PySide6 実践講座 #4 統計画面 — QPainter で草むらヒートマップを描く

# src/daily/core/stats.py
from datetime import date, timedelta


def current_streak(checked: set[str], today: date) -> int:
    """今日(または昨日)からさかのぼって続いた連続チェック日数。"""
    streak = 0
    day = today
    # 今日まだチェックしていなければ昨日から数え始める
    if day.isoformat() not in checked:
        day -= timedelta(days=1)
    while day.isoformat() in checked:
        streak += 1
        day -= timedelta(days=1)
    return streak


def completion_rate(checked: set[str], start: date, end: date) -> float:
    total = (end - start).days + 1
    done = sum(
        1 for i in range(total)
        if (start + timedelta(days=i)).isoformat() in checked
    )
    return done / total if total else 0.0

# src/daily/ui/heatmap.py
from datetime import date, timedelta

from PySide6.QtCore import QRect, QSize, Qt
from PySide6.QtGui import QColor, QPainter
from PySide6.QtWidgets import QWidget

CELL = 14        # セルの一辺(px)
GAP = 3          # セル間の隙間
WEEKS = 20       # 表示する週数


class HeatmapWidget(QWidget):
    def __init__(self) -> None:
        super().__init__()
        self._checked: set[str] = set()
        self.setMouseTracking(True)   # クリックなしでも mouseMoveEvent を受けるため

    def set_data(self, checked: set[str]) -> None:
        self._checked = checked
        self.update()                 # 再描画の「依頼」

    # --- サイズの契約 ---
    def sizeHint(self) -> QSize:
        return QSize(WEEKS * (CELL + GAP), 7 * (CELL + GAP))

    # --- 描画 ---
    def paintEvent(self, event) -> None:
        painter = QPainter(self)
        today = date.today()
        # 格子の開始日: WEEKS 週前のその週の月曜日
        start = today - timedelta(days=today.weekday() + 7 * (WEEKS - 1))

        for week in range(WEEKS):
            for dow in range(7):
                day = start + timedelta(weeks=week, days=dow)
                if day > today:
                    continue
                rect = QRect(
                    week * (CELL + GAP), dow * (CELL + GAP), CELL, CELL
                )
                on = day.isoformat() in self._checked
                color = QColor("#39d353") if on else QColor("#2d333b")
                painter.fillRect(rect, color)

    # --- ヒットテスト: マウスの下のセルを探す ---
    def mouseMoveEvent(self, event) -> None:
        pos = event.position().toPoint()
        week, dow = pos.x() // (CELL + GAP), pos.y() // (CELL + GAP)
        if 0 <= week < WEEKS and 0 <= dow < 7:
            today = date.today()
            start = today - timedelta(days=today.weekday() + 7 * (WEEKS - 1))
            day = start + timedelta(weeks=int(week), days=int(dow))
            if day <= today:
                state = "完了" if day.isoformat() in self._checked else "未完了"
                self.setToolTip(f"{day.isoformat()} — {state}")

# src/daily/ui/stats_page.py
from datetime import date, timedelta

from PySide6.QtWidgets import QComboBox, QLabel, QVBoxLayout, QWidget

from daily.core.stats import completion_rate, current_streak
from daily.data.repository import HabitRepository
from daily.ui.heatmap import HeatmapWidget


class StatsPage(QWidget):
    def __init__(self, repo: HabitRepository) -> None:
        super().__init__()
        self._repo = repo
        self._select = QComboBox()
        self._summary = QLabel()
        self._heatmap = HeatmapWidget()

        layout = QVBoxLayout(self)
        layout.addWidget(self._select)
        layout.addWidget(self._summary)
        layout.addWidget(self._heatmap)
        layout.addStretch()

        self._select.currentIndexChanged.connect(self._refresh)
        self.reload_habits()

    def reload_habits(self) -> None:
        self._select.clear()
        for habit in self._repo.active_habits():
            self._select.addItem(habit.name, userData=habit.id)

    def _refresh(self) -> None:
        habit_id = self._select.currentData()
        if habit_id is None:
            return
        checked = self._repo.checked_days(habit_id)
        today = date.today()
        rate = completion_rate(checked, today - timedelta(days=27), today)
        self._summary.setText(
            f"直近 4 週の達成率 {rate:.0%} · 現在の連続 {current_streak(checked, today)} 日"
        )
        self._heatmap.set_data(checked)