package imageproxy

import (
	"errors"
	"os"
	"testing"

	"sneak.berlin/go/pixa/internal/imagerequest"
)

// TestProxy_Get_ServesCachedVariantOfNegativeCachedURL caches a variant of
// the test photo, then keeps a failed fetch of the photo's URL in the negative
// cache, as a failed fetch for another variant does once the source has been
// evicted. The cached variant is still served, and a variant not in the cache
// is made from the cached source. Once the source is evicted, a variant not in
// the cache needs a fetch and is refused.
func TestProxy_Get_ServesCachedVariantOfNegativeCachedURL(t *testing.T) {
	t.Parallel()

	svc, fixtures := setupTestProxy(t)

	resp, err := svc.Get(t.Context(), photoVariant(fixtures, 85, imagerequest.FitCover))
	if err != nil {
		t.Fatalf("Get() first request error = %v", err)
	}

	_ = resp.Content.Close()

	err = svc.cache.PutFailure(t.Context(),
		photoVariant(fixtures, 85, imagerequest.FitCover).Source)
	if err != nil {
		t.Fatalf("PutFailure() error = %v", err)
	}

	resp, err = svc.Get(t.Context(), photoVariant(fixtures, 85, imagerequest.FitCover))
	if err != nil {
		t.Fatalf("Get() of the cached variant error = %v", err)
	}

	_ = resp.Content.Close()

	if resp.CacheStatus != CacheHit {
		t.Errorf("cached variant CacheStatus = %q, want %q",
			resp.CacheStatus, CacheHit)
	}

	resp, err = svc.Get(t.Context(), photoVariant(fixtures, 40, imagerequest.FitCover))
	t.Logf("Get() of a variant made from the cached source: error = %v", err)

	if err != nil {
		t.Fatalf("Get() of a variant made from the cached source error = %v", err)
	}

	_ = resp.Content.Close()

	source := photoVariant(fixtures, 85, imagerequest.FitCover).Source

	reader, _, err := svc.cache.Source(t.Context(), source)
	if err != nil {
		t.Fatalf("Source() error = %v, want the cached source", err)
	}

	_ = reader.Close()

	// Evicts the source as the cache's eviction does: its row, then its file
	_, err = svc.db.ExecContext(t.Context(),
		`DELETE FROM source_content WHERE source_key = ?`, string(source.Key()))
	if err != nil {
		t.Fatalf("deleting the source's row: %v", err)
	}

	err = os.Remove(sourceFilePath(svc, source.Key()))
	if err != nil {
		t.Fatalf("removing the source's file: %v", err)
	}

	_, err = svc.Get(t.Context(), photoVariant(fixtures, 60, imagerequest.FitCover))
	t.Logf("Get() of a variant whose source was evicted: error = %v", err)

	if !errors.Is(err, ErrNegativeCached) {
		t.Errorf("Get() of a variant whose source was evicted error = %v, want %v",
			err, ErrNegativeCached)
	}
}

func TestProxy_Get_ReturnsErrorForNegativeCachedURL(t *testing.T) {
	t.Parallel()

	// This test verifies that Proxy.Get() checks the negative cache
	// We can't easily test the full pipeline without vips, but we can
	// verify the error type
	err := ErrNegativeCached
	if !errors.Is(err, ErrNegativeCached) {
		t.Error("ErrNegativeCached should be identifiable with errors.Is")
	}
}