package apply

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/novox/mesh-host/internal/store"
)

// A file the host wrote whole is deleted only when it holds exactly what the host wrote; anything
// else is moved aside, never destroyed (novox/hq issue 241).
func TestAnUndeclaredFileIsDeletedOnlyWhenItIsWhatTheMeshWrote(t *testing.T) {
	dir := t.TempDir()
	now := time.Date(2026, 10, 5, 9, 30, 0, 0, time.UTC)

	pure := filepath.Join(dir, "config.conf")
	if err := os.WriteFile(pure, []byte("what the mesh wrote\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	action, _, err := removeFile(store.Applied{Type: "file", Target: pure, Wrote: digestOf("what the mesh wrote\n")}, now)
	if err != nil || action != "removed" {
		t.Fatalf("a file holding only the mesh's content was %q (%v)", action, err)
	}
	if _, err := os.Stat(pure); !os.IsNotExist(err) {
		t.Fatal("the mesh's own file is still there")
	}

	for name, a := range map[string]store.Applied{
		"filled since":    {Type: "file", Wrote: digestOf("seed\n")},
		"no record of it": {Type: "file"},
	} {
		path := filepath.Join(dir, strings.ReplaceAll(name, " ", "-")+".db")
		if err := os.WriteFile(path, []byte("seed\nand a program's data\n"), 0o600); err != nil {
			t.Fatal(err)
		}
		a.Target = path
		action, detail, err := removeFile(a, now)
		if err != nil || action != "kept" {
			t.Fatalf("%s: was %q (%v)", name, action, err)
		}
		aside := path + ".removed-20261005-093000"
		got, err := os.ReadFile(aside)
		if err != nil || string(got) != "seed\nand a program's data\n" {
			t.Fatalf("%s: not moved aside intact to %s: %v", name, aside, err)
		}
		if !strings.Contains(detail, aside) {
			t.Errorf("%s: the report does not say where it went: %s", name, detail)
		}
	}

	if action, _, _ := removeFile(store.Applied{Type: "file", Target: filepath.Join(dir, "gone")}, now); action != "forgotten" {
		t.Errorf("a file already gone was %q", action)
	}
}