use crate::bare::GitBare;
use crate::error::GitResult;
use crate::pb::*;

impl GitBare {
    /// Find the best merge base for a set of revisions (OIDs).
    pub fn find_merge_base(&self, request: FindMergeBaseRequest) -> GitResult<FindMergeBaseResponse> {
        if request.revisions.is_empty() {
            return Ok(FindMergeBaseResponse::default());
        }

        let revisions: Vec<String> = request
            .revisions
            .iter()
            .map(|b| String::from_utf8_lossy(b).to_string())
            .collect();

        if revisions.len() < 2 {
            return Ok(FindMergeBaseResponse {
                base_oid: revisions.first().cloned().unwrap_or_default(),
            });
        }

        let mut args = vec![
            "--git-dir".to_string(),
            self.bare_dir.to_string_lossy().into_owned(),
            "merge-base".to_string(),
        ];
        args.extend(revisions.iter().cloned());

        let output = std::process::Command::new("git")
            .args(&args)
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::piped())
            .output()
            .map_err(|e| crate::error::GitError::CommandFailed {
                status_code: None,
                stderr: e.to_string(),
            })?;

        if !output.status.success() {
            return Ok(FindMergeBaseResponse {
                base_oid: String::new(),
            });
        }

        let base_oid = String::from_utf8_lossy(&output.stdout).trim().to_string();
        Ok(FindMergeBaseResponse { base_oid })
    }

    /// Check if one commit is an ancestor of another.
    pub fn commit_is_ancestor(&self, request: CommitIsAncestorRequest) -> GitResult<CommitIsAncestorResponse> {
        crate::sanitize::validate_revision(&request.ancestor_oid)?;
        crate::sanitize::validate_revision(&request.descendant_oid)?;

        let result = std::process::Command::new("git")
            .args([
                "--git-dir",
                &self.bare_dir.to_string_lossy(),
                "merge-base",
                "--is-ancestor",
                &request.ancestor_oid,
                &request.descendant_oid,
            ])
            .stdout(std::process::Stdio::null())
            .stderr(std::process::Stdio::null())
            .status()
            .map(|s| s.success())
            .unwrap_or(false);

        Ok(CommitIsAncestorResponse { is_ancestor: result })
    }
}