vtcode-core 0.123.2

use std::path::Path;

use crate::config::VTCodeConfig;
use crate::project_doc::build_instruction_appendix;
use crate::prompts::PromptContext;
use crate::prompts::system::compose_system_instruction_text;
use anyhow::Result;
use serde_json::Value;

pub(super) fn detect_textual_exec_tool_call(text: &str) -> Option<Value> {
    const FENCE_PREFIXES: [&str; 4] = [
        "```tool:unified_exec",
        "```unified_exec",
        "```tool:run_pty_cmd",
        "```run_pty_cmd",
    ];

    let (start_idx, prefix) = FENCE_PREFIXES
        .iter()
        .filter_map(|candidate| text.find(candidate).map(|idx| (idx, *candidate)))
        .min_by_key(|(idx, _)| *idx)?;

    // Require a fenced block owned by the model to avoid executing echoed examples.
    let mut remainder = &text[start_idx + prefix.len()..];
    if remainder.starts_with('\r') {
        remainder = &remainder[1..];
    }
    remainder = remainder.strip_prefix('\n')?;

    let fence_close = remainder.find("```")?;
    let block = remainder[..fence_close].trim();
    if block.is_empty() {
        return None;
    }

    let parsed = serde_json::from_str::<Value>(block)
        .or_else(|_| json5::from_str::<Value>(block))
        .ok()?;
    parsed.as_object()?;
    Some(parsed)
}

/// Compose the system prompt for a workspace using the configured prompt
/// context, then optionally append an instruction appendix derived from
/// `AGENTS.md` and `.vtcode/rules/` files.
///
/// The persistent-memory section of the appendix is disabled when
/// `config.memories_enabled()` returns `false` so the resulting prompt stays
/// consistent with the configured memory policy.
pub(super) async fn compose_system_prompt_with_appendix(
    workspace: &Path,
    config: &VTCodeConfig,
    prompt_context: &PromptContext,
) -> Result<String> {
    let mut system_prompt =
        compose_system_instruction_text(workspace, Some(config), Some(prompt_context)).await;

    let mut appendix_config = config.agent.clone();
    if !config.memories_enabled() {
        appendix_config.persistent_memory.enabled = false;
    }
    if let Some(appendix) = build_instruction_appendix(&appendix_config, workspace).await {
        system_prompt.push_str("\n\n# INSTRUCTIONS\n");
        system_prompt.push_str(&appendix);
    }

    Ok(system_prompt)
}

#[cfg(test)]
mod tests {
    use super::detect_textual_exec_tool_call;
    use serde_json::json;

    #[test]
    fn detects_unified_exec_fence() {
        let text = "```tool:unified_exec\n{\"command\":\"pwd\"}\n```";
        assert_eq!(
            detect_textual_exec_tool_call(text),
            Some(json!({"command":"pwd"}))
        );
    }

    #[test]
    fn detects_legacy_run_pty_cmd_fence() {
        let text = "```run_pty_cmd\n{\"command\":\"pwd\"}\n```";
        assert_eq!(
            detect_textual_exec_tool_call(text),
            Some(json!({"command":"pwd"}))
        );
    }

    #[test]
    fn ignores_non_object_payloads() {
        let text = "```unified_exec\n[\"pwd\"]\n```";
        assert!(detect_textual_exec_tool_call(text).is_none());
    }
}