koda-cli 0.2.11

A high-performance AI coding agent for macOS and Linux
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
//! Slash command handler for the TUI event loop.
//!
//! Dispatches `/command` input to the appropriate handler. Most commands
//! are handled via [`crate::repl::handle_command`] (shared with headless),
//! then translated into TUI-specific actions here.
//!
//! See [`crate`] module docs for the full command table.
//!
//! All output flows through the [`crate::scroll_buffer::ScrollBuffer`] render cache.

use crate::repl::ReplAction;
use crate::scroll_buffer::ScrollBuffer;
use crate::tui_output;
use crate::tui_render::TuiRenderer;
use koda_core::persistence::Persistence;
use koda_core::trust;
// For /copy transcript export:
use crate::mouse_select::copy_to_clipboard;
use crate::transcript;

use koda_core::agent::KodaAgent;
use koda_core::config::KodaConfig;
use koda_core::providers::LlmProvider;
use koda_core::session::KodaSession;
use ratatui::text::{Line, Span};
use std::sync::Arc;
use tokio::sync::RwLock;

pub enum SlashAction {
    Continue,
    Quit,
    OpenKeyMenu,
}

use tui_output::{BOLD, CYAN, DIM};

// ── Main handler ────────────────────────────────────────

#[allow(clippy::too_many_arguments, unused_variables)]
pub async fn handle_slash_command(
    buffer: &mut ScrollBuffer,
    input: &str,
    config: &mut KodaConfig,
    provider: &Arc<RwLock<Box<dyn LlmProvider>>>,
    session: &mut KodaSession,
    shared_mode: &trust::SharedTrustMode,
    renderer: &mut TuiRenderer,
    project_root: &std::path::Path,
    agent: &Arc<KodaAgent>,
    pending_command: &mut Option<String>,
    menu: &mut crate::tui_types::MenuContent,
) -> SlashAction {
    match crate::repl::handle_command(input, config, provider).await {
        ReplAction::Quit => SlashAction::Quit,
        ReplAction::SwitchModel(model) => {
            // Check if it's an alias first
            if let Some(resolved) = koda_core::model_alias::resolve(&model) {
                let ptype = resolved.provider;
                if ptype.requires_api_key() && !koda_core::runtime_env::is_set(ptype.env_key_name())
                {
                    tui_output::err_msg(
                        buffer,
                        format!("{} not set. Run /key to configure.", ptype.env_key_name()),
                    );
                } else if resolved.needs_auto_detect() {
                    tui_output::warn_msg(
                        buffer,
                        "Use /model to pick local models interactively.".to_string(),
                    );
                } else {
                    config.provider_type = ptype;
                    config.base_url = ptype.default_base_url().to_string();
                    config.model = resolved.model_id.to_string();
                    config.model_settings.model = config.model.clone();
                    config.recalculate_model_derived();
                    *provider.write().await = koda_core::providers::create_provider(config);
                    {
                        let prov = provider.read().await;
                        config.query_and_apply_capabilities(prov.as_ref()).await;
                    }
                    crate::tui_wizards::save_provider(config, &session.db).await;
                    tui_output::ok_msg(
                        buffer,
                        format!(
                            "Model: {} ({}, {})",
                            resolved.alias, resolved.model_id, ptype
                        ),
                    );
                }
            } else {
                // Literal model ID — switch on current provider
                config.model = model.clone();
                config.model_settings.model = model.clone();
                config.recalculate_model_derived();
                {
                    let prov = provider.read().await;
                    config.query_and_apply_capabilities(prov.as_ref()).await;
                }
                crate::tui_wizards::save_provider(config, &session.db).await;
                tui_output::ok_msg(buffer, format!("Model set to: {model}"));
            }
            SlashAction::Continue
        }
        ReplAction::PickModel => SlashAction::Continue,
        ReplAction::SetupProvider(_ptype, _base_url) => SlashAction::Continue,
        ReplAction::PickProvider => SlashAction::Continue,
        ReplAction::ShowHelp => {
            show_help(buffer);
            SlashAction::Continue
        }
        ReplAction::Undo => {
            match agent.tools.undo.lock() {
                Ok(mut undo) => match undo.undo() {
                    Some(summary) => tui_output::ok_msg(buffer, summary),
                    None => tui_output::warn_msg(buffer, "Nothing to undo.".to_string()),
                },
                Err(e) => tui_output::err_msg(buffer, format!("Undo error: {e}")),
            }
            SlashAction::Continue
        }
        ReplAction::ListSessions => SlashAction::Continue,
        ReplAction::DeleteSession(ref id) => {
            handle_delete_session(buffer, session, id, project_root).await;
            SlashAction::Continue
        }
        ReplAction::ResumeSession(ref id) => {
            handle_resume_session(buffer, session, id, project_root, shared_mode).await;
            SlashAction::Continue
        }
        ReplAction::InjectPrompt(prompt) => {
            *pending_command = Some(prompt);
            SlashAction::Continue
        }
        ReplAction::Compact => {
            crate::tui_wizards::handle_compact(buffer, session, config, provider).await;
            SlashAction::Continue
        }
        ReplAction::Purge(ref age_filter) => {
            crate::tui_wizards::handle_purge(buffer, session, age_filter.as_deref(), menu).await;
            SlashAction::Continue
        }
        ReplAction::Expand(n) => {
            handle_expand(buffer, renderer, n);
            SlashAction::Continue
        }
        ReplAction::Verbose(v) => {
            renderer.verbose = match v {
                Some(val) => val,
                None => !renderer.verbose,
            };
            let state = if renderer.verbose { "on" } else { "off" };
            tui_output::emit_line(
                buffer,
                Line::styled(format!("  Verbose tool output: {state}"), CYAN),
            );
            SlashAction::Continue
        }
        ReplAction::ListAgents => {
            crate::tui_wizards::handle_list_agents(buffer, project_root);
            SlashAction::Continue
        }
        ReplAction::ShowDiff => {
            crate::tui_wizards::handle_diff(buffer);
            SlashAction::Continue
        }
        ReplAction::MemoryCommand(ref arg) => {
            crate::tui_wizards::handle_memory(buffer, arg.as_deref(), project_root);
            SlashAction::Continue
        }
        ReplAction::ListSkills(ref query) => {
            crate::tui_wizards::handle_list_skills(buffer, query.as_deref(), &agent.tools);
            SlashAction::Continue
        }
        ReplAction::ManageKeys => {
            crate::tui_wizards::handle_keys(buffer);
            SlashAction::OpenKeyMenu
        }
        ReplAction::CopyResponse(n) => {
            handle_copy_response(buffer, session, n).await;
            SlashAction::Continue
        }
        ReplAction::Export(ref dest) => {
            handle_export(buffer, session, dest.as_deref()).await;
            SlashAction::Continue
        }
        ReplAction::Handled => SlashAction::Continue,
        ReplAction::NotACommand => SlashAction::Continue,
    }
}

