package hostfiles

import (
	"fmt"
	"strings"
)

// EnvItem is the host's env file (<host>.env) among the manifest's
// platform items. A release flush stages it beside the wake state so a
// relocation's prepared manifest carries it (region HA spec 1 §5.6:
// always continuous, whatever the setting); the local install restores it
// with ReadPlatform.
const EnvItem = "host.env"

// StagePlatformDelete records that a platform item is gone: the next
// Commit publishes a revision without it, at a new sequence, so a reader
// of that revision gets os.ErrNotExist from ReadPlatform instead of the
// last bytes it published. Deleting an item the manifest does not hold
// is a no-op, like StageDelete.
func (p *Publisher) StagePlatformDelete(name string) error {
	if name == "" || strings.ContainsAny(name, "/\x00") {
		return fmt.Errorf("hostfiles: platform item %q is not a plain name", name)
	}
	p.mu.Lock()
	defer p.mu.Unlock()
	if _, ok := p.man.Platform[name]; !ok {
		return nil
	}
	p.next++
	delete(p.man.Platform, name)
	p.dirty = true
	return nil
}