package storage

import (
	"context"
	"errors"
	"io"
)

type EntryType string

const (
	EntryTypeFile      EntryType = "file"
	EntryTypeDirectory EntryType = "directory"
	EntryTypeSymlink   EntryType = "symlink"
	EntryTypeOther     EntryType = "other"
)

type Entry struct {
	Path string
	Type EntryType
	Size int64
}

type Backend interface {
	ReadFile(ctx context.Context, path string) ([]byte, error)
	OpenReader(ctx context.Context, path string) (io.ReadCloser, error)
	WriteFile(ctx context.Context, path string, data []byte, opts WriteOptions) (Entry, error)
	WriteFrom(ctx context.Context, path string, r io.Reader, opts WriteOptions) (Entry, error)
	Stat(ctx context.Context, path string) (Entry, error)
	Walk(ctx context.Context, prefix string, opts WalkOptions, fn WalkFunc) error
	HasAny(ctx context.Context, prefix string) (bool, error)
	DeleteManagedOutputs(ctx context.Context, bundlePath string, managedOutputPaths []string, opts DeleteOptions) error
	DeleteManagedBundle(ctx context.Context, bundlePath string, managedOutputPaths []string, opts DeleteOptions) error
	DeletePrefix(ctx context.Context, prefix string, opts DeleteOptions) error
}

type WalkOptions struct {
	Recursive bool
	Limit     int
}

type WalkFunc func(Entry) error

var ErrStopWalk = errors.New("stop walk")

type WriteOptions struct {
	ContentType  string
	Overwrite    bool
	PreferAtomic bool
	Size         int64
	SizeKnown    bool
}

type DeleteOptions struct {
	IgnoreMissing  bool
	PruneEmptyDirs bool
}

func List(ctx context.Context, backend Backend, prefix string, opts WalkOptions) ([]Entry, error) {
	var entries []Entry
	err := backend.Walk(ctx, prefix, opts, func(entry Entry) error {
		entries = append(entries, entry)
		return nil
	})
	if err != nil {
		return nil, err
	}
	SortEntries(entries)
	return entries, nil
}