// ── Sub-handlers ────────────────────────────────────────

async fn handle_delete_session(
    buffer: &mut ScrollBuffer,
    session: &KodaSession,
    id: &str,
    project_root: &std::path::Path,
) {
    if id == session.id {
        tui_output::err_msg(buffer, "Cannot delete the current session.".into());
    } else {
        match session.db.list_sessions(100, project_root).await {
            Ok(sessions) => {
                let matches: Vec<_> = sessions.iter().filter(|s| s.id.starts_with(id)).collect();
                match matches.len() {
                    0 => tui_output::err_msg(buffer, format!("No session found matching '{id}'.")),
                    1 => {
                        let full_id = &matches[0].id;
                        match session.db.delete_session(full_id).await {
                            Ok(true) => tui_output::ok_msg(
                                buffer,
                                format!("Deleted session {}", &full_id[..8]),
                            ),
                            Ok(false) => tui_output::err_msg(buffer, "Session not found.".into()),
                            Err(e) => tui_output::err_msg(buffer, format!("Error: {e}")),
                        }
                    }
                    n => tui_output::err_msg(
                        buffer,
                        format!("Ambiguous: '{id}' matches {n} sessions. Be more specific."),
                    ),
                }
            }
            Err(e) => tui_output::err_msg(buffer, format!("Error: {e}")),
        }
    }
}

