huskies/server/src/agent_log.rs

//! Agent log persistence — reads and writes JSONL agent event logs to disk.
use crate::agents::AgentEvent;
use chrono::Utc;
use serde::{Deserialize, Serialize};
use std::fs::{self, File, OpenOptions};
use std::io::{BufRead, BufReader, Write};
use std::path::{Path, PathBuf};


/// A single line in the agent log file (JSONL format).
#[derive(Debug, Serialize, Deserialize)]
pub struct LogEntry {
    pub timestamp: String,
    #[serde(flatten)]
    pub event: serde_json::Value,
}

/// Writes agent events to a persistent log file (JSONL format).
///
/// Each agent session gets its own log file at:
///   `.huskies/logs/{story_id}/{agent_name}-{session_id}.log`
pub struct AgentLogWriter {
    file: File,
}

impl AgentLogWriter {
    /// Create a new log writer, creating the directory structure as needed.
    ///
    /// The log file is opened in append mode so that a restart mid-session
    /// won't overwrite earlier output.
    pub fn new(
        project_root: &Path,
        story_id: &str,
        agent_name: &str,
        session_id: &str,
    ) -> Result<Self, String> {
        let dir = log_dir(project_root, story_id);
        fs::create_dir_all(&dir)
            .map_err(|e| format!("Failed to create log directory {}: {e}", dir.display()))?;

        let path = dir.join(format!("{agent_name}-{session_id}.log"));
        let file = OpenOptions::new()
            .create(true)
            .append(true)
            .open(&path)
            .map_err(|e| format!("Failed to open log file {}: {e}", path.display()))?;

        Ok(Self { file })
    }

    /// Write an agent event as a JSONL line with an ISO 8601 timestamp.
    pub fn write_event(&mut self, event: &AgentEvent) -> Result<(), String> {
        let event_value =
            serde_json::to_value(event).map_err(|e| format!("Failed to serialize event: {e}"))?;

        let entry = LogEntry {
            timestamp: Utc::now().to_rfc3339(),
            event: event_value,
        };

        let mut line =
            serde_json::to_string(&entry).map_err(|e| format!("Failed to serialize entry: {e}"))?;
        line.push('\n');

        self.file
            .write_all(line.as_bytes())
            .map_err(|e| format!("Failed to write log entry: {e}"))?;

        Ok(())
    }
}

/// Return the log directory for a story.
fn log_dir(project_root: &Path, story_id: &str) -> PathBuf {
    project_root
        .join(".huskies")
        .join("logs")
        .join(story_id)
}

/// Return the path to a specific log file.
#[allow(dead_code)]
pub fn log_file_path(
    project_root: &Path,
    story_id: &str,
    agent_name: &str,
    session_id: &str,
) -> PathBuf {
    log_dir(project_root, story_id).join(format!("{agent_name}-{session_id}.log"))
}

/// Read all log entries from a log file.
pub fn read_log(path: &Path) -> Result<Vec<LogEntry>, String> {
    let file =
        File::open(path).map_err(|e| format!("Failed to open log file {}: {e}", path.display()))?;
    let reader = BufReader::new(file);
    let mut entries = Vec::new();

    for line in reader.lines() {
        let line = line.map_err(|e| format!("Failed to read log line: {e}"))?;
        let trimmed = line.trim();
        if trimmed.is_empty() {
            continue;
        }
        let entry: LogEntry = serde_json::from_str(trimmed)
            .map_err(|e| format!("Failed to parse log entry: {e}"))?;
        entries.push(entry);
    }

