package game

// Persistence/economy durability regressions: the economy journal's directory
// entry must be synced, recovery must order payout evidence by the record's
// creation order (not by its last-written line), the recovery checkpoint
// re-anchor must respect the economy cap, the journal-unavailable settlement
// fallback must only resolve the stakes it settles, and a bank credit move
// whose save failed must be refused instead of leaving memory ahead of the
// durable file.

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"testing"
	"time"

	"thehouseoficarus/internal/casino"
	"thehouseoficarus/internal/player"

	"gopkg.in/yaml.v3"
)

// waitForConnText blocks until the session's writer flushes text containing
// substr; the writer goroutine is asynchronous.
func waitForConnText(t *testing.T, conn *chanConn, substr string) {
	t.Helper()
	deadline := time.Now().Add(2 * time.Second)
	for !conn.Contains(substr) && time.Now().Before(deadline) {
		time.Sleep(time.Millisecond)
	}
	if !conn.Contains(substr) {
		t.Errorf("expected %q in session output; got=%s", substr, conn.Bytes())
	}
}

// TestRecoveryIgnoresRewrittenOlderPayoutAsStakeEvidence: payout evidence for
// a stake is ordered by the payout's CREATION sequence, not by the line of its
// latest write. A payout created before the stake that is rewritten afterwards
// (a settle marker, or a recovery checkpoint re-anchor) must not be read as
// the stake's settlement — otherwise recovery settles the stake without
// refunding it and the wager is silently lost.
func TestRecoveryIgnoresRewrittenOlderPayoutAsStakeEvidence(t *testing.T) {
	h := newHarness(t)
	h.seedAccount("alice")
	p := h.seedCharacter("alice", "alice")
	h.g.RunOnOwner(func() {
		p.Credits = 1000
		if err := h.g.AccountStore.SaveCharacter(p); err != nil {
			t.Error(err)
			return
		}
		// An older payout record (created first) ...
		old, err := h.g.Economy.start("payout", p, 0, 20, 1000, 1020, 0, 0)
		if err != nil {
			t.Error(err)
			return
		}
		// ... then the stake ...
		if _, err := h.g.Economy.start("wager", p, 0, 50, 1000, 950, 0, 0); err != nil {
			t.Error(err)
			return
		}
		// ... and finally a later write of the OLD payout lands after the
		// stake's line, so line order alone would call it the stake's
		// settlement.
		if !h.g.Economy.settleDurable(old) {
			t.Error("the older payout's settle marker could not be journaled")
			return
		}
		// The stake's debit is durable; the crashed round is recoverable.
		p.Credits = 950
		if err := h.g.AccountStore.SaveCharacter(p); err != nil {
			t.Error(err)
			return
		}
		h.g.recoverEconomy()
	})
	loaded, err := h.g.AccountStore.LoadCharacter("alice")
	if err != nil {
		t.Fatal(err)
	}
	if loaded.Credits != 1000 {
		t.Errorf("balance after recovery = %d, want 1000: a payout created before the stake must not settle it (the stake is refunded, not silently kept)",
			loaded.Credits)
	}
	if open := h.g.Economy.mustLoadOpen(t); len(open) != 0 {
		t.Errorf("records left open after recovery: %+v", open)
	}
}

// TestRecoveryReanchorKeepsCheckpointsWithinCreditCap: when the economy cap
// blocks a payout's re-application, the re-anchored checkpoints must stay
// within the cap. An impossible post-state above the cap can never be read as
// durability, and the record is owed at the current balance: it must keep
// reading that way across repeated recoveries instead of being settled as
// "already durable". Legacy records without the tracked-evidence flag take
// this checkpoint-compensating path.
func TestRecoveryReanchorKeepsCheckpointsWithinCreditCap(t *testing.T) {
	dir := t.TempDir()
	seedWorld(t, dir)

	hash, _ := player.HashPassword("pw")
	accData, _ := yaml.Marshal(&player.Account{Name: "alice", PasswordHash: hash})
	writeSeedFile(t, filepath.Join(dir, "players", "accounts", "alice.yaml"), accData)
	p := player.New("alice")
	p.Credits = casino.MaxCredits - 30
	p.Account = "alice"
	pData, _ := yaml.Marshal(p)
	writeSeedFile(t, filepath.Join(dir, "players", "characters", "alice.yaml"), pData)

	// Two identical open payouts of 20 at the cap: the first can be
	// re-applied, the second cannot. Each record is its own journal line.
	var journal []byte
	for i := 0; i < 2; i++ {
		line, err := json.Marshal(economyRecord{
			ID: fmt.Sprintf("unpaid-%d", i), Player: "alice", Kind: "payout",
			Credit: 20, Status: "open",
			CreditsBefore: casino.MaxCredits - 30, CreditsAfter: casino.MaxCredits - 10,
		})
		if err != nil {
			t.Fatal(err)
		}
		journal = append(journal, line...)
		journal = append(journal, '\n')
	}
	journalDir := filepath.Join(dir, "economy")
	if err := os.MkdirAll(journalDir, 0700); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(journalDir, "journal.jsonl"), journal, 0600); err != nil {
		t.Fatal(err)
	}

