//go:build integration

package store

import (
	"context"
	"os"
	"testing"
	"time"

	"github.com/cosmic-clash/cosmic-clash/server/domain"
	"github.com/redis/go-redis/v9"
)

// This binary is deliberately opt-in, mirroring postgres_integration_test.go:
// it requires a disposable real Redis supplied by
// scripts/run_redis_integration.sh, as distinct from the miniredis-backed
// unit tests in redis_candidates_test.go and candidate_projection_test.go.
// miniredis is a from-scratch Go reimplementation of the Redis command set --
// it does not run real Redis's own float64 score encoding, real TTL/expiry,
// or real RESP wire behavior, so it cannot by itself prove this code works
// against the real thing, only that it works against a same-language model of
// it.
func openIntegrationRedis(t *testing.T) *redis.Client {
	t.Helper()
	addr := os.Getenv("COSMIC_CLASH_REDIS_ADDR")
	if addr == "" {
		t.Skip("COSMIC_CLASH_REDIS_ADDR is not set")
	}
	client := redis.NewClient(&redis.Options{Addr: addr})
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	if err := client.Ping(ctx).Err(); err != nil {
		client.Close()
		t.Fatalf("ping Redis: %v", err)
	}
	if err := client.FlushAll(ctx).Err(); err != nil {
		client.Close()
		t.Fatalf("reset Redis: %v", err)
	}
	t.Cleanup(func() { client.Close() })
	return client
}

func TestRealRedisCandidateIndexUpsertSnapshotRemove(t *testing.T) {
	client := openIntegrationRedis(t)
	ctx := context.Background()
	index := RedisCandidateIndex{Client: client, Prefix: "integration-real", TTL: time.Minute}
	now := time.Now().UTC().Truncate(time.Microsecond)

	a := domain.Candidate{TicketID: "real-ticket-a", PlayerID: "real-player-a", Playlist: domain.Casual, ClientBuild: "build-1", ProtocolVersion: 1, EnqueuedAt: now}
	b := domain.Candidate{TicketID: "real-ticket-b", PlayerID: "real-player-b", Playlist: domain.Casual, ClientBuild: "build-1", ProtocolVersion: 1, EnqueuedAt: now.Add(time.Second)}
	if err := index.Upsert(ctx, a); err != nil {
		t.Fatalf("upsert a: %v", err)
	}
	if err := index.Upsert(ctx, b); err != nil {
		t.Fatalf("upsert b: %v", err)
	}
	got, err := index.Snapshot(ctx, now.Add(time.Hour))
	if err != nil {
		t.Fatalf("snapshot: %v", err)
	}
	if len(got) != 2 || got[0].TicketID != "real-ticket-a" || got[1].TicketID != "real-ticket-b" {
		t.Fatalf("snapshot after upsert = %+v", got)
	}

	if err := index.Remove(ctx, "real-ticket-a"); err != nil {
		t.Fatalf("remove: %v", err)
	}
	got, err = index.Snapshot(ctx, now.Add(time.Hour))
	if err != nil {
		t.Fatalf("snapshot after remove: %v", err)
	}
	if len(got) != 1 || got[0].TicketID != "real-ticket-b" {
		t.Fatalf("snapshot after remove = %+v", got)
	}

	// A real TTL, actually waited out, not miniredis's manual FastForward.
	shortLived := RedisCandidateIndex{Client: client, Prefix: "integration-real-ttl", TTL: 1500 * time.Millisecond}
	if err := shortLived.Upsert(ctx, domain.Candidate{TicketID: "real-ticket-ttl", PlayerID: "real-player-ttl", EnqueuedAt: now}); err != nil {
		t.Fatalf("upsert ttl candidate: %v", err)
	}
	time.Sleep(2 * time.Second)
	got, err = shortLived.Snapshot(ctx, now.Add(time.Hour))
	if err != nil {
		t.Fatalf("snapshot after real TTL expiry: %v", err)
	}
	if len(got) != 0 {
		t.Fatalf("candidate survived its real TTL: %+v", got)
	}
}

// TestRealRedisCandidateProjectionRepairsAfterFlush proves the documented
// "Redis restart or lost keyspace" repair path against an actual data loss
// event on a real server -- FLUSHALL -- not a simulated empty map.
func TestRealRedisCandidateProjectionRepairsAfterFlush(t *testing.T) {
	client := openIntegrationRedis(t)
	ctx := context.Background()
	index := RedisCandidateIndex{Client: client, Prefix: "integration-real-repair", TTL: time.Minute}
	now := time.Now().UTC().Truncate(time.Microsecond)

	durable := []domain.Candidate{
		{TicketID: "repair-ticket-a", PlayerID: "repair-player-a", EnqueuedAt: now},
		{TicketID: "repair-ticket-b", PlayerID: "repair-player-b", EnqueuedAt: now.Add(time.Second)},
	}
	sourceCalls := 0
	projection := CandidateProjection{Index: index, Source: func(context.Context, time.Time) ([]domain.Candidate, error) {
		sourceCalls++
		return durable, nil
	}}

	if err := index.Upsert(ctx, durable[0]); err != nil {
		t.Fatalf("seed upsert: %v", err)
	}
	// Simulate the actual failure mode this path exists for: the whole Redis
	// instance loses its data (restart without persistence, failover to an
	// empty replica, an operator FLUSHALL) mid-operation, not just "this one
	// key expired".
	if err := client.FlushAll(ctx).Err(); err != nil {
		t.Fatalf("flush: %v", err)
	}

	got, err := projection.Snapshot(ctx, now.Add(time.Hour))
	if err != nil {
		t.Fatalf("snapshot after flush: %v", err)
	}
	if sourceCalls != 1 {
		t.Fatalf("expected exactly one durable repair call, got %d", sourceCalls)
	}
	if len(got) != 2 || got[0].TicketID != "repair-ticket-a" || got[1].TicketID != "repair-ticket-b" {
		t.Fatalf("snapshot after repair = %+v", got)
	}

	// The repair must actually have written back to Redis, not just returned
	// the durable source's answer in memory -- confirm a second snapshot
	// (Redis not flushed again) reads it back without a second Source call.
	got, err = index.Snapshot(ctx, now.Add(time.Hour))
	if err != nil {
		t.Fatalf("snapshot directly against Redis after repair: %v", err)
	}
	if len(got) != 2 {
		t.Fatalf("repaired data was not actually persisted to Redis: %+v", got)
	}
	if sourceCalls != 1 {
		t.Fatalf("expected repair to persist so a second read needs no further Source call, got %d calls", sourceCalls)
	}
}