package gitcmd

import (
	"fmt"
	"strings"
)

func (r *Repository) refSHA(ref string) (string, error) {
	out, _, err := NewCommand("rev-parse", "--verify", "--quiet").
		AddDynamicArguments(ref).
		WithDir(r.Path).RunStdString(r.ctx)
	if err != nil {
		return "", nil
	}
	return strings.TrimSpace(out), nil
}

func (r *Repository) hashObject(content, dir string) (string, error) {
	out, _, err := NewCommand("hash-object", "-w", "--stdin").
		WithStdin(strings.NewReader(content)).
		WithDir(dir).RunStdString(r.ctx)
	if err != nil {
		return "", fmt.Errorf("hash-object: %w", err)
	}
	return strings.TrimSpace(out), nil
}

func (r *Repository) commitTree(tree, message, authorName, authorEmail, dir string, parents ...string) (string, error) {
	cmd := NewCommand("commit-tree").AddDynamicArguments(tree).WithDir(dir)
	for _, p := range parents {
		cmd.Add("-p").AddDynamicArguments(p)
	}
	cmd.WithEnv(
		"GIT_AUTHOR_NAME="+authorName,
		"GIT_AUTHOR_EMAIL="+authorEmail,
		"GIT_COMMITTER_NAME="+authorName,
		"GIT_COMMITTER_EMAIL="+authorEmail,
	).WithStdin(strings.NewReader(message))
	out, _, err := cmd.RunStdString(r.ctx)
	if err != nil {
		return "", fmt.Errorf("commit-tree: %w", err)
	}
	return strings.TrimSpace(out), nil
}

func (r *Repository) updateRef(ref, newSHA, expectedSHA string) error {
	cmd := NewCommand("update-ref").AddDynamicArguments(ref, newSHA).WithDir(r.Path)
	if expectedSHA != "" {
		cmd.AddDynamicArguments(expectedSHA)
	}
	if _, _, err := cmd.RunStdString(r.ctx); err != nil {
		return fmt.Errorf("update-ref %s: %w", ref, err)
	}
	return nil
}

func (r *Repository) isAncestor(ancestor, descendant string) bool {
	err := NewCommand("merge-base", "--is-ancestor").
		AddDynamicArguments(ancestor, descendant).
		WithDir(r.Path).Run(r.ctx)
	return err == nil
}

func (r *Repository) removePathFromIndex(dir, path string, env ...string) error {
	entry := "0 " + strings.Repeat("0", 40) + "\t" + path + "\x00"
	cmd := NewCommand("update-index", "--remove", "-z", "--index-info").
		WithStdin(strings.NewReader(entry)).
		WithDir(dir)
	if len(env) > 0 {
		cmd.WithEnv(env...)
	}
	if _, _, err := cmd.RunStdString(r.ctx); err != nil {
		return fmt.Errorf("update-index --index-info (remove): %w", err)
	}
	return nil
}