package reconcile

import (
	"os"
	"path/filepath"
	"testing"

	"github.com/wild-cloud/wild-central/internal/config"
	"github.com/wild-cloud/wild-central/internal/dnsmasq"
	"github.com/wild-cloud/wild-central/internal/domains"
	"github.com/wild-cloud/wild-central/internal/haproxy"
	"github.com/wild-cloud/wild-central/internal/sse"
)

// --- Stubs ---

type stubDomainManager struct {
	domains []domains.Domain
	err     error
}

func (s *stubDomainManager) List() ([]domains.Domain, error) {
	return s.domains, s.err
}

type stubHAProxy struct {
	generateCalls int
	lastL4Routes  []haproxy.L4Route
	writtenConfig string
	writeErr      error
	reloadCalled  bool
}

func (s *stubHAProxy) GenerateWithOpts(l4 []haproxy.L4Route, _ []haproxy.CustomRoute, _ haproxy.GenerateOpts) string {
	s.generateCalls++
	s.lastL4Routes = l4
	return "generated-config"
}
func (s *stubHAProxy) SafeApply(c string) error    { s.writtenConfig = c; return s.writeErr }
func (s *stubHAProxy) WriteConfig(c string) error  { s.writtenConfig = c; return s.writeErr }
func (s *stubHAProxy) ReloadService() error        { s.reloadCalled = true; return nil }

type stubDNS struct {
	entries      []dnsmasq.DNSEntry
	filterPath   string
	applyCalled  bool
}

func (s *stubDNS) Generate(_ *config.State, entries []dnsmasq.DNSEntry) string {
	s.entries = entries
	return "generated-dns-config"
}
func (s *stubDNS) SafeApply(_ string) error {
	s.applyCalled = true
	return nil
}
func (s *stubDNS) SetFilterConfPath(p string)                  { s.filterPath = p }
func (s *stubDNS) GetStatus() (*dnsmasq.Status, error)         { return nil, nil }

type stubAuth struct {
	userCount      int
	restartCalled  bool
}

func (s *stubAuth) UserCount() int             { return s.userCount }
func (s *stubAuth) RestartService() error       { s.restartCalled = true; return nil }

type stubDDNS struct{ triggerCalled bool }

func (s *stubDDNS) Trigger() { s.triggerCalled = true }

type stubDNSFilter struct{ hostsPath string }

func (s *stubDNSFilter) HostsFilePath() string { return s.hostsPath }

type stubSSE struct{ events []*sse.Event }

func (s *stubSSE) Broadcast(e *sse.Event) { s.events = append(s.events, e) }

func newTestReconciler(t *testing.T, doms []domains.Domain) (*Reconciler, *stubHAProxy, *stubDNS, *stubDDNS) {
	t.Helper()
	tmpDir := t.TempDir()
	statePath := filepath.Join(tmpDir, "state.yaml")
	// Write minimal state
	_ = config.SaveState(&config.State{}, statePath)

	hp := &stubHAProxy{}
	dns := &stubDNS{}
	ddns := &stubDDNS{}

	r := &Reconciler{
		Domains:   &stubDomainManager{domains: doms},
		HAProxy:   hp,
		DNS:       dns,
		Auth:      &stubAuth{},
		DDNS:      ddns,
		DNSFilter: &stubDNSFilter{},
		SSE:       &stubSSE{},
		StatePath: statePath,
	}
	return r, hp, dns, ddns
}

// --- Pure function tests ---

func TestBuildRoutes_MixedBackendTypes(t *testing.T) {
	doms := []domains.Domain{
		{DomainName: "cloud.example.com", Backend: domains.Backend{Address: "192.168.1.10:443", Type: domains.BackendTCPPassthrough}, Subdomains: true},
		{DomainName: "api.example.com", Backend: domains.Backend{Address: "192.168.1.20:8080", Type: domains.BackendHTTP}},
		{DomainName: "ssh.example.com", Backend: domains.Backend{Address: "192.168.1.30:22", Type: domains.BackendDNSOnly}},
	}

	l4, http := buildRoutes(doms)

	if len(l4) != 1 {
		t.Fatalf("expected 1 L4 route, got %d", len(l4))
	}
	if l4[0].Domain != "cloud.example.com" || l4[0].BackendIP != "192.168.1.10" || !l4[0].Subdomains {
		t.Errorf("L4 route mismatch: %+v", l4[0])
	}

	if len(http) != 1 {
		t.Fatalf("expected 1 HTTP route, got %d", len(http))
	}
	if http[0].Domain != "api.example.com" {
		t.Errorf("HTTP route domain = %q, want api.example.com", http[0].Domain)
	}
	if len(http[0].Routes) != 1 || http[0].Routes[0].Backend != "192.168.1.20:8080" {
		t.Errorf("HTTP route backend mismatch: %+v", http[0].Routes)
	}
}

func TestBuildRoutes_EmptyDomains(t *testing.T) {
	l4, http := buildRoutes(nil)
	if l4 != nil || http != nil {
		t.Error("expected nil routes for nil domains")
	}
}

func TestBuildDNSEntries_IPAssignment(t *testing.T) {
	centralIP := "10.0.0.1"
	doms := []domains.Domain{
		{DomainName: "central.example.com", Backend: domains.Backend{Address: "127.0.0.1:5055", Type: domains.BackendHTTP}},
		{DomainName: "cloud.example.com", Backend: domains.Backend{Address: "192.168.1.10:443", Type: domains.BackendTCPPassthrough}},
		{DomainName: "ssh.example.com", Backend: domains.Backend{Address: "192.168.1.30:22", Type: domains.BackendDNSOnly}},
	}

