package controller

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"reflect"
	"sync"
	"sync/atomic"
	"testing"

	"github.com/oracle/oci-go-sdk/v65/common"
	"github.com/oracle/oci-go-sdk/v65/core"
	kcore "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
	"k8s.io/apimachinery/pkg/runtime"
	dynfake "k8s.io/client-go/dynamic/fake"
	"k8s.io/client-go/kubernetes/fake"
	"quorate.dev/services/short/cloud"
	"quorate.dev/services/short/config"
	"quorate.dev/services/short/vault"
	"quorate.dev/services/short/wan"
)

type publishedCloud struct {
	cloud.Network
	phase atomic.Int32
}

func (f *publishedCloud) generations() []int {
	switch f.phase.Load() {
	case 0:
		return []int{0}
	case 1:
		return []int{0, 1}
	default:
		return []int{1}
	}
}

func (f *publishedCloud) ListCpes(context.Context, core.ListCpesRequest) (core.ListCpesResponse, error) {
	var result core.ListCpesResponse
	for _, i := range f.generations() {
		result.Items = append(result.Items, core.Cpe{Id: common.String(fmt.Sprint(i)), IpAddress: common.String(fmt.Sprintf("192.0.2.%d", i+2)), FreeformTags: map[string]string{"owner": "short"}})
	}
	return result, nil
}

func (f *publishedCloud) ListIPSecConnections(context.Context, core.ListIPSecConnectionsRequest) (core.ListIPSecConnectionsResponse, error) {
	var result core.ListIPSecConnectionsResponse
	for _, i := range f.generations() {
		result.Items = append(result.Items, core.IpSecConnection{Id: common.String(fmt.Sprint(i)), CpeId: common.String(fmt.Sprint(i)), LifecycleState: core.IpSecConnectionLifecycleStateAvailable, StaticRoutes: []string{"198.18.0.10/32"}, FreeformTags: map[string]string{"owner": "short"}})
	}
	return result, nil
}

func (f *publishedCloud) ListIPSecConnectionTunnels(_ context.Context, r core.ListIPSecConnectionTunnelsRequest) (core.ListIPSecConnectionTunnelsResponse, error) {
	var result core.ListIPSecConnectionTunnelsResponse
	for i := 1; i <= 2; i++ {
		result.Items = append(result.Items, core.IpSecConnectionTunnel{
			Id: common.String(fmt.Sprintf("%s-%d", *r.IpscId, i)), VpnIp: common.String(fmt.Sprintf("192.0.2.%s%d", map[string]string{"0": "1", "1": "2"}[*r.IpscId], i)),
			LifecycleState: core.IpSecConnectionTunnelLifecycleStateAvailable, Status: core.IpSecConnectionTunnelStatusDown,
			OracleCanInitiate: core.IpSecConnectionTunnelOracleCanInitiateInitiatorOrResponder,
		})
	}
	return result, nil
}

func (f *publishedCloud) GetIPSecConnectionTunnelSharedSecret(_ context.Context, r core.GetIPSecConnectionTunnelSharedSecretRequest) (core.GetIPSecConnectionTunnelSharedSecretResponse, error) {
	return core.GetIPSecConnectionTunnelSharedSecretResponse{IpSecConnectionTunnelSharedSecret: core.IpSecConnectionTunnelSharedSecret{SharedSecret: common.String("synthetic-" + *r.TunnelId)}}, nil
}

