🚀 ZCH

A blazing-fast TUI dashboard for competitive programming in the Zed editor on macOS.

A single Rust binary that receives problems from the Competitive Companion extension, runs your samples with precise timings, and submits to Codeforces via Safari automation — all from one local TUI.

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✨ Features

• 🖥️ Live TUI dashboard — directory bar, message console, verdict cards, and a footer that always shows every key.
• ✔️ Instant verdicts — each test case gets a chip (✔ AC · 4ms, ✘ WA, ⏱ TLE, ✘ RE, ✘ CE) and auto-collapses on AC; on WA the Got box marks the exact characters that differ in red.
• 📥 Auto-parses problems — payloads are captured on 127.0.0.1:10043; the file is created from ~/.zch/boilerplate.cpp with a // URL: header, tests live in ~/.zch/.tc/, and the file opens in Zed automatically.
• ⚡ Blazing fast execution — compile once, replay every case with 1ms polling, per-case timing, and hard TLE kills.
• 🤖 One-key Codeforces submissions — a confirmation modal shows every detail, then async verdicts stream into the Submissions bar (⠹ submitting → ✔ ACCEPTED); Safari tabs are tracked by URL (INTERRUPTED / TIMED OUT handled) and CAPTCHAs raise the window automatically. zch submit works from the terminal too.
• 🎛️ Command palette from Zed — Zed tasks drive the running TUI over HTTP (send r, send s, …) with the active ${ZED_FILE}.
• 📁 Live directory switching — cd, ls, pwd console with TAB path completion; new problems are saved wherever you point it.
• 🧩 Multi-language — C++17/20/23, Python 3, Java; language + flags persist in ~/.zch/config.json via the c menu.

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📋 Prerequisites

• macOS (relies on native Apple Events for Safari automation)
• A Nerd Font in your terminal (e.g. JetBrainsMono Nerd Font) so the file/folder icons render the same on every machine.
• Safari with "Allow JavaScript from Apple Events" enabled:
  • Safari → Settings → Advanced → check "Show features for web developers"
  • Develop → Allow JavaScript from Apple Events
• Zed Code Editor
• C++ compiler (g++ via Homebrew, or Apple Clang)
• Competitive Companion browser extension.

💡 Why Safari only? Submission automation requires the browser to run JavaScript in the background without stealing focus. Only Safari supports this natively via AppleScript. Other browsers would foreground the window mid-solve.

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🛠️ Installation

1. Install

Homebrew (recommended):

brew install prsweet/tap/zch

Or:

curl -fsSL https://github.com/prsweet/zch/releases/latest/download/zch-installer.sh | sh

2. Setup Zed tasks

Append to ~/.config/zed/tasks.json (press cmd+shift+R to spawn tasks):

[
  {
    "label": "CP: Start Listener (Current Folder)",
    "command": "zch",
    "use_new_terminal": true,
    "allow_concurrent_runs": false,
    "hide": "never",
    "reveal_target": "center"
  },
  {
    "label": "CP: Run Tests",
    "command": "zch send r \"${ZED_FILE}\"",
    "use_new_terminal": false,
    "allow_concurrent_runs": false,
    "reveal": "never",
    "hide": "always"
  },
  {
    "label": "CP: Submit to Codeforces",
    "command": "zch submit \"${ZED_FILE}\"",
    "use_new_terminal": true,
    "allow_concurrent_runs": true,
    "reveal": "always",
    "hide": "never"
  }
]

3. Optimize your keymap

Add to ~/.config/zed/keymap.json:

[
  {
    "context": "Editor",
    "bindings": {
      "cmd-'": ["task::Spawn", { "task_name": "CP: Run Tests" }],
      "cmd-enter": ["task::Spawn", { "task_name": "CP: Submit to Codeforces" }],
      "cmd-r": ["workspace::SendKeystrokes", "cmd-alt-shift-r cmd-\\"]
    }
  },
  {
    "context": "Workspace",
    "bindings": {
      "cmd-alt-shift-r": ["task::Spawn", { "task_name": "CP: Start Listener (Current Folder)" }]
    }
  }
]

The cmd-r macro spawns the dashboard in the center pane and then splits the pane right (cmd-\ is Zed's built-in Split Right), so the TUI lands beside your code — no dock settings touched.

