package validate

import (
	"net/netip"
	"strings"
	"testing"

	"steward/internal/model"
)

func pool(s string) model.Pool {
	p, err := model.ParsePool(s)
	if err != nil {
		panic(err)
	}
	return p
}

func good() *model.State {
	return &model.State{
		Settings: model.DefaultSettings(),
		Subnets: []*model.Subnet{
			{ID: 1, Name: "office", Interface: "eth0", Prefix: netip.MustParsePrefix("10.0.10.0/24"), Pools: []model.Pool{pool("10.0.10.100-10.0.10.199")},
				Options: []model.OptionValue{{Code: 3, Value: "10.0.10.1"}}},
			{ID: 2, Name: "iot", Interface: "eth0.20", Prefix: netip.MustParsePrefix("10.0.20.0/24")},
		},
		Reservations: []*model.Reservation{
			{ID: 3, MAC: "aa:bb:cc:dd:ee:01", IP: netip.MustParseAddr("10.0.10.20"), Hostname: "nas"},
		},
	}
}

func codes(ps []Problem) string {
	var out []string
	for _, p := range ps {
		out = append(out, p.Severity+":"+p.Code)
	}
	return strings.Join(out, " ")
}

func TestGoodConfig(t *testing.T) {
	st := good()
	st.Subnets[1].Pools = []model.Pool{pool("10.0.20.100-10.0.20.200")}
	if ps := Check(st, nil); len(ps) != 0 {
		t.Errorf("problems: %v", ps)
	}
}

func TestProblems(t *testing.T) {
	cases := []struct {
		name string
		edit func(st *model.State)
		want string
	}{
		{"host bits", func(st *model.State) { st.Subnets[0].Prefix = netip.MustParsePrefix("10.0.10.5/24") }, "error:subnet_prefix"},
		{"too small", func(st *model.State) { st.Subnets[0].Prefix = netip.MustParsePrefix("10.0.10.0/31") }, "error:subnet_size"},
		{"ipv6", func(st *model.State) { st.Subnets[0].Prefix = netip.MustParsePrefix("2001:db8::/64") }, "error:subnet_prefix"},
		{"overlap", func(st *model.State) { st.Subnets[1].Prefix = netip.MustParsePrefix("10.0.0.0/16") }, "error:subnet_overlap"},
		{"name taken", func(st *model.State) { st.Subnets[1].Name = "Office" }, "error:subnet_name_taken"},
		{"no interface", func(st *model.State) { st.Subnets[0].Interface = "" }, "error:subnet_interface_missing"},
		{"bad interface", func(st *model.State) { st.Subnets[0].Interface = "eth 0" }, "error:subnet_interface_name"},
		{"no pools", func(st *model.State) {}, "warning:subnet_no_pools"},
		{"pool outside", func(st *model.State) { st.Subnets[0].Pools = []model.Pool{pool("10.0.11.1-10.0.11.9")} }, "error:pool_outside_subnet"},
		{"pool network", func(st *model.State) { st.Subnets[0].Pools = []model.Pool{pool("10.0.10.0/24")} }, "error:pool_network_address"},
		{"pool overlap", func(st *model.State) {
			st.Subnets[0].Pools = append(st.Subnets[0].Pools, pool("10.0.10.150-10.0.10.250"))
		}, "error:pool_overlap"},
		{"lease time", func(st *model.State) { st.Subnets[0].LeaseTime = 10 }, "error:lease_time_range"},
		{"reserved option", func(st *model.State) { st.Settings.Options = []model.OptionValue{{Code: 51, Value: "1"}} }, "error:option_reserved"},
		{"bad option", func(st *model.State) { st.Subnets[0].Options = []model.OptionValue{{Code: 6, Value: "dns.example"}} }, "error:option_invalid"},
		{"duplicate option", func(st *model.State) {
			st.Subnets[0].Options = append(st.Subnets[0].Options, model.OptionValue{Code: 3, Value: "10.0.10.2"})
		}, "error:option_duplicate"},
		{"router outside", func(st *model.State) { st.Subnets[0].Options = []model.OptionValue{{Code: 3, Value: "10.0.11.1"}} }, "warning:router_outside_subnet"},
		{"router in pool", func(st *model.State) { st.Subnets[0].Options = []model.OptionValue{{Code: 3, Value: "10.0.10.150"}} }, "warning:router_in_pool"},
		{"no client", func(st *model.State) { st.Reservations[0].MAC = "" }, "error:reservation_no_client"},
		{"no subnet", func(st *model.State) { st.Reservations[0].IP = netip.MustParseAddr("192.168.1.5") }, "error:reservation_no_subnet"},
		{"broadcast", func(st *model.State) { st.Reservations[0].IP = netip.MustParseAddr("10.0.10.255") }, "error:reservation_network_address"},
		{"ip taken", func(st *model.State) {
			st.Reservations = append(st.Reservations, &model.Reservation{ID: 9, MAC: "aa:bb:cc:dd:ee:02", IP: netip.MustParseAddr("10.0.10.20")})
		}, "error:reservation_ip_taken"},
		{"client taken", func(st *model.State) {
			st.Reservations = append(st.Reservations, &model.Reservation{ID: 9, MAC: "aa:bb:cc:dd:ee:01", IP: netip.MustParseAddr("10.0.10.21")})
		}, "error:reservation_client_taken"},
		{"hostname", func(st *model.State) { st.Reservations[0].Hostname = "my_nas" }, "error:reservation_hostname"},
	}
	for _, c := range cases {
		st := good()
		st.Subnets[1].Pools = []model.Pool{pool("10.0.20.100-10.0.20.200")}
		if c.name == "no pools" {
			st.Subnets[1].Pools = nil
		}
		c.edit(st)
		got := codes(Check(st, nil))
		if !strings.Contains(" "+got+" ", " "+c.want+" ") {
			t.Errorf("%s: got %q, want %s", c.name, got, c.want)
		}
	}
}

