package gitcmd

import (
	"strconv"
	"strings"
)

type EntryType string

const (
	EntryBlob EntryType = "blob"
	EntryTree EntryType = "tree"
)

type TreeEntry struct {
	Name string    `json:"name"`
	Path string    `json:"path"`
	Type EntryType `json:"type"`
	Mode string    `json:"mode"`
	Size int64     `json:"size"`
	SHA  string    `json:"sha"`
}

type Tree struct {
	Ref     string      `json:"ref"`
	Path    string      `json:"path"`
	Entries []TreeEntry `json:"entries"`
}

func (r *Repository) GetTree(ref, path string) (*Tree, error) {

	if empty, err := r.IsEmpty(); err != nil {
		return nil, err
	} else if empty {
		return &Tree{Ref: ref, Path: path, Entries: []TreeEntry{}}, nil
	}

	treeRef := ref
	if path != "" {
		treeRef = ref + ":" + path
	}

	out, _, err := NewCommand("ls-tree", "-l").
		AddDynamicArguments(treeRef).
		WithDir(r.Path).
		RunStdString(r.ctx)
	if err != nil {
		return nil, err
	}

	entries := make([]TreeEntry, 0)
	for _, line := range strings.Split(strings.TrimSpace(out), "\n") {
		if line == "" {
			continue
		}

		tabIdx := strings.IndexByte(line, '\t')
		if tabIdx < 0 {
			continue
		}
		header := strings.Fields(line[:tabIdx])
		name := line[tabIdx+1:]
		if len(header) < 4 {
			continue
		}
		mode, objType, sha, sizeStr := header[0], header[1], header[2], header[3]

		var size int64
		if sizeStr != "-" {
			size, _ = strconv.ParseInt(sizeStr, 10, 64)
		}

		entryPath := name
		if path != "" {
			entryPath = path + "/" + name
		}

		entries = append(entries, TreeEntry{
			Name: name,
			Path: entryPath,
			Type: EntryType(objType),
			Mode: mode,
			Size: size,
			SHA:  sha,
		})
	}

	return &Tree{
		Ref:     ref,
		Path:    path,
		Entries: entries,
	}, nil
}