package agent

import (
	"context"
	"crypto/tls"
	"crypto/x509"
	"encoding/json"
	"fmt"
	"net/http"
	"net/http/httptest"
	"os"
	"path/filepath"
	"testing"
	"time"

	"crypto/x509/pkix"

	"git.dws.rip/dubey/kat/internal/pki"
)

func TestAgentHeartbeat(t *testing.T) {
	// Create temporary directory for test PKI files
	tempDir, err := os.MkdirTemp("", "kat-test-agent-*")
	if err != nil {
		t.Fatalf("Failed to create temp directory: %v", err)
	}
	defer os.RemoveAll(tempDir)

	// Generate CA for testing
	pkiDir := filepath.Join(tempDir, "pki")
	caKeyPath := filepath.Join(pkiDir, "ca.key")
	caCertPath := filepath.Join(pkiDir, "ca.crt")
	err = pki.GenerateCA(pkiDir, caKeyPath, caCertPath)
	if err != nil {
		t.Fatalf("Failed to generate test CA: %v", err)
	}

	// Generate node certificate
	nodeKeyPath := filepath.Join(pkiDir, "node.key")
	nodeCSRPath := filepath.Join(pkiDir, "node.csr")
	nodeCertPath := filepath.Join(pkiDir, "node.crt")
	err = pki.GenerateCertificateRequest("test-node", nodeKeyPath, nodeCSRPath)
	if err != nil {
		t.Fatalf("Failed to generate node key and CSR: %v", err)
	}
	err = pki.SignCertificateRequest(caKeyPath, caCertPath, nodeCSRPath, nodeCertPath, 24*time.Hour)
	if err != nil {
		t.Fatalf("Failed to sign node CSR: %v", err)
	}

	// Create a test server that requires client certificates
	server := httptest.NewTLSServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Verify the request path
		if r.URL.Path != "/v1alpha1/nodes/test-node/status" {
			t.Errorf("Expected path /v1alpha1/nodes/test-node/status, got %s", r.URL.Path)
			http.Error(w, "Invalid path", http.StatusBadRequest)
			return
		}

		// Verify the request method
		if r.Method != "POST" {
			t.Errorf("Expected method POST, got %s", r.Method)
			http.Error(w, "Invalid method", http.StatusMethodNotAllowed)
			return
		}

		// Parse the request body
		var status NodeStatus
		decoder := json.NewDecoder(r.Body)
		if err := decoder.Decode(&status); err != nil {
			t.Errorf("Failed to decode request body: %v", err)
			http.Error(w, "Invalid request body", http.StatusBadRequest)
			return
		}

		// Verify the node name
		if status.NodeName != "test-node" {
			t.Errorf("Expected node name test-node, got %s", status.NodeName)
			http.Error(w, "Invalid node name", http.StatusBadRequest)
			return
		}

		// Verify that resources are present
		if status.Resources.Capacity.CPU == "" || status.Resources.Capacity.Memory == "" {
			t.Errorf("Missing resource capacity information")
			http.Error(w, "Missing resource information", http.StatusBadRequest)
			return
		}

		// Return success
		w.WriteHeader(http.StatusOK)
	}))
	defer server.Close()

	// Configure the server to require client certificates
	server.TLS.ClientAuth = tls.RequireAndVerifyClientCert
	server.TLS.ClientCAs = x509.NewCertPool()
	caCertData, err := os.ReadFile(caCertPath)
	if err != nil {
		t.Fatalf("Failed to read CA certificate: %v", err)
	}
	server.TLS.ClientCAs.AppendCertsFromPEM(caCertData)

	// Set the server certificate to use the test node name as CN
	// to match what our test agent will expect
	server.TLS.Certificates = []tls.Certificate{
		{
			Certificate: [][]byte{[]byte("test-cert")},
			PrivateKey:  nil,
			Leaf: &x509.Certificate{
				Subject: pkix.Name{
					CommonName: "leader.kat.cluster.local",
				},
			},
		},
	}

	// Extract the host:port from the server URL
	serverURL := server.URL
	hostPort := serverURL[8:] // Remove "https://" prefix

	// Create an agent
	agent, err := NewAgent("test-node", "test-uid", hostPort, "192.168.1.100", pkiDir, 1)
	if err != nil {
		t.Fatalf("Failed to create agent: %v", err)
	}

	// Setup mTLS client
	err = agent.SetupMTLSClient()
	if err != nil {
		t.Fatalf("Failed to setup mTLS client: %v", err)
	}

	// Create a context with timeout
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	// Start heartbeat
	err = agent.StartHeartbeat(ctx)
	if err != nil {
		t.Fatalf("Failed to start heartbeat: %v", err)
	}

	// Wait for at least one heartbeat
	time.Sleep(2 * time.Second)

	// Stop heartbeat
	agent.StopHeartbeat()

	// Test passed if we got here without errors
	fmt.Println("Agent heartbeat test passed")
}