From 12dcbb460c933f79d2f21bc4eb4c0f0439ab5bad Mon Sep 17 00:00:00 2001
From: Justin Lin <wancat@wancat.cc>
Date: Fri, 25 Jul 2025 02:01:57 +1000
Subject: [PATCH] feat: add parseParams

---
 main.go   | 11 +++++++----
 params.go | 23 +++++++++++++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 params.go

diff --git a/main.go b/main.go
index babc45f..c72ee05 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 )
 
 var tmpl = `
@@ -27,8 +28,10 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
-	fmt.Printf("'%s'", templateMeta)
-	render(body, map[string]string{
-		"from": "2025-07-15",
-	})
+	fmt.Println(templateMeta)
+	ctx, err := parseParams(templateMeta)
+	if err != nil {
+		log.Fatal(err)
+	}
+	render(body, ctx)
 }
diff --git a/params.go b/params.go
new file mode 100644
index 0000000..65e4a36
--- /dev/null
+++ b/params.go
@@ -0,0 +1,23 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+)
+
+func parseParams(meta TemplateMeta) (ctx TemplateContext, err error) {
+	result := make(map[string]*string)
+	for key, spec := range meta.Params {
+		result[key] = flag.String(key, spec.Default, key)
+	}
+	flag.Parse()
+	ctx = make(TemplateContext)
+	for key, spec := range meta.Params {
+		if spec.Required && *result[key] == "" {
+			err = fmt.Errorf("parameter '%s' required but not provided", key)
+			return
+		}
+		ctx[key] = *result[key]
+	}
+	return
+}