//
use crate::messages::MessageToken;
use git_next_core::RepoConfig;
use git_next_git::{self as git, repository::open::OpenRepositoryLike};

use derive_more::Display;
use tracing::{info, warn};

// advance next to the next commit towards the head of the dev branch
#[tracing::instrument(fields(next), skip_all)]
pub fn advance_next(
    next: &git::Commit,
    dev_commit_history: &[git::Commit],
    repo_details: git::RepoDetails,
    repo_config: RepoConfig,
    open_repository: &dyn OpenRepositoryLike,
    message_token: MessageToken,
) -> Result<MessageToken> {
    let commit =
        find_next_commit_on_dev(next, dev_commit_history).ok_or_else(|| Error::NextAtDev)?;
    validate_commit_message(commit.message())?;
    info!("Advancing next to commit '{}'", commit);
    git::push::reset(
        open_repository,
        &repo_details,
        &repo_config.branches().next(),
        &commit.into(),
        &git::push::Force::No,
    )?;
    Ok(message_token)
}

#[tracing::instrument]
fn validate_commit_message(message: &git::commit::Message) -> Result<()> {
    let message = &message.to_string();
    if message.to_ascii_lowercase().starts_with("wip") {
        return Err(Error::IsWorkInProgress);
    }
    match git_conventional::Commit::parse(message) {
        Ok(commit) => {
            info!(?commit, "Pass");
            Ok(())
        }
        Err(err) => {
            warn!(?err, "Fail");
            Err(Error::InvalidCommitMessage {
                reason: err.kind().to_string(),
            })
        }
    }
}

pub fn find_next_commit_on_dev(
    next: &git::Commit,
    dev_commit_history: &[git::Commit],
) -> Option<git::Commit> {
    let mut next_commit: Option<&git::Commit> = None;
    for commit in dev_commit_history.iter() {
        if commit == next {
            break;
        };
        next_commit.replace(commit);
    }
    next_commit.cloned()
}

// advance main branch to the commit 'next'
#[tracing::instrument(fields(next), skip_all)]
pub fn advance_main(
    next: git::Commit,
    repo_details: &git::RepoDetails,
    repo_config: &RepoConfig,
    open_repository: &dyn OpenRepositoryLike,
) -> Result<()> {
    info!("Advancing main to next");
    git::push::reset(
        open_repository,
        repo_details,
        &repo_config.branches().main(),
        &next.into(),
        &git::push::Force::No,
    )?;
    Ok(())
}

pub type Result<T> = core::result::Result<T, Error>;
#[derive(Debug, thiserror::Error, Display)]
pub enum Error {
    #[display("push: {}", 0)]
    Push(#[from] git::push::Error),

    #[display("no commits to advance next to")]
    NextAtDev,

    #[display("commit is a Work-in-progress")]
    IsWorkInProgress,

    #[display("commit message is not in conventional commit format: {reason}")]
    InvalidCommitMessage { reason: String },
}