package game

// Crash-safety regressions for the owner goroutine and the account-menu
// handlers. The owner goroutine is the single execution authority for live
// game state, so an unrecovered panic there (from command parsing, a tick
// system, or a session whose account/player has gone away) takes down every
// session and all unsaved state. These tests pin both halves of the fix: the
// loop contains panics, and the menu handlers refuse to dereference a nil
// account.

import (
	"strings"
	"testing"

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

// TestOwnerLoopSurvivesPanickingTask proves a panicking task is contained and
// counted, and that the loop keeps draining the queue afterwards.
func TestOwnerLoopSurvivesPanickingTask(t *testing.T) {
	h := newHarness(t)

	before := h.g.owner.panics.Load()
	h.g.RunOnOwner(func() { panic("boom") })
	// Game.run releases its caller from the task's OWN defer (close(task)),
	// which unwinds before runTask's deferred recover runs. The panic counter
	// is incremented by that recover, so reading it right here could observe
	// before+0. Submit a no-op task and wait for it: the owner drains tasks in
	// FIFO order, so the panicking task's runTask — recover and counter
	// increment included — has fully settled before the no-op task executes.
	h.barrier()
	if got := h.g.owner.panics.Load(); got != before+1 {
		t.Fatalf("panic counter = %d, want %d", got, before+1)
	}

	ran := false
	h.g.RunOnOwner(func() { ran = true })
	if !ran {
		t.Fatal("owner loop did not execute a task submitted after a panic")
	}
}

// TestOwnerSessionInputPanicDoesNotKillLoop reproduces the production crash
// path: a session in StateGame with no Player (a departed session whose
// connection goroutine is still dispatching buffered input) dereferences a nil
// Player. The owner must log and contain the panic instead of taking the
// process down with it.
func TestOwnerSessionInputPanicDoesNotKillLoop(t *testing.T) {
	h := newHarness(t)
	sess := &net.Session{Conn: newChanConn()}
	sess.SetState(net.StateGame)

	h.g.HandleSessionOnOwner(sess, "look")

	if got := h.g.owner.panics.Load(); got == 0 {
		t.Fatal("expected the nil-Player dispatch to panic and be contained")
	}
	h.barrier() // the owner loop is still alive and serving tasks
}

// assertResetToAccountName requires a session to be back at the account-name
// prompt with no account bound.
func assertResetToAccountName(t *testing.T, sess *net.Session, conn *chanConn) {
	t.Helper()
	if got := sess.State(); got != net.StateAccountName {
		t.Fatalf("state = %v, want StateAccountName", got)
	}
	if sess.Account != nil {
		t.Fatalf("account not cleared: %+v", sess.Account)
	}
	if out := string(conn.Bytes()); !strings.Contains(out, "Account name: ") {
		t.Fatalf("missing account-name prompt; output = %q", out)
	}
}

// TestNilAccountHandlersResetToAccountName drives every menu-state handler with
// a session whose account is nil (purged, or republished from another session)
// and requires each to fall back to the account-name prompt instead of
// dereferencing the nil account. The handlers run on the test goroutine so an
// unguarded dereference fails loudly here rather than being absorbed by the
// owner loop's panic barrier.
func TestNilAccountHandlersResetToAccountName(t *testing.T) {
	h := newHarness(t)

	cases := []struct {
		name  string
		state net.SessionState
		input string
		run   func(*Game, *net.Session, string)
	}{
		{"menu-connect", net.StateMenu, "c", (*Game).handleMenu},
		{"menu-list", net.StateMenu, "l", (*Game).handleMenu},
		{"menu-new", net.StateMenu, "n", (*Game).handleMenu},
		{"menu-rename-account", net.StateMenu, "a", (*Game).handleMenu},
		{"menu-rename-char", net.StateMenu, "r", (*Game).handleMenu},
		{"menu-delete-char", net.StateMenu, "d", (*Game).handleMenu},
		{"menu-purge", net.StateMenu, "p", (*Game).handleMenu},
		{"menu-default", net.StateMenu, "zzz", (*Game).handleMenu},
		{"color-choice", net.StateColorChoice, "y", (*Game).handleColorChoice},
		{"new-account-confirm", net.StateNewAccount, "pw", (*Game).handleNewAccount},
		{"new-char-name", net.StateNewCharName, "bob", (*Game).handleNewCharName},
		{"rename-account", net.StateRenameAccount, "bob", (*Game).handleRenameAccount},
		{"rename-char", net.StateRenameChar, "1", (*Game).handleRenameChar},
		{"rename-char-name", net.StateRenameCharName, "bob", (*Game).handleRenameCharName},
		{"delete-char", net.StateDeleteChar, "1", (*Game).handleDeleteChar},
		{"purge-account", net.StatePurgeAccount, "PURGE bob", (*Game).handlePurgeAccount},
	}

	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			conn := newChanConn()
			sess := &net.Session{Conn: conn}
			sess.SetState(tc.state)
			tc.run(h.g, sess, tc.input)
			assertResetToAccountName(t, sess, conn)
		})
	}

	t.Run("show-menu", func(t *testing.T) {
		conn := newChanConn()
		sess := &net.Session{Conn: conn}
		sess.SetState(net.StateGame)
		h.g.showMenu(sess)
		assertResetToAccountName(t, sess, conn)
	})

	t.Run("connect-character", func(t *testing.T) {
		conn := newChanConn()
		sess := &net.Session{Conn: conn}
		sess.SetState(net.StateMenu)
		h.g.connectCharacter(sess, "bob")
		assertResetToAccountName(t, sess, conn)
	})

	t.Run("apply-password-auth", func(t *testing.T) {
		conn := newChanConn()
		sess := &net.Session{Conn: conn}
		sess.SetState(net.StatePassword)
		h.g.applyPasswordAuth(sess, passwordAuth{ok: true, stored: "stale-hash"})
		assertResetToAccountName(t, sess, conn)
	})
}

// TestCommandsTolerateNilAccount covers the in-game command handlers that
// persist to the account: with the account gone they must still work for the
// live player instead of faulting on the nil account.
func TestCommandsTolerateNilAccount(t *testing.T) {
	h := newHarness(t)
	sess := &net.Session{Conn: newChanConn(), Player: player.New("alice")}
	sess.SetState(net.StateGame)

	h.g.doOption(sess, "unicode off")
	if sess.Player.Options["unicode"] != false {
		t.Fatalf("unicode option not applied to the player: %v", sess.Player.Options["unicode"])
	}

	h.g.doColor(sess, "room_name D0")
	h.g.saveAccountColor(sess, "room_name", "D0")
	h.g.doAlias(sess, []string{"x", "look"})
	h.g.doUnalias(sess, []string{"x"})
}