package backup

import (
	"context"
	"errors"
	"strings"
	"testing"

	"gitea.dooplex.hu/admin/felhom-agent/internal/proxmox"
)

// R-1012: a snapshot backup that fails carries the orphan finding in its error — the text the controller mails to
// the operator (`whole_guest_backup_failed`). The check runs ONCE, after the failure — never before the run.
// RED-PROOF (P1/redproof-thincheck.txt): with explainFailure's append removed this test fails. RED-PROOF (2026-10-17
// night, felhom-agent REPORT.md): with the v0.159.0 pre-run check restored, calls = 2 and this test fails.
func TestBackup_SnapshotFailure_NamesTheOrphan(t *testing.T) {
	const why = "probable cause: thin pool pve/data holds device 4 that LVM does not know"
	for name, api := range map[string]*fakeBackupAPI{
		"task fails":  {vzdumpUPID: "UPID:x", waitErr: errors.New("task failed: job errors")},
		"start fails": {vzdumpErr: errors.New("vzdump: 500")},
	} {
		t.Run(name, func(t *testing.T) {
			r := NewBackupRunner(api, "local", "", "", "", quiet())
			calls := 0
			r.SetThinCheck(func(context.Context, int) string { calls++; return why })
			rec, err := r.Backup(context.Background(), 9201)
			if err == nil || rec.Success {
				t.Fatalf("want a failure, got %+v", rec)
			}
			if !strings.Contains(rec.Error, why) {
				t.Fatalf("the failure does not name the orphan: %q", rec.Error)
			}
			if calls != 1 {
				t.Fatalf("thin check ran %d times, want 1 (after the failure only)", calls)
			}
		})
	}
}

// A successful backup never runs the check (it takes a metadata snapshot of the live pool, and nobody needs the answer)
// and keeps a clean record; a stop-mode backup takes no snapshot, so the check never runs; an unwired runner behaves
// exactly as before. RED-PROOF (2026-10-17 night): with the v0.159.0 pre-run check restored, the success leg fails
// with calls=1.
func TestBackup_ThinCheck_SilentWhenNotApplicable(t *testing.T) {
	ok := &fakeBackupAPI{vzdumpUPID: "UPID:x",
		content: []proxmox.StorageContent{{VolID: "local:backup/vzdump-lxc-9201-x", Content: "backup", VMID: 9201, Size: 100, CTime: 1}}}
	r := NewBackupRunner(ok, "local", "", "", "", quiet())
	calls := 0
	r.SetThinCheck(func(context.Context, int) string { calls++; return "probable cause: x" })
	rec, err := r.Backup(context.Background(), 9201)
	if err != nil || !rec.Success || rec.Error != "" || calls != 0 {
		t.Fatalf("success: err=%v rec=%+v calls=%d (want no check on a successful backup, clean record)", err, rec, calls)
	}

	stop := NewBackupRunner(&fakeBackupAPI{vzdumpUPID: "UPID:x", waitErr: errors.New("boom")}, "local", proxmox.ModeStop, "", "", quiet())
	calls = 0
	stop.SetThinCheck(func(context.Context, int) string { calls++; return "probable cause: x" })
	rec, _ = stop.Backup(context.Background(), 9201)
	if calls != 0 || strings.Contains(rec.Error, "probable cause") {
		t.Fatalf("stop mode: calls=%d error=%q", calls, rec.Error)
	}

	plain := NewBackupRunner(&fakeBackupAPI{vzdumpUPID: "UPID:x", waitErr: errors.New("boom")}, "local", "", "", "", quiet())
	if rec, _ := plain.Backup(context.Background(), 9201); rec.Error != "boom" {
		t.Fatalf("unwired: error = %q, want the task error unchanged", rec.Error)
	}
}