package testsupport

import (
	"bytes"
	"fmt"
)

// MinimalApk builds a valid-enough Alpine package in pure Go (no committed
// binary fixture, no abuild): two concatenated, independently gzipped tar
// streams -- a control stream carrying .PKGINFO and a data stream carrying a
// single payload file. It mirrors MinimalDeb/MinimalRPM and is parseable by the
// alpine provider (which derives arch/name/version and the Q1 pull checksum from
// the control stream).
func MinimalApk(name, version, arch string) []byte {
	pkginfo := fmt.Sprintf(
		"# generated by testsupport\n"+
			"pkgname = %s\n"+
			"pkgver = %s\n"+
			"arch = %s\n"+
			"pkgdesc = minimal test package\n"+
			"url = https://example.com/%s\n"+
			"license = MIT\n"+
			"origin = %s\n"+
			"maintainer = e2e <e2e@example.com>\n"+
			"builddate = 1700000000\n"+
			"size = 4\n"+
			"depend = so:libc.musl-x86_64.so.1\n"+
			"provides = cmd:%s=%s\n",
		name, version, arch, name, name, name, version)

	control := gzipBytes(tarSingle(".PKGINFO", []byte(pkginfo)))
	data := gzipBytes(tarSingle("usr/bin/"+name, []byte("body")))

	var buf bytes.Buffer
	buf.Write(control)
	buf.Write(data)
	return buf.Bytes()
}