feat(cli): --format json|ical calendar emitters with range + validation

1 files changed, 38 insertions, 4 deletions

diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index 364e080..f65774f 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -61,6 +61,11 @@ Flags:
       --pdf              export the readings as PDF (to --out or stdout)
       --out FILE         write --md/--pdf/--calendar output to FILE
       --calendar YYYY-MM export the month as a printable A4 PDF calendar
+      --format WHICH     json|ical: emit the computed calendar and exit
+      --from DATE        range start YYYY-MM-DD (with --to; needs --format)
+      --to DATE          range end YYYY-MM-DD (with --from; needs --format)
+      --year YYYY        emit the whole year YYYY (needs --format)
+      --form WHICH       override calendar form old|new (needs --format)
   -v, --version          print the version and exit
   -h, --help             this help
 
@@ -129,6 +134,7 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	var calNew, calCheck string
 	var corpusCheck string
 	var jsonOut bool
+	var format, fromFlag, toFlag, yearFlag, formFlag string
 
 	fs := flag.NewFlagSet("lectio", flag.ContinueOnError)
 	fs.SetOutput(stderr)
@@ -179,6 +185,11 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	fs.StringVar(&calCheck, "cal-check", "", "validate the calendar-layer file NAME.ini and exit")
 	fs.StringVar(&corpusCheck, "corpus-check", "", "validate a bible corpus (code or path to <code>.tsv) and exit")
 	fs.BoolVar(&jsonOut, "json", false, "with --corpus-check, print the report as JSON")
+	fs.StringVar(&format, "format", "", "json|ical: emit the computed calendar and exit")
+	fs.StringVar(&fromFlag, "from", "", "range start YYYY-MM-DD (with --to; needs --format)")
+	fs.StringVar(&toFlag, "to", "", "range end YYYY-MM-DD (with --from; needs --format)")
+	fs.StringVar(&yearFlag, "year", "", "emit the whole year YYYY (needs --format)")
+	fs.StringVar(&formFlag, "form", "", "override calendar form: old|new (needs --format)")
 
 	if err := fs.Parse(rest); err != nil {
 		return 2
@@ -235,6 +246,10 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 		cfg.UILanguage = config.NormalizeUILanguage(uiLang)
 	}
 
+	if format != "" || fromFlag != "" || toFlag != "" || yearFlag != "" || formFlag != "" {
+		return runFeed(cfg, format, date, fromFlag, toFlag, yearFlag, formFlag, stdout, stderr)
+	}
+
 	if liturgy {
 		return runLiturgy(cfg, date, stdout, stderr)
 	}
@@ -553,15 +568,34 @@ func wantsVersion(args []string) bool {
 	return false
 }
 
+// rangeDateFlags are the flags whose own value is itself a YYYY-MM-DD date
+// (--from/--to, in either one- or two-dash spelling -- Go's flag package
+// treats them the same). extractDate must not mistake such a value for the
+// positional DATE token.
+var rangeDateFlags = map[string]bool{"--from": true, "-from": true, "--to": true, "-to": true}
+
 // extractDate pulls the single positional DATE token (YYYY-MM-DD, matching
 // dateRe) out of args, wherever it appears, and returns it along with the
-// remaining tokens for flag.FlagSet to parse. No flag's own value can match
-// dateRe's shape (width is an int, versions/lists/lang/lectionary are short
-// codes), so scanning raw tokens this way is unambiguous. Defaults to
-// today() when no date token is present; errors if more than one is found.
+// remaining tokens for flag.FlagSet to parse. No other flag's own value can
+// match dateRe's shape (width is an int, versions/lists/lang/lectionary are
+// short codes) except --from/--to's, which are skipped explicitly via
+// rangeDateFlags, so scanning raw tokens this way is unambiguous. Defaults
+// to today() when no date token is present; errors if more than one is
+// found.
 func extractDate(args []string) (date string, rest []string, err error) {
 	found := false
+	skipNext := false
 	for _, a := range args {
+		if skipNext {
+			rest = append(rest, a)
+			skipNext = false
+			continue
+		}
+		if rangeDateFlags[a] {
+			rest = append(rest, a)
+			skipNext = true
+			continue
+		}
 		if dateRe.MatchString(a) {
 			if found {
 				return "", nil, fmt.Errorf("multiple dates given (%q and %q)", date, a)