    Ok(entries)
}

/// List all log files for a story, optionally filtered by agent name prefix.
///
/// Returns files sorted by modification time (oldest first) so that when all
/// sessions are concatenated the timeline reads chronologically.
pub fn list_story_log_files(
    project_root: &Path,
    story_id: &str,
    agent_name_filter: Option<&str>,
) -> Vec<PathBuf> {
    let dir = log_dir(project_root, story_id);
    if !dir.is_dir() {
        return Vec::new();
    }

    let prefix = agent_name_filter.map(|n| format!("{n}-"));
    let mut files: Vec<(PathBuf, std::time::SystemTime)> = Vec::new();

    if let Ok(entries) = fs::read_dir(&dir) {
        for entry in entries.flatten() {
            let path = entry.path();
            let name = match path.file_name().and_then(|n| n.to_str()) {
                Some(n) => n.to_string(),
                None => continue,
            };
            if !name.ends_with(".log") {
                continue;
            }
            if let Some(ref pfx) = prefix
                && !name.starts_with(pfx.as_str())
            {
                continue;
            }
            let modified = entry
                .metadata()
                .and_then(|m| m.modified())
                .unwrap_or(std::time::SystemTime::UNIX_EPOCH);
            files.push((path, modified));
        }
    }

    files.sort_by_key(|(_, t)| *t);
    files.into_iter().map(|(p, _)| p).collect()
}

/// Format a single log entry as a human-readable text line.
///
/// `timestamp` is an ISO 8601 string; `event` is the flattened `AgentEvent`
/// value (has `type`, `agent_name`, etc. at the top level).
///
/// Returns `None` for entries that should be skipped (raw streaming noise,
/// trivial status changes, empty output, etc.).
pub fn format_log_entry_as_text(timestamp: &str, event: &serde_json::Value) -> Option<String> {
    let agent_name = event
        .get("agent_name")
        .and_then(|v| v.as_str())
        .unwrap_or("?");
    // Extract HH:MM:SS from ISO 8601 "2026-04-10T12:48:02.123456789+00:00"
    let ts_short = if timestamp.len() >= 19 {
        &timestamp[11..19]
    } else {
        timestamp
    };
    let pfx = format!("[{ts_short}][{agent_name}]");

    match event.get("type").and_then(|v| v.as_str()) {
        Some("output") => {
            let text = event
                .get("text")
                .and_then(|v| v.as_str())
                .unwrap_or("")
                .trim();
            if text.is_empty() {
                None
            } else {
                Some(format!("{pfx} {text}"))
            }
        }
        Some("error") => {
            let msg = event
                .get("message")
                .and_then(|v| v.as_str())
                .unwrap_or("(unknown error)");
            Some(format!("{pfx} ERROR: {msg}"))
        }
        Some("done") => Some(format!("{pfx} DONE")),
        Some("status") => {
            // Skip trivial running/started noise
            let status = event
                .get("status")
                .and_then(|v| v.as_str())
                .unwrap_or("?");
            match status {
                "running" | "started" => None,
                _ => Some(format!("{pfx} STATUS: {status}")),
            }
        }
        Some("agent_json") => {
            let data = event.get("data")?;
            match data.get("type").and_then(|v| v.as_str()) {
                Some("assistant") => {
                    let mut parts: Vec<String> = Vec::new();
                    if let Some(arr) = data
                        .pointer("/message/content")
                        .and_then(|v| v.as_array())
                    {
                        for item in arr {
                            match item.get("type").and_then(|v| v.as_str()) {
                                Some("text") => {
                                    let text = item
                                        .get("text")
                                        .and_then(|v| v.as_str())
                                        .unwrap_or("")
                                        .trim();
                                    if !text.is_empty() {
                                        parts.push(format!("{pfx} {text}"));
                                    }
                                }
                                Some("tool_use") => {
                                    let name = item
                                        .get("name")
                                        .and_then(|v| v.as_str())
                                        .unwrap_or("?");
                                    let input = item
                                        .get("input")
                                        .map(|v| {
                                            serde_json::to_string(v).unwrap_or_default()
                                        })
                                        .unwrap_or_default();
                                    let display = if input.len() > 200 {
                                        format!("{}...", &input[..200])
                                    } else {
                                        input
                                    };
                                    parts.push(format!("{pfx} TOOL: {name}({display})"));
                                }
                                _ => {}
                            }
                        }
                    }
                    if parts.is_empty() {
                        None
                    } else {
                        Some(parts.join("\n"))
                    }
                }
                Some("user") => {
                    let mut parts: Vec<String> = Vec::new();
                    if let Some(arr) = data
                        .pointer("/message/content")
                        .and_then(|v| v.as_array())
                    {
                        for item in arr {
                            if item.get("type").and_then(|v| v.as_str())
                                != Some("tool_result")
                            {
                                continue;
                            }
                            let content_str = match item.get("content") {
                                Some(serde_json::Value::String(s)) => s.clone(),
                                Some(v) => v.to_string(),
                                None => String::new(),
                            };
                            let display = if content_str.len() > 500 {
                                format!(
                                    "{}... [{} chars total]",
                                    &content_str[..500],
                                    content_str.len()
                                )
                            } else {
                                content_str
                            };
                            if !display.trim().is_empty() {
                                parts.push(format!("{pfx} RESULT: {display}"));
                            }
                        }
                    }
                    if parts.is_empty() {
                        None
                    } else {
                        Some(parts.join("\n"))
                    }
                }
                _ => None, // Skip stream_event, system init, etc.
            }
        }
        _ => None,
    }
}