async fn handle_resume_session(
    buffer: &mut ScrollBuffer,
    session: &mut KodaSession,
    id: &str,
    project_root: &std::path::Path,
    shared_mode: &trust::SharedTrustMode,
) {
    use tui_output::GREEN;
    if session.id.starts_with(id) {
        tui_output::dim_msg(buffer, "Already in this session.".into());
    } else {
        match session.db.list_sessions(100, project_root).await {
            Ok(sessions) => {
                let matches: Vec<_> = sessions.iter().filter(|s| s.id.starts_with(id)).collect();
                match matches.len() {
                    0 => tui_output::err_msg(buffer, format!("No session found matching '{id}'.")),
                    1 => {
                        let target = &matches[0];
                        session.id = target.id.clone();
                        session.title_set = true;
                        let short_id = target.id[..8].to_string();
                        let title_part = target
                            .title
                            .as_deref()
                            .map(|t| format!("{}", t.chars().take(40).collect::<String>()))
                            .unwrap_or_default();
                        let detail = format!(
                            "{title_part}  {}  {} msgs",
                            target.created_at, target.message_count
                        );
                        tui_output::emit_line(
                            buffer,
                            Line::from(vec![
                                Span::styled("  \u{2713} ", GREEN),
                                Span::raw("Resumed session "),
                                Span::styled(short_id, CYAN),
                                Span::styled(detail, DIM),
                            ]),
                        );
                        // Restore persisted approval mode (#590)
                        if let Ok(Some(mode_str)) = session.db.get_session_mode(&session.id).await
                            && let Some(m) = trust::TrustMode::parse(&mode_str)
                        {
                            trust::set_trust(shared_mode, m);
                        }
                        // Read idle time BEFORE load_context updates last_accessed_at.
                        let idle_secs = session
                            .db
                            .get_session_idle_secs(&session.id)
                            .await
                            .ok()
                            .flatten();
                        // Show away-summary + interrupted-turn banners (#590, #594)
                        if let Ok(msgs) = session.db.load_context(&session.id).await {
                            use koda_core::persistence::Role;
                            let user_msgs = msgs.iter().filter(|m| m.role == Role::User).count();
                            let tool_calls = msgs.iter().filter(|m| m.role == Role::Tool).count();
                            let total_tokens: i64 = msgs
                                .iter()
                                .map(|m| {
                                    m.prompt_tokens.unwrap_or(0) + m.completion_tokens.unwrap_or(0)
                                })
                                .sum();
                            buffer.push_lines(tui_output::away_summary_banner(
                                idle_secs,
                                None, // title already in the confirmation line above
                                user_msgs,
                                tool_calls,
                                total_tokens,
                            ));
                            if let Some(kind) = koda_core::db::queries::detect_interruption(&msgs) {
                                buffer.push_lines(tui_output::interrupted_turn_banner(&kind));
                            }
                        }
                    }
                    n => tui_output::err_msg(
                        buffer,
                        format!("Ambiguous: '{id}' matches {n} sessions. Be more specific."),
                    ),
                }
            }
            Err(e) => tui_output::err_msg(buffer, format!("Error: {e}")),
        }
    }
}

/// Print help output generated from the `SLASH_COMMANDS` registry.
///
/// Single source of truth: `completer::SLASH_COMMANDS` drives both
/// Tab completion and this help screen.
///
/// Sections:
/// 1. Commands — slash commands from the registry
/// 2. Input — text entry and file attachment
/// 3. Navigation — scroll and history search
/// 4. Session control — cancel, quit, clipboard
/// 5. Approval — keys shown when the engine requests tool approval
fn show_help(buffer: &mut ScrollBuffer) {
    use crate::completer::SLASH_COMMANDS;

    // Column width: longest command label (cmd + arg_hint) + padding
    let max_cmd_len = SLASH_COMMANDS
        .iter()
        .map(|(cmd, _, hint)| cmd.len() + hint.map(|h| h.len() + 1).unwrap_or(0))
        .max()
        .unwrap_or(10);
    let col = max_cmd_len.max(16) + 4; // at least 20 chars wide

