//! Act phase: execute planned actions with safety checks.
//!
//! Actions are executed through a caller-provided executor callback, which
//! typically dispatches to the [`ToolRegistry`] or runs shell commands.
//! All file access must go through function calls (tools), never direct
//! filesystem operations.
//!
//! [`ToolRegistry`]: crate::tool::ToolRegistry

use std::future::Future;
use std::pin::Pin;
use std::process::Command;
use std::time::Duration;

use super::types::{
    ActionResult, ActionType, ActionVerdict, OraoConfig, PlannedAction, SafetyLevel,
};

/// Callback for executing a planned action.
///
/// The caller (service layer) provides this to wire up tool execution.
/// Returns `ActionResult` on completion.
pub type ActionExecutor =
    Box<dyn Fn(PlannedAction) -> Pin<Box<dyn Future<Output = ActionResult> + Send>> + Send + Sync>;

/// Check whether an action is allowed under the given safety configuration.
///
/// Returns `None` if allowed, or `Some(reason)` if blocked.
pub fn check_safety(action: &PlannedAction, config: &OraoConfig) -> Option<String> {
    let safety = SafetyLevel::classify_command(&action.command_or_content);

    if safety > config.max_safety_level {
        return Some(format!(
            "Action denied: safety level {:?} exceeds max allowed {:?}",
            safety, config.max_safety_level
        ));
    }

    // Check for dangerous command patterns
    if let Some(reason) = check_dangerous_command(&action.command_or_content) {
        return Some(reason);
    }

    None
}

/// Execute a single planned action via the provided executor.
///
/// Applies safety checks and timeout, then delegates to the executor.
pub async fn execute_action(
    action: PlannedAction,
    config: &OraoConfig,
    executor: &ActionExecutor,
) -> ActionResult {
    // ── Safety gate ────────────────────────────────────────────────────
    if let Some(reason) = check_safety(&action, config) {
        return ActionResult {
            action,
            exit_code: Some(1),
            stdout: String::new(),
            stderr: reason,
            file_changes: Vec::new(),
            verdict: ActionVerdict::Failure,
        };
    }

    // ── Execute with timeout ──────────────────────────────────────────
    let action_clone = action.clone();
    let exec_future = executor(action);

    match tokio::time::timeout(Duration::from_secs(config.action_timeout_secs), exec_future).await {
        Ok(result) => result,
        Err(_elapsed) => ActionResult {
            action: action_clone,
            exit_code: None,
            stdout: String::new(),
            stderr: format!(
                "Action timed out after {} seconds",
                config.action_timeout_secs
            ),
            file_changes: Vec::new(),
            verdict: ActionVerdict::Failure,
        },
    }
}

/// Build a default action executor that runs shell commands directly.
///
/// This is suitable for `shell_command` and `git_operation` action types.
/// For `tool_invoke`, the caller should provide a custom executor that
/// dispatches to the [`ToolRegistry`].
///
/// [`ToolRegistry`]: crate::tool::ToolRegistry
pub fn shell_executor(working_dir: String) -> ActionExecutor {
    Box::new(move |action: PlannedAction| {
        let dir = working_dir.clone();
        Box::pin(async move {
            match action.action_type {
                ActionType::ShellCommand | ActionType::GitOperation | ActionType::ToolInvoke => {
                    run_shell_command(&action, &dir).await
                }
                ActionType::FileWrite | ActionType::FileEdit => {
                    // File operations should use tool_invoke with a file-writing tool.
                    // Direct file access is discouraged; return an error directing to tools.
                    ActionResult {
                        exit_code: Some(1),
                        stdout: String::new(),
                        stderr: "File operations must use tool_invoke with registered file tools. Use shell_command with sed/echo for inline edits.".to_string(),
                        file_changes: Vec::new(),
                        verdict: ActionVerdict::Failure,
                        action,
                    }
                }
                ActionType::UserDialog => ActionResult {
                    exit_code: None,
                    stdout: "User dialog requested".to_string(),
                    stderr: String::new(),
                    file_changes: Vec::new(),
                    verdict: ActionVerdict::Success,
                    action,
                },
            }
        })
    })
}

async fn run_shell_command(action: &PlannedAction, working_dir: &str) -> ActionResult {
    let cmd = &action.command_or_content;

    let output = Command::new("sh")
        .args(["-c", cmd])
        .current_dir(working_dir)
        .output();

    match output {
        Ok(out) => {
            let exit_code = out.status.code();
            let stdout = String::from_utf8_lossy(&out.stdout).to_string();
            let stderr = String::from_utf8_lossy(&out.stderr).to_string();

            let verdict = match exit_code {
                Some(0) if !stderr_has_errors(&stderr) => ActionVerdict::Success,
                Some(0) => ActionVerdict::SuccessWithWarnings,
                _ => ActionVerdict::Failure,
            };

            ActionResult {
                action: action.clone(),
                exit_code,
                stdout,
                stderr,
                file_changes: Vec::new(),
                verdict,
            }
        }
        Err(e) => ActionResult {
            action: action.clone(),
            exit_code: None,
            stdout: String::new(),
            stderr: format!("Failed to spawn command: {}", e),
            file_changes: Vec::new(),
            verdict: ActionVerdict::Failure,
        },
    }
}

fn stderr_has_errors(stderr: &str) -> bool {
    let lower = stderr.to_lowercase();
    lower.contains("error") || lower.contains("fail") || lower.contains("panic")
}

/// Check whether a shell command contains dangerous patterns.
///
/// Returns `Some(reason)` if the command is blocked, `None` if it's safe.
pub fn check_dangerous_command(cmd: &str) -> Option<String> {
    let dangerous = [
        ("rm -rf /", "Recursive root deletion"),
        ("rm -rf ~", "Recursive home deletion"),
        (":(){ :|:& };:", "Fork bomb"),
        ("mkfs.", "Filesystem format"),
        ("dd if=", "Raw device write"),
        ("> /dev/sda", "Raw device write"),
        ("chmod 777 /", "World-writable root"),
    ];

    for (pattern, reason) in &dangerous {
        if cmd.contains(pattern) {
            return Some(format!("Blocked: {} — {}", pattern, reason));
        }
    }

    None
}