/// Read log entries from a file and convert them to human-readable text lines,
/// stripping raw streaming noise and JSON internals.
pub fn read_log_as_readable_lines(path: &Path) -> Result<Vec<String>, String> {
    let entries = read_log(path)?;
    let mut result = Vec::new();
    for entry in &entries {
        if let Some(line) = format_log_entry_as_text(&entry.timestamp, &entry.event) {
            result.push(line);
        }
    }
    Ok(result)
}

/// Find the most recent log file for a given story+agent combination.
///
/// Scans `.huskies/logs/{story_id}/` for files matching `{agent_name}-*.log`
/// and returns the one with the most recent modification time.
pub fn find_latest_log(
    project_root: &Path,
    story_id: &str,
    agent_name: &str,
) -> Option<PathBuf> {
    let dir = log_dir(project_root, story_id);
    if !dir.is_dir() {
        return None;
    }

    let prefix = format!("{agent_name}-");
    let mut best: Option<(PathBuf, std::time::SystemTime)> = None;

    let entries = fs::read_dir(&dir).ok()?;
    for entry in entries.flatten() {
        let path = entry.path();
        let name = match path.file_name().and_then(|n| n.to_str()) {
            Some(n) => n.to_string(),
            None => continue,
        };
        if !name.starts_with(&prefix) || !name.ends_with(".log") {
            continue;
        }
        let modified = match entry.metadata().and_then(|m| m.modified()) {
            Ok(t) => t,
            Err(_) => continue,
        };
        if best.as_ref().is_none_or(|(_, t)| modified > *t) {
            best = Some((path, modified));
        }
    }

    best.map(|(p, _)| p)
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::agents::AgentEvent;
    use tempfile::tempdir;

    #[test]
    fn test_log_writer_creates_directory_and_file() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let _writer =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-abc123").unwrap();

        let expected_path = root
            .join(".huskies")
            .join("logs")
            .join("42_story_foo")
            .join("coder-1-sess-abc123.log");
        assert!(expected_path.exists(), "Log file should exist");
    }

    #[test]
    fn test_log_writer_writes_jsonl_with_timestamps() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let mut writer =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-001").unwrap();

        let event = AgentEvent::Status {
            story_id: "42_story_foo".to_string(),
            agent_name: "coder-1".to_string(),
            status: "running".to_string(),
        };
        writer.write_event(&event).unwrap();

        let event2 = AgentEvent::Output {
            story_id: "42_story_foo".to_string(),
            agent_name: "coder-1".to_string(),
            text: "Hello world".to_string(),
        };
        writer.write_event(&event2).unwrap();