    // ── Commands ───────────────────────────────────────────────
    tui_output::blank(buffer);
    tui_output::emit_line(buffer, Line::styled("  Commands", BOLD));
    tui_output::blank(buffer);
    for &(cmd, desc, arg_hint) in SLASH_COMMANDS {
        let label = match arg_hint {
            Some(hint) => format!("{cmd} {hint}"),
            None => cmd.to_string(),
        };
        tui_output::emit_line(
            buffer,
            Line::from(vec![
                Span::styled(format!("  {label:<col$}"), CYAN),
                Span::styled(desc, DIM),
            ]),
        );
    }

    // ── Input ──────────────────────────────────────────────────
    tui_output::blank(buffer);
    tui_output::emit_line(buffer, Line::styled("  Input", BOLD));
    tui_output::blank(buffer);
    let input_keys: &[(&str, &str)] = &[
        ("Enter", "Send message"),
        ("Alt+Enter", "Insert newline (multi-line input)"),
        ("@file.rs", "Attach file context to your message"),
        ("@image.png", "Attach image (vision-capable models)"),
        ("↑ / ↓", "Cycle through input history"),
        ("Ctrl+R", "Reverse history search"),
        ("Tab", "Autocomplete @file path or /command"),
        ("Shift+Tab", "Cycle approval mode (auto ↔ confirm)"),
    ];
    for (key, desc) in input_keys {
        tui_output::emit_line(
            buffer,
            Line::from(vec![
                Span::styled(format!("  {key:<col$}"), CYAN),
                Span::styled(*desc, DIM),
            ]),
        );
    }

    // ── Navigation ─────────────────────────────────────────────
    tui_output::blank(buffer);
    tui_output::emit_line(buffer, Line::styled("  Navigation", BOLD));
    tui_output::blank(buffer);
    let nav_keys: &[(&str, &str)] = &[
        ("PgUp / PgDn", "Scroll history up / down one page"),
        ("Home", "Jump to top of history"),
        ("End", "Jump to bottom (latest output)"),
        ("Mouse scroll", "Scroll history"),
    ];
    for (key, desc) in nav_keys {
        tui_output::emit_line(
            buffer,
            Line::from(vec![
                Span::styled(format!("  {key:<col$}"), CYAN),
                Span::styled(*desc, DIM),
            ]),
        );
    }

    // ── Session control ────────────────────────────────────────
    tui_output::blank(buffer);
    tui_output::emit_line(buffer, Line::styled("  Session control", BOLD));
    tui_output::blank(buffer);
    let session_keys: &[(&str, &str)] = &[
        ("Esc / Ctrl+C", "Cancel running inference"),
        ("Ctrl+D", "Quit koda"),
    ];
    for (key, desc) in session_keys {
        tui_output::emit_line(
            buffer,
            Line::from(vec![
                Span::styled(format!("  {key:<col$}"), CYAN),
                Span::styled(*desc, DIM),
            ]),
        );
    }

    // ── Approval (shown when a tool needs confirmation) ────────
    tui_output::blank(buffer);
    tui_output::emit_line(
        buffer,
        Line::from(vec![
            Span::styled("  Approval ", BOLD),
            Span::styled("(when the agent asks to run a tool)", DIM),
        ]),
    );
    tui_output::blank(buffer);
    let approval_keys: &[(&str, &str)] = &[
        ("y", "Approve this tool call"),
        ("n", "Reject this tool call"),
        ("a", "Approve and switch to auto mode (no more prompts)"),
        ("f", "Reject and provide written feedback"),
        ("Esc", "Reject (same as n)"),
    ];
    for (key, desc) in approval_keys {
        tui_output::emit_line(
            buffer,
            Line::from(vec![
                Span::styled(format!("  {key:<col$}"), CYAN),
                Span::styled(*desc, DIM),
            ]),
        );
    }
    tui_output::blank(buffer);
}

