Structured search filters: status:, source:

Closes another top item from the Burp/ZAP/Caido gap research: status-
code and MIME/type filtering alongside free text is used constantly in
practice (Caido's HTTPQL, Burp's proxy history filter). Scoped to
status and source for now - method: already works today via FTS5's own
method column (a plain text match on "POST" is effectively exact for a
short alphanumeric token), so it didn't need special handling.

status_code isn't a text column FTS5 can index, and doesn't benefit
from full-text matching anyway (it's a numeric comparison, not a word
search), so extractStructured pulls status:/source: tokens out of the
query before it reaches FTS5 and turns them into real parameterized SQL
predicates against history's typed columns: status:404 (exact),
status:>=400 / status:!=200 (comparison operators), status:4xx (also
2xx/3xx/5xx - the shorthand people actually reach for: "show me the
errors"), source:repeater/intruder/proxy. Whatever text remains after
extraction still goes through the existing FTS5 path, so "admin
status:200" correctly ANDs a real full-text match with a real status
predicate in one query. When nothing remains (pure "status:4xx"),
Search skips the FTS5 join entirely and queries history directly.

store_test.go covers the parsing (exact/operator/range/source,
combined with free text, and two "looks like it but isn't" cases -
status:banana and the malformed 4-digit status:4004 - to confirm they
fall through as literal search text instead of being misparsed).

Verified live against real varied traffic (status 200/404/500 requests
plus a POST with an "admin" body) - status:4xx matched only the 404;
status:>=400 matched both 404 and 500; "admin status:200" correctly
matched only the POST and excluded the other unrelated 200; source:proxy
matched everything captured so far. All against the actual SQL execution
path, not just the pure parsing function.

3 files changed, 197 insertions, 17 deletions

diff --git a/cmd/mitmux/main.go b/cmd/mitmux/main.go
index 360b68d..aa659cd 100644
--- a/cmd/mitmux/main.go
+++ b/cmd/mitmux/main.go
@@ -194,7 +194,7 @@ func newModel(client *ipc.Client, subCh <-chan store.Summary, socketPath string)
 
 	si := textinput.New()
 	si.Prompt = "/"
-	si.Placeholder = "search - plain text, or host:example.com / AND / OR / NOT"
+	si.Placeholder = "search - plain text, host:x, status:404 / status:4xx / status:>=400, source:repeater"
 
 	rulesCols := []table.Column{
 		{Title: "On", Width: 3},
@@ -1022,7 +1022,8 @@ func (m *model) helpView() string {
 		"enter        view request/response detail",
 		"r            open in Repeater",
 		"i            open in Intruder",
-		"/            search (plain text, host:value, AND/OR/NOT)",
+		"/            search: plain text, host:value, AND/OR/NOT,",
+		"             status:404 / status:4xx / status:>=400, source:repeater",
 		"esc          clear active search filter",
 		"m            match-and-replace rules",
 		"q            quit",
diff --git a/internal/store/store.go b/internal/store/store.go
index eb017db..d04887b 100644
--- a/internal/store/store.go
+++ b/internal/store/store.go
@@ -8,6 +8,8 @@ package store
 import (
 	"database/sql"
 	"fmt"
+	"regexp"
+	"strconv"
 	"strings"
 	"time"
 