        // Read the file and verify
        let path = log_file_path(root, "42_story_foo", "coder-1", "sess-001");
        let content = fs::read_to_string(&path).unwrap();
        let lines: Vec<&str> = content.lines().collect();
        assert_eq!(lines.len(), 2, "Should have 2 log lines");

        // Parse each line as valid JSON with a timestamp
        for line in &lines {
            let entry: LogEntry = serde_json::from_str(line).unwrap();
            assert!(!entry.timestamp.is_empty(), "Timestamp should be present");
            // Verify it's a valid ISO 8601 timestamp
            chrono::DateTime::parse_from_rfc3339(&entry.timestamp)
                .expect("Timestamp should be valid RFC3339");
        }

        // Verify the first entry is a status event
        let entry1: LogEntry = serde_json::from_str(lines[0]).unwrap();
        assert_eq!(entry1.event["type"], "status");
        assert_eq!(entry1.event["status"], "running");

        // Verify the second entry is an output event
        let entry2: LogEntry = serde_json::from_str(lines[1]).unwrap();
        assert_eq!(entry2.event["type"], "output");
        assert_eq!(entry2.event["text"], "Hello world");
    }

    #[test]
    fn test_read_log_parses_written_events() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let mut writer =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-002").unwrap();

        let events = vec![
            AgentEvent::Status {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                status: "running".to_string(),
            },
            AgentEvent::Output {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                text: "Processing...".to_string(),
            },
            AgentEvent::AgentJson {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                data: serde_json::json!({"type": "tool_use", "name": "read_file"}),
            },
            AgentEvent::Done {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                session_id: Some("sess-002".to_string()),
            },
        ];

        for event in &events {
            writer.write_event(event).unwrap();
        }

        let path = log_file_path(root, "42_story_foo", "coder-1", "sess-002");
        let entries = read_log(&path).unwrap();
        assert_eq!(entries.len(), 4, "Should read back all 4 events");

        // Verify event types round-trip correctly
        assert_eq!(entries[0].event["type"], "status");
        assert_eq!(entries[1].event["type"], "output");
        assert_eq!(entries[2].event["type"], "agent_json");
        assert_eq!(entries[3].event["type"], "done");
    }

    #[test]
    fn test_separate_sessions_produce_separate_files() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let mut writer1 =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-aaa").unwrap();
        let mut writer2 =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-bbb").unwrap();

        writer1
            .write_event(&AgentEvent::Output {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                text: "from session aaa".to_string(),
            })
            .unwrap();

        writer2
            .write_event(&AgentEvent::Output {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                text: "from session bbb".to_string(),
            })
            .unwrap();

        let path1 = log_file_path(root, "42_story_foo", "coder-1", "sess-aaa");
        let path2 = log_file_path(root, "42_story_foo", "coder-1", "sess-bbb");

        assert_ne!(path1, path2, "Different sessions should use different files");

        let entries1 = read_log(&path1).unwrap();
        let entries2 = read_log(&path2).unwrap();

        assert_eq!(entries1.len(), 1);
        assert_eq!(entries2.len(), 1);
        assert_eq!(entries1[0].event["text"], "from session aaa");
        assert_eq!(entries2[0].event["text"], "from session bbb");
    }

    #[test]
    fn test_find_latest_log_returns_most_recent() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        // Create two log files with a small delay
        let mut writer1 =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-old").unwrap();
        writer1
            .write_event(&AgentEvent::Output {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                text: "old".to_string(),
            })
            .unwrap();
        drop(writer1);

        // Touch the second file to ensure it's newer
        std::thread::sleep(std::time::Duration::from_millis(50));

        let mut writer2 =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-new").unwrap();
        writer2
            .write_event(&AgentEvent::Output {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                text: "new".to_string(),
            })
            .unwrap();
        drop(writer2);

        let latest = find_latest_log(root, "42_story_foo", "coder-1").unwrap();
        assert!(
            latest.to_string_lossy().contains("sess-new"),
            "Should find the newest log file, got: {}",
            latest.display()
        );
    }

