package game

// Regression: picking up a stackable item must merge into an existing stack
// even when every inventory slot is occupied — capacity is required only
// when a NEW slot is needed, matching the get-all paths.

import (
	"path/filepath"
	"testing"

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

func TestPickupMergesIntoFullInventory(t *testing.T) {
	h := newHarness(t)
	h.seedAccount("alice")
	p := h.seedCharacter("alice", "alice")
	writeSeedFile(t, filepath.Join(h.dir, "items", "chips.yaml"), []byte("id: chips\nname: chips\nstackable: true\n"))
	sess := &net.Session{Conn: newChanConn(), Player: p}
	sess.SetState(net.StateGame)
	h.g.RunOnOwner(func() {
		h.g.ItemStore.Reload(h.dir)
		for i := 0; i < 28; i++ {
			p.SetInvSlot(i, &player.InventorySlot{ItemID: "filler", Quantity: 1})
		}
		p.SetInvSlot(0, &player.InventorySlot{ItemID: "chips", Quantity: 10})
		h.g.World.AddGroundItem(1, "chips", 5)
		h.g.doGet(sess, "chips")
		if got := countChips(p); got != 15 {
			t.Errorf("pickup rejected despite existing chip stack: have %d, want 15", got)
		}
	})
}

func TestPickupFullInventoryWithoutStackStillRefused(t *testing.T) {
	h := newHarness(t)
	h.seedAccount("alice")
	p := h.seedCharacter("alice", "alice")
	writeSeedFile(t, filepath.Join(h.dir, "items", "chips.yaml"), []byte("id: chips\nname: chips\nstackable: true\n"))
	sess := &net.Session{Conn: newChanConn(), Player: p}
	sess.SetState(net.StateGame)
	h.g.RunOnOwner(func() {
		h.g.ItemStore.Reload(h.dir)
		for i := 0; i < 28; i++ {
			p.SetInvSlot(i, &player.InventorySlot{ItemID: "filler", Quantity: 1})
		}
		h.g.World.AddGroundItem(1, "chips", 5)
		h.g.doGet(sess, "chips")
		if got := countChips(p); got != 0 {
			t.Errorf("pickup without an existing stack must be refused, have %d", got)
		}
		if got := h.g.World.GroundItems(1)["chips"]; got != 5 {
			t.Errorf("refused pickup must leave the ground stack intact, have %d", got)
		}
	})
}