editor/ROADMAP.md

# Native Kotlin Editor Roadmap

## Current State

- Odin editor core with piece-table storage.
- File-backed editor buffers.
- Cursor movement and line/column mapping.
- SDL3 native window mode.
- SDL3 GPU command-buffer renderer path when a GPU backend is available.
- Basic text input, Enter with auto-indent, Backspace, Delete, Tab indent, arrows, Ctrl+Left/Ctrl+Right, selection, mouse click/drag cursor placement, and Ctrl+S save.
- JVM daemon over TCP JSON-lines.
- Gradle workspace import via Tooling API.
- Kotlin diagnostics using compiler embeddable.
- Async `diagnostics/publish` events rendered in the SDL gutter/status area and stored by file path for open buffers.

## Phase 1: Usable Editor

- Open arbitrary files in SDL mode.
- Add project file tree. Done.
- Support multiple open buffers.
- Add proper viewport scrolling independent of cursor.
- Add PageUp/PageDown/Home/End.
- Add Ctrl+Left/Ctrl+Right word movement. Done.
- Add mouse wheel scrolling.
- Add click-to-move-cursor. Done.
- Add mouse drag selection. Done.
- Add undo/redo.
- Add selection. Done.
- Add copy/cut/paste. Done.
- Add Delete key. Done.
- Add Tab/indent/outdent. Done: Tab inserts four spaces and Shift+Tab outdents the current or selected lines.
- Add auto-indent on Enter. Done.
- Add search in file. Started: Ctrl+F find panel with next/previous navigation and visible match highlights.
- Add Save All. Done.
- Replace SDL debug text with proper font rendering. Started: direct GPU path uses an `stb_truetype` baked Noto Sans Mono atlas.
- Replace renderer-backed drawing with a direct SDL3 GPU command-buffer quad/text pipeline. Started: rectangles, lines, panels, selection, cursor, and temporary text render through SDL3 GPU with SDL renderer fallback.
- Add shader compilation pipeline. Started: GLSL sources plus `scripts/compile-shaders.sh` using `glslc` to emit SPIR-V.
- Add syntax highlighting. Started: lightweight visible-line Kotlin/Java tokenizer in the GPU renderer.

## Phase 2: Daemon Integration

- Start JVM daemon automatically from Odin. Done.
- Read daemon `PORT` from stdout. Done.
- Stop daemon on editor exit. Done.
- Restart daemon if it crashes. Done for auto-started SDL daemons; explicit external-port mode reports disconnects without spawning a replacement.
- Replace ad-hoc JSON parsing in Odin. Done.
- Track request IDs and pending responses. Done.
- Distinguish responses and events cleanly. Done.
- Store diagnostics per file, not only active file. Done: diagnostics events are queued and applied to the matching open buffer path.
- Clear stale diagnostics on workspace reload.
- Render diagnostic underlines/squiggles. Started: GPU renderer draws red dashed underlines on diagnostic lines.
- Add next/previous diagnostic navigation. Done: F8 and Shift+F8 navigate active-file diagnostics.
- Add diagnostics panel. Done: Ctrl+Shift+M opens active-file diagnostics with keyboard navigation.
- Show Gradle tasks in UI. Started: Ctrl+Shift+T requests and displays tasks in a docked GPU right sidebar; responses are matched by request id.
- Run selected Gradle task. Started: Enter in the Gradle tasks panel runs the selected task and reports success/failure.
- Stream Gradle task output. Started: Gradle run lifecycle and stdout/stderr line events are surfaced in the tasks sidebar with recent output retained.
- Add workspace reload/import action. Started: command palette Reload Workspace refreshes the file tree, sends `workspace/open`, clears stale diagnostics, and resyncs the active buffer.

## Phase 3: Kotlin And Java Intelligence

- Implement `kotlin/completion` in the daemon. Started: prefix-filtered Kotlin keywords plus heuristic current-buffer/workspace identifiers and declarations.
- Add completion popup in SDL UI. Done: popup renders returned items and applies the selected completion with Enter or row click, using a single undoable replace edit.
- Add keyboard navigation in completion popup. Done.
- Implement `kotlin/hover`. Started: keyword hover plus heuristic declaration line/location lookup from the current buffer and workspace.
- Render hover tooltip. Done.
- Implement `kotlin/definition`. Started: heuristic simple declaration scan.
- Open target file and jump to line/column. Done.
- Add back/forward navigation stack. Done.
- Add find references. Started: heuristic source scan with SDL references popup.
- Add rename/refactor support. Started: daemon preview-only rename edits with SDL preview panel.
- Add Java diagnostics/completion/navigation. Started: `.java` diagnostics use the JDK compiler with Gradle module classpath/sourcepath; completion/hover/definition/references scan Java source declarations heuristically.