@@ -238,6 +240,14 @@ func (s *Store) List(limit int, beforeID int64) ([]Summary, error) {
 // plain terms need help: FTS5's query grammar treats characters like
 // '.', '-', '/', '@' as syntax, so an unquoted domain name is a parse
 // error, not a search term, unless quoted first.
+//
+// Two more filters are recognized ahead of the FTS5 layer, since neither
+// fits it - status_code isn't a text column FTS5 can index, and doesn't
+// benefit from full-text matching (numeric comparison, not word search),
+// and source is a plain low-cardinality column better matched exactly:
+// status:404, status:>=400, status:!=200, status:4xx (also 2xx/3xx/5xx),
+// and source:proxy / source:repeater / source:intruder. These combine
+// with AND against any remaining free-text/FTS5 portion of the query.
 func (s *Store) Search(query string, limit int, beforeID int64) ([]Summary, error) {
 	if limit <= 0 || limit > 1000 {
 		limit = 200
@@ -245,21 +255,47 @@ func (s *Store) Search(query string, limit int, beforeID int64) ([]Summary, erro
 	if beforeID <= 0 {
 		beforeID = 1<<63 - 1
 	}
-	query = prepareFTSQuery(query)
-	// history_fts must appear unaliased for MATCH/bm25 to resolve against
-	// it - this SQLite build doesn't support querying FTS5 through a
-	// table alias (confirmed directly against the sqlite3 CLI: aliasing
-	// it raises "no such column").
-	rows, err := s.db.Query(
-		`SELECT h.id, h.started_at, h.duration_ms, h.method, h.scheme, h.host, h.path,
-		        COALESCE(h.status_code, 0), length(h.request_raw), COALESCE(length(h.response_raw), 0),
-		        h.error, h.source
-		 FROM history_fts
-		 JOIN history h ON h.id = history_fts.rowid
-		 WHERE history_fts MATCH ? AND h.id < ?
-		 ORDER BY bm25(history_fts), h.id DESC LIMIT ?`,
-		query, beforeID, limit,
-	)
+
+	remaining, pred := extractStructured(query)
+	where := []string{"h.id < ?"}
+	args := []any{beforeID}
+	if pred.statusSQL != "" {
+		where = append(where, pred.statusSQL)
+		args = append(args, pred.statusArgs...)
+	}
+	if pred.source != "" {
+		where = append(where, "h.source = ?")
+		args = append(args, pred.source)
+	}
+
+	var q string
+	if remaining == "" {
+		// No free-text component left - query history directly, no
+		// FTS5 join or ranking needed.
+		q = `SELECT h.id, h.started_at, h.duration_ms, h.method, h.scheme, h.host, h.path,
+		            COALESCE(h.status_code, 0), length(h.request_raw), COALESCE(length(h.response_raw), 0),
+		            h.error, h.source
+		     FROM history h
+		     WHERE ` + strings.Join(where, " AND ") + `
+		     ORDER BY h.id DESC LIMIT ?`
+	} else {
+		// history_fts must appear unaliased for MATCH/bm25 to resolve
+		// against it - this SQLite build doesn't support querying FTS5
+		// through a table alias (confirmed directly against the sqlite3
+		// CLI: aliasing it raises "no such column").
+		where = append([]string{"history_fts MATCH ?"}, where...)
+		args = append([]any{prepareFTSQuery(remaining)}, args...)
+		q = `SELECT h.id, h.started_at, h.duration_ms, h.method, h.scheme, h.host, h.path,
+		            COALESCE(h.status_code, 0), length(h.request_raw), COALESCE(length(h.response_raw), 0),
+		            h.error, h.source
+		     FROM history_fts
+		     JOIN history h ON h.id = history_fts.rowid
+		     WHERE ` + strings.Join(where, " AND ") + `
+		     ORDER BY bm25(history_fts), h.id DESC LIMIT ?`
+	}
+	args = append(args, limit)
+
+	rows, err := s.db.Query(q, args...)
 	if err != nil {
 		return nil, fmt.Errorf("search history: %w", err)
 	}
@@ -280,6 +316,54 @@ func (s *Store) Search(query string, limit int, beforeID int64) ([]Summary, erro
 	return out, rows.Err()
 }
 
