package git

import (
	"fmt"
	"os"
	"path/filepath"
	"slices"
	"strings"
)

const NotesRef = "refs/notes/byre"

const notesFetch = NotesRef + "*:" + NotesRef + "*"

func ConfigureNotesFetch(repo string) error {
	key := "remote." + Remote + ".fetch"
	out, stderr, code, err := runCode(repo, nil, "config", "--get-all", key)
	if err != nil {
		return err
	}
	if code != 0 && code != 1 {
		return fmt.Errorf("git config --get-all %s: exit status %d: %s", key, code, stderr)
	}
	if slices.Contains(strings.Split(out, "\n"), notesFetch) {
		return nil
	}
	_, err = run(repo, "config", "--add", key, notesFetch)
	return err
}

func NoteCommit(repo, commit, note string, env []string) (string, error) {
	blob, err := runInput(repo, nil, note, "hash-object", "-w", "--stdin")
	if err != nil {
		return "", err
	}

	parent, stderr, code, err := runCode(repo, nil, "rev-parse", "--verify", "--quiet", NotesRef)
	if err != nil {
		return "", err
	}
	if code != 0 && code != 1 {
		return "", fmt.Errorf("git rev-parse %s: exit status %d: %s", NotesRef, code, stderr)
	}

	dir, err := os.MkdirTemp("", "byre-notes-*")
	if err != nil {
		return "", err
	}
	defer os.RemoveAll(dir)
	index := []string{"GIT_INDEX_FILE=" + filepath.Join(dir, "index")}

	commitArgs := []string{"commit-tree", "-m", "Notes added by byre"}
	if code == 0 {
		_, err = runEnv(repo, index, "read-tree", parent)
		if err != nil {
			return "", err
		}
		commitArgs = append(commitArgs, "-p", parent)
	}
	_, err = runEnv(repo, index, "update-index", "--add", "--cacheinfo", "100644,"+blob+","+commit)
	if err != nil {
		return "", err
	}
	tree, err := runEnv(repo, index, "write-tree")
	if err != nil {
		return "", err
	}

	return runEnv(repo, env, append(commitArgs, tree)...)
}

func SetNotes(repo, notes string) error {
	_, err := run(repo, "update-ref", NotesRef, notes)
	return err
}