	entries := buildDNSEntries(doms, centralIP)

	if len(entries) != 3 {
		t.Fatalf("expected 3 entries, got %d", len(entries))
	}

	// HTTP → centralIP
	if entries[0].IP != centralIP {
		t.Errorf("HTTP domain IP = %q, want %q", entries[0].IP, centralIP)
	}
	// TCP passthrough → backend IP
	if entries[1].IP != "192.168.1.10" {
		t.Errorf("TCP domain IP = %q, want 192.168.1.10", entries[1].IP)
	}
	// DNS-only → backend IP
	if entries[2].IP != "192.168.1.30" {
		t.Errorf("DNS-only domain IP = %q, want 192.168.1.30", entries[2].IP)
	}
}

func TestBuildDNSEntries_SkipsEmptyDomainName(t *testing.T) {
	entries := buildDNSEntries([]domains.Domain{{DomainName: ""}}, "10.0.0.1")
	if len(entries) != 0 {
		t.Error("expected empty domain to be skipped")
	}
}

func TestBuildDNSEntries_WildcardFlag(t *testing.T) {
	doms := []domains.Domain{
		{DomainName: "cloud.example.com", Backend: domains.Backend{Address: "192.168.1.10:443", Type: domains.BackendTCPPassthrough}, Subdomains: true},
		{DomainName: "exact.example.com", Backend: domains.Backend{Address: "192.168.1.20:443", Type: domains.BackendTCPPassthrough}, Subdomains: false},
	}
	entries := buildDNSEntries(doms, "10.0.0.1")
	if !entries[0].Wildcard {
		t.Error("expected first entry to be wildcard")
	}
	if entries[1].Wildcard {
		t.Error("expected second entry to not be wildcard")
	}
}

// --- Integration tests with stubs ---

func TestReconcile_EmptyDomains(t *testing.T) {
	r, hp, dns, ddns := newTestReconciler(t, nil)
	r.Reconcile()

	if !dns.applyCalled {
		t.Error("expected dnsmasq update")
	}
	if len(dns.entries) != 0 {
		t.Errorf("expected 0 DNS entries, got %d", len(dns.entries))
	}
	if !hp.reloadCalled {
		// No routes but config is still generated and written
	}
	if !ddns.triggerCalled {
		t.Error("expected DDNS trigger")
	}
	// With no routes, HAProxy should still generate (empty config is valid)
	if hp.generateCalls != 1 {
		t.Errorf("expected 1 HAProxy generate call, got %d", hp.generateCalls)
	}
}

func TestReconcile_DDNSTriggered(t *testing.T) {
	doms := []domains.Domain{
		{DomainName: "test.example.com", Backend: domains.Backend{Address: "127.0.0.1:80", Type: domains.BackendHTTP}},
	}
	r, _, _, ddns := newTestReconciler(t, doms)
	r.Reconcile()

	if !ddns.triggerCalled {
		t.Error("expected DDNS.Trigger() to be called")
	}
}

func TestReconcile_DNSEntriesBuiltFromDomains(t *testing.T) {
	doms := []domains.Domain{
		{DomainName: "app.example.com", Backend: domains.Backend{Address: "127.0.0.1:8080", Type: domains.BackendHTTP}},
		{DomainName: "k8s.example.com", Backend: domains.Backend{Address: "192.168.1.50:443", Type: domains.BackendTCPPassthrough}},
	}
	r, _, dns, _ := newTestReconciler(t, doms)
	r.Reconcile()

	if len(dns.entries) != 2 {
		t.Fatalf("expected 2 DNS entries, got %d", len(dns.entries))
	}
	// HTTP domain should use centralIP (127.0.0.1 fallback since state has no IP)
	if dns.entries[0].Domain != "app.example.com" {
		t.Errorf("first DNS entry domain = %q", dns.entries[0].Domain)
	}
	// TCP passthrough should use backend IP directly
	if dns.entries[1].IP != "192.168.1.50" {
		t.Errorf("TCP DNS entry IP = %q, want 192.168.1.50", dns.entries[1].IP)
	}
}

// --- Helper tests ---

func TestIsValidCertFile_Valid(t *testing.T) {
	tmp := t.TempDir()
	path := filepath.Join(tmp, "test.pem")
	if err := os.WriteFile(path, []byte("--- cert content ---"), 0600); err != nil {
		t.Fatal(err)
	}
	if !isValidCertFile(path) {
		t.Error("expected valid cert file to return true")
	}
}

func TestIsValidCertFile_Empty(t *testing.T) {
	tmp := t.TempDir()
	path := filepath.Join(tmp, "empty.pem")
	if err := os.WriteFile(path, nil, 0600); err != nil {
		t.Fatal(err)
	}
	if isValidCertFile(path) {
		t.Error("expected 0-byte cert file to return false")
	}
}

func TestIsValidCertFile_Missing(t *testing.T) {
	if isValidCertFile("/nonexistent/path.pem") {
		t.Error("expected missing file to return false")
	}
}

func TestExtractHost(t *testing.T) {
	tests := []struct {
		input, want string
	}{
		{"192.168.1.1:8080", "192.168.1.1"},
		{"example.com:443", "example.com"},
		{"localhost", "localhost"},
		{"127.0.0.1", "127.0.0.1"},
	}
	for _, tt := range tests {
		if got := extractHost(tt.input); got != tt.want {
			t.Errorf("extractHost(%q) = %q, want %q", tt.input, got, tt.want)
		}
	}
}