feat(core): implement Git repository operations with gRPC services

- Add advertise_refs functionality for Git protocol communication
- Implement archive service with TAR/ZIP format support and streaming
- Create blame service for Git file annotation with line tracking
- Add branch management including create, delete, rename and compare operations
- Implement merge checking with conflict detection and fast-forward handling
- Add cherry-pick functionality for applying commits between branches
- Integrate gix library for Git repository operations and object handling
- Add comprehensive test suite covering all Git operations
- Implement proper error handling and repository validation
- Add pagination support for large result sets
- Create protobuf definitions for all Git operations and data structures
- Add build system for gRPC code generation and dependency management

branch/compare_branch.rs

@@ -0,0 +1,54 @@
+use crate::bare::GitBare;
+use crate::error::{GitError, GitResult};
+use crate::pb::{CompareBranchRequest, CompareBranchResponse};
+
+impl GitBare {
+    pub fn compare_branch(
+        &self,
+        request: CompareBranchRequest,
+    ) -> GitResult<CompareBranchResponse> {
+        let repo = self.gix_repo()?;
+        let source_ref = format!("refs/heads/{}", request.source_branch);
+        let target_ref = format!("refs/heads/{}", request.target_branch);
+        let source_id = repo.find_reference(source_ref.as_str())?.peel_to_id()?;
+        let target_id = repo.find_reference(target_ref.as_str())?.peel_to_id()?;
+        let source_hex = source_id.to_string();
+        let target_hex = target_id.to_string();
+        let merge_base = repo
+            .merge_base(source_id.detach(), target_id.detach())
+            .ok()
+            .map(|id| self.oid_to_pb(id.to_string()));
+        let result = duct::cmd(
+            "git",
+            [
+                "--git-dir",
+                self.bare_dir.to_string_lossy().as_ref(),
+                "rev-list",
+                "--left-right",
+                "--count",
+                &format!("{}...{}", source_hex, target_hex),
+            ],
+        )
+        .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(),
+            });
+        }
+        let output = String::from_utf8_lossy(&result.stdout);
+        let parts: Vec<&str> = output.split_whitespace().collect();
+        let ahead_by = parts.first().and_then(|s| s.parse().ok()).unwrap_or(0);
+        let behind_by = parts.get(1).and_then(|s| s.parse().ok()).unwrap_or(0);
+        Ok(CompareBranchResponse {
+            ahead: ahead_by > 0,
+            behind: behind_by > 0,
+            ahead_by,
+            behind_by,
+            merge_base,
+        })
+    }
+}

branch/create_branch.rs

@@ -0,0 +1,36 @@
+use std::process::Command;
+
+use crate::bare::GitBare;
+use crate::error::{GitError, GitResult};
+use crate::pb::{Branch, CreateBranchRequest, GetBranchRequest, object_selector};
+
+impl GitBare {
+    pub fn create_branch(&self, request: CreateBranchRequest) -> GitResult<Branch> {
+        let revision = match request.start_point.and_then(|s| s.selector) {
+            Some(object_selector::Selector::Oid(oid)) => oid.hex,
+            Some(object_selector::Selector::Revision(name)) => name.revision,
+            None => "HEAD".into(),
+        };
+        let mut args = vec!["branch".to_string()];
+        if request.force {
+            args.push("-f".into());
+        }
+        args.push(request.name.clone());
+        args.push(revision);
+        let output = Command::new("git")
+            .arg("--git-dir")
+            .arg(&self.bare_dir)
+            .args(&args)
+            .output()?;
+        if !output.status.success() {
+            return Err(GitError::CommandFailed {
+                status_code: output.status.code(),
+                stderr: String::from_utf8_lossy(&output.stderr).into_owned(),
+            });
+        }
+        self.get_branch(GetBranchRequest {
+            repository: request.repository,
+            name: request.name,
+        })
+    }
+}

