// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

//go:build !gogit

package git

import (
	"context"
	"io"

	"gitea.dev/modules/git/gitcmd"
)

// Tree represents a flat directory listing.
type Tree struct {
	TreeCommon

	entries       Entries
	entriesParsed bool
}

// ListEntries returns all entries of current tree.
func (t *Tree) ListEntries(ctx context.Context, gitRepo *Repository) (Entries, error) {
	if t.entriesParsed {
		return t.entries, nil
	}

	batch, cancel, err := gitRepo.CatFileBatch(ctx)
	if err != nil {
		return nil, err
	}
	defer cancel()

	info, rd, err := batch.QueryContent(t.ID.String())
	if err != nil {
		return nil, err
	}

	if info.Type == "commit" {
		treeID, err := ReadTreeID(rd, info.Size)
		if err != nil && err != io.EOF {
			return nil, err
		}
		info, rd, err = batch.QueryContent(treeID)
		if err != nil {
			return nil, err
		}
	}
	if info.Type == "tree" {
		t.entries, err = catBatchParseTreeEntries(t.ID.Type(), t, rd, info.Size)
		if err != nil {
			return nil, err
		}
		t.entriesParsed = true
		return t.entries, nil
	}

	// Not a tree just use ls-tree instead
	if err := DiscardFull(rd, info.Size+1); err != nil {
		return nil, err
	}

	stdout, _, runErr := gitcmd.NewCommand("ls-tree", "-l").AddDynamicArguments(t.ID.String()).WithDir(gitRepo.Path).RunStdBytes(ctx)
	if runErr != nil {
		if gitcmd.IsStderr(runErr, gitcmd.StderrNotValidObjectName) || gitcmd.IsStderr(runErr, gitcmd.StderrNotTreeObject) {
			return nil, ErrNotExist{
				ID: t.ID.String(),
			}
		}
		return nil, runErr
	}

	t.entries, err = parseTreeEntries(stdout, t)
	if err == nil {
		t.entriesParsed = true
	}

	return t.entries, err
}

// listEntriesRecursive returns all entries of current tree recursively including all subtrees
// extraArgs could be "-l" to get the size, which is slower
func (t *Tree) listEntriesRecursive(ctx context.Context, gitRepo *Repository, extraArgs gitcmd.TrustedCmdArgs) (Entries, error) {
	stdout, _, runErr := gitcmd.NewCommand("ls-tree", "-t", "-r").
		AddArguments(extraArgs...).
		AddDynamicArguments(t.ID.String()).
		WithDir(gitRepo.Path).
		RunStdBytes(ctx)
	if runErr != nil {
		return nil, runErr
	}

	// FIXME: the "name" field is abused, here it is a full path
	// FIXME: this ptree is not right, fortunately it isn't really used
	return parseTreeEntries(stdout, t)
}

// ListEntriesRecursiveFast returns all entries of current tree recursively including all subtrees, no size
func (t *Tree) ListEntriesRecursiveFast(ctx context.Context, gitRepo *Repository) (Entries, error) {
	return t.listEntriesRecursive(ctx, gitRepo, nil)
}

// ListEntriesRecursiveWithSize returns all entries of current tree recursively including all subtrees, with size
func (t *Tree) ListEntriesRecursiveWithSize(ctx context.Context, gitRepo *Repository) (Entries, error) {
	return t.listEntriesRecursive(ctx, gitRepo, gitcmd.TrustedCmdArgs{"--long"})
}