package watcher

import (
	"errors"
	"fmt"
	"io/fs"
	"path/filepath"
	"strings"

	"github.com/mathiasbq/hyperguild/ingestion/internal/brainfs"
)

// Kept out of watcher.go on purpose: that file is covered by the raw-reader
// guard (internal/extract/callsites_test.go), which forbids any .Open selector
// there. This function reads nothing from raw/; it creates a file under the
// brain root, which refuses symlinked directories and never follows a final
// symlink.

// createParked writes data to raw/needs-review/<filename> through the brain
// root, never replacing a parked note: on a name clash it tries -2, -3, ...
// A needs-review that is a symlink, or any non-directory, is refused.
func createParked(brainDir, filename string, data []byte) error {
	bfs, err := brainfs.Open(brainDir)
	if err != nil {
		return err
	}
	defer func() { _ = bfs.Close() }()
	ext := filepath.Ext(filename)
	stem := strings.TrimSuffix(filename, ext)
	for n := 1; n < 10000; n++ {
		name := filename
		if n > 1 {
			name = fmt.Sprintf("%s-%d%s", stem, n, ext)
		}
		err := bfs.CreateRegular("raw/needs-review/"+name, data)
		if err == nil {
			return nil
		}
		if !errors.Is(err, fs.ErrExist) {
			return err
		}
	}
	return fmt.Errorf("no free name for %q in raw/needs-review", filename)
}