package api

import (
	"encoding/json"
	"io"
	"log"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"

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

// snapshotsStubProvider implements backup.StackDataProvider for the F1 endpoint tests: one known
// stack ("app") living on `hdd`. Everything else is inert.
type snapshotsStubProvider struct{ hdd string }

func (p *snapshotsStubProvider) GetStackComposePath(name string) (string, bool) {
	if name == "app" {
		return filepath.Join(p.hdd, "compose", "docker-compose.yml"), true
	}
	return "", false
}
func (p *snapshotsStubProvider) ListDeployedStacks() []backup.StackSummary { return nil }
func (p *snapshotsStubProvider) GetStackHDDMounts(string) []string         { return nil }
func (p *snapshotsStubProvider) GetStackHDDPath(string) string             { return p.hdd }
func (p *snapshotsStubProvider) GetDockerVolumes(string) []string          { return nil }
func (p *snapshotsStubProvider) StopStack(string) error                    { return nil }
func (p *snapshotsStubProvider) StartStack(string) error                   { return nil }
func (p *snapshotsStubProvider) RefreshAndIsRunning(string) bool           { return true }
func (p *snapshotsStubProvider) GetStackRecoveryInfo(string) (backup.RecoveryInfo, bool) {
	return backup.RecoveryInfo{}, false
}
func (p *snapshotsStubProvider) GetStackClassifiedBinds(string) ([]backup.ClassifiedBind, bool) {
	return nil, false
}
func (p *snapshotsStubProvider) RecoverStackSecrets(string, []string) map[string]string { return nil }
func (p *snapshotsStubProvider) RecreateStackFromUnit(string, string, map[string]string) error {
	return nil
}

// newSnapshotsRouter wires a Router with a real backup.Manager over a tempdir drive.
func newSnapshotsRouter(t *testing.T) (*Router, string) {
	t.Helper()
	drive := filepath.Join(t.TempDir(), "drive")
	cfg := &config.Config{}
	cfg.Paths.SystemDataPath = filepath.Join(t.TempDir(), "sys")
	mgr := backup.NewManager(cfg, nil, log.New(io.Discard, "", 0))
	mgr.SetStackProvider(&snapshotsStubProvider{hdd: drive})
	return &Router{cfg: cfg, backupMgr: mgr, logger: log.New(io.Discard, "", 0)}, drive
}

// getSnapshots dispatches through Router.ServeHTTP so the tests also prove the ROUTE is
// registered — the F1 bug was precisely a fetch to a route that did not exist.
func getSnapshots(t *testing.T, r *Router, rawQuery string) *httptest.ResponseRecorder {
	t.Helper()
	req := httptest.NewRequest(http.MethodGet, "/api/backup/snapshots?"+rawQuery, nil)
	rec := httptest.NewRecorder()
	r.ServeHTTP(rec, req)
	return rec
}

type snapshotsResp struct {
	OK    bool   `json:"ok"`
	Error string `json:"error"`
	Data  []struct {
		Time       string `json:"time"`
		ShortID    string `json:"short_id"`
		Tier       int    `json:"tier"`
		DriveLabel string `json:"drive_label"`
	} `json:"data"`
}

func decodeSnapshots(t *testing.T, rec *httptest.ResponseRecorder) snapshotsResp {
	t.Helper()
	var v snapshotsResp
	if err := json.Unmarshal(rec.Body.Bytes(), &v); err != nil {
		t.Fatalf("decode %q: %v", rec.Body.String(), err)
	}
	return v
}

// Scenario A (data half): a recovery unit on disk → 200 with EXACTLY ONE tier-1 "helyi" entry the
// restore panel JS can render and POST back.
func TestBackupSnapshots_UnitOnDisk(t *testing.T) {
	r, drive := newSnapshotsRouter(t)
	manifest := backup.RecoveryUnitManifestPath(drive, "app")
	if err := os.MkdirAll(filepath.Dir(manifest), 0755); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(manifest, []byte("{}"), 0644); err != nil {
		t.Fatal(err)
	}

	rec := getSnapshots(t, r, "stack=app")
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	v := decodeSnapshots(t, rec)
	if !v.OK || len(v.Data) != 1 {
		t.Fatalf("want ok with exactly 1 entry, got %+v", v)
	}
	if v.Data[0].Tier != 1 || v.Data[0].ShortID != "helyi" || v.Data[0].Time == "" {
		t.Errorf("entry = %+v (want tier 1, short_id helyi, non-empty time)", v.Data[0])
	}
}

// Scenario B: known stack, no recovery unit yet → ok:true with an EMPTY data list (the JS shows
// "Nincs elérhető mentés" and keeps the button disabled — reached honestly, not via a 404).
func TestBackupSnapshots_NoBackupYet(t *testing.T) {
	r, _ := newSnapshotsRouter(t)
	rec := getSnapshots(t, r, "stack=app")
	if rec.Code != http.StatusOK {
		t.Fatalf("status = %d, want 200; body=%s", rec.Code, rec.Body.String())
	}
	v := decodeSnapshots(t, rec)
	if !v.OK || len(v.Data) != 0 {
		t.Errorf("want ok with empty list, got %+v", v)
	}
}

// Scenario C: guards — traversal and empty names are 400 BEFORE any filesystem work; an unknown
// stack is 404; a Router without a backup manager is 400.
func TestBackupSnapshots_Guards(t *testing.T) {
	r, _ := newSnapshotsRouter(t)

	for _, q := range []string{"stack=../../etc", "stack=", "stack=a/b", "stack=.."} {
		rec := getSnapshots(t, r, q)
		if rec.Code != http.StatusBadRequest {
			t.Errorf("%q: status = %d, want 400; body=%s", q, rec.Code, rec.Body.String())
		}
	}

	rec := getSnapshots(t, r, "stack=ghost")
	if rec.Code != http.StatusNotFound {
		t.Errorf("unknown stack: status = %d, want 404; body=%s", rec.Code, rec.Body.String())
	}

	noMgr := &Router{cfg: &config.Config{}, logger: log.New(io.Discard, "", 0)}
	rec = getSnapshots(t, noMgr, "stack=app")
	if rec.Code != http.StatusBadRequest {
		t.Errorf("nil backupMgr: status = %d, want 400", rec.Code)
	}
}