branch/delete_branch.rs

@@ -0,0 +1,23 @@
+use std::process::Command;
+
+use crate::bare::GitBare;
+use crate::error::{GitError, GitResult};
+use crate::pb::DeleteBranchRequest;
+
+impl GitBare {
+    pub fn delete_branch(&self, request: DeleteBranchRequest) -> GitResult<()> {
+        let flag = if request.force { "-D" } else { "-d" };
+        let output = Command::new("git")
+            .arg("--git-dir")
+            .arg(&self.bare_dir)
+            .args(["branch", flag, &request.name])
+            .output()?;
+        if !output.status.success() {
+            return Err(GitError::CommandFailed {
+                status_code: output.status.code(),
+                stderr: String::from_utf8_lossy(&output.stderr).into_owned(),
+            });
+        }
+        Ok(())
+    }
+}

branch/get_branch.rs

@@ -0,0 +1,23 @@
+use crate::bare::GitBare;
+use crate::error::GitResult;
+use crate::pb::{Branch, GetBranchRequest};
+
+impl GitBare {
+    pub fn get_branch(&self, request: GetBranchRequest) -> GitResult<Branch> {
+        let repo = self.gix_repo()?;
+        let refname = format!("refs/heads/{}", request.name);
+        let mut r = repo.find_reference(refname.as_str())?;
+        let hex = r.peel_to_id()?.to_string();
+        Ok(Branch {
+            name: request.name,
+            full_ref: refname,
+            target_oid: Some(self.oid_to_pb(hex)),
+            commit: None,
+            upstream: None,
+            is_default: false,
+            is_head: false,
+            is_merged: false,
+            is_detached: false,
+        })
+    }
+}

branch/list_branches.rs

@@ -0,0 +1,78 @@
+use crate::bare::GitBare;
+use crate::error::GitResult;
+use crate::paginate;
+use crate::pb::{Branch, ListBranchesRequest, ListBranchesResponse};
+
+impl GitBare {
+    pub fn list_branches(&self, request: ListBranchesRequest) -> GitResult<ListBranchesResponse> {
+        let repo = self.gix_repo()?;
+
+        let merged_set = if request.merged_into_head || request.not_merged_into_head {
+            let flag = if request.merged_into_head {
+                "--merged"
+            } else {
+                "--no-merged"
+            };
+            let check = duct::cmd(
+                "git",
+                [
+                    "--git-dir",
+                    self.bare_dir.to_string_lossy().as_ref(),
+                    "branch",
+                    flag,
+                    "HEAD",
+                ],
+            )
+            .stdout_capture()
+            .stderr_capture()
+            .unchecked()
+            .run();
+            match check {
+                Ok(out) => String::from_utf8_lossy(&out.stdout)
+                    .lines()
+                    .map(|l| l.trim().trim_start_matches("* ").to_string())
+                    .collect::<Vec<_>>(),
+                Err(_) => Vec::new(),
+            }
+        } else {
+            Vec::new()
+        };
+
+        let mut branches: Vec<Branch> = Vec::new();
+        for r in repo.references()?.local_branches()? {
+            let mut r = r.map_err(|e| crate::error::GitError::Gix(e.to_string()))?;
+            let name = r.name().shorten().to_string();
+            if !request.pattern.is_empty() && !name.contains(&request.pattern) {
+                continue;
+            }
+            if request.merged_into_head && !merged_set.contains(&name) {
+                continue;
+            }
+            if request.not_merged_into_head && merged_set.contains(&name) {
+                continue;
+            }
+            let hex = r
+                .peel_to_id()
+                .ok()
+                .map(|id| id.to_string())
+                .unwrap_or_default();
+            branches.push(Branch {
+                name,
+                full_ref: r.name().to_string(),
+                target_oid: Some(self.oid_to_pb(hex)),
+                commit: None,
+                upstream: None,
+                is_default: false,
+                is_head: false,
+                is_merged: false,
+                is_detached: false,
+            });
+        }
+        paginate::apply_sort(&mut branches, request.sort_direction);
+        let (branches, page_info) = paginate::paginate(&branches, request.pagination.as_ref());
+        Ok(ListBranchesResponse {
+            branches,
+            page_info: Some(page_info),
+        })
+    }
+}

