          and LinkBattle.newHost(self.game, self.net, self.pendingBattleOpts)
+          or LinkBattle.newGuest(self.game, self.net, self.pendingBattleOpts)
+        if not battle then
+          self:exitWith(why or "Link battle\ncan't start.")
+          return
+        end
+        -- anything after `party` in this same batch belongs to the
+        -- battle now, not to Tournament -- put it back for its own poll()
+        for j = #msgs, i + 1, -1 do
+          table.insert(self.net.inbox, 1, msgs[j])
+        end
+        self.activeBattle = battle
+        self.game.stack:push(battle)
+        self.stage = "matchRunning"
+        return
+      else
+        self:handleMessage(msg)
+      end
+    end
+    return
+  elseif self.stage == "spectateWait" then
+    if input:wasPressed("b") then self:exitWith(nil) return end
+    local msgs = self.net:poll()
+    for i, msg in ipairs(msgs) do
+      if msg.type == "spectate" and msg.msg.type == "party" then
+        local inner = msg.msg
+        if msg.side == "host" then
+          self.spectate.hostParty = inner.mons
+          self.spectate.seed = inner.seed
+        else
+          self.spectate.guestParty = inner.mons
+        end
+        if self.spectate.hostParty and self.spectate.guestParty then
+          local battle, why = LinkBattle.newSpectator(self.game, self.net, {
+            hostParty = self.spectate.hostParty, guestParty = self.spectate.guestParty,
+            hostName = self.spectate.hostName, guestName = self.spectate.guestName,
+            seed = self.spectate.seed,
+          })
+          if not battle then
+            self:exitWith(why or "Can't watch this\nmatch.")
+            return
+          end
+          for j = #msgs, i + 1, -1 do
+            table.insert(self.net.inbox, 1, msgs[j])
+          end
+          self.activeBattle = battle
+          self.game.stack:push(battle)
+          self.stage = "spectateRunning"
+          return
+        end
+      else
+        self:handleMessage(msg)
+      end
+    end
+    return
+  end
+
+  if self.net then
+    for _, msg in ipairs(self.net:poll()) do self:handleMessage(msg) end
+  end
+
+  if self.stage == "menu" then
+    if input:wasPressed("up") or input:wasPressed("down") then
+      self.index = self.index == 1 and 2 or 1
+    elseif input:wasPressed("b") then
+      self:exitWith(nil)
+    elseif input:wasPressed("a") then
+      if self.index == 1 then
+        self.stage = "hostSettings"
+        self.settingsIndex = 1
+      else
+        self.stage = "codeEntry"
+        self.codeEntry = CodeEntry.new()
+      end
+    end
+
+  elseif self.stage == "hostSettings" then
+    if input:wasPressed("b") then
+      self.stage = "menu"
+      self.index = 1
+    elseif input:wasPressed("up") then
+      self.settingsIndex = self.settingsIndex == 1 and SETTINGS_ROWS or self.settingsIndex - 1
+    elseif input:wasPressed("down") then
+      self.settingsIndex = self.settingsIndex % SETTINGS_ROWS + 1
+    elseif input:wasPressed("left") or input:wasPressed("right") then
+      local delta = input:wasPressed("right") and 1 or -1
+      if self.settingsIndex == 1 then
+        local i = indexOf(PARTY_SIZES, self.settings.requiredPartySize)
+        i = ((i - 1 + delta) % #PARTY_SIZES) + 1
+        self.settings.requiredPartySize = PARTY_SIZES[i]
+      elseif self.settingsIndex == 2 then
+        local i = indexOf(LEVEL_STEPS, self.settings.minLevel)
+        i = ((i - 1 + delta) % #LEVEL_STEPS) + 1
+        self.settings.minLevel = LEVEL_STEPS[i]
+      elseif self.settingsIndex == 3 then
+        local i = indexOf(LEVEL_STEPS, self.settings.maxLevel)
+        i = ((i - 1 + delta) % #LEVEL_STEPS) + 1
+        self.settings.maxLevel = LEVEL_STEPS[i]
+      elseif self.settingsIndex == 4 then
+        local i = indexOf(TURN_LIMITS, self.settings.turnLimit)
+        i = ((i - 1 + delta) % #TURN_LIMITS) + 1
+        self.settings.turnLimit = TURN_LIMITS[i]
+      elseif self.settingsIndex == 5 then
+        self.settings.participating = not self.settings.participating
+      end
+    elseif input:wasPressed("a") or input:wasPressed("start") then
+      self:startHosting()
+    end
+
+  elseif self.stage == "codeEntry" then
+    if input:wasPressed("b") then
+      self.stage = "menu"
+      self.index = 2
+    elseif input:wasPressed("up") then
+      CodeEntry.up(self.codeEntry)
+    elseif input:wasPressed("down") then
+      CodeEntry.down(self.codeEntry)