    #[test]
    fn test_list_story_log_files_returns_empty_for_missing_dir() {
        let tmp = tempdir().unwrap();
        let files = list_story_log_files(tmp.path(), "nonexistent", None);
        assert!(files.is_empty());
    }

    #[test]
    fn test_list_story_log_files_no_filter_returns_all_logs() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let mut w1 = AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-aaa").unwrap();
        w1.write_event(&AgentEvent::Output {
            story_id: "42_story_foo".to_string(),
            agent_name: "coder-1".to_string(),
            text: "from coder-1".to_string(),
        })
        .unwrap();
        drop(w1);
        std::thread::sleep(std::time::Duration::from_millis(10));

        let mut w2 =
            AgentLogWriter::new(root, "42_story_foo", "mergemaster", "sess-bbb").unwrap();
        w2.write_event(&AgentEvent::Output {
            story_id: "42_story_foo".to_string(),
            agent_name: "mergemaster".to_string(),
            text: "from mergemaster".to_string(),
        })
        .unwrap();
        drop(w2);

        let files = list_story_log_files(root, "42_story_foo", None);
        assert_eq!(files.len(), 2, "Should find both log files");
        // Oldest first
        assert!(
            files[0].to_string_lossy().contains("coder-1"),
            "coder-1 should be first (older)"
        );
    }

    #[test]
    fn test_list_story_log_files_with_agent_filter() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let mut w1 = AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-a").unwrap();
        w1.write_event(&AgentEvent::Output {
            story_id: "42_story_foo".to_string(),
            agent_name: "coder-1".to_string(),
            text: "from coder-1".to_string(),
        })
        .unwrap();
        drop(w1);

        let mut w2 =
            AgentLogWriter::new(root, "42_story_foo", "mergemaster", "sess-b").unwrap();
        w2.write_event(&AgentEvent::Output {
            story_id: "42_story_foo".to_string(),
            agent_name: "mergemaster".to_string(),
            text: "from mergemaster".to_string(),
        })
        .unwrap();
        drop(w2);

        let files = list_story_log_files(root, "42_story_foo", Some("coder-1"));
        assert_eq!(files.len(), 1, "Should find only coder-1 log");
        assert!(files[0].to_string_lossy().contains("coder-1"));
    }

    #[test]
    fn test_format_log_entry_output_event() {
        let ts = "2026-04-10T12:48:02.123456789+00:00";
        let event = serde_json::json!({
            "type": "output",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "text": "Hello world"
        });
        let result = format_log_entry_as_text(ts, &event).unwrap();
        assert!(result.contains("12:48:02"), "should include timestamp");
        assert!(result.contains("coder-1"), "should include agent name");
        assert!(result.contains("Hello world"), "should include text");
    }

    #[test]
    fn test_format_log_entry_skips_empty_output() {
        let ts = "2026-04-10T12:48:02.123456789+00:00";
        let event = serde_json::json!({
            "type": "output",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "text": "   "
        });
        assert!(format_log_entry_as_text(ts, &event).is_none());
    }

    #[test]
    fn test_format_log_entry_error_event() {
        let ts = "2026-04-10T12:48:02.123+00:00";
        let event = serde_json::json!({
            "type": "error",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "message": "Something went wrong"
        });
        let result = format_log_entry_as_text(ts, &event).unwrap();
        assert!(result.contains("ERROR"));
        assert!(result.contains("Something went wrong"));
    }

    #[test]
    fn test_format_log_entry_done_event() {
        let ts = "2026-04-10T12:48:02.123+00:00";
        let event = serde_json::json!({
            "type": "done",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "session_id": null
        });
        let result = format_log_entry_as_text(ts, &event).unwrap();
        assert!(result.contains("DONE"));
    }