branch/mod.rs

@@ -0,0 +1,8 @@
+pub mod compare_branch;
+pub mod create_branch;
+pub mod delete_branch;
+pub mod get_branch;
+pub mod list_branches;
+pub mod rename_branch;
+pub mod set_branch_upstream;
+pub mod update_branch_target;

branch/rename_branch.rs

@@ -0,0 +1,25 @@
+use std::process::Command;
+
+use crate::bare::GitBare;
+use crate::error::{GitError, GitResult};
+use crate::pb::{Branch, GetBranchRequest, RenameBranchRequest};
+
+impl GitBare {
+    pub fn rename_branch(&self, request: RenameBranchRequest) -> GitResult<Branch> {
+        let output = Command::new("git")
+            .arg("--git-dir")
+            .arg(&self.bare_dir)
+            .args(["branch", "-m", &request.old_name, &request.new_name])
+            .output()?;
+        if !output.status.success() {
+            return Err(GitError::CommandFailed {
+                status_code: output.status.code(),
+                stderr: String::from_utf8_lossy(&output.stderr).into_owned(),
+            });
+        }
+        self.get_branch(GetBranchRequest {
+            repository: request.repository,
+            name: request.new_name,
+        })
+    }
+}

branch/set_branch_upstream.rs

@@ -0,0 +1,36 @@
+use crate::bare::GitBare;
+use crate::error::{GitError, GitResult};
+use crate::pb::{Branch, GetBranchRequest, SetBranchUpstreamRequest};
+
+impl GitBare {
+    pub fn set_branch_upstream(&self, request: SetBranchUpstreamRequest) -> GitResult<Branch> {
+        if let Some(upstream) = request.upstream {
+            let tracking = format!("{}/{}", upstream.remote_name, upstream.remote_branch_name);
+            let result = duct::cmd(
+                "git",
+                [
+                    "--git-dir",
+                    self.bare_dir.to_string_lossy().as_ref(),
+                    "branch",
+                    "--set-upstream-to",
+                    &tracking,
+                    &request.name,
+                ],
+            )
+            .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(),
+                });
+            }
+        }
+        self.get_branch(GetBranchRequest {
+            repository: request.repository,
+            name: request.name,
+        })
+    }
+}

branch/update_branch_target.rs

@@ -0,0 +1,39 @@
+#![allow(clippy::collapsible_if)]
+use std::process::Command;
+
+use crate::bare::GitBare;
+use crate::error::{GitError, GitResult};
+use crate::pb::{Branch, GetBranchRequest, UpdateBranchTargetRequest};
+
+impl GitBare {
+    pub fn update_branch_target(&self, request: UpdateBranchTargetRequest) -> GitResult<Branch> {
+        let new_oid = request
+            .new_oid
+            .as_ref()
+            .ok_or_else(|| GitError::InvalidArgument("new_oid is required".into()))?
+            .hex
+            .clone();
+        let refname = format!("refs/heads/{}", request.name);
+        let mut args = vec!["update-ref".to_string(), refname.clone(), new_oid];
+        if !request.force
+            && let Some(old) = request.expected_old_oid.as_ref()
+        {
+            args.push(old.hex.clone());
+        }
+        let output = Command::new("git")
+            .arg("--git-dir")
+            .arg(&self.bare_dir)
+            .args(&args)
+            .output()?;
+        if !output.status.success() {
+            return Err(GitError::CommandFailed {
+                status_code: output.status.code(),
+                stderr: String::from_utf8_lossy(&output.stderr).into_owned(),
+            });
+        }
+        self.get_branch(GetBranchRequest {
+            repository: request.repository,
+            name: refname.trim_start_matches("refs/heads/").to_string(),
+        })
+    }
+}