package main

import (
	"fmt"
	"os"

	"github.com/nilsmagnus/grib/griblib"
)

func main() {
	f, err := os.Open("C:/tmp/grib/gfs.t18z.pgrb2.0p25.f000")
	if err != nil {
		fmt.Printf("Error opening file: %v\n", err)
		return
	}
	defer f.Close()

	messages, err := griblib.ReadMessages(f)
	if err != nil {
		fmt.Printf("Error reading GRIB: %v\n", err)
		return
	}

	fmt.Printf("Found %d messages\n\n", len(messages))

	for i, m := range messages {
		product := m.Section4.ProductDefinitionTemplate
		if product.ParameterCategory != 2 || product.ParameterNumber != 2 {
			continue // only u-wind
		}
		fmt.Printf("UGRD Msg %d: SurfType=%d SurfValue=%d SurfScale=%d DataLen=%d\n",
			i,
			product.FirstSurface.Type,
			product.FirstSurface.Value,
			product.FirstSurface.Scale,
			len(m.Data()))
	}
}