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🎮 Usage

1. Start the TUI

Press cmd-r inside your problems folder (or run zch in a terminal). The keymap macro opens the dashboard split to the right of your editor; it listens on 127.0.0.1:10043.

2. Receive a problem

Click the Competitive Companion extension on any Codeforces problem page. The file is created in the current directory, saved to the test database, and opened in Zed automatically.

3. Test & submit from the TUI

Key	Action
r	compile & run all test cases
a	add a custom test case
e	edit existing test cases
s	submit to Codeforces (confirmation modal → Enter submits / Backspace cancels)
d	console: cd <path> · ls · pwd (TAB completes paths)
c	config: language + extra compile flags
q	quit

While editing, Tab switches between Input / Expected (and wraps to the previous/next case with Shift+Tab), Esc saves.

4. Test & submit from Zed

• Run (cmd-') — asks the running TUI to load ${ZED_FILE} and run it.
• Submit (cmd-enter) — opens a dedicated terminal tab that shows every submission detail (platform, problem ID, URL, language, browser, local tests) and waits for Enter to submit or Backspace to cancel. The verdict (and any CAPTCHA warning) streams into that tab.

The send subcommand talks to the TUI over HTTP, while submit runs standalone in its own terminal:

zch send r /path/to/Problem.cpp   # run
zch send s /path/to/Problem.cpp   # submit (confirmation modal inside the TUI)
zch submit /path/to/Problem.cpp   # submit here (Enter/Backspace prompt, -y to skip)

Set ZCH_PORT to run on a different port than 10043.

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🛡️ Dealing with CAPTCHAs

Codeforces occasionally serves an invisible CAPTCHA. When automation hits one, the TUI alerts you (⚠ CAPTCHA — solve it, submission continues automatically) and Safari foregrounds itself. Solve it, and the live verdict polling resumes on its own.

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🧱 Architecture

src/
  main.rs               — event loop: one channel, four actors
  helper.rs             — UI state machine (input modes, commands, verdicts)
  components/           — ratatui widgets
    dir_terminal.rs     — working-directory console (cd/ls/pwd + completion)
    tc_list.rs          — scrollable test case list with verdict chips
    testcase.rs         — one case: input / expected / got, diff highlighting
    config.rs           — language + compile flags popup
    splash.rs           — empty-state screen
  core/
    receiver.rs         — Competitive Companion HTTP listener (:10043) + command API
    runner.rs           — compile + run all cases (timings, TLE kills)
    submitter.rs        — Safari AppleScript automation + platform detection
    fs_ops.rs           — boilerplate, test DB, config, binary pruning
  error.rs              — shared error type

Everything runs on one channel: the UI thread owns all state, and the receiver / runner / submitter workers only exchange PassingCommand envelopes with it — no worker holds a handle to another.

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💡 Pro-tips for maximum performance

1. Drop execution latency to 3-4ms ⚡

macOS security scans (syspolicyd) add ~200ms of lag when running newly compiled binaries. Fix:

1. System Settings → Privacy & Security → Developer Tools: add Zed and your terminal emulator, toggle them ON.
2. Add the same under Full Disk Access.

2. Ultra-fast precompiled headers (PCH) 🔥

Compiling #include <bits/stdc++.h> costs 1.5s–3.0s per compile. A PCH drops this under 0.20s.

For Clang (macOS default):

clang++ -std=c++23 -O2 -x c++-header /usr/local/include/bits/stdc++.h -o /usr/local/include/bits/stdc++.h.pch

Then open the config menu (c) and add to extra compile flags:

-include-pch /usr/local/include/bits/stdc++.h.pch

The flag is appended to g++ -std=c++23 -O2 -Wall -Wextra … for every compile.

3. Fast policy-based data structures (PBDS) on Clang 🌲

Apple Clang doesn't ship bits/stdc++.h or PBDS. The std-with-pbds helper repo sets up both for Apple Clang.