// SPDX-License-Identifier: GPL-3.0-or-later

package plan

import (
	"testing"
	"time"
)

// FuzzExpand: expanding any template against any file name never panics,
// gives the same answer twice, and never succeeds with a {N} beyond the
// capture groups there are - MaxIndex and Expand read placeholders alike.
func FuzzExpand(f *testing.F) {
	for _, s := range []string{"{name}", "{stem}{ext}", "{mtime:%Y/%m}", "{1}_{2}", "{{literal}}", "{", "}", "{now:%", "{0}", "{9}", "{99999999999999999999}"} {
		f.Add(s, "a.b.pdf")
	}
	f.Fuzz(func(t *testing.T, tmpl, name string) {
		facts := Facts{
			Name:     name,
			Captures: []string{name, "x", ".."},
			ModTime:  time.Date(2026, 8, 15, 12, 0, 0, 0, time.UTC),
			Now:      time.Date(2026, 9, 14, 0, 0, 0, 0, time.UTC),
		}
		a, errA := Expand(tmpl, facts)
		b, errB := Expand(tmpl, facts)
		if a != b || (errA == nil) != (errB == nil) {
			t.Fatalf("Expand(%q) differs between two calls: %q/%v, %q/%v", tmpl, a, errA, b, errB)
		}
		if n, err := MaxIndex(tmpl); err == nil && n > 2 && errA == nil {
			t.Fatalf("Expand(%q) = %q, though it uses {%d} and only 2 groups exist", tmpl, a, n)
		}
	})
}