package backup

import (
	"context"
	"strings"
	"testing"

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

// R-685 (v0.134.0) — a whole-box backup that cannot fit its LOCAL target is a named skip BEFORE anything
// starts, with the numbers in the record's Error, never a vzdump that fills the disk and fails.

const gib = int64(1) << 30

func spaceAPI(avail int64, lastArchive int64, typ string) *fakeBackupAPI {
	api := &fakeBackupAPI{vzdumpUPID: "UPID:vzdump:1",
		storages: []proxmox.Storage{{Storage: "local", Type: typ, Content: "backup", Avail: avail}}}
	if lastArchive > 0 {
		api.content = []proxmox.StorageContent{{VolID: "local:backup/vzdump-lxc-9201-2026_09_24-21_59_25.tar.zst",
			Content: "backup", VMID: 9201, Size: lastArchive, CTime: 1790280000}}
	}
	return api
}

// TestR685_BackupThatCannotFitIsSkipped — demo-hp's shape: an 8.2 GB archive, 4 GiB free. No vzdump is
// started; the record says why, with the numbers, under a stable prefix.
//
// COMPANION RED-PROOF (REPORT.md): drop the spaceFits call from backup() — this test fails at "a vzdump
// was started on a target that cannot hold it".
func TestR685_BackupThatCannotFitIsSkipped(t *testing.T) {
	api := spaceAPI(4*gib, 8182759056, "dir")
	r := NewBackupRunner(api, "local", proxmox.ModeSnapshot, "", "keep-last=1", quiet())
	rec, err := r.Backup(context.Background(), 9201)
	if len(api.vzdumps) != 0 {
		t.Fatalf("a vzdump was started on a target that cannot hold it: %+v", api.vzdumps)
	}
	if err == nil || rec.Success || !strings.HasPrefix(rec.Error, BackupSkipNoSpacePrefix) {
		t.Fatalf("want a named skip, got err=%v rec=%+v", err, rec)
	}
	for _, want := range []string{"4.0 GiB free", "7.6 GiB", "10.5 GiB"} {
		if !strings.Contains(rec.Error, want) {
			t.Errorf("the reason must carry the numbers (%q missing): %s", want, rec.Error)
		}
	}
}

// TestR685_BackupThatFitsRuns — the same archive with 16 GiB free (demo-hp after tonight's prune) runs.
func TestR685_BackupThatFitsRuns(t *testing.T) {
	api := spaceAPI(16*gib, 8182759056, "dir")
	r := NewBackupRunner(api, "local", proxmox.ModeSnapshot, "", "keep-last=1", quiet())
	_, _ = r.Backup(context.Background(), 9201)
	if len(api.vzdumps) != 1 {
		t.Fatalf("a backup that fits must run, vzdumps=%d", len(api.vzdumps))
	}
}

// TestR685_FailsOpen — never refuse on what is not KNOWN: a PBS target, a first backup (no archive to
// size from), an unknown free figure, or a storage list that cannot be read.
func TestR685_FailsOpen(t *testing.T) {
	cases := map[string]*fakeBackupAPI{
		"pbs target":    spaceAPI(1*gib, 8*gib, "pbs"),
		"first backup":  spaceAPI(1*gib, 0, "dir"),
		"avail unknown": spaceAPI(0, 8*gib, "dir"),
		"storage list error": func() *fakeBackupAPI {
			a := spaceAPI(1*gib, 8*gib, "dir")
			a.storageErr = context.DeadlineExceeded
			return a
		}(),
	}
	for name, api := range cases {
		target := "local"
		if name == "pbs target" {
			api.storages[0].Storage = "felhom-pbs"
			target = "felhom-pbs"
		}
		r := NewBackupRunner(api, target, proxmox.ModeSnapshot, "", "", quiet())
		_, _ = r.Backup(context.Background(), 9201)
		if len(api.vzdumps) != 1 {
			t.Errorf("%s: the preflight must fail OPEN, but no vzdump ran", name)
		}
	}
}