//! Copyright (c) 2022-2026 GitDataAi All rights reserved.

use crate::bare::GitBare;
use crate::error::{GitError, GitResult};
use crate::pb::{GetPatchRequest, GetPatchResponse};
use crate::resolve_revision;

const MAX_PATCH_BYTES: usize = 64 * 1024 * 1024;

impl GitBare {
    pub fn get_patch(&self, request: GetPatchRequest) -> GitResult<Vec<GetPatchResponse>> {
        let base = resolve_revision!(request.base);
        let head = resolve_revision!(request.head);
        let result = duct::cmd(
            "git",
            [
                "--git-dir",
                self.bare_dir.to_string_lossy().as_ref(),
                "diff",
                "--patch",
                &base,
                &head,
            ],
        )
        .stdout_capture()
        .stderr_capture()
        .unchecked()
        .run()?;
        if !result.status.success() {
            return Err(GitError::CommandFailed {
                status_code: result.status.code(),
                stderr: String::from_utf8_lossy(&result.stderr).into_owned(),
            });
        }
        if result.stdout.len() > MAX_PATCH_BYTES {
            return Err(GitError::InvalidArgument(format!(
                "patch output too large (max {MAX_PATCH_BYTES} bytes)"
            )));
        }
        Ok(vec![GetPatchResponse {
            data: result.stdout,
        }])
    }
}