package game

// Tick and lifecycle liveness regressions: a pending aggro retry must never
// start combat for a departed player, an in-combat disconnect must not pin the
// character in the registry forever, per-tick systems must stay safe with a
// nil Hub and must advance in a reproducible order, and the per-tick session
// snapshots must not drop the wander broadcasts they replaced.

import (
	"fmt"
	"path/filepath"
	"strings"
	"testing"

	"thehouseoficarus/internal/behavior"
	"thehouseoficarus/internal/net"
	"thehouseoficarus/internal/player"
)

// TestFireTickNilHubIsSafe guards the mandatory tick-system guard: FireTick
// reaches cancelStokers -> g.Hub.PlayersInRoom when a fire burns out, and the
// master tick subscriber can fire before SetHub during startup.
func TestFireTickNilHubIsSafe(t *testing.T) {
	t.Run("nil_hub_burning_fire", func(t *testing.T) {
		g := escapeTestGame()
		// Quality 1 burns out on this tick, which is the path that touches
		// the hub; without the guard it panics on g.Hub == nil.
		g.World.AddObjInstance(1, "fire", 1)
		g.Hub = nil

		defer func() {
			if r := recover(); r != nil {
				t.Fatalf("FireTick panicked with a nil Hub: %v", r)
			}
		}()
		g.FireTick()
	})

	t.Run("hub_present_still_burns_out", func(t *testing.T) {
		h := newHarness(t)
		h.g.RunOnOwner(func() {
			h.g.World.AddObjInstance(1, "fire", 1)
			h.g.FireTick()
			if fires := h.g.World.AllFireStates(); len(fires) != 0 {
				t.Errorf("fire should have burned out, %d states remain", len(fires))
			}
		})
	})
}

// TestSequenceTickFiresInDeterministicOrder guards the sorted iteration over
// g.sequences: map iteration randomly chose which simultaneous sequence
// advanced first, contradicting the determinism contract in
// dev_guide/tick_order.md.
func TestSequenceTickFiresInDeterministicOrder(t *testing.T) {
	g := escapeTestGame()
	g.sequences = make(map[string]*sequence)
	g.loggedInChars = make(map[string]*net.Session)

	const rounds = 32
	for round := 0; round < rounds; round++ {
		conn := newChanConn()
		p := player.New(fmt.Sprintf("seq_order_%d", round))
		p.RoomID = 1
		sess := &net.Session{Player: p, Conn: conn}
		sess.SetState(net.StateGame)
		g.loggedInChars[p.Name] = sess

		// Inserted in reverse key order: only sorting can make the advance
		// order stable.
		g.seqMu.Lock()
		g.sequences["z_second"] = &sequence{
			sess: sess, player: p, playerName: p.Name, roomID: p.RoomID,
			steps: []behavior.Step{{Messages: []string{"ORDER-MARKER-SECOND"}}},
			scope: scopePlayer, key: "z_second",
		}
		g.sequences["a_first"] = &sequence{
			sess: sess, player: p, playerName: p.Name, roomID: p.RoomID,
			steps: []behavior.Step{{Messages: []string{"ORDER-MARKER-FIRST"}}},
			scope: scopePlayer, key: "a_first",
		}
		g.seqMu.Unlock()

		g.SequenceTick()

		out := string(conn.Bytes())
		first, second := strings.Index(out, "ORDER-MARKER-FIRST"), strings.Index(out, "ORDER-MARKER-SECOND")
		if first < 0 || second < 0 {
			t.Fatalf("round %d: both sequences should have fired, got %q", round, out)
		}
		if first > second {
			t.Fatalf("round %d: sequences advanced in map order instead of key order: %q", round, out)
		}
	}
}

// TestWanderTickBroadcastsWithSingleSessionSnapshot guards the hoisted
// AllSessions snapshot: the mob leave/enter broadcasts to other rooms must
// still fire after the per-move snapshot was replaced by one per system.
func TestWanderTickBroadcastsWithSingleSessionSnapshot(t *testing.T) {
	h := newHarness(t)
	writeSeedFile(t, filepath.Join(h.dir, "mobs", "wanderer.yaml"), []byte(
		"id: wanderer\nname: wanderer\ncombat:\n    kind: combat\n    stats:\n        hp: 1\n"))

	// Sessions without a write queue: broadcasts reach the transport
	// synchronously with the tick, so the assertions need no polling.
	aliceConn := wanderTestSession(h, "alice", 1)
	bobConn := wanderTestSession(h, "bob", 2)

	var mobRoom int
	h.g.RunOnOwner(func() {
		// Room 1 has a north exit to room 2 (see seedWorld).
		h.g.MobStore.ReloadDefs(h.dir)
		def, err := h.g.MobStore.LoadDef("wanderer")
		if err != nil {
			t.Errorf("load seeded mob: %v", err)
			return
		}
		inst := h.g.MobStore.SpawnTransient(def, &behavior.SpawnMobConfig{ID: "wanderer"}, 1, "")
		if inst.HP <= 0 {
			t.Errorf("seeded mob has no HP (%d); it would be skipped", inst.HP)
			return
		}
		inst.WanderInterval = 1
		inst.WanderTickCounter = 1
		inst.WanderRooms = []int{2}

		h.g.WanderTick()
		mobRoom = inst.RoomID
	})

	if mobRoom != 2 {
		t.Fatalf("mob did not wander into room 2 (room %d)", mobRoom)
	}
	if sessions := h.g.Hub.AllSessions(); len(sessions) != 2 {
		t.Fatalf("snapshot changed hub membership: %d sessions", len(sessions))
	}

	leaving := string(aliceConn.Bytes())
	entering := string(bobConn.Bytes())
	if !strings.Contains(leaving, "wanderer") || !strings.Contains(leaving, "moves away.") {
		t.Errorf("departing room did not get the leave broadcast: %q", leaving)
	}
	if !strings.Contains(entering, "wanderer") || !strings.Contains(entering, "drifts in.") {
		t.Errorf("arrival room did not get the enter broadcast: %q", entering)
	}
	if strings.Contains(leaving, "drifts in.") {
		t.Errorf("enter broadcast leaked into the departing room: %q", leaving)
	}
	if strings.Contains(entering, "moves away.") {
		t.Errorf("leave broadcast leaked into the arrival room: %q", entering)
	}
}

