feat: add opencode ai agent option

src-tauri/src/opencode_discovery.rs

@@ -0,0 +1,159 @@
+use crate::ai_agents::AiAgentAvailability;
+use std::path::{Path, PathBuf};
+
+pub(crate) fn check_cli() -> AiAgentAvailability {
+    match find_binary() {
+        Ok(binary) => AiAgentAvailability {
+            installed: true,
+            version: version_for_binary(&binary),
+        },
+        Err(_) => AiAgentAvailability {
+            installed: false,
+            version: None,
+        },
+    }
+}
+
+pub(crate) fn find_binary() -> Result<PathBuf, String> {
+    if let Some(binary) = find_binary_on_path() {
+        return Ok(binary);
+    }
+
+    if let Some(binary) = find_binary_in_user_shell() {
+        return Ok(binary);
+    }
+
+    if let Some(binary) = find_existing_binary(opencode_binary_candidates()) {
+        return Ok(binary);
+    }
+
+    Err("OpenCode CLI not found. Install it: https://opencode.ai/docs/".into())
+}
+
+fn version_for_binary(binary: &PathBuf) -> Option<String> {
+    crate::hidden_command(binary)
+        .arg("--version")
+        .output()
+        .ok()
+        .filter(|output| output.status.success())
+        .map(|output| String::from_utf8_lossy(&output.stdout).trim().to_string())
+}
+
+fn find_binary_on_path() -> Option<PathBuf> {
+    crate::hidden_command("which")
+        .arg("opencode")
+        .output()
+        .ok()
+        .and_then(|output| path_from_successful_output(&output))
+}
+
+fn find_binary_in_user_shell() -> Option<PathBuf> {
+    user_shell_candidates()
+        .into_iter()
+        .filter(|shell| shell.exists())
+        .find_map(|shell| command_path_from_shell(&shell, "opencode"))
+}
+
+fn user_shell_candidates() -> Vec<PathBuf> {
+    let mut shells = Vec::new();
+    if let Some(shell) = std::env::var_os("SHELL") {
+        if !shell.is_empty() {
+            shells.push(PathBuf::from(shell));
+        }
+    }
+    shells.push(PathBuf::from("/bin/zsh"));
+    shells.push(PathBuf::from("/bin/bash"));
+    shells
+}
+
+fn command_path_from_shell(shell: &Path, command: &str) -> Option<PathBuf> {
+    crate::hidden_command(shell)
+        .arg("-lc")
+        .arg(format!("command -v {command}"))
+        .output()
+        .ok()
+        .and_then(|output| path_from_successful_output(&output))
+}
+
+fn path_from_successful_output(output: &std::process::Output) -> Option<PathBuf> {
+    if output.status.success() {
+        first_existing_path(&String::from_utf8_lossy(&output.stdout))
+    } else {
+        None
+    }
+}
+
+fn first_existing_path(stdout: &str) -> Option<PathBuf> {
+    stdout.lines().find_map(|line| {
+        let trimmed = line.trim();
+        if trimmed.is_empty() {
+            return None;
+        }
+        let candidate = PathBuf::from(trimmed);
+        candidate.exists().then_some(candidate)
+    })
+}
+
+fn find_existing_binary(candidates: Vec<PathBuf>) -> Option<PathBuf> {
+    candidates.into_iter().find(|candidate| candidate.exists())
+}
+
+fn opencode_binary_candidates() -> Vec<PathBuf> {
+    dirs::home_dir()
+        .map(|home| opencode_binary_candidates_for_home(&home))
+        .unwrap_or_default()
+}
+
+fn opencode_binary_candidates_for_home(home: &Path) -> Vec<PathBuf> {
+    vec![
+        home.join(".local/bin/opencode"),
+        home.join(".opencode/bin/opencode"),
+        home.join(".local/share/mise/shims/opencode"),
+        home.join(".asdf/shims/opencode"),
+        home.join(".npm-global/bin/opencode"),
+        home.join(".npm/bin/opencode"),
+        home.join(".bun/bin/opencode"),
+        PathBuf::from("/usr/local/bin/opencode"),
+        PathBuf::from("/opt/homebrew/bin/opencode"),
+    ]
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn binary_candidates_include_supported_local_installs() {
+        let home = PathBuf::from("/Users/alex");
+        let candidates = opencode_binary_candidates_for_home(&home);
+        let expected = [
+            home.join(".local/bin/opencode"),
+            home.join(".opencode/bin/opencode"),
+            home.join(".local/share/mise/shims/opencode"),
+            home.join(".asdf/shims/opencode"),
+            home.join(".npm-global/bin/opencode"),
+            home.join(".bun/bin/opencode"),
+            PathBuf::from("/opt/homebrew/bin/opencode"),
+        ];
+
+        for candidate in expected {
+            assert!(
+                candidates.contains(&candidate),
+                "missing {}",
+                candidate.display()
+            );
+        }
+    }
+
+    #[test]
+    fn first_existing_path_skips_empty_and_missing_lines() {
+        let dir = tempfile::tempdir().unwrap();
+        let missing = dir.path().join("missing-opencode");
+        let opencode = dir.path().join("opencode");
+        std::fs::write(&opencode, "#!/bin/sh\n").unwrap();
+
+        let stdout = format!("\n{}\n{}\n", missing.display(), opencode.display());
+
+        assert_eq!(first_existing_path(&stdout), Some(opencode));
+    }
+}