package postgres

import (
	"context"
	"errors"
	"testing"

	"telesrv/internal/domain"
)

// TestStarsLedgerPostgres 回归迁移 0009：Stars 本地账本对真实 PG 的原子语义
// （首读授予幂等 / 贷记 / 借记原子 / 余额不足拦截且不动账 / keyset 分页末页无游标）。
func TestStarsLedgerPostgres(t *testing.T) {
	pool := testPool(t)
	ctx := context.Background()
	st := NewStarsStore(pool)

	users := NewUserStore(pool)
	suffix := randomSuffix(t)
	u, err := users.Create(ctx, domain.User{AccessHash: 92, Phone: "+1665" + suffix + "01", FirstName: "StarsLedger"})
	if err != nil {
		t.Fatalf("create user: %v", err)
	}
	t.Cleanup(func() {
		_, _ = pool.Exec(ctx, "DELETE FROM stars_transactions WHERE user_id = $1", u.ID)
		_, _ = pool.Exec(ctx, "DELETE FROM stars_balances WHERE user_id = $1", u.ID)
		_, _ = pool.Exec(ctx, "DELETE FROM users WHERE id = $1", u.ID)
	})

	// 空账号：余额 0、未授予。
	if bal, err := st.GetBalance(ctx, u.ID); err != nil || bal.Balance != 0 || bal.Granted {
		t.Fatalf("empty balance = %+v err %v, want 0 not granted", bal, err)
	}

	// 首读授予一次。
	bal, applied, err := st.EnsureGrant(ctx, u.ID, 1000, 1700000000)
	if err != nil || !applied || bal.Balance != 1000 || !bal.Granted {
		t.Fatalf("first grant = %+v applied %v err %v, want 1000 granted applied", bal, applied, err)
	}
	// 再次授予幂等：不重复。
	bal, applied, err = st.EnsureGrant(ctx, u.ID, 1000, 1700000001)
	if err != nil || applied || bal.Balance != 1000 {
		t.Fatalf("second grant = %+v applied %v err %v, want 1000 not applied", bal, applied, err)
	}

	// 借记原子扣减 + 写负流水。
	peer := domain.Peer{Type: domain.PeerTypeChannel, ID: 4242}
	bal, err = st.Debit(ctx, u.ID, 300, domain.StarsReasonReaction, peer, 1700000002, "paid reaction", "")
	if err != nil || bal.Balance != 700 {
		t.Fatalf("debit = %+v err %v, want 700", bal, err)
	}

	// 余额不足：拦截且不动账（CHECK + FOR UPDATE 双保险）。
	if _, err := st.Debit(ctx, u.ID, 100000, domain.StarsReasonReaction, peer, 1700000003, "", ""); !errors.Is(err, domain.ErrStarsInsufficient) {
		t.Fatalf("over-debit err = %v, want ErrStarsInsufficient", err)
	}
	if bal, err := st.GetBalance(ctx, u.ID); err != nil || bal.Balance != 700 {
		t.Fatalf("balance after failed debit = %+v err %v, want 700 unchanged", bal, err)
	}

	// 贷记。
	bal, err = st.Credit(ctx, u.ID, 50, domain.StarsReasonGift, domain.Peer{Type: domain.PeerTypeUser, ID: 9}, 1700000004, "gift", "")
	if err != nil || bal.Balance != 750 {
		t.Fatalf("credit = %+v err %v, want 750", bal, err)
	}

	// 流水：grant(+1000) / debit(-300) / credit(+50) 共 3 条，倒序最新在前。
	page, err := st.ListTransactions(ctx, u.ID, "", 2)
	if err != nil {
		t.Fatalf("list page1: %v", err)
	}
	if len(page.Transactions) != 2 || page.NextOffset == "" {
		t.Fatalf("page1 = %d txns next=%q, want 2 + next", len(page.Transactions), page.NextOffset)
	}
	if page.Transactions[0].Amount != 50 || page.Transactions[0].Reason != domain.StarsReasonGift {
		t.Fatalf("page1[0] = %+v, want +50 gift (newest)", page.Transactions[0])
	}
	if page.Balance != 750 {
		t.Fatalf("page balance = %d, want 750", page.Balance)
	}
	page2, err := st.ListTransactions(ctx, u.ID, page.NextOffset, 2)
	if err != nil {
		t.Fatalf("list page2: %v", err)
	}
	if len(page2.Transactions) != 1 || page2.NextOffset != "" {
		t.Fatalf("page2 = %d txns next=%q, want 1 + empty (terminal)", len(page2.Transactions), page2.NextOffset)
	}
	if page2.Transactions[0].Reason != domain.StarsReasonGrant || page2.Transactions[0].Amount != 1000 {
		t.Fatalf("page2[0] = %+v, want +1000 grant (oldest)", page2.Transactions[0])
	}
}