package service

import (
	"context"
	"errors"
	"os"
	"path/filepath"
	"testing"

	"github.com/google/uuid"
	"github.com/joho/godotenv"
	"github.com/prabhupadasays/spsays-bff/internal/repository"
	"go.uber.org/zap"
)

func testRewardRepo(t *testing.T) (*repository.RewardRepo, *repository.Postgres) {
	t.Helper()
	uri := os.Getenv("POSTGRES_URI")
	if uri == "" {
		_ = godotenv.Load(filepath.Join("..", "..", ".env"))
		uri = os.Getenv("POSTGRES_URI")
	}
	if uri == "" {
		t.Skip("POSTGRES_URI not set")
	}
	pg, err := repository.NewPostgres(context.Background(), uri, zap.NewNop())
	if err != nil {
		t.Skipf("postgres unreachable: %v", err)
	}
	t.Cleanup(pg.Close)
	return repository.NewRewardRepo(pg), pg
}

func giftUser(t *testing.T, pg *repository.Postgres) string {
	t.Helper()
	id := uuid.NewString()
	suffix := id[:8]
	if _, err := pg.Pool.Exec(context.Background(), `
		INSERT INTO users (id, email, password_hash, name, handle)
		VALUES ($1, $2, 'x', 'Gift User', $3)`,
		id, "gift-"+suffix+"@example.invalid", "gift_"+suffix); err != nil {
		t.Fatalf("create user: %v", err)
	}
	t.Cleanup(func() {
		_, _ = pg.Pool.Exec(context.Background(), `DELETE FROM users WHERE id = $1`, id)
	})
	return id
}

func giftReward(t *testing.T, pg *repository.Postgres) string {
	t.Helper()
	key := "gift_" + uuid.NewString()[:8]
	if _, err := pg.Pool.Exec(context.Background(), `
		INSERT INTO sadhna_rewards (key, name, image_url)
		VALUES ($1, 'Occasional Gift', 'https://example.invalid/g.png')`, key); err != nil {
		t.Fatalf("create reward: %v", err)
	}
	t.Cleanup(func() {
		_, _ = pg.Pool.Exec(context.Background(), `DELETE FROM sadhna_rewards WHERE key = $1`, key)
	})
	return key
}

// A gift arrives wrapped, opens once, and lands in the vault — and re-gifting
// must not duplicate it.
func TestGift_ArrivesWrappedAndOpensOnce(t *testing.T) {
	rewards, pg := testRewardRepo(t)
	ctx := context.Background()
	user := giftUser(t, pg)
	key := giftReward(t, pg)

	reward, err := rewards.ByKey(ctx, key)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := rewards.GrantGiftToEveryone(ctx, reward.ID); err != nil {
		t.Fatal(err)
	}

	find := func() (found bool, opened bool) {
		grants, err := rewards.GrantsByUser(ctx, user)
		if err != nil {
			t.Fatal(err)
		}
		for _, g := range grants {
			if g.Reward.Key == key {
				if g.Source != "gift" {
					t.Errorf("source = %q, want gift", g.Source)
				}
				if g.Milestone != nil {
					t.Errorf("milestone = %v, want nil — a gift isn't a streak day", *g.Milestone)
				}
				return true, g.Opened
			}
		}
		return false, false
	}

	found, opened := find()
	if !found {
		t.Fatal("the gift did not reach an existing account")
	}
	if opened {
		t.Error("a new gift should arrive wrapped")
	}

	// It must NOT hijack the streak confetti — that stays for streak rewards.
	if pending, _ := rewards.PendingGrant(ctx, user); pending != nil {
		t.Errorf("a gift appeared as a pending streak celebration: %+v", pending)
	}

	if err := rewards.OpenGift(ctx, user, key); err != nil {
		t.Fatal(err)
	}
	if _, opened = find(); !opened {
		t.Error("opening the gift did not un-blur it")
	}
	// Opening twice is harmless.
	if err := rewards.OpenGift(ctx, user, key); err != nil {
		t.Errorf("second open should be a no-op: %v", err)
	}

	// Re-gifting tops up newcomers without duplicating anyone's tile.
	if _, err := rewards.GrantGiftToEveryone(ctx, reward.ID); err != nil {
		t.Fatal(err)
	}
	grants, _ := rewards.GrantsByUser(ctx, user)
	n := 0
	for _, g := range grants {
		if g.Reward.Key == key {
			n++
		}
	}
	if n != 1 {
		t.Errorf("holdings of the gift = %d, want 1", n)
	}
	// ...and it must not silently re-wrap what was already opened.
	if _, opened = find(); !opened {
		t.Error("re-gifting re-wrapped an already opened gift")
	}
}

// Deleting a custom gift must clear it from every gallery it reached, and must
// refuse to touch the seeded catalog — a seeded reward would return on the
// next Seed run, after having been ripped out of people's galleries.
func TestGift_DeleteRemovesItFromEveryGallery(t *testing.T) {
	rewards, pg := testRewardRepo(t)
	ctx := context.Background()
	user := giftUser(t, pg)

	// A custom reward, as the admin panel creates them.
	key := "custom_probe_" + uuid.NewString()[:8]
	if _, err := pg.Pool.Exec(ctx, `
		INSERT INTO sadhna_rewards (key, name, image_url)
		VALUES ($1, 'Probe Gift', 'https://example.invalid/p.png')`, key); err != nil {
		t.Fatal(err)
	}
	reward, err := rewards.ByKey(ctx, key)
	if err != nil {
		t.Fatal(err)
	}
	if _, err := rewards.GrantGiftToEveryone(ctx, reward.ID); err != nil {
		t.Fatal(err)
	}

	held := func() int {
		grants, err := rewards.GrantsByUser(ctx, user)
		if err != nil {
			t.Fatal(err)
		}
		n := 0
		for _, g := range grants {
			if g.Reward.Key == key {
				n++
			}
		}
		return n
	}
	if held() != 1 {
		t.Fatalf("setup: the gift did not reach the gallery")
	}

	if err := rewards.DeleteCustom(ctx, key); err != nil {
		t.Fatal(err)
	}
	if held() != 0 {
		t.Error("deleting the reward left it in a devotee's gallery")
	}
	if _, err := rewards.ByKey(ctx, key); !errors.Is(err, repository.ErrRewardNotFound) {
		t.Errorf("reward still in the catalog: %v", err)
	}

	// Seeded rewards are off limits.
	var seeded string
	if err := pg.Pool.QueryRow(ctx,
		`SELECT key FROM sadhna_rewards WHERE key NOT LIKE 'custom\_%' LIMIT 1`,
	).Scan(&seeded); err != nil {
		t.Skip("no seeded rewards to test against")
	}
	if err := rewards.DeleteCustom(ctx, seeded); !errors.Is(err, repository.ErrRewardNotFound) {
		t.Errorf("a seeded reward was deletable: %v", err)
	}
	if _, err := rewards.ByKey(ctx, seeded); err != nil {
		t.Errorf("the seeded reward was removed: %v", err)
	}
}