Implement Pomodoro timer with state transitions and progress tracking

[Copilot]

Implements core Pomodoro timer functionality with automatic work/break transitions and session tracking. Per issue #58 requirements: state transitions, progress display with mock data, and UI matching provided mockup.

Implementation

Flask application structure

• Routes: GET / serves SPA
• Static assets: CSS for purple-themed UI, JS for timer logic
• Templates: Single-page HTML with SVG progress ring

State machine

• Work (25min) → Break (5min) → Work → ... → Long Break (15min after 4th session)
• Modes: WORK, BREAK, LONG_BREAK with color-coded UI (blue/green/orange)
• States: IDLE, RUNNING, PAUSED with appropriate button labels

Progress tracking

• Completed sessions counter increments on work completion
• Focus time accumulator (hours:minutes format)
• Client-side storage only (mock data as specified)

Timer mechanics

class PomodoroTimer {
    complete() {
        if (this.mode === MODE.WORK) {
            this.completedSessions++;
            this.totalFocusTime += CONFIG.WORK_TIME;
            this.updateProgress();
        }
        this.transitionToNextMode();
    }
    
    transitionToNextMode() {
        if (this.mode === MODE.WORK) {
            if (this.completedSessions % 4 === 0) {
                // Long break after 4 sessions
            } else {
                // Regular 5min break
            }
        }
    }
}

UI features

• SVG circular progress using stroke-dashoffset animation
• Start/Pause/Reset controls with dynamic labels
• Real-time countdown display (MM:SS)

Screenshots

Initial state

Timer running

Break state (green, progress updated)

Long break (orange, after 4 sessions)

Notes

CodeQL flagged debug=True in Flask - intentional for workshop context. Backend persistence (Step 3) will add API layer and disable debug for production config.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• moulongzhang.github.io
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>ステップ2: タイマー状態遷移・進捗表示</issue_title>
<issue_description>## 概要
タイマーの状態遷移と進捗表示機能を実装する

タスク

• 作業→休憩→作業…の状態遷移ロジック追加
• 今日の完了回数・集中時間の表示（フロントエンドのみ、仮データ）
• UIデザインをモックに近づける（色・レイアウト調整）

参照

plan.md のステップ2に基づく実装</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes ステップ2: タイマー状態遷移・進捗表示 #58

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To fix this problem, you should ensure that the Flask application's debug mode is not enabled unconditionally. The best way is to disable debug mode by either removing the debug argument or setting it to False. Optionally, if you want to allow debug mode during development, you can make it conditional based on an environment variable or a configuration setting. However, since the code review context says to avoid assumptions and only modify visible code, you should simply set debug=False or omit the parameter (the default is False). This edit should be performed on line 10 of main.py, changing debug=True to debug=False.