package bash

import (
	"sort"
	"testing"
)

func TestNewFilesystem(t *testing.T) {
	fs := newFilesystem("testhost")

	// Standard directories should exist.
	for _, dir := range []string{"/etc", "/root", "/home", "/var/log", "/tmp", "/usr/bin"} {
		if !fs.isDirectory(dir) {
			t.Errorf("%s should be a directory", dir)
		}
	}

	// Standard files should exist.
	for _, file := range []string{"/etc/passwd", "/etc/hostname", "/root/.bashrc", "/tmp/notes.txt"} {
		if !fs.exists(file) {
			t.Errorf("%s should exist", file)
		}
	}
}

func TestFilesystemHostname(t *testing.T) {
	fs := newFilesystem("myhost")
	content, err := fs.read("/etc/hostname")
	if err != nil {
		t.Fatalf("read /etc/hostname: %v", err)
	}
	if content != "myhost\n" {
		t.Errorf("hostname content = %q, want %q", content, "myhost\n")
	}
}

func TestResolvePath(t *testing.T) {
	tests := []struct {
		cwd  string
		arg  string
		want string
	}{
		{"/root", "file.txt", "/root/file.txt"},
		{"/root", "/etc/passwd", "/etc/passwd"},
		{"/root", "..", "/"},
		{"/var/log", "../..", "/"},
		{"/root", ".", "/root"},
		{"/root", "./sub/file", "/root/sub/file"},
		{"/", "etc", "/etc"},
	}
	for _, tt := range tests {
		got := resolvePath(tt.cwd, tt.arg)
		if got != tt.want {
			t.Errorf("resolvePath(%q, %q) = %q, want %q", tt.cwd, tt.arg, got, tt.want)
		}
	}
}

func TestFilesystemList(t *testing.T) {
	fs := newFilesystem("testhost")

	names, err := fs.list("/etc")
	if err != nil {
		t.Fatalf("list /etc: %v", err)
	}
	sort.Strings(names)

	// Should contain at least passwd, hostname, hosts.
	found := map[string]bool{}
	for _, n := range names {
		found[n] = true
	}
	for _, want := range []string{"passwd", "hostname", "hosts"} {
		if !found[want] {
			t.Errorf("list /etc missing %q, got %v", want, names)
		}
	}
}

func TestFilesystemListNonexistent(t *testing.T) {
	fs := newFilesystem("testhost")
	_, err := fs.list("/nonexistent")
	if err == nil {
		t.Fatal("expected error listing nonexistent directory")
	}
}

func TestFilesystemListFile(t *testing.T) {
	fs := newFilesystem("testhost")
	_, err := fs.list("/etc/passwd")
	if err == nil {
		t.Fatal("expected error listing a file")
	}
}

func TestFilesystemRead(t *testing.T) {
	fs := newFilesystem("testhost")
	content, err := fs.read("/etc/passwd")
	if err != nil {
		t.Fatalf("read: %v", err)
	}
	if content == "" {
		t.Error("expected non-empty content")
	}
}

func TestFilesystemReadNonexistent(t *testing.T) {
	fs := newFilesystem("testhost")
	_, err := fs.read("/no/such/file")
	if err == nil {
		t.Fatal("expected error for nonexistent file")
	}
}

func TestFilesystemReadDirectory(t *testing.T) {
	fs := newFilesystem("testhost")
	_, err := fs.read("/etc")
	if err == nil {
		t.Fatal("expected error for reading a directory")
	}
}

func TestFilesystemDirectoryListing(t *testing.T) {
	fs := newFilesystem("testhost")
	names, err := fs.list("/")
	if err != nil {
		t.Fatalf("list /: %v", err)
	}

	// Root directories should end with /
	found := map[string]bool{}
	for _, n := range names {
		found[n] = true
	}
	for _, want := range []string{"etc/", "root/", "home/", "var/", "tmp/", "usr/"} {
		if !found[want] {
			t.Errorf("list / missing %q, got %v", want, names)
		}
	}
}