+// structuredPredicate holds filters extracted from a search query that
+// get applied as real SQL predicates instead of going through FTS5.
+type structuredPredicate struct {
+	statusSQL  string
+	statusArgs []any
+	source     string
+}
+
+var (
+	statusExactRe = regexp.MustCompile(`^(>=|<=|!=|>|<|=)?(\d{3})$`)
+	statusRangeRe = regexp.MustCompile(`^([2-5])xx$`)
+)
+
+// extractStructured pulls status:/source: tokens out of query, returning
+// what's left (for the FTS5 layer, if anything) and the predicates found.
+func extractStructured(query string) (remaining string, pred structuredPredicate) {
+	fields := strings.Fields(query)
+	kept := fields[:0:0]
+	for _, f := range fields {
+		lower := strings.ToLower(f)
+		switch {
+		case strings.HasPrefix(lower, "status:"):
+			val := strings.ToLower(strings.TrimPrefix(f, "status:"))
+			if m := statusRangeRe.FindStringSubmatch(val); m != nil {
+				lo, _ := strconv.Atoi(m[1] + "00")
+				pred.statusSQL = "status_code >= ? AND status_code < ?"
+				pred.statusArgs = []any{lo, lo + 100}
+				continue
+			}
+			if m := statusExactRe.FindStringSubmatch(val); m != nil {
+				op := m[1]
+				if op == "" {
+					op = "="
+				}
+				n, _ := strconv.Atoi(m[2])
+				pred.statusSQL = "status_code " + op + " ?"
+				pred.statusArgs = []any{n}
+				continue
+			}
+		case strings.HasPrefix(lower, "source:"):
+			pred.source = strings.ToLower(strings.TrimPrefix(f, "source:"))
+			continue
+		}
+		kept = append(kept, f)
+	}
+	return strings.Join(kept, " "), pred
+}
+
 // Get returns the full entry (including raw bytes) for id.
 func (s *Store) Get(id int64) (*Entry, error) {
 	row := s.db.QueryRow(
diff --git a/internal/store/store_test.go b/internal/store/store_test.go
new file mode 100644
index 0000000..7999ac3
--- /dev/null
+++ b/internal/store/store_test.go
@@ -0,0 +1,95 @@
+package store
+
+import "testing"
+
+func TestExtractStructured(t *testing.T) {
+	tests := []struct {
+		name       string
+		query      string
+		remaining  string
+		statusSQL  string
+		statusArgs []any
+		source     string
+	}{
+		{
+			name:      "plain text only",
+			query:     "admin login",
+			remaining: "admin login",
+		},
+		{
+			name:       "exact status",
+			query:      "status:404",
+			remaining:  "",
+			statusSQL:  "status_code = ?",
+			statusArgs: []any{404},
+		},
+		{
+			name:       "status with operator",
+			query:      "status:>=400",
+			remaining:  "",
+			statusSQL:  "status_code >= ?",
+			statusArgs: []any{400},
+		},
+		{
+			name:       "status not-equal",
+			query:      "status:!=200",
+			remaining:  "",
+			statusSQL:  "status_code != ?",
+			statusArgs: []any{200},
+		},
+		{
+			name:       "status range shorthand",
+			query:      "status:4xx",
+			remaining:  "",
+			statusSQL:  "status_code >= ? AND status_code < ?",
+			statusArgs: []any{400, 500},
+		},
+		{
+			name:      "source filter",
+			query:     "source:repeater",
+			remaining: "",
+			source:    "repeater",
+		},
+		{
+			name:       "combined with free text",
+			query:      "admin status:>=400 source:proxy",
+			remaining:  "admin",
+			statusSQL:  "status_code >= ?",
+			statusArgs: []any{400},
+			source:     "proxy",
+		},
+		{
+			name:      "not a real status token falls through as text",
+			query:     "status:banana",
+			remaining: "status:banana",
+		},
+		{
+			name:      "malformed 4-digit status falls through as text",
+			query:     "status:4004",
+			remaining: "status:4004",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			remaining, pred := extractStructured(tt.query)
+			if remaining != tt.remaining {
+				t.Errorf("remaining = %q, want %q", remaining, tt.remaining)
+			}
+			if pred.statusSQL != tt.statusSQL {
+				t.Errorf("statusSQL = %q, want %q", pred.statusSQL, tt.statusSQL)
+			}
+			if len(pred.statusArgs) != len(tt.statusArgs) {
+				t.Fatalf("statusArgs = %v, want %v", pred.statusArgs, tt.statusArgs)
+			}
+			for i := range pred.statusArgs {
+				if pred.statusArgs[i] != tt.statusArgs[i] {
+					t.Errorf("statusArgs[%d] = %v, want %v", i, pred.statusArgs[i], tt.statusArgs[i])
+				}
+			}
+			if pred.source != tt.source {
+				t.Errorf("source = %q, want %q", pred.source, tt.source)
+			}
+		})
+	}
+}