func TestDisabledReservationsDontConflict(t *testing.T) {
	st := good()
	st.Subnets[1].Pools = []model.Pool{pool("10.0.20.100-10.0.20.200")}
	st.Reservations[0].Disabled = true
	// The same client and address again, enabled: fine while the first is
	// disabled.
	st.Reservations = append(st.Reservations, &model.Reservation{ID: 9, MAC: "aa:bb:cc:dd:ee:01", IP: netip.MustParseAddr("10.0.10.20")})
	if ps := Check(st, nil); len(ps) != 0 {
		t.Errorf("problems: %v", ps)
	}
	st.Reservations[0].Disabled = false
	if got := codes(Check(st, nil)); !strings.Contains(got, "reservation_ip_taken") {
		t.Errorf("enabling it again: %q", got)
	}
}

func TestSameMACInTwoSubnets(t *testing.T) {
	st := good()
	st.Subnets[1].Pools = []model.Pool{pool("10.0.20.100-10.0.20.200")}
	st.Reservations = append(st.Reservations, &model.Reservation{ID: 9, MAC: "aa:bb:cc:dd:ee:01", IP: netip.MustParseAddr("10.0.20.20")})
	if ps := Check(st, nil); len(ps) != 0 {
		t.Errorf("a laptop on two VLANs: %v", ps)
	}
}

func TestHostInterfaces(t *testing.T) {
	st := good()
	st.Subnets[1].Pools = []model.Pool{pool("10.0.20.100-10.0.20.200")}
	st.Subnets[0].Pools = []model.Pool{pool("10.0.10.1-10.0.10.199")}
	st.Subnets[0].Options = nil
	env := &Env{Interfaces: map[string][]netip.Prefix{
		"eth0": {netip.MustParsePrefix("10.0.10.2/24")},
		"wg0":  {netip.MustParsePrefix("10.9.0.1/24")},
	}}
	got := codes(Check(st, env))
	for _, want := range []string{"warning:pool_includes_server", "warning:interface_unknown"} {
		if !strings.Contains(got, want) {
			t.Errorf("got %q, want %s", got, want)
		}
	}
	env.Interfaces["eth0.20"] = []netip.Prefix{netip.MustParsePrefix("192.168.5.1/24")}
	if got := codes(Check(st, env)); !strings.Contains(got, "warning:interface_no_address") {
		t.Errorf("got %q, want interface_no_address", got)
	}
}