package backup

import (
	"io"
	"log"
	"os"
	"path/filepath"
	"testing"

	"gitea.dooplex.hu/admin/felhom-controller/internal/config"
)

// exclFake is volDumpFakeProvider plus the production adapter's exclusion answer.
type exclFake struct {
	volDumpFakeProvider
	excluded []string
}

func (f *exclFake) GetExcludedDockerVolumes(string) []string { return f.excluded }

// R-49 (D21 = B) — the consequence across a whole dump run, through the F7 tar seam (no Docker): the excluded cache
// volume is not dumped, the other volume is, and the cache's OLD tar (from before the template marked it) is gone
// from the unit, so no later copy carries it.
// RED-PROOF: with DumpAppVolumes listing GetDockerVolumes again (no exclusion), the cache is dumped and its old tar
// replaced, not removed — seen failing 2026-10-22.
func TestR49_AnExcludedVolumeLeavesTheUnit(t *testing.T) {
	drive := t.TempDir()
	cfg := &config.Config{}
	cfg.Paths.SystemDataPath = drive
	fake := &exclFake{volDumpFakeProvider: volDumpFakeProvider{
		stacks:  []StackSummary{{Name: "immich"}},
		volumes: map[string][]string{"immich": {"immich_immich_ml_cache", "immich_immich_postgres_data"}},
	}, excluded: []string{"immich_immich_ml_cache"}}
	var tarred []string
	m := &Manager{cfg: cfg, logger: log.New(io.Discard, "", 0), systemDataPath: drive, stackProvider: fake,
		tarVolume: func(vol, dir string) ([]byte, error) {
			tarred = append(tarred, vol)
			return nil, os.WriteFile(filepath.Join(dir, vol+".tar.tmp"), []byte("TAR "+vol), 0o644)
		}}
	dumpDir := AppVolumeDumpPath(m.namespaceRoot(drive), "immich")
	os.MkdirAll(dumpDir, 0o755)
	old := filepath.Join(dumpDir, "immich_immich_ml_cache.tar")
	os.WriteFile(old, []byte("824 MB OF MODELS"), 0o644)

	if err := m.DumpAppVolumes("immich"); err != nil {
		t.Fatalf("DumpAppVolumes: %v", err)
	}
	if len(tarred) != 1 || tarred[0] != "immich_immich_postgres_data" {
		t.Fatalf("dumped %v, want only the database volume", tarred)
	}
	if _, err := os.Stat(old); !os.IsNotExist(err) {
		t.Fatal("the excluded cache's old tar is still in the unit — every later copy would carry it")
	}
	if _, err := os.Stat(filepath.Join(dumpDir, "immich_immich_postgres_data.tar")); err != nil {
		t.Fatalf("the database volume's tar is missing: %v", err)
	}
}

// A provider without the exclusion answer (every test fake, an older wiring) dumps every volume, as before.
func TestR49_NoExclusionProviderDumpsEverything(t *testing.T) {
	m := &Manager{logger: log.New(io.Discard, "", 0), stackProvider: &volDumpFakeProvider{
		volumes: map[string][]string{"a": {"a_x", "a_y"}}}}
	if got := m.dumpableVolumes("a"); len(got) != 2 {
		t.Fatalf("dumpable = %v, want both", got)
	}
}