refactor(deps): replace git2 with system git and add vcs support

src/utils/git.rs

@@ -0,0 +1,112 @@
+// DCR — Cargo-like C/C++ project manager.
+//
+// Copyright (C) 2026 Dexoron (Bezotechestvo Vladimir) <main@dexoron.su>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+use std::path::Path;
+use std::process::Command;
+
+// checking installed git on system
+pub fn is_git_available() -> bool {
+    Command::new("git")
+        .arg("--version")
+        .output()
+        .map(|o| o.status.success())
+        .unwrap_or(false)
+}
+
+// warning of git not in system
+#[allow(dead_code)]
+pub fn warn_if_git_missing() {
+    if !is_git_available() {
+        crate::utils::log::warn(
+            "Git is not installed or not found in PATH. Some features (like dependency cloning and VCS initialization) may fail.",
+        );
+    }
+}
+
+// init repo in folder
+pub fn git_init(path: &Path) -> Result<(), String> {
+    if !is_git_available() {
+        return Err("git executable not found in PATH".to_string());
+    }
+
+    let status = Command::new("git")
+        .arg("init")
+        .current_dir(path)
+        .status()
+        .map_err(|e| format!("failed to execute git init: {}", e))?;
+
+    if !status.success() {
+        return Err("git init failed".to_string());
+    }
+
+    Ok(())
+}
+
+// Clone the dependency and switch to the branch/tag/commit
+#[allow(dead_code)]
+pub fn git_clone_and_checkout(
+    url: &str,
+    target_dir: &Path,
+    branch: Option<&str>,
+    tag: Option<&str>,
+    rev: Option<&str>,
+) -> Result<(), String> {
+    if !is_git_available() {
+        return Err("git executable not found in PATH".to_string());
+    }
+
+    let mut args = vec!["clone"];
+
+    if let Some(b) = branch {
+        args.push("--branch");
+        args.push(b);
+        args.push("--single-branch");
+    } else if let Some(t) = tag {
+        args.push("--branch");
+        args.push(t);
+        args.push("--single-branch");
+    }
+
+    args.push(url);
+
+    let target_dir_str = target_dir.to_string_lossy().to_string();
+    args.push(&target_dir_str);
+
+    let status = Command::new("git")
+        .args(&args)
+        .status()
+        .map_err(|e| format!("failed to execute git clone: {}", e))?;
+
+    if !status.success() {
+        return Err(format!("git clone of {} failed", url));
+    }
+
+    if let Some(r) = rev {
+        let checkout_status = Command::new("git")
+            .arg("checkout")
+            .arg(r)
+            .current_dir(target_dir)
+            .status()
+            .map_err(|e| format!("failed to execute git checkout: {}", e))?;
+
+        if !checkout_status.success() {
+            return Err(format!("git checkout to revision {} failed", r));
+        }
+    }
+
+    Ok(())
+}