package agent

import (
	"context"
	"net/http"
	"net/http/httptest"
	"path/filepath"
	"sync/atomic"
	"testing"

	"git.unkin.net/unkin/tomswall/internal/config"
)

func TestTranslateInterfaceAgnosticRule(t *testing.T) {
	rc := &RenderedConfig{
		Generation: 5,
		Device:     "fw-a",
		Enforcing:  true,
		Settings:   RenderedSettings{AddressFamily: "inet", LogLevel: "info", TableName: "tomswall"},
		Bindings:   map[string][]string{"zone-a": {"eth1"}},
		Sets: []RenderedSet{
			{Name: "asn_cloudflare", Kind: "asn", Members: []string{"104.16.0.0/13", "1.1.1.0/24"}},
		},
		Rules: []RenderedRule{
			{
				Action: "accept",
				Source: []RenderedMatch{{Zone: "zone-a", Subnets: []string{"10.1.0.0/24"}}},
				Dest:   []RenderedMatch{{Zone: "net", Set: "asn_cloudflare"}},
				Proto:  "tcp",
				Ports:  []string{"443"},
			},
		},
	}

	cfg, err := Translate(rc)
	if err != nil {
		t.Fatalf("Translate: %v", err)
	}
	// fw zone + zone-a.
	if _, ok := cfg.Zones["fw"]; !ok {
		t.Error("missing firewall zone")
	}
	if _, ok := cfg.Zones["zone-a"]; !ok {
		t.Error("missing zone-a")
	}
	// binding -> interface.
	if len(cfg.Interfaces) != 1 || cfg.Interfaces[0].Interface != "eth1" {
		t.Errorf("expected one eth1 interface, got %+v", cfg.Interfaces)
	}
	// 1 source addr x 2 dest addrs (asn set members) = 2 rules.
	if len(cfg.Rules) != 2 {
		t.Fatalf("expected 2 expanded rules, got %d: %+v", len(cfg.Rules), cfg.Rules)
	}
	for _, r := range cfg.Rules {
		if r.Source != "all:10.1.0.0/24" {
			t.Errorf("source not interface-agnostic saddr match: %q", r.Source)
		}
		if r.Action != config.RuleAccept || r.Proto != "tcp" || len(r.DPort) != 1 || r.DPort[0] != "443" {
			t.Errorf("unexpected rule: %+v", r)
		}
	}
	dests := map[string]bool{cfg.Rules[0].Dest: true, cfg.Rules[1].Dest: true}
	if !dests["all:104.16.0.0/13"] || !dests["all:1.1.1.0/24"] {
		t.Errorf("dest set members not inlined: %v", dests)
	}
}

func TestTranslateBareZone(t *testing.T) {
	rc := &RenderedConfig{
		Enforcing: true,
		Rules: []RenderedRule{{
			Action: "accept",
			Source: []RenderedMatch{{Zone: "zone-a", Subnets: []string{"10.1.0.0/24"}}},
			Dest:   []RenderedMatch{{Zone: "zone-b", Subnets: []string{"10.4.0.0/24"}}},
			Proto:  "tcp", Ports: []string{"22"},
		}},
	}
	cfg, err := Translate(rc)
	if err != nil {
		t.Fatalf("Translate: %v", err)
	}
	if len(cfg.Rules) != 1 || cfg.Rules[0].Source != "all:10.1.0.0/24" || cfg.Rules[0].Dest != "all:10.4.0.0/24" {
		t.Errorf("unexpected zone-to-zone rule: %+v", cfg.Rules)
	}
}

func TestTranslateRejectsUnknownAction(t *testing.T) {
	rc := &RenderedConfig{Enforcing: true, Rules: []RenderedRule{{Action: "bogus"}}}
	if _, err := Translate(rc); err == nil {
		t.Fatal("expected error for unknown action")
	}
}

// fakeApplier records applied configs.
type fakeApplier struct {
	count   int32
	lastGen int
}

func (f *fakeApplier) Apply(_ context.Context, cfg *config.Config) error {
	atomic.AddInt32(&f.count, 1)
	f.lastGen = len(cfg.Rules)
	return nil
}

const renderedYAML = `generation: 7
device: fw-a
enforcing: true
settings:
  address_family: inet
  log_level: info
  table_name: tomswall
bindings:
  zone-a: [eth1]
rules:
  - action: accept
    source:
      - zone: zone-a
        subnets: ["10.1.0.0/24"]
    dest:
      - zone: zone-b
        subnets: ["10.4.0.0/24"]
    proto: tcp
    ports: ["22"]
`

func TestRunOnceAppliesAndReports(t *testing.T) {
	var reported int64
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch {
		case r.Method == http.MethodGet && r.URL.Path == "/api/v1/devices/fw-a/config":
			w.Header().Set("Content-Type", "application/yaml")
			_, _ = w.Write([]byte(renderedYAML))
		case r.Method == http.MethodPost && r.URL.Path == "/api/v1/devices/fw-a/status":
			atomic.StoreInt64(&reported, 1)
			w.WriteHeader(http.StatusNoContent)
		default:
			w.WriteHeader(http.StatusNotFound)
		}
	}))
	defer srv.Close()

	applier := &fakeApplier{}
	a := &Agent{
		Client:  NewClient(srv.URL, "fw-a", "tok"),
		Cache:   Cache{Path: filepath.Join(t.TempDir(), "cache.yaml")},
		Applier: applier,
	}
	if err := a.RunOnce(context.Background()); err != nil {
		t.Fatalf("RunOnce: %v", err)
	}
	if atomic.LoadInt32(&applier.count) != 1 {
		t.Errorf("expected 1 apply, got %d", applier.count)
	}
	if atomic.LoadInt64(&reported) != 1 {
		t.Error("expected status to be reported")
	}
	// Cache should now be populated.
	if cached, err := a.Cache.Read(); err != nil || cached == nil || cached.Generation != 7 {
		t.Errorf("cache not written correctly: %+v (err %v)", cached, err)
	}
}

func TestRunOnceFallsBackToCacheNeverFailsClosed(t *testing.T) {
	// Server always errors — the control plane is "unreachable".
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer srv.Close()

	cachePath := filepath.Join(t.TempDir(), "cache.yaml")
	if err := (Cache{Path: cachePath}).Write([]byte(renderedYAML)); err != nil {
		t.Fatalf("seed cache: %v", err)
	}

	applier := &fakeApplier{}
	a := &Agent{
		Client:  NewClient(srv.URL, "fw-a", "tok"),
		Cache:   Cache{Path: cachePath},
		Applier: applier,
	}
	// Fetch fails, but the cached config must still be applied (fail-safe).
	if err := a.RunOnce(context.Background()); err != nil {
		t.Fatalf("RunOnce should not error when a cache exists: %v", err)
	}
	if atomic.LoadInt32(&applier.count) != 1 {
		t.Errorf("expected cached config to be applied, got %d applies", applier.count)
	}
}

func TestRunOnceNoCacheReturnsError(t *testing.T) {
	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.WriteHeader(http.StatusInternalServerError)
	}))
	defer srv.Close()

	a := &Agent{
		Client:  NewClient(srv.URL, "fw-a", "tok"),
		Cache:   Cache{Path: filepath.Join(t.TempDir(), "absent.yaml")},
		Applier: &fakeApplier{},
	}
	if err := a.RunOnce(context.Background()); err == nil {
		t.Fatal("expected error when unreachable and no cache exists")
	}
}