package stacks

import (
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
)

// C6B-F1 (v0.130.0) — ExportDataMounts is the .fab export's mount discovery: the ${HDD_PATH}
// binds UNIONed with the ${USERDATA_PATH} root. These tests pin the union, the containment
// dedupe, and — as the red-proof's contrast — that the old ${HDD_PATH}-only scanner alone
// finds NOTHING for the standard media-app compose shape (the exact hollow-bundle cause).

func writeCompose(t *testing.T, body string) string {
	t.Helper()
	dir := t.TempDir()
	p := filepath.Join(dir, "docker-compose.yml")
	if err := os.WriteFile(p, []byte(body), 0644); err != nil {
		t.Fatal(err)
	}
	return p
}

// the sonarr shape: named volume + ${USERDATA_PATH} binds, NO direct ${HDD_PATH} bind.
const sonarrShapeCompose = `services:
  sonarr:
    image: lscr.io/linuxserver/sonarr:4.0.13
    volumes:
      - sonarr_config:/config
      - ${USERDATA_PATH}/media/tv:/media/tv
      - ${USERDATA_PATH}/downloads:/downloads
    networks:
      - traefik-public

volumes:
  sonarr_config:
`

func TestExportDataMounts_UserdataConvention(t *testing.T) {
	compose := writeCompose(t, sonarrShapeCompose)
	hdd := filepath.Join(string(filepath.Separator)+"mnt", "drive", "sonarr")

	// RED-PROOF CONTRAST (C6B-F1 cause 2): the pre-fix scanner alone finds ZERO mounts for
	// this compose — this is exactly why 12/13 needs_hdd apps exported hollow bundles.
	if old := ParseComposeHDDMounts(compose, hdd); len(old) != 0 {
		t.Fatalf("precondition drifted: ParseComposeHDDMounts found %v — the compose shape no longer reproduces C6B-F1", old)
	}

	got := ExportDataMounts(compose, hdd, hdd)
	want := []string{filepath.Join(hdd, "userdata")}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("ExportDataMounts = %v, want the userdata ROOT %v", got, want)
	}
	// The basename MUST be "userdata" — a direct child of HDD_PATH — so the import side's
	// basename→<HDD_PATH>/<subdir> fallback places the tar correctly without import changes.
	if filepath.Base(got[0]) != "userdata" {
		t.Fatalf("userdata mount bases to %q — the restore mapping requires \"userdata\"", filepath.Base(got[0]))
	}
}

func TestExportDataMounts_HDDDirectAppUnchanged(t *testing.T) {
	// The 1/13 app that worked pre-fix: direct ${HDD_PATH} binds, no userdata refs.
	compose := writeCompose(t, `services:
  app:
    image: x
    volumes:
      - ${HDD_PATH}/data:/data
      - ${HDD_PATH}/incoming:/incoming
`)
	hdd := filepath.Join(string(filepath.Separator)+"mnt", "drive", "app")
	got := ExportDataMounts(compose, hdd, hdd)
	want := []string{filepath.Join(hdd, "data"), filepath.Join(hdd, "incoming")}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("ExportDataMounts = %v, want unchanged HDD mounts %v (regression: the one working app must keep working)", got, want)
	}
}

func TestExportDataMounts_MixedBindsUnion(t *testing.T) {
	compose := writeCompose(t, `services:
  app:
    image: x
    volumes:
      - ${HDD_PATH}/direct:/direct
      - ${USERDATA_PATH}/media:/media
`)
	hdd := filepath.Join(string(filepath.Separator)+"mnt", "drive", "app")
	got := ExportDataMounts(compose, hdd, hdd)
	want := []string{filepath.Join(hdd, "direct"), filepath.Join(hdd, "userdata")}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("ExportDataMounts = %v, want the union %v", got, want)
	}
}