func TestWANPublication(t *testing.T) {
	ctx := context.Background()
	api := &publishedCloud{}
	dyn := dynfake.NewSimpleDynamicClient(runtime.NewScheme(), &unstructured.Unstructured{Object: map[string]any{
		"apiVersion": "cilium.io/v2", "kind": "CiliumCIDRGroup", "metadata": map[string]any{"name": "short"}, "spec": map[string]any{"externalCIDRs": []any{}},
	}})
	kube := fake.NewClientset(&kcore.Service{ObjectMeta: metav1.ObjectMeta{Name: "cilium-gateway-gateway-short", Namespace: "kube-system"}, Spec: kcore.ServiceSpec{ClusterIP: "192.0.2.100", Ports: []kcore.ServicePort{{Port: 8080}}}})
	var mu sync.Mutex
	version := 1
	data := map[string]any{"config": "{}"}
	writes := 0
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		mu.Lock()
		defer mu.Unlock()
		w.Header().Set("Content-Type", "application/json")
		switch req.URL.Path {
		case "/api/interfaces/overview/interfaces_info":
			if req.Method != http.MethodGet {
				t.Error("WAN reader attempted a mutation")
			}
			address := "192.0.2.2"
			if api.phase.Load() > 0 {
				address = "192.0.2.3"
			}
			fmt.Fprintf(w, `{"rows":[{"identifier":"WAN","ipv4":[{"ipaddr":%q}]}]}`, address)
		case "/v1/secret/data/short/peers":
			if req.Method == http.MethodGet {
				json.NewEncoder(w).Encode(map[string]any{"data": map[string]any{"data": data, "metadata": map[string]int{"version": version}}})
				return
			}
			var input struct {
				Options struct{ CAS int } `json:"options"`
				Data    map[string]any    `json:"data"`
			}
			if err := json.NewDecoder(req.Body).Decode(&input); err != nil {
				t.Error(err)
			}
			if req.Method != http.MethodPost || input.Options.CAS != version {
				t.Error("configuration publication lost its CAS contract")
				http.Error(w, "conflict", http.StatusBadRequest)
				return
			}
			var published config.Runtime
			if err := json.Unmarshal([]byte(input.Data["config"].(string)), &published); err != nil {
				t.Error(err)
			}
			current, _ := dyn.Resource(group).Get(ctx, "short", metav1.GetOptions{})
			allowed, _, _ := unstructured.NestedStringSlice(current.Object, "spec", "externalCIDRs")
			for _, p := range published.Peers {
				found := false
				for _, cidr := range allowed {
					found = found || cidr == p.Address+"/32"
				}
				if !found {
					t.Error("published a peer before admitting its address")
				}
			}
			data = input.Data
			version++
			writes++
		default:
			t.Errorf("unexpected request: %s", req.URL.Path)
			http.NotFound(w, req)
		}
	}))
	defer server.Close()
	r := Runner{Cloud: &cloud.Client{API: api, Config: config.Cloud{Address: "198.18.0.10", Network: "198.18.1.0/24"}}, WAN: &wan.Client{URL: server.URL, HTTP: server.Client()}, Kube: kube, Dynamic: dyn}
	kv := &vault.Client{URL: server.URL, HTTP: server.Client(), Token: "synthetic-token"}
	for phase, wantCIDRs := range []int{2, 4, 2} {
		api.phase.Store(int32(phase))
		if err := r.step(ctx, kv); err != nil {
			t.Fatal(err)
		}
		mu.Lock()
		value := data["config"].(string)
		count := writes
		mu.Unlock()
		var published config.Runtime
		if err := json.Unmarshal([]byte(value), &published); err != nil {
			t.Fatal(err)
		}
		wantWAN, wantWrites := "192.0.2.2", 1
		if phase > 0 {
			wantWAN, wantWrites = "192.0.2.3", 2
		}
		if published.WAN != wantWAN || count != wantWrites || published.Path.Address != "198.18.0.10" || published.Path.Network != "198.18.1.0/24" || published.Path.Gateway != "192.0.2.100" || !reflect.DeepEqual(published.Path.Ports, []uint16{8080}) {
			t.Fatalf("wrong runtime publication: %s; writes=%d", value, count)
		}
		current, _ := dyn.Resource(group).Get(ctx, "short", metav1.GetOptions{})
		cidrs, _, _ := unstructured.NestedStringSlice(current.Object, "spec", "externalCIDRs")
		if len(cidrs) != wantCIDRs {
			t.Fatalf("wrong peer admission transition: %v", cidrs)
		}
		if directory := os.Getenv("SHORT_FIXTURE"); directory != "" && phase < 2 {
			if err := os.WriteFile(filepath.Join(directory, fmt.Sprintf("runtime%d.json", phase)), []byte(value), 0600); err != nil {
				t.Fatal(err)
			}
		}
	}
}