package store

import (
	"context"
	"strings"
	"testing"
	"time"

	"github.com/jackc/pgx/v5/pgconn"
)

// A full store (SQLSTATE 53300, "too many clients already") is not asked again every 250 ms: Ready backs off,
// doubling its wait up to a bound, and says once that the store is full (issues 1945 and 1277, 2026-10-25 16:08: the
// controller's retries kept novox's store full).
func TestReadyBacksOffOnAFullStore(t *testing.T) {
	wasPing, wasWait, wasSay := pingStore, readyWait, readySay
	t.Cleanup(func() { pingStore, readyWait, readySay = wasPing, wasWait, wasSay })
	asked := 0
	pingStore = func(context.Context, *Store) error {
		asked++
		if asked <= 8 {
			return &pgconn.PgError{Code: "53300", Message: "sorry, too many clients already"}
		}
		return nil
	}
	var waits []time.Duration
	readyWait = func(_ context.Context, d time.Duration) error { waits = append(waits, d); return nil }
	var said []string
	readySay = func(line string) { said = append(said, line) }

	if err := (&Store{context: "example"}).Ready(context.Background(), time.Hour); err != nil {
		t.Fatalf("Ready: %v", err)
	}
	if len(waits) != 8 {
		t.Fatalf("waited %d times, want 8: %v", len(waits), waits)
	}
	for i := 1; i < len(waits); i++ {
		if waits[i] < waits[i-1] {
			t.Fatalf("wait %d (%s) is shorter than the one before (%s): %v", i, waits[i], waits[i-1], waits)
		}
	}
	if waits[1] <= waits[0] {
		t.Fatalf("Ready does not back off on a full store: %v", waits)
	}
	if most := waits[len(waits)-1]; most > fullStoreMostWait {
		t.Fatalf("the wait grew past its bound %s: %v", fullStoreMostWait, waits)
	}
	full := 0
	for _, l := range said {
		if strings.Contains(l, "full") {
			full++
		}
	}
	if full != 1 {
		t.Fatalf("said that the store is full %d times, want once: %q", full, said)
	}
}

// A store that does not answer for another reason (not up yet) is still asked again every 250 ms.
func TestReadyWaitsShortlyOnAStoreNotUp(t *testing.T) {
	wasPing, wasWait, wasSay := pingStore, readyWait, readySay
	t.Cleanup(func() { pingStore, readyWait, readySay = wasPing, wasWait, wasSay })
	asked := 0
	pingStore = func(context.Context, *Store) error {
		asked++
		if asked <= 3 {
			return context.DeadlineExceeded
		}
		return nil
	}
	var waits []time.Duration
	readyWait = func(_ context.Context, d time.Duration) error { waits = append(waits, d); return nil }
	readySay = func(string) {}
	if err := (&Store{context: "example"}).Ready(context.Background(), time.Hour); err != nil {
		t.Fatalf("Ready: %v", err)
	}
	for _, w := range waits {
		if w != 250*time.Millisecond {
			t.Fatalf("waits %v, want 250ms each", waits)
		}
	}
}