Initial release

1 files changed, 239 insertions, 0 deletions

diff --git a/internal/store/har.go b/internal/store/har.go
new file mode 100644
index 0000000..047300a
--- /dev/null
+++ b/internal/store/har.go
@@ -0,0 +1,239 @@
+package store
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+// HAR 1.2 — https://w3c.github.io/web-performance/specs/HAR/Overview.html
+
+type HAR struct {
+	Log HARLog `json:"log"`
+}
+
+type HARLog struct {
+	Version string     `json:"version"`
+	Creator HARCreator `json:"creator"`
+	Entries []HAREntry `json:"entries"`
+}
+
+type HARCreator struct {
+	Name    string `json:"name"`
+	Version string `json:"version"`
+}
+
+type HAREntry struct {
+	StartedDateTime string      `json:"startedDateTime"`
+	Time            int64       `json:"time"`
+	Request         HARRequest  `json:"request"`
+	Response        HARResponse `json:"response"`
+	Timings         HARTimings  `json:"timings"`
+}
+
+type HARRequest struct {
+	Method      string         `json:"method"`
+	URL         string         `json:"url"`
+	HTTPVersion string         `json:"httpVersion"`
+	Headers     []HARNameValue `json:"headers"`
+	QueryString []HARNameValue `json:"queryString"`
+	PostData    *HARPostData   `json:"postData,omitempty"`
+	HeadersSize int            `json:"headersSize"`
+	BodySize    int            `json:"bodySize"`
+}
+
+type HARResponse struct {
+	Status      int            `json:"status"`
+	StatusText  string         `json:"statusText"`
+	HTTPVersion string         `json:"httpVersion"`
+	Headers     []HARNameValue `json:"headers"`
+	Content     HARContent     `json:"content"`
+	RedirectURL string         `json:"redirectURL"`
+	HeadersSize int            `json:"headersSize"`
+	BodySize    int            `json:"bodySize"`
+}
+
+type HARNameValue struct {
+	Name  string `json:"name"`
+	Value string `json:"value"`
+}
+
+type HARPostData struct {
+	MimeType string `json:"mimeType"`
+	Text     string `json:"text"`
+}
+
+type HARContent struct {
+	Size     int    `json:"size"`
+	MimeType string `json:"mimeType"`
+	Text     string `json:"text,omitempty"`
+}
+
+type HARTimings struct {
+	Send    int64 `json:"send"`
+	Wait    int64 `json:"wait"`
+	Receive int64 `json:"receive"`
+}
+
+// ExportHAR serialises the given transactions into a HAR 1.2 JSON byte slice.
+// Pass only the transactions you want exported — scope and out-of-scope
+// filtering is the caller's responsibility.
+func ExportHAR(txs []Transaction) ([]byte, error) {
+	har := HAR{
+		Log: HARLog{
+			Version: "1.2",
+			Creator: HARCreator{
+				Name:    "Shiv",
+				Version: "1.0",
+			},
+			Entries: make([]HAREntry, 0, len(txs)),
+		},
+	}
+
+	for _, tx := range txs {
+		entry := HAREntry{
+			StartedDateTime: tx.Timestamp.UTC().Format(time.RFC3339),
+			Time:            tx.DurationMs,
+			Request:         buildHARRequest(tx),
+			Response:        buildHARResponse(tx),
+			Timings: HARTimings{
+				Send:    0,
+				Wait:    tx.DurationMs,
+				Receive: 0,
+			},
+		}
+		har.Log.Entries = append(har.Log.Entries, entry)
+	}
+
+	data, err := json.MarshalIndent(har, "", "  ")
+	if err != nil {
+		return nil, fmt.Errorf("har: marshal: %w", err)
+	}
+	return data, nil
+}
+
+func stripDefaultPort(rawURL string) string {
+	for _, prefix := range []string{"https://", "http://"} {
+		if !strings.HasPrefix(rawURL, prefix) {
+			continue
+		}
+		rest := rawURL[len(prefix):]
+		slash := strings.Index(rest, "/")
+		if slash < 0 {
+			slash = len(rest)
+		}
+		host := rest[:slash]
+		path := rest[slash:]
+		h, port, err := net.SplitHostPort(host)
+		if err != nil {
+			return rawURL
+		}
+		if (prefix == "https://" && port == "443") || (prefix == "http://" && port == "80") {
+			return prefix + h + path
+		}
+		return rawURL
+	}
+	return rawURL
+}
+
+func buildHARRequest(tx Transaction) HARRequest {
+	headers := make([]HARNameValue, 0, len(tx.ReqHeaders))
+	for k, vals := range tx.ReqHeaders {
+		for _, v := range vals {
+			headers = append(headers, HARNameValue{Name: k, Value: v})
+		}
+	}
+
+	httpVersion := tx.Proto
+	if httpVersion == "" {
+		httpVersion = "HTTP/1.1"
+	}
+
+	req := HARRequest{
+		Method:      tx.Method,
+		URL:         stripDefaultPort(tx.URL),
+		HTTPVersion: httpVersion,
+		Headers:     headers,
+		QueryString: extractQueryString(tx.URL),
+		HeadersSize: -1,
+		BodySize:    len(tx.ReqBody),
+	}
+
+	if len(tx.ReqBody) > 0 {
+		mimeType := tx.ReqHeaders.Get("Content-Type")
+		if mimeType == "" {
+			mimeType = "application/octet-stream"
+		}
+		req.PostData = &HARPostData{
+			MimeType: mimeType,
+			Text:     string(tx.ReqBody),
+		}
+	}
+
+	return req
+}
+
+func buildHARResponse(tx Transaction) HARResponse {
+	headers := make([]HARNameValue, 0, len(tx.RespHeaders))
+	for k, vals := range tx.RespHeaders {
+		for _, v := range vals {
+			headers = append(headers, HARNameValue{Name: k, Value: v})
+		}
+	}
+
+	httpVersion := tx.Proto
+	if httpVersion == "" {
+		httpVersion = "HTTP/1.1"
+	}
+
+	mimeType := tx.RespHeaders.Get("Content-Type")
+	if mimeType == "" {
+		mimeType = "application/octet-stream"
+	}
+
+	redirectURL := tx.RespHeaders.Get("Location")
+
+	return HARResponse{
+		Status:      tx.StatusCode,
+		StatusText:  statusText(tx.StatusCode),
+		HTTPVersion: httpVersion,
+		Headers:     headers,
+		Content: HARContent{
+			Size:     len(tx.RespBody),
+			MimeType: mimeType,
+			Text:     string(tx.RespBody),
+		},
+		RedirectURL: redirectURL,
+		HeadersSize: -1,
+		BodySize:    len(tx.RespBody),
+	}
+}
+
+func extractQueryString(rawURL string) []HARNameValue {
+	idx := strings.Index(rawURL, "?")
+	if idx < 0 {
+		return []HARNameValue{}
+	}
+	parsed, err := url.ParseQuery(rawURL[idx+1:])
+	if err != nil || len(parsed) == 0 {
+		return []HARNameValue{}
+	}
+	pairs := make([]HARNameValue, 0, len(parsed))
+	for k, vals := range parsed {
+		for _, v := range vals {
+			pairs = append(pairs, HARNameValue{Name: k, Value: v})
+		}
+	}
+	return pairs
+}
+
+func statusText(code int) string {
+	if t := http.StatusText(code); t != "" {
+		return t
+	}
+	return fmt.Sprintf("%d", code)
+}