fn handle_expand(buffer: &mut ScrollBuffer, renderer: &TuiRenderer, n: usize) {
    match renderer.tool_history.get(n) {
        Some(record) => {
            tui_output::blank(buffer);
            tui_output::emit_line(
                buffer,
                Line::from(vec![
                    Span::styled(format!("  \u{1f50d} Expand: {}", record.tool_name), BOLD),
                    Span::styled(format!(" ({} lines)", record.output.lines().count()), DIM),
                ]),
            );
            for line in record.output.lines() {
                tui_output::emit_line(
                    buffer,
                    Line::from(vec![
                        Span::styled("  \u{2502} ", DIM),
                        Span::raw(line.to_string()),
                    ]),
                );
            }
            tui_output::blank(buffer);
        }
        None => {
            let total = renderer.tool_history.len();
            if total == 0 {
                tui_output::dim_msg(buffer, "No tool outputs recorded yet.".into());
            } else {
                tui_output::warn_msg(
                    buffer,
                    format!(
                        "No tool output #{n}. Have {total} recorded (use /expand 1\u{2013}{total})."
                    ),
                );
            }
        }
    }
}

// ── /copy ────────────────────────────────────────────────

/// Export the session transcript to clipboard or a Markdown file.
///
/// `/copy [n]` — copy the Nth-most-recent assistant response to clipboard.
///
/// Loads messages from the DB, filters to assistant turns with text content,
/// and copies the Nth-last one (1 = most recent).
async fn handle_copy_response(
    buffer: &mut ScrollBuffer,
    session: &koda_core::session::KodaSession,
    n: usize,
) {
    let messages = match session.db.load_all_messages(&session.id).await {
        Ok(msgs) => msgs,
        Err(e) => {
            tui_output::err_msg(buffer, format!("Could not load messages: {e}"));
            return;
        }
    };

    // Collect assistant messages that have non-empty text content.
    let responses: Vec<&str> = messages
        .iter()
        .filter_map(|m| {
            use koda_core::persistence::Role;
            if m.role == Role::Assistant {
                m.content.as_deref().filter(|c| !c.trim().is_empty())
            } else {
                None
            }
        })
        .collect();

    let total = responses.len();
    if total == 0 {
        tui_output::dim_msg(buffer, "No assistant responses to copy.".into());
        return;
    }
    if n > total {
        tui_output::err_msg(
            buffer,
            format!(
                "Only {total} response{} in this session.",
                if total == 1 { "" } else { "s" }
            ),
        );
        return;
    }

    // responses is oldest-first; Nth-last = index (total - n)
    let content = responses[total - n];
    let label = if n == 1 {
        "last response".to_string()
    } else {
        format!("response #{n} from end")
    };

    match copy_to_clipboard(content) {
        Ok(msg) => {
            let preview: String = content.chars().take(60).collect();
            let preview = preview.replace('\n', " ");
            tui_output::ok_msg(buffer, format!("Copied {label} {msg}{preview}\u{2026}"));
        }
        Err(e) => tui_output::err_msg(buffer, e),
    }
}

/// `/export [<file.md>]` — export the full session transcript.
///
/// - `dest = None`        → auto-name from first user prompt + timestamp, write to CWD
/// - `dest = Some(path)`  → write Markdown to that explicit path
///
/// Uses `transcript::render` to produce a structured Markdown document
/// from all session messages (system messages excluded).
async fn handle_export(
    buffer: &mut ScrollBuffer,
    session: &koda_core::session::KodaSession,
    dest: Option<&str>,
) {
    // Fetch all messages — `load_all_messages` includes compacted history.
    let messages = match session.db.load_all_messages(&session.id).await {
        Ok(msgs) => msgs,
        Err(e) => {
            tui_output::err_msg(buffer, format!("Could not load messages: {e}"));
            return;
        }
    };

    // Try to get the session title for a nicer header.
    let title_storage;
    let session_title: Option<&str> = match session
        .db
        .list_sessions(200, std::path::Path::new("/"))
        .await
    {
        Ok(sessions) => {
            title_storage = sessions
                .into_iter()
                .find(|s| s.id == session.id)
                .and_then(|s| s.title);
            title_storage.as_deref()
        }
        Err(_) => None,
    };

    let md = transcript::render(&messages, session_title);

    let path_owned;
    let path: &str = match dest {
        Some(p) => {
            // Reject paths that escape CWD — absolute paths and ".." traversal.
            let dest_path = std::path::Path::new(p);
            if dest_path.is_absolute() || p.contains("..") {
                tui_output::err_msg(
                    buffer,
                    "Export path must be relative to the current directory \
                     (no absolute paths or \"..\" traversal)."
                        .into(),
                );
                return;
            }
            p
        }
        None => {
            path_owned = export_default_filename(&messages);
            &path_owned
        }
    };

    match std::fs::write(path, &md) {
        Ok(()) => {
            let lines = md.lines().count();
            tui_output::ok_msg(buffer, format!("Saved {lines} lines \u{2192} {path}"));
        }
        Err(e) => {
            tui_output::err_msg(buffer, format!("Could not write {path}: {e}"));
        }
    }
}