+    elseif input:wasPressed("left") then
+      CodeEntry.left(self.codeEntry)
+    elseif input:wasPressed("right") then
+      CodeEntry.right(self.codeEntry)
+    elseif input:wasPressed("a") then
+      self:startJoining(CodeEntry.text(self.codeEntry))
+    end
+
+  elseif self.stage == "registering" then
+    if input:wasPressed("b") then self:exitWith(nil) end
+
+  elseif self.stage == "bracket" then
+    if input:wasPressed("b") then self:exitWith(nil) return end
+    if input:wasPressed("a") and self.isCreator and #self.roster >= 2 then
+      self.net:send({ type = "start_tournament" })
+    end
+
+  elseif self.stage == "done" then
+    if input:wasPressed("a") or input:wasPressed("b") then
+      self:exitWith(nil)
+    end
+  end
+end
+
+-- -------------------------------------------------------------------
+-- draw
+-- -------------------------------------------------------------------
+
+local function drawTitle(text)
+  love.graphics.setColor(1, 1, 1, 1)
+  love.graphics.rectangle("fill", 0, 0, 160, 144)
+  love.graphics.setColor(0, 0, 0, 1)
+  Font.draw(text, 8, 6)
+end
+
+local SETTINGS_LABELS = { "POKEMON", "MIN LV", "MAX LV", "TIMER", "PLAYING" }
+
+function Tournament:draw()
+  if self.stage == "menu" then
+    drawTitle("TOURNAMENT")
+    Font.draw("HOST", 32, 48)
+    Font.draw("JOIN", 32, 68)
+    Font.drawCode(CURSOR, 24, self.index == 1 and 48 or 68)
+
+  elseif self.stage == "hostSettings" then
+    drawTitle("TOURNAMENT RULES")
+    local values = {
+      tostring(self.settings.requiredPartySize),
+      levelLabel(self.settings.minLevel),
+      levelLabel(self.settings.maxLevel),
+      self.settings.turnLimit .. "s",
+      self.settings.participating and "YES" or "NO",
+    }
+    for i, label in ipairs(SETTINGS_LABELS) do
+      local y = 32 + (i - 1) * 16
+      Font.draw(label, 16, y)
+      Font.draw(values[i], 96, y)
+      if i == self.settingsIndex then Font.drawCode(CURSOR, 8, y) end
+    end
+    Font.draw("START: create", 8, 128)
+
+  elseif self.stage == "codeEntry" then
+    drawTitle("ENTER CODE")
+    for i = 1, CodeEntry.LENGTH do
+      local x = 16 + (i - 1) * 16
+      local ch = CodeEntry.CHARSET:sub(self.codeEntry.chars[i], self.codeEntry.chars[i])
+      Font.draw(ch, x, 64)
+      if i == self.codeEntry.pos then
+        Font.drawCode(0xEE, x, 76)
+      end
+    end
+    Font.draw("A: join  B: back", 8, 128)
+
+  elseif self.stage == "registering" then
+    drawTitle("CONNECTING...")
+    Font.draw("B: cancel", 8, 128)
+
+  elseif self.stage == "bracket" or self.stage == "matchHello"
+      or self.stage == "matchWaitParty" or self.stage == "spectateWait" then
+    drawTitle(("TOURNAMENT %s"):format(self.code or "??????"))
+    if self.bracket then
+      local y = 20
+      for _, round in ipairs(self.bracket.rounds) do
+        Font.draw(("ROUND %d"):format(round.round), 8, y)
+        y = y + 10
+        for _, m in ipairs(round.matches) do
+          local line
+          if m.bye then
+            line = ("%s (bye)"):format(m.a or m.b or "?")
+          else
+            local mark = m.state == "live" and "*" or (m.winner and "" or "")
+            line = ("%s%s vs %s%s"):format(
+              m.winner == m.a and ">" or " ", m.a or "?",
+              m.b or "?", m.winner == m.b and "<" or (mark == "*" and " *" or ""))
+          end
+          Font.draw(line, 12, y)
+          y = y + 10
+          if y > 120 then break end
+        end
+      end
+    else
+      if self.participating == false then
+        Font.draw("(organizing --", 16, 32)
+        Font.draw("not playing)", 16, 42)
+      end
+      Font.draw("Waiting for", 16, 48)
+      Font.draw("players to join:", 16, 60)
+      local y = 60
+      for i, name in ipairs(self.roster) do
+        y = 60 + i * 10
+        Font.draw(name, 24, y)
+      end
+      for _, name in ipairs(self.spectatorRoster) do
+        y = y + 10
+        Font.draw(name .. " (watch)", 24, y)
+      end
+    end
+    if self.isCreator and #self.roster >= 2 and not self.bracket then
+      Font.draw("A: START  B: cancel", 8, 132)
+    else
+      Font.draw("B: cancel", 8, 132)
+    end
+
+  elseif self.stage == "done" then
+    drawTitle("TOURNAMENT OVER")
+    if self.champion then
+      Font.draw(("%s is the"):format(self.champion), 16, 56)
+      Font.draw("champion!", 16, 68)
+    end
+    Font.draw("A: continue", 8, 128)
+  end
+  love.graphics.setColor(1, 1, 1, 1)
+end
+
+return Tournament