    #[test]
    fn test_format_log_entry_skips_running_status() {
        let ts = "2026-04-10T12:48:02.123+00:00";
        let event = serde_json::json!({
            "type": "status",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "status": "running"
        });
        assert!(format_log_entry_as_text(ts, &event).is_none());
    }

    #[test]
    fn test_format_log_entry_agent_json_tool_use() {
        let ts = "2026-04-10T12:48:03.000+00:00";
        let event = serde_json::json!({
            "type": "agent_json",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "data": {
                "type": "assistant",
                "message": {
                    "content": [
                        {
                            "type": "tool_use",
                            "id": "tool-1",
                            "name": "Read",
                            "input": {"file_path": "/some/file.rs"}
                        }
                    ]
                }
            }
        });
        let result = format_log_entry_as_text(ts, &event).unwrap();
        assert!(result.contains("TOOL: Read"), "should show tool call: {result}");
        assert!(result.contains("file_path"), "should show input: {result}");
    }

    #[test]
    fn test_format_log_entry_agent_json_text() {
        let ts = "2026-04-10T12:48:04.000+00:00";
        let event = serde_json::json!({
            "type": "agent_json",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "data": {
                "type": "assistant",
                "message": {
                    "content": [
                        {
                            "type": "text",
                            "text": "Now I will read the file."
                        }
                    ]
                }
            }
        });
        let result = format_log_entry_as_text(ts, &event).unwrap();
        assert!(result.contains("Now I will read the file."), "should show text: {result}");
    }

    #[test]
    fn test_format_log_entry_skips_stream_events() {
        let ts = "2026-04-10T12:48:04.000+00:00";
        let event = serde_json::json!({
            "type": "agent_json",
            "story_id": "42_story",
            "agent_name": "coder-1",
            "data": {
                "type": "stream_event",
                "event": {"type": "content_block_delta", "delta": {"type": "text_delta", "text": "chunk"}}
            }
        });
        assert!(format_log_entry_as_text(ts, &event).is_none(), "stream events should be skipped");
    }

    #[test]
    fn test_read_log_as_readable_lines_produces_formatted_output() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let mut writer =
            AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-readable").unwrap();
        writer
            .write_event(&AgentEvent::Output {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                text: "Let me read the file".to_string(),
            })
            .unwrap();
        writer
            .write_event(&AgentEvent::Done {
                story_id: "42_story_foo".to_string(),
                agent_name: "coder-1".to_string(),
                session_id: Some("sess-readable".to_string()),
            })
            .unwrap();

        let path = log_file_path(root, "42_story_foo", "coder-1", "sess-readable");
        let lines = read_log_as_readable_lines(&path).unwrap();
        assert_eq!(lines.len(), 2, "Should produce 2 readable lines");
        assert!(lines[0].contains("Let me read the file"), "first line: {}", lines[0]);
        assert!(lines[1].contains("DONE"), "second line: {}", lines[1]);
    }

    #[test]
    fn test_find_latest_log_returns_none_for_missing_dir() {
        let tmp = tempdir().unwrap();
        let result = find_latest_log(tmp.path(), "nonexistent", "coder-1");
        assert!(result.is_none());
    }

    #[test]
    fn test_log_files_persist_on_disk() {
        let tmp = tempdir().unwrap();
        let root = tmp.path();

        let path = {
            let mut writer =
                AgentLogWriter::new(root, "42_story_foo", "coder-1", "sess-persist").unwrap();
            writer
                .write_event(&AgentEvent::Status {
                    story_id: "42_story_foo".to_string(),
                    agent_name: "coder-1".to_string(),
                    status: "running".to_string(),
                })
                .unwrap();
            log_file_path(root, "42_story_foo", "coder-1", "sess-persist")
            // writer is dropped here
        };

        // File should still exist and be readable
        assert!(path.exists(), "Log file should persist after writer is dropped");
        let entries = read_log(&path).unwrap();
        assert_eq!(entries.len(), 1);
        assert_eq!(entries[0].event["type"], "status");
    }
}