use itertools::Itertools;use jj_lib::commit::Commit;use jj_lib::matchers::EverythingMatcher;use jj_lib::merged_tree::MergedTree;use jj_lib::repo::ReadonlyRepo;use jj_lib::settings::UserSettings; use crate::cli_util::{edit_temp_file, CommandError, WorkspaceCommandHelper};use crate::diff_util::{self, DiffFormat};use crate::formatter::PlainTextFormatter;use crate::text_util;use crate::ui::Ui; pub fn edit_description(    repo: &ReadonlyRepo,    description: &str,    settings: &UserSettings,) -> Result<String, CommandError> {    let description = format!(        r#"{}JJ: Lines starting with "JJ: " (like this one) will be removed."#,        description    );     let description = edit_temp_file(        "description",        ".jjdescription",        repo.repo_path(),        &description,        settings,    )?;     // Normalize line ending, remove leading and trailing blank lines.    let description = description        .lines()        .filter(|line| !line.starts_with("JJ: "))        .join("\n");    Ok(text_util::complete_newline(description.trim_matches('\n')))} pub fn combine_messages(    repo: &ReadonlyRepo,    source: &Commit,    destination: &Commit,    settings: &UserSettings,    abandon_source: bool,) -> Result<String, CommandError> {    let description = if abandon_source {        if source.description().is_empty() {            destination.description().to_string()        } else if destination.description().is_empty() {            source.description().to_string()        } else {            let combined = "JJ: Enter a description for the combined commit.\n".to_string()                + "JJ: Description from the destination commit:\n"                + destination.description()                + "\nJJ: Description from the source commit:\n"                + source.description();            edit_description(repo, &combined, settings)?        }    } else {        destination.description().to_string()    };    Ok(description)} pub fn description_template_for_describe(    ui: &Ui,    settings: &UserSettings,    workspace_command: &WorkspaceCommandHelper,    commit: &Commit,) -> Result<String, CommandError> {    let mut diff_summary_bytes = Vec::new();    diff_util::show_patch(        ui,        &mut PlainTextFormatter::new(&mut diff_summary_bytes),        workspace_command,        commit,        &EverythingMatcher,        &[DiffFormat::Summary],    )?;    let description = if commit.description().is_empty() {        settings.default_description()    } else {        commit.description().to_owned()    };    if diff_summary_bytes.is_empty() {        Ok(description)    } else {        Ok(description + "\n" + &diff_summary_to_description(&diff_summary_bytes))    }} pub fn description_template_for_commit(    ui: &Ui,    settings: &UserSettings,    workspace_command: &WorkspaceCommandHelper,    intro: &str,    overall_commit_description: &str,    from_tree: &MergedTree,    to_tree: &MergedTree,) -> Result<String, CommandError> {    let mut diff_summary_bytes = Vec::new();    diff_util::show_diff(        ui,        &mut PlainTextFormatter::new(&mut diff_summary_bytes),        workspace_command,        from_tree,        to_tree,        &EverythingMatcher,        &[DiffFormat::Summary],    )?;    let mut template_chunks = Vec::new();    if !intro.is_empty() {        template_chunks.push(format!("JJ: {intro}\n"));    }    template_chunks.push(if overall_commit_description.is_empty() {        settings.default_description()    } else {        overall_commit_description.to_owned()    });    if !diff_summary_bytes.is_empty() {        template_chunks.push("\n".to_owned());        template_chunks.push(diff_summary_to_description(&diff_summary_bytes));    }    Ok(template_chunks.concat())} pub fn diff_summary_to_description(bytes: &[u8]) -> String {    let text = std::str::from_utf8(bytes).expect(        "Summary diffs and repo paths must always be valid UTF8.",        // Double-check this assumption for diffs that include file content.    );    "JJ: This commit contains the following changes:\n".to_owned()        + &textwrap::indent(text, "JJ:     ")}