package cmd

import (
	"fmt"

	"github.com/aptly-dev/aptly/deb"
	"github.com/smira/commander"

	"github.com/aptly-dev/aptly/database/goleveldb"
)

// aptly db recover
func aptlyDBRecover(cmd *commander.Command, args []string) error {
	var err error

	if len(args) != 0 {
		cmd.Usage()
		return commander.ErrCommandError
	}

	context.Progress().Printf("Recovering database...\n")
	if err = goleveldb.RecoverDB(context.DBPath()); err != nil {
		return err
	}

	context.Progress().Printf("Checking database integrity...\n")
	err = checkIntegrity()

	return err
}

func makeCmdDBRecover() *commander.Command {
	cmd := &commander.Command{
		Run:       aptlyDBRecover,
		UsageLine: "recover",
		Short:     "recover DB after crash",
		Long: `
Database recover does its' best to recover the database after a crash.
It is recommended to backup the DB before running recover.

Example:

  $ aptly db recover
`,
	}

	return cmd
}

func checkIntegrity() error {
	return context.NewCollectionFactory().LocalRepoCollection().ForEach(checkRepo)
}

func checkRepo(repo *deb.LocalRepo) error {
	collectionFactory := context.NewCollectionFactory()
	repos := collectionFactory.LocalRepoCollection()

	err := repos.LoadComplete(repo)
	if err != nil {
		return fmt.Errorf("load complete repo %q: %s", repo.Name, err)
	}

	dangling, err := deb.FindDanglingReferences(repo.RefList(), collectionFactory.PackageCollection())
	if err != nil {
		return fmt.Errorf("find dangling references: %w", err)
	}

	if len(dangling.Refs) > 0 {
		for _, ref := range dangling.Refs {
			context.Progress().Printf("Removing dangling database reference %q\n", ref)
		}

		repo.UpdateRefList(repo.RefList().Subtract(dangling))

		if err = repos.Update(repo); err != nil {
			return fmt.Errorf("update repo: %w", err)
		}
	}

	return nil
}