package storage

import (
	"testing"

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

// Role classification is AGENT-AUTHORITATIVE (the agent's own storage view + host topology). These
// assert the demo storages map to the right protection tier, and that ambiguity fails safe to the
// MOST-PROTECTED role (system) — never silently user-data.

// demoHost models the demo N100: the OS disk /dev/sda (ESP at /dev/sda1, root at /dev/sda2) plus an
// external data disk /dev/sdb (felhom-usb at /dev/sdb1).
func demoHost() *fakeHostReader {
	return &fakeHostReader{
		mounts: []Mount{
			{Device: "/dev/sda2", MountPoint: "/", FSType: "ext4"},
			{Device: "/dev/sda1", MountPoint: "/boot/efi", FSType: "vfat"},
			{Device: "/dev/sdb1", MountPoint: "/mnt/hdd_1", FSType: "ext4"},
		},
	}
}

func TestSystemDisks_FromBootMounts(t *testing.T) {
	sys, ok := SystemDisks(demoHost())
	if !ok {
		t.Fatal("SystemDisks should resolve the OS disk from / and /boot/efi")
	}
	if !sys["/dev/sda"] {
		t.Fatalf("OS whole-disk /dev/sda not in system set: %v", sys)
	}
	if sys["/dev/sdb"] {
		t.Fatalf("external data disk /dev/sdb wrongly classified as system: %v", sys)
	}
}

func TestRoleForStorage_DemoMapping(t *testing.T) {
	sys, ok := SystemDisks(demoHost())
	cases := []struct {
		name   string
		typ    string
		device string
		want   DeviceRole
	}{
		{"builtin local (root fs)", hub.StorageTypeLocal, "", RoleSystem},
		{"local-lvm (lvmthin)", hub.StorageTypeLVMThin, "", RoleSystem},
		{"felhom-pbs (backup net)", hub.StorageTypePBS, "", RoleBackup},
		{"nfs share", hub.StorageTypeNFS, "", RoleSystem},
		{"felhom-usb on external /dev/sdb1", hub.StorageTypeUSB, "/dev/sdb1", RoleUserData},
		{"local-dir on external /dev/sdb1", hub.StorageTypeLocalDir, "/dev/sdb1", RoleUserData},
		{"usb-typed but ON the system disk", hub.StorageTypeUSB, "/dev/sda2", RoleSystem},
		{"local-dir with no device (on root)", hub.StorageTypeLocalDir, "", RoleSystem},
	}
	for _, c := range cases {
		if got := RoleForStorage(c.typ, c.device, sys, ok); got != c.want {
			t.Errorf("%s: got role %q, want %q", c.name, got, c.want)
		}
	}
}

func TestRoleForRawDevice_SystemVsUserData(t *testing.T) {
	sys, ok := SystemDisks(demoHost())
	if got := RoleForRawDevice("/dev/sdb1", sys, ok); got != RoleUserData {
		t.Errorf("external /dev/sdb1: got %q, want user-data", got)
	}
	if got := RoleForRawDevice("/dev/sda2", sys, ok); got != RoleSystem {
		t.Errorf("system /dev/sda2: got %q, want system", got)
	}
	// A partition on the OS disk is treated as system (protected), not user-data.
	if got := RoleForRawDevice("/dev/sda3", sys, ok); got != RoleSystem {
		t.Errorf("OS-disk partition /dev/sda3: got %q, want system", got)
	}
}

// Ambiguity fails safe: if the system disks cannot be determined, EVERY candidate is system.
func TestRole_FailsSafeWhenSystemUnknown(t *testing.T) {
	noMounts := &fakeHostReader{mountsErr: errFake}
	sys, ok := SystemDisks(noMounts)
	if ok {
		t.Fatal("SystemDisks should report not-ok when mounts cannot be read")
	}
	if got := RoleForRawDevice("/dev/sdb1", sys, ok); got != RoleSystem {
		t.Errorf("unknown system disks → external device must default to system, got %q", got)
	}
	if got := RoleForStorage(hub.StorageTypeUSB, "/dev/sdb1", sys, ok); got != RoleSystem {
		t.Errorf("unknown system disks → usb target must default to system, got %q", got)
	}
}

var errFake = &fakeErr{}

type fakeErr struct{}

func (*fakeErr) Error() string { return "fake" }