hg-git-fast-import 1.5.0

use std::{path::Path, time::Instant};

use indicatif::{HumanDuration, ProgressBar, ProgressStyle};
use tracing::{debug, info};

use crate::error::ErrorKind;

use super::{config, env, MercurialRepo, RepositorySavedState, TargetRepository};

pub fn hg2git<P: AsRef<Path>>(
    repourl: P,
    verify: bool,
    git_active_branches: Option<usize>,
    ignore_unknown_requirements: bool,
    target: &mut dyn TargetRepository,
    env: &env::Environment,
    repository_config: &config::RepositoryConfig,
) -> Result<(), ErrorKind> {
    debug!("Config: {:?}", repository_config);
    debug!("Environment: {:?}", env);

    let repo = MercurialRepo::open_with_pull(
        repourl.as_ref(),
        repository_config,
        ignore_unknown_requirements,
        env,
    )?;

    if !repo.verify_heads(repository_config.allow_unnamed_heads)? {
        return Err(ErrorKind::VerifyFailure("Verify heads failed".into()));
    };

    let tip = repo.changelog_len()?;

    let to = if let Some(limit_high) = repository_config.limit_high {
        tip.min(limit_high)
    } else {
        tip
    };

    debug!("Checking saved state...");
    let mut brmap = repository_config.branches.clone().unwrap_or_default();
    let mut counter: usize = 0;
    let offset = repository_config.offset.unwrap_or(0);

    let mut errors = None;
    let from_tag = {
        let (output, saved_state, default_branch) =
            target.start_import(git_active_branches, repository_config.default_branch())?;

        let (from, from_tag) = if let Some(saved_state) = saved_state.as_ref() {
            match saved_state {
                RepositorySavedState::OffsetedRevision(rev, from_tag) => {
                    (rev - offset, from_tag - offset)
                }
            }
        } else {
            (0, 0)
        };

        info!("Exporting commits from {}", from);

        let show_progress_bar = !env.cron;

        let start = Instant::now();
        let progress_bar = ProgressBar::new((to - from) as u64);
        if show_progress_bar {
            progress_bar.set_style(ProgressStyle::default_bar().template(
                "{spinner:.green}[{elapsed_precise}] [{wide_bar:.cyan/blue}] {msg} ({eta})",
            )?);
        }
        for mut changeset in repo.range(from..to) {
            if show_progress_bar {
                progress_bar.inc(1);
                progress_bar.set_message(format!("{:6}/{}", changeset.revision.0, to));
            }

            match repo.export_commit(&mut changeset, counter, &mut brmap, output, &default_branch) {
                Ok(progress) => counter = progress,
                x => {
                    errors = Some((x, changeset.revision.0));
                    break;
                }
            }
        }

        if errors.is_none() {
            if show_progress_bar {
                progress_bar.finish_with_message(format!(
                    "Repository {} [{from};{to}). Elapsed: {}",
                    repourl.as_ref().to_str().unwrap(),
                    HumanDuration(start.elapsed())
                ));
            }

            counter = repo.export_tags(from_tag..to, counter, output)?;
        }

        from_tag
    };

    if let Some((error, at)) = errors {
        if at > 0 {
            let at = at as usize;
            eprintln!("Import failed at {}", at);
            info!("Saving last success state at {}...", at);
            target.save_state(RepositorySavedState::OffsetedRevision(
                at + offset,
                from_tag + offset,
            ))?;
        }
        error?;
    }

    info!("Issued {} commands", counter);
    info!("Saving state...");
    target.save_state(RepositorySavedState::OffsetedRevision(
        to + offset,
        to + offset,
    ))?;

    target.finish()?;

    if verify {
        target.verify(
            repourl.as_ref().to_str().unwrap(),
            repository_config.path_prefix.as_ref().map(|x| &x[..]),
        )?;
    }

    Ok(())
}