/// Generate a default export filename from the first user message + UTC timestamp.
///
/// Format: `koda-YYYYMMDD-HHMMSS-<slug>.md`  (slug from first user prompt, max 40 chars).
/// Falls back to `koda-YYYYMMDD-HHMMSS.md` when no user message exists.
fn export_default_filename(messages: &[koda_core::persistence::Message]) -> String {
    let dt = crate::util::utc_now();
    let ts = format!(
        "{:04}{:02}{:02}-{:02}{:02}{:02}",
        dt.year(),
        dt.month() as u8,
        dt.day(),
        dt.hour(),
        dt.minute(),
        dt.second(),
    );

    let slug: String = messages
        .iter()
        .find(|m| {
            use koda_core::persistence::Role;
            m.role == Role::User
        })
        .and_then(|m| m.content.as_deref())
        .map(|c| {
            c.lines()
                .next()
                .unwrap_or("")
                .trim()
                .chars()
                .filter(|c| c.is_alphanumeric() || c.is_whitespace())
                .take(50)
                .collect::<String>()
                .split_whitespace()
                .collect::<Vec<_>>()
                .join("-")
                .to_lowercase()
        })
        .filter(|s| !s.is_empty())
        .map(|s| {
            // Hard cap at 40 chars, respecting char boundaries.
            let truncated: String = s.chars().take(40).collect();
            truncated.trim_end_matches('-').to_string()
        })
        .unwrap_or_default();

    if slug.is_empty() {
        format!("koda-{ts}.md")
    } else {
        format!("koda-{ts}-{slug}.md")
    }
}

#[cfg(test)]
mod tests {
    use super::export_default_filename;
    use koda_core::persistence::{Message, Role};

    fn user_msg(content: &str) -> Message {
        Message {
            id: 0,
            session_id: "test".into(),
            role: Role::User,
            content: Some(content.to_string()),
            full_content: None,
            tool_calls: None,
            tool_call_id: None,
            prompt_tokens: None,
            completion_tokens: None,
            cache_read_tokens: None,
            cache_creation_tokens: None,
            thinking_tokens: None,
            thinking_content: None,
            created_at: None,
        }
    }

    #[test]
    fn filename_format_no_messages() {
        let name = export_default_filename(&[]);
        // koda-YYYYMMDD-HHMMSS.md
        assert!(name.starts_with("koda-"), "got: {name}");
        assert!(name.ends_with(".md"), "got: {name}");
    }

    #[test]
    fn filename_includes_slug_from_first_user_msg() {
        let msgs = vec![user_msg("Refactor the auth module")];
        let name = export_default_filename(&msgs);
        assert!(name.contains("refactor"), "got: {name}");
        assert!(name.contains("auth"), "got: {name}");
        assert!(name.ends_with(".md"), "got: {name}");
    }

    #[test]
    fn filename_slug_is_lowercase_hyphenated() {
        let msgs = vec![user_msg("Fix Bug In Parser")];
        let name = export_default_filename(&msgs);
        assert!(name.contains("fix-bug-in-parser"), "got: {name}");
    }

    #[test]
    fn filename_slug_capped_at_40_chars() {
        let long = "a".repeat(200);
        let msgs = vec![user_msg(&long)];
        let name = export_default_filename(&msgs);
        // slug portion after the second "-" should be <= 40 chars
        let slug_part = name
            .trim_start_matches("koda-")
            .split('-')
            .skip(2) // skip YYYYMMDD and HHMMSS
            .collect::<Vec<_>>()
            .join("-");
        let slug_no_ext = slug_part.trim_end_matches(".md");
        assert!(
            slug_no_ext.len() <= 40,
            "slug too long ({} chars): {slug_no_ext}",
            slug_no_ext.len()
        );
    }
}