install go2rtc on bob

installs_on_host/go2rtc/pkg/expr/expr.go

@@ -0,0 +1,166 @@
+package expr
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/cookiejar"
+	"net/url"
+	"regexp"
+	"strings"
+	"time"
+
+	"github.com/expr-lang/expr"
+	"github.com/expr-lang/expr/vm"
+)
+
+func newRequest(rawURL string, options map[string]any) (*http.Request, error) {
+	var method, contentType string
+	var rd io.Reader
+
+	// method from js fetch
+	if s, ok := options["method"].(string); ok {
+		method = s
+	} else {
+		method = "GET"
+	}
+
+	// params key from python requests
+	if kv, ok := options["params"].(map[string]any); ok {
+		rawURL += "?" + url.Values(kvToString(kv)).Encode()
+	}
+
+	// json key from python requests
+	// data key from python requests
+	// body key from js fetch
+	if v, ok := options["json"]; ok {
+		b, err := json.Marshal(v)
+		if err != nil {
+			return nil, err
+		}
+		contentType = "application/json"
+		rd = bytes.NewReader(b)
+	} else if kv, ok := options["data"].(map[string]any); ok {
+		contentType = "application/x-www-form-urlencoded"
+		rd = strings.NewReader(url.Values(kvToString(kv)).Encode())
+	} else if s, ok := options["body"].(string); ok {
+		rd = strings.NewReader(s)
+	}
+
+	req, err := http.NewRequest(method, rawURL, rd)
+	if err != nil {
+		return nil, err
+	}
+
+	if kv, ok := options["headers"].(map[string]any); ok {
+		req.Header = kvToString(kv)
+	}
+
+	if contentType != "" && req.Header.Get("Content-Type") == "" {
+		req.Header.Set("Content-Type", contentType)
+	}
+
+	return req, nil
+}
+
+func kvToString(kv map[string]any) map[string][]string {
+	dst := make(map[string][]string, len(kv))
+	for k, v := range kv {
+		dst[k] = []string{fmt.Sprintf("%v", v)}
+	}
+	return dst
+}
+
+func regExp(params ...any) (*regexp.Regexp, error) {
+	exp := params[0].(string)
+	if len(params) >= 2 {
+		// support:
+		//   i  case-insensitive (default false)
+		//   m  multi-line mode: ^ and $ match begin/end line (default false)
+		//   s  let . match \n (default false)
+		// https://pkg.go.dev/regexp/syntax
+		flags := params[1].(string)
+		exp = "(?" + flags + ")" + exp
+	}
+	return regexp.Compile(exp)
+}
+
+func Compile(input string) (*vm.Program, error) {
+	// support http sessions
+	jar, _ := cookiejar.New(nil)
+	client := http.Client{
+		Jar:     jar,
+		Timeout: 5 * time.Second,
+	}
+
+	return expr.Compile(
+		input,
+		expr.Function(
+			"fetch",
+			func(params ...any) (any, error) {
+				var req *http.Request
+				var err error
+
+				rawURL := params[0].(string)
+
+				if len(params) == 2 {
+					options := params[1].(map[string]any)
+					req, err = newRequest(rawURL, options)
+				} else {
+					req, err = http.NewRequest("GET", rawURL, nil)
+				}
+
+				if err != nil {
+					return nil, err
+				}
+
+				res, err := client.Do(req)
+				if err != nil {
+					return nil, err
+				}
+
+				b, _ := io.ReadAll(res.Body)
+
+				return map[string]any{
+					"ok":     res.StatusCode < 400,
+					"status": res.Status,
+					"text":   string(b),
+					"json": func() (v any) {
+						_ = json.Unmarshal(b, &v)
+						return
+					},
+				}, nil
+			},
+			//new(func(url string) map[string]any),
+			//new(func(url string, options map[string]any) map[string]any),
+		),
+		expr.Function(
+			"match",
+			func(params ...any) (any, error) {
+				re, err := regExp(params[1:]...)
+				if err != nil {
+					return nil, err
+				}
+				str := params[0].(string)
+				return re.FindStringSubmatch(str), nil
+			},
+			//new(func(str, expr string) []string),
+			//new(func(str, expr, flags string) []string),
+		),
+	)
+}
+
+func Eval(input string, env any) (any, error) {
+	program, err := Compile(input)
+	if err != nil {
+		return nil, err
+	}
+
+	return expr.Run(program, env)
+}
+
+func Run(program *vm.Program, env any) (any, error) {
+	return vm.Run(program, env)
+}

installs_on_host/go2rtc/pkg/expr/expr_test.go

@@ -0,0 +1,17 @@
+package expr
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMatchHost(t *testing.T) {
+	v, err := Eval(`
+let url = "rtsp://user:pass@192.168.1.123/cam/realmonitor?...";
+let host = match(url, "//[^/]+")[0][2:];
+host
+`, nil)
+	require.Nil(t, err)
+	require.Equal(t, "user:pass@192.168.1.123", v)
+}