feat: add 'todofinish' tool to mark tasks as completed in the todo list; update system prompts for task execution

src/tool/mod.rs

@@ -158,6 +158,7 @@ pub fn all_tools() -> Vec<Box<dyn Tool>> {
         Box::new(super::tool::utility::dir_cache_update::DirCacheUpdate),
         Box::new(super::tool::utility::pong::Pong),
         Box::new(super::tool::utility::todowrite::Todowrite),
+        Box::new(super::tool::utility::todofinish::Todofinish),
         Box::new(super::tool::lsp::LspConnect),
         Box::new(super::tool::lsp::LspDiagnostics),
         Box::new(super::tool::lsp::LspHover),

src/tool/utility/mod.rs

@@ -5,3 +5,4 @@ pub mod dir_cache_update;
 pub mod dir_list;
 pub mod pong;
 pub mod todowrite;
+pub mod todofinish;

src/tool/utility/todofinish.rs

@@ -0,0 +1,81 @@
+//! Tool for marking tasks as finished in the session's todo list.
+
+use serde_json::{json, Value};
+use anyhow::{Result, anyhow};
+use std::path::PathBuf;
+use super::super::{Tool, ToolCtx};
+
+/// Tool that marks tasks as finished in the session's todo.md.
+pub struct Todofinish;
+
+impl Tool for Todofinish {
+    fn name(&self) -> &'static str {
+        "todofinish"
+    }
+
+    fn description(&self) -> &'static str {
+        "Mark tasks as finished in the session todo list (todo.md). You can mark all tasks as finished by leaving the 'task_index' empty, or specify a 1-based index to finish a specific task."
+    }
+
+    fn parameters(&self) -> Value {
+        json!({
+            "type": "object",
+            "properties": {
+                "task_index": {
+                    "type": "integer",
+                    "description": "Optional 1-based index of the task to mark as finished. If omitted, ALL unfinished tasks will be marked as finished."
+                }
+            }
+        })
+    }
+
+    fn run(&self, ctx: &ToolCtx, args: &Value) -> Result<String> {
+        let path: PathBuf = ctx.session_dir.join("todo.md");
+        if !path.exists() {
+            return Ok("No todo.md found in session directory. Nothing to finish.".to_string());
+        }
+
+        let content = std::fs::read_to_string(&path)
+            .map_err(|e| anyhow!("failed to read todo.md: {}", e))?;
+
+        let task_index = args.get("task_index").and_then(|v| v.as_i64());
+
+        let mut new_content = String::new();
+        let mut task_count = 0;
+        let mut modified = false;
+
+        for line in content.lines() {
+            if line.trim_start().starts_with("- [ ]") {
+                task_count += 1;
+                if let Some(target) = task_index {
+                    if task_count == target {
+                        new_content.push_str(&line.replacen("- [ ]", "- [x]", 1));
+                        modified = true;
+                    } else {
+                        new_content.push_str(line);
+                    }
+                } else {
+                    // Mark all as finished
+                    new_content.push_str(&line.replacen("- [ ]", "- [x]", 1));
+                    modified = true;
+                }
+            } else {
+                new_content.push_str(line);
+            }
+            new_content.push('\n');
+        }
+
+        if !modified {
+            return Ok("No unfinished tasks found or index out of bounds.".to_string());
+        }
+
+        std::fs::write(&path, new_content)
+            .map_err(|e| anyhow!("failed to write to todo.md: {}", e))?;
+
+        if let Some(idx) = task_index {
+            Ok(format!("Successfully marked task {} as finished.", idx))
+        } else {
+            Ok("Successfully marked ALL tasks as finished.".to_string())
+        }
+    }
+}