use crate::error::AppError;
use crate::service::RepoService;
use crate::session::Session;

fn rev(revision: &str) -> crate::pb::repo::ObjectSelector {
    crate::pb::repo::ObjectSelector {
        selector: Some(crate::pb::repo::object_selector::Selector::Revision(
            crate::pb::repo::ObjectName {
                revision: revision.to_string(),
            },
        )),
    }
}

impl RepoService {
    pub async fn git_diff(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        base: &str,
        head: &str,
        page_size: u32,
    ) -> Result<crate::pb::repo::GetDiffResponse, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo = self.resolve_repo(wk_name, repo_name).await?;
        self.ensure_repo_readable(user_uid, &repo).await?;
        let ws = self.resolve_workspace(wk_name).await?;
        let header = self.repo_header(&repo, &ws);
        let mut svc = self.git_client(&repo)?.diff;
        let resp = svc
            .get_diff(tonic::Request::new(crate::pb::repo::GetDiffRequest {
                repository: Some(header),
                base: Some(rev(base)),
                head: Some(rev(head)),
                options: None,
                pagination: Some(crate::pb::repo::Pagination {
                    page_size,
                    page_token: String::new(),
                }),
            }))
            .await
            .map_err(|e| AppError::InternalServerError(e.to_string()))?;
        Ok(resp.into_inner())
    }

    pub async fn git_diff_stats(
        &self,
        ctx: &Session,
        wk_name: &str,
        repo_name: &str,
        base: &str,
        head: &str,
    ) -> Result<crate::pb::repo::DiffStats, AppError> {
        let user_uid = ctx.user().ok_or(AppError::Unauthorized)?;
        let repo = self.resolve_repo(wk_name, repo_name).await?;
        self.ensure_repo_readable(user_uid, &repo).await?;
        let ws = self.resolve_workspace(wk_name).await?;
        let header = self.repo_header(&repo, &ws);
        let mut svc = self.git_client(&repo)?.diff;
        let resp = svc
            .get_diff_stats(tonic::Request::new(crate::pb::repo::GetDiffStatsRequest {
                repository: Some(header),
                base: Some(rev(base)),
                head: Some(rev(head)),
                options: None,
            }))
            .await
            .map_err(|e| AppError::InternalServerError(e.to_string()))?;
        Ok(resp.into_inner())
    }
}