feat: support function calling (#514)

* feat: support function calling

* fix on Windows OS

* implement multi-steps function calling

* fix on Windows OS

* add error for client not support function calling

* refactor message data structure and make claude client supporting function calling

* support reuse previous call results

* improve error handling for function calling

* use prefix `may_`  as indicator for `execute` type fucntions

1 files changed, 82 insertions, 0 deletions

diff --git a/src/utils/command.rs b/src/utils/command.rs
new file mode 100644
index 0000000..77ca813
--- /dev/null
+++ b/src/utils/command.rs
@@ -0,0 +1,82 @@
+use std::{collections::HashMap, env, ffi::OsStr, process::Command};
+
+use anyhow::{Context, Result};
+
+pub fn detect_os() -> String {
+    let os = env::consts::OS;
+    if os == "linux" {
+        if let Ok(contents) = std::fs::read_to_string("/etc/os-release") {
+            for line in contents.lines() {
+                if let Some(id) = line.strip_prefix("ID=") {
+                    return format!("{os}/{id}");
+                }
+            }
+        }
+    }
+    os.to_string()
+}
+
+pub fn detect_shell() -> (String, String, &'static str) {
+    let os = env::consts::OS;
+    if os == "windows" {
+        if env::var("NU_VERSION").is_ok() {
+            ("nushell".into(), "nu.exe".into(), "-c")
+        } else if let Some(ret) = env::var("PSModulePath").ok().and_then(|v| {
+            let v = v.to_lowercase();
+            if v.split(';').count() >= 3 {
+                if v.contains("powershell\\7\\") {
+                    Some(("pwsh".into(), "pwsh.exe".into(), "-c"))
+                } else {
+                    Some(("powershell".into(), "powershell.exe".into(), "-Command"))
+                }
+            } else {
+                None
+            }
+        }) {
+            ret
+        } else {
+            ("cmd".into(), "cmd.exe".into(), "/C")
+        }
+    } else if env::var("NU_VERSION").is_ok() {
+        ("nushell".into(), "nu".into(), "-c")
+    } else {
+        let shell_cmd = env::var("SHELL").unwrap_or_else(|_| "/bin/sh".to_string());
+        let shell_name = match shell_cmd.rsplit_once('/') {
+            Some((_, name)) => name.to_string(),
+            None => shell_cmd.clone(),
+        };
+        let shell_name = if shell_name == "nu" {
+            "nushell".into()
+        } else {
+            shell_name
+        };
+        (shell_name, shell_cmd, "-c")
+    }
+}
+
+pub fn run_command<T: AsRef<OsStr>>(
+    cmd: &str,
+    args: &[T],
+    envs: Option<HashMap<String, String>>,
+) -> Result<i32> {
+    let status = Command::new(cmd)
+        .args(args.iter())
+        .envs(envs.unwrap_or_default())
+        .status()?;
+    Ok(status.code().unwrap_or_default())
+}
+
+pub fn run_command_with_output<T: AsRef<OsStr>>(
+    cmd: &str,
+    args: &[T],
+    envs: Option<HashMap<String, String>>,
+) -> Result<(bool, String, String)> {
+    let output = Command::new(cmd)
+        .args(args.iter())
+        .envs(envs.unwrap_or_default())
+        .output()?;
+    let status = output.status;
+    let stdout = std::str::from_utf8(&output.stdout).context("Invalid UTF-8 in stdout")?;
+    let stderr = std::str::from_utf8(&output.stderr).context("Invalid UTF-8 in stderr")?;
+    Ok((status.success(), stdout.to_string(), stderr.to_string()))
+}