// wanderTestSession registers a live in-game session for a fresh character in
// roomID, bypassing the login menu and the write queue.
func wanderTestSession(h *harness, name string, roomID int) *chanConn {
	h.t.Helper()
	p := player.New(name)
	p.RoomID = roomID
	conn := newChanConn()
	sess := &net.Session{Conn: conn, Player: p}
	sess.SetState(net.StateGame)
	h.hub.Add(sess)
	h.hub.EnterRoom(sess, roomID)
	return conn
}

// TestAggroRetryStopsForDepartedPlayer guards keepRolling's liveness guard: a
// pending aggro timer outlives its session, and must never start combat for a
// player who has logged out, disconnected, or re-logged in elsewhere.
func TestAggroRetryStopsForDepartedPlayer(t *testing.T) {
	t.Run("player_detached", func(t *testing.T) {
		defer patchAggroRand(0.5)()
		g := escapeTestGame()
		spawnTestMob(g, 100)
		p := player.New("aggro_ghost")
		p.RoomID = 100
		sess := escapeTestSession(p)

		g.checkAggro(sess)
		if g.Combat.Get(p.Name) != nil {
			t.Fatal("inline roll should have missed (val=0.5)")
		}
		// The logout path nils the session's player before the retry fires.
		sess.Player = nil
		rollAggroRand = func() float64 { return 0.0 }
		g.Ticks.Tick()

		if cs := g.Combat.Get(p.Name); cs != nil {
			t.Fatalf("combat started for a departed player: %+v", cs)
		}
	})

	t.Run("session_disconnecting", func(t *testing.T) {
		defer patchAggroRand(0.5)()
		g := escapeTestGame()
		spawnTestMob(g, 150)
		p := player.New("aggro_offline")
		p.RoomID = 150
		sess := escapeTestSession(p)

		g.checkAggro(sess)
		sess.StartDisconnect(10)
		rollAggroRand = func() float64 { return 0.0 }
		g.Ticks.Tick()

		if g.Combat.Get(p.Name) != nil {
			t.Error("combat started for a session whose transport is gone")
		}
	})

	t.Run("replaced_by_new_session", func(t *testing.T) {
		defer patchAggroRand(0.5)()
		g := escapeTestGame()
		spawnTestMob(g, 200)
		p := player.New("aggro_relogin")
		p.RoomID = 200
		sess := escapeTestSession(p)

		g.checkAggro(sess)
		// The same character logged in again on another connection.
		g.loggedInChars = map[string]*net.Session{p.Name: escapeTestSession(p)}
		rollAggroRand = func() float64 { return 0.0 }
		g.Ticks.Tick()

		if g.Combat.Get(p.Name) != nil {
			t.Error("combat started for the retired session of a re-logged-in character")
		}
	})

	t.Run("live_session_still_rolls", func(t *testing.T) {
		defer patchAggroRand(0.5)()
		g := escapeTestGame()
		spawnTestMob(g, 300)
		p := player.New("aggro_live")
		p.RoomID = 300
		sess := escapeTestSession(p)
		g.loggedInChars = map[string]*net.Session{p.Name: sess}

		g.checkAggro(sess)
		rollAggroRand = func() float64 { return 0.0 }
		g.Ticks.Tick()

		if g.Combat.Get(p.Name) == nil {
			t.Error("the live session's retry should still start combat")
		}
	})
}

// TestDisconnectTickCombatDeferralIsBounded guards the disconnect countdown:
// an unresolvable fight used to freeze it forever, so the session (and the
// character's "logged in elsewhere" lock) never cleared.
func TestDisconnectTickCombatDeferralIsBounded(t *testing.T) {
	h := newHarness(t)
	h.seedAccount("alice")
	h.seedCharacter("alice", "alice")
	sess, _ := h.connect("alice")
	p := sess.Player

	var sessionsAfterFirstTick, remaining int
	h.g.RunOnOwner(func() {
		sess.StartDisconnect(1)
		// A fight that never resolves (no subscriber ever ends it).
		h.g.Combat.Enter(p.Name, "skeleton")

		h.g.DisconnectTick()
		sessionsAfterFirstTick = len(h.g.Hub.AllSessions())

		for i := 0; i < disconnectCombatGraceTicks+5 && len(h.g.Hub.AllSessions()) > 0; i++ {
			h.g.DisconnectTick()
		}
		remaining = len(h.g.Hub.AllSessions())
	})

	if sessionsAfterFirstTick != 1 {
		t.Fatalf("in-combat session should be deferred on the first tick, %d sessions remain", sessionsAfterFirstTick)
	}
	if remaining != 0 {
		t.Fatalf("in-combat disconnect never completed: %d sessions remain", remaining)
	}
	if _, err := h.g.AccountStore.LoadCharacter("alice"); err != nil {
		t.Fatalf("character was not saved before the hard remove: %v", err)
	}
	h.g.charsMu.Lock()
	_, stillRegistered := h.g.loggedInChars["alice"]
	h.g.charsMu.Unlock()
	if stillRegistered {
		t.Error("character registry entry survived the hard remove")
	}
}