func TestExportDataMounts_HDDRootCoversUserdata(t *testing.T) {
	// An app binding ${HDD_PATH} itself already captures the userdata subtree — the root
	// must NOT be added again (double-tar).
	compose := writeCompose(t, `services:
  app:
    image: x
    volumes:
      - ${HDD_PATH}:/all
      - ${USERDATA_PATH}/media:/media
`)
	hdd := filepath.Join(string(filepath.Separator)+"mnt", "drive", "app")
	got := ExportDataMounts(compose, hdd, hdd)
	want := []string{hdd}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("ExportDataMounts = %v, want just the covering HDD root %v", got, want)
	}
}

func TestExportDataMounts_LiteralUserdataBindDeduped(t *testing.T) {
	// A literal ${HDD_PATH}/userdata/foo bind is INSIDE the userdata root — keeping it would
	// double-tar and basename-collide with the root tar.
	compose := writeCompose(t, `services:
  app:
    image: x
    volumes:
      - ${HDD_PATH}/userdata/foo:/foo
      - ${USERDATA_PATH}/bar:/bar
`)
	hdd := filepath.Join(string(filepath.Separator)+"mnt", "drive", "app")
	got := ExportDataMounts(compose, hdd, hdd)
	want := []string{filepath.Join(hdd, "userdata")}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("ExportDataMounts = %v, want only the userdata root %v", got, want)
	}
}

func TestExportDataMounts_EmptyHDDPath(t *testing.T) {
	compose := writeCompose(t, sonarrShapeCompose)
	if got := ExportDataMounts(compose, "", ""); got != nil {
		t.Fatalf("ExportDataMounts with empty HDD_PATH = %v, want nil", got)
	}
}

// R-203 / Scenario E — the export-mount resolver on BOTH drive kinds, and what it does NOT return.
//
// This function lives in delete.go, which reads as a destructive path; it is not. Its only production
// caller is the .fab export adapter. The assertions below therefore prove the NEGATIVE that matters
// for an export: no path outside the app's own data roots is ever emitted.
func TestExportDataMounts_BothDriveKinds(t *testing.T) {
	const sys = "/mnt/sys_drive"
	compose := writeCompose(t, `services:
  app:
    volumes:
      - ${USERDATA_PATH}/media/books:/books
      - ${HDD_PATH}/appdata/app:/data
`)
	cases := []struct {
		name, hdd, nsRoot, wantUD string
	}{
		{"enrolled drive", "/mnt/felhom-usb", "/mnt/felhom-usb", "/mnt/felhom-usb/userdata"},
		{"system drive", sys, sys + "/felhom-data", sys + "/felhom-data/userdata"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			got := ExportDataMounts(compose, tc.hdd, tc.nsRoot)
			var sawUD bool
			for _, m := range got {
				if m == tc.wantUD {
					sawUD = true
				}
				// THE NEGATIVE: nothing outside the app's own roots, on either kind.
				if !strings.HasPrefix(m, tc.hdd) && !strings.HasPrefix(m, tc.nsRoot) {
					t.Errorf("emitted %q, which is outside both %q and %q", m, tc.hdd, tc.nsRoot)
				}
				for _, forbidden := range []string{"/etc", "/opt/docker/stacks", "/var/lib/docker", "/root"} {
					if strings.HasPrefix(m, forbidden) {
						t.Errorf("emitted a path outside the app's data: %q", m)
					}
				}
			}
			if !sawUD {
				t.Errorf("userdata root %q not emitted; got %v", tc.wantUD, got)
			}
		})
	}
}

// An empty nsRoot falls back to hddPath — the pre-R-203 shape — so a caller that has not been
// updated keeps working on enrolled drives rather than emitting an empty-rooted path.
func TestExportDataMounts_EmptyNamespaceRootFallsBack(t *testing.T) {
	compose := writeCompose(t, `services:
  app:
    volumes:
      - ${USERDATA_PATH}/x:/x
`)
	withNS := ExportDataMounts(compose, "/mnt/felhom-usb", "/mnt/felhom-usb")
	without := ExportDataMounts(compose, "/mnt/felhom-usb", "")
	if len(withNS) != len(without) {
		t.Fatalf("fallback changed the result: %v vs %v", withNS, without)
	}
	for i := range withNS {
		if withNS[i] != without[i] {
			t.Fatalf("fallback changed %q to %q", withNS[i], without[i])
		}
	}
}