//! Tool implementations for interacting with background bash jobs: `bash_output`
//! and `bash_kill`. Both take a `job_id` produced by `bash` with `run_in_background=true`.

use serde_json::{json, Value};
use anyhow::{Result, anyhow};
use super::Tool;
use super::ToolCtx;

/// Tool: fetch buffered output from a background bash job by `job_id`.
pub struct BashOutput;

impl Tool for BashOutput {
    fn name(&self) -> &'static str {
        "bash_output"
    }

    fn description(&self) -> &'static str {
        "Retrieve output from a background bash job by job_id"
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "job_id": {
                    "type": "string",
                    "description": "Job ID returned by bash with run_in_background=true"
                }
            },
            "required": ["job_id"]
        })
    }

    fn run(&self, _ctx: &ToolCtx, args: &Value) -> Result<String> {
        let job_id = args.get("job_id")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow!("missing required argument: job_id"))?
            .to_string();
        // Validate that job_id looks like a UUID to prevent injection
        // into the global job registry.
        if !is_valid_job_id(&job_id) {
            anyhow::bail!("invalid job_id format: expected UUID");
        }
        match crate::app::bgbash::control::bash_output(&job_id) {
            Some(lines) => Ok(lines.join("\n")),
            None => Ok(format!("No new output from job '{job_id}'")),
        }
    }
}

/// Tool: terminate a running background bash job by `job_id`.
pub struct BashKill;

impl Tool for BashKill {
    fn name(&self) -> &'static str {
        "bash_kill"
    }

    fn description(&self) -> &'static str {
        "Kill a background bash job by job_id"
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "job_id": {
                    "type": "string",
                    "description": "Job ID returned by bash with run_in_background=true"
                }
            },
            "required": ["job_id"]
        })
    }

    fn run(&self, _ctx: &ToolCtx, args: &Value) -> Result<String> {
        let job_id = args.get("job_id")
            .and_then(|v| v.as_str())
            .ok_or_else(|| anyhow!("missing required argument: job_id"))?
            .to_string();
        if !is_valid_job_id(&job_id) {
            anyhow::bail!("invalid job_id format: expected UUID");
        }
        crate::app::bgbash::control::bash_kill(&job_id)?;
        Ok(format!("Killed background job '{job_id}'"))
    }
}

/// Validate that a `job_id` matches UUID v4 format (hex with dashes).
fn is_valid_job_id(id: &str) -> bool {
    // UUID v4 format: 8-4-4-4-12 hex digits
    let parts: Vec<&str> = id.split('-').collect();
    if parts.len() != 5 {
        return false;
    }
    parts.iter().all(|p| !p.is_empty() && p.chars().all(|c| c.is_ascii_hexdigit()))
        && parts[0].len() == 8
        && parts[1].len() == 4
        && parts[2].len() == 4
        && parts[3].len() == 4
        && parts[4].len() == 12
}