## Phase 4: Backend Quality

- Replace compiler-per-request diagnostics with long-lived analysis state.
- Cache Gradle module classpaths and source roots.
- Move toward Kotlin Analysis API where feasible.
- Correctly model multi-module projects. Started: diagnostics choose the module with the most specific matching source root.
- Separate main/test source-set analysis. Started: diagnostics use main roots for main files and main+test roots for test files.
- Include generated sources. Started: common existing `build/generated/` Kotlin/Java roots, including KSP/Kotlin Multiplatform source-set layouts, are added to Gradle module source roots.
- Improve classpath and project dependency handling. Started: diagnostics include existing module output directories from `build/classes/` and `build/resources/`, including common JVM/KMP layouts; Kotlin diagnostics include Java sources from the matching Gradle source roots.

## Phase 5: Product Shape

- Add sidebar file tree.
- Add editor tabs. Done: GPU tab strip shows open buffers and supports click-to-switch, close buttons, and drag reorder.
- Add bottom panel for diagnostics/tasks/output.
- Add command palette. Started: Ctrl+Shift+P opens a filterable GPU command palette for existing editor actions.
- Add configurable keybindings.
- Add theme settings.
- Add font settings.
- Persist last workspace, open files, cursor positions, and window layout. Started: window size, sidebars, open files, active tab, and cursor offsets are cached per workspace.

## Performance Work

- Incrementally update line index.
- Compact piece table after many edits.
- Cache rendered text/glyphs.
- Avoid full-buffer `text/change` sync on every edit. Started: edit-triggered sync is debounced.
- Debounce native-to-daemon text sync. Done: text edits schedule a delayed sync; file open/switch/navigation and daemon-backed commands still flush immediately.

## Next Work Queue

1. Open arbitrary file from SDL mode. Done.
2. Add scrolling/PageUp/PageDown/Home/End. Done.
3. Add undo/redo. Done.
4. Add daemon auto-start. Done.
5. Add robust protocol parser. Done.
6. Add project file tree. Done.
7. Add completion popup skeleton. Done.
8. Wire completion responses into popup. Done.
9. Implement real `kotlin/completion` in the daemon. Started: prefix-filtered Kotlin keywords plus heuristic current-buffer/workspace identifiers and declarations.
10. Implement `kotlin/hover` and render hover tooltip. Started: keyword hover plus heuristic declaration line/location lookup from the current buffer and workspace.
11. Implement `kotlin/definition` and Ctrl+B navigation. Started: heuristic simple declaration scan.
12. Add back/forward navigation stack. Done.
13. Add find references. Started: heuristic source scan with SDL references popup.
14. Add rename/refactor support. Started: daemon preview-only rename edits with SDL preview panel.
15. Add Ctrl+Left/Ctrl+Right word movement. Done.
16. Add click-to-move-cursor. Done.
17. Add Delete key. Done.
18. Add Tab indentation and auto-indent. Done: Tab inserts four spaces, Shift+Tab outdents, and Enter preserves leading whitespace.
19. Improve mouse support. Done: sidebar/editor wheel routing, sidebar scrolling, click-to-place-cursor, drag selection.
20. Add selection. Done: mouse drag and Shift+movement selection with replacement on edit.

## Immediate Stabilization Goals

1. Text metrics correctness. In progress: GPU text uses explicit fixed-cell atlas placement, widened cell advance, GPU-aware hit-testing, and `Ctrl+M` metrics overlay.
2. Font portability. Done for the prototype: bundled Noto Sans Mono is loaded from `client/odin/assets/fonts/` with system fallback paths.
3. Proper font shaping baseline. Replace baked ASCII-only atlas with a more deliberate atlas/SDF pipeline.
4. Renderer abstraction cleanup. Split UI drawing from SDL fallback/GPU backend details.
5. Input consistency. Started: cursor, hit-testing, syntax spans, and selection use shared metrics in the GPU path; command palette, completion, references, diagnostics, and Gradle panels now keep keyboard selection visible, support row clicks, route wheel events when hovered, and handle PageUp/PageDown plus Home/End.
6. Syntax quality. Started: visible-line tokenizer now carries `/* ... */` block comment and Kotlin triple-quoted string state across rendered lines, with Kotlin/Java keywords and character literals. Still needs semantic tokens.
7. Editor essentials. Done for the current prototype: clipboard copy/cut/paste, Save All, richer Ctrl+F search, clickable GPU tabs, safe Ctrl+W tab close, tab close buttons, drag reorder, stale overlay cleanup after edits, dirty tracking by saved buffer version, robust open-buffer diagnostic matching, and single-step/no-op-aware undo for selection/full-buffer replacement are implemented.