	// The first recovery runs in New.
	h := harnessFromDir(t, dir)
	for round := 1; round <= 3; round++ {
		if round > 1 {
			h.g.recoverEconomy()
		}
		open := h.g.Economy.mustLoadOpen(t)
		if len(open) != 1 {
			t.Fatalf("recovery %d: the unpaid liability must stay open exactly once, open=%d: %+v", round, len(open), open)
		}
		for _, rec := range open {
			if rec.CreditsBefore > casino.MaxCredits || rec.CreditsAfter > casino.MaxCredits {
				t.Fatalf("recovery %d re-anchored %s outside the economy cap: before=%d after=%d cap=%d",
					round, rec.ID, rec.CreditsBefore, rec.CreditsAfter, casino.MaxCredits)
			}
		}
	}
	loaded, err := h.g.AccountStore.LoadCharacter("alice")
	if err != nil {
		t.Fatal(err)
	}
	if loaded.Credits != casino.MaxCredits-10 {
		t.Fatalf("balance after repeated recovery = %d, want %d (one 20-credit payout applied, the other still owed)",
			loaded.Credits, casino.MaxCredits-10)
	}
}

// TestJournalUnavailableSettlementSettlesOnlyItsOwnStakes: when the economy
// journal is unavailable, the character-file fallback records resolution
// evidence only for the stakes the payout settles. A sibling hand's stake is
// settled by its own payout, so a crash before that payout must still refund
// it.
func TestJournalUnavailableSettlementSettlesOnlyItsOwnStakes(t *testing.T) {
	h := newHarness(t)
	h.seedAccount("alice")
	p := h.seedCharacter("alice", "alice")
	h.g.RunOnOwner(func() {
		p.Credits = 100
		w := casinoWallet{g: h.g, p: p}
		// Two sibling stakes (a split, or two spots). The sibling is placed
		// first so its post-debit balance is the durable one.
		if _, err := w.Wager(10); err != nil {
			t.Error(err)
			return
		}
		settled, err := w.Wager(10)
		if err != nil {
			t.Error(err)
			return
		}
		// The journal breaks for the second hand's push: the payout lands in
		// the character file only, and may record evidence only for the
		// stake it settles.
		failJournalDuring(h, func() {
			if err := w.PayStakeCover(10, []string{settled.ID}); err != nil {
				t.Errorf("fallback settlement failed: %v", err)
				return
			}
		})
		if p.Credits != 90 {
			t.Errorf("after the fallback settlement: credits=%d, want 90", p.Credits)
			return
		}
		h.g.recoverEconomy()
	})
	loaded, err := h.g.AccountStore.LoadCharacter("alice")
	if err != nil {
		t.Fatal(err)
	}
	if loaded.Credits != 100 {
		t.Errorf("balance after recovery = %d, want 100: the sibling hand's stake must be refunded, not resolved by the other hand's settlement",
			loaded.Credits)
	}
	if open := h.g.Economy.mustLoadOpen(t); len(open) != 0 {
		t.Errorf("records left open after recovery: %+v", open)
	}
}

// TestBankCreditTransferRefusedWhenSaveFails: a credit move between the wallet
// and the bank that cannot be made durable is reverted and refused. Leaving it
// in memory only would put the balance ahead of the character file, and a
// wager taken from that phantom balance journals checkpoints recovery can
// never match.
func TestBankCreditTransferRefusedWhenSaveFails(t *testing.T) {
	h := newHarness(t)
	h.seedAccount("alice")
	p := h.seedCharacter("alice", "alice")
	p.Credits = 100
	p.BankedCredits = 50
	if err := h.g.AccountStore.SaveCharacter(p); err != nil {
		t.Fatal(err)
	}
	sess, conn := h.connect("alice")

	h.g.RunOnOwner(func() {
		failingSaveDuring(h.g, h.dir, func() {
			h.g.doBankDepositCredits(sess, []string{"deposit", "credits", "40"})
		})
	})
	if sess.Player.Credits != 100 || sess.Player.BankedCredits != 50 {
		t.Errorf("a deposit whose save failed must be reverted in memory: credits=%d banked=%d, want 100/50",
			sess.Player.Credits, sess.Player.BankedCredits)
	}
	waitForConnText(t, conn, "nothing was moved")
	if loaded, err := h.g.AccountStore.LoadCharacter("alice"); err != nil {
		t.Error(err)
	} else if loaded.Credits != 100 || loaded.BankedCredits != 50 {
		t.Errorf("durable balances after a refused deposit: credits=%d banked=%d, want 100/50",
			loaded.Credits, loaded.BankedCredits)
	}

	h.g.RunOnOwner(func() {
		failingSaveDuring(h.g, h.dir, func() {
			h.g.doBankWithdrawCredits(sess, []string{"withdraw", "credits", "10"})
		})
	})
	if sess.Player.Credits != 100 || sess.Player.BankedCredits != 50 {
		t.Errorf("a withdrawal whose save failed must be reverted in memory: credits=%d banked=%d, want 100/50",
			sess.Player.Credits, sess.Player.BankedCredits)
	}
	waitForConnText(t, conn, "nothing was moved")

	// A durable move still works.
	h.g.RunOnOwner(func() {
		h.g.doBankWithdrawCredits(sess, []string{"withdraw", "credits", "10"})
	})
	if sess.Player.Credits != 110 || sess.Player.BankedCredits != 40 {
		t.Errorf("successful withdrawal: credits=%d banked=%d, want 110/40",
			sess.Player.Credits, sess.Player.BankedCredits)
	}
	if loaded, err := h.g.AccountStore.LoadCharacter("alice"); err != nil {
		t.Error(err)
	} else if loaded.Credits != 110 || loaded.BankedCredits != 40 {
		t.Errorf("durable balances after a successful withdrawal: credits=%d banked=%d, want 110/40",
			loaded.Credits, loaded.BankedCredits)
	}
}