package hws_test

import (
	"io"
	"math/rand/v2"
	"net/http"
	"slices"
	"testing"

	"git.haelnorr.com/h/golib/hlog"
	"git.haelnorr.com/h/golib/hws"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

var ports []uint64

func randomPort() uint64 {
	port := uint64(3000 + rand.IntN(1001))
	for slices.Contains(ports, port) {
		port = uint64(3000 + rand.IntN(1001))
	}
	ports = append(ports, port)
	return port
}

func createTestServer(t *testing.T, w io.Writer) *hws.Server {
	server, err := hws.NewServer(&hws.Config{
		Host:          "127.0.0.1",
		Port:          randomPort(),
		ShutdownDelay: 0, // No delay for tests
	})
	require.NoError(t, err)

	logger, err := hlog.NewLogger(hlog.LogLevel("Debug"), w, nil, "")
	require.NoError(t, err)

	err = server.AddLogger(logger)
	require.NoError(t, err)

	return server
}

var testHandler http.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(http.StatusOK)
	w.Write([]byte("hello world"))
})

func startTestServer(t *testing.T, server *hws.Server) {
	err := server.AddRoutes(hws.Route{
		Path:    "/",
		Method:  hws.MethodGET,
		Handler: testHandler,
	})
	require.NoError(t, err)
	err = server.Start(t.Context())
	require.NoError(t, err)
	t.Log("Test server started")
}

func Test_NewServer(t *testing.T) {
	server, err := hws.NewServer(&hws.Config{
		Host: "localhost",
		Port: randomPort(),
	})
	require.NoError(t, err)
	require.NotNil(t, server)

	t.Run("Nil config returns error", func(t *testing.T) {
		server, err := hws.NewServer(nil)
		assert.Error(t, err)
		assert.Nil(t, server)
		assert.Contains(t, err.Error(), "Config cannot be nil")
	})

	tests := []struct {
		name  string
		host  string
		port  uint64
		valid bool
	}{
		{
			name:  "Valid localhost on http",
			host:  "127.0.0.1",
			port:  80,
			valid: true,
		},
		{
			name:  "Valid IP on https",
			host:  "192.168.1.1",
			port:  443,
			valid: true,
		},
		{
			name:  "Valid IP on port 65535",
			host:  "10.0.0.5",
			port:  65535,
			valid: true,
		},
		{
			name:  "0.0.0.0 on port 8080",
			host:  "0.0.0.0",
			port:  8080,
			valid: true,
		},
		{
			name:  "Broadcast IP on port 1",
			host:  "255.255.255.255",
			port:  1,
			valid: true,
		},
		{
			name:  "Port 0 gets default",
			host:  "127.0.0.1",
			port:  0,
			valid: true, // port 0 now gets default value of 3000
		},
		{
			name:  "Invalid port 65536",
			host:  "127.0.0.1",
			port:  65536,
			valid: true, // port is accepted (validated at OS level)
		},
		{
			name:  "No hostname provided gets default",
			host:  "",
			port:  80,
			valid: true, // empty hostname gets default 127.0.0.1
		},
		{
			name:  "Spaces provided for host",
			host:  " ",
			port:  80,
			valid: false,
		},
		{
			name:  "Localhost as string",
			host:  "localhost",
			port:  8080,
			valid: true,
		},
		{
			name:  "Number only host",
			host:  "1234",
			port:  80,
			valid: true,
		},
		{
			name:  "Valid domain on http",
			host:  "example.com",
			port:  80,
			valid: true,
		},
		{
			name:  "Valid domain on https",
			host:  "a-b-c.example123.co",
			port:  443,
			valid: true,
		},
		{
			name:  "Valid domain starting with a digit",
			host:  "1example.com",
			port:  8080,
			valid: true, // labels may start with digits (RFC 1123)
		},
		{
			name:  "Single character hostname",
			host:  "a",
			port:  1,
			valid: true, // single-label hostname, min length
		},

		{
			name:  "Hostname starts with a hyphen",
			host:  "-example.com",
			port:  80,
			valid: false, // label starts with hyphen
		},
		{
			name:  "Hostname ends with a hyphen",
			host:  "example-.com",
			port:  80,
			valid: false, // label ends with hyphen
		},
		{
			name:  "Empty label in hostname",
			host:  "ex..ample.com",
			port:  80,
			valid: false, // empty label
		},
		{
			name:  "Invalid character: '_'",
			host:  "exa_mple.com",
			port:  80,
			valid: false, // invalid character (_)
		},
		{
			name:  "Trailing dot",
			host:  "example.com.",
			port:  80,
			valid: false, // trailing dot not allowed per spec
		},
		{
			name:  "Valid IPv6 localhost",
			host:  "::1",
			port:  8080,
			valid: true, // IPv6 localhost
		},
		{
			name:  "Valid IPv6 shortened",
			host:  "2001:db8::1",
			port:  80,
			valid: true, // shortened IPv6
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			server, err := hws.NewServer(&hws.Config{
				Host: tt.host,
				Port: tt.port,
			})
			if tt.valid {
				assert.NoError(t, err)
				assert.NotNil(t, server)
			} else {
				assert.Error(t, err)
			}
		})
	}

}