feat: redesign stats chart with donut + comparison bars

SubMind.py

@@ -425,7 +425,7 @@ def make_autopct(values, currency_code):
 
 async def stats(update: Update, context: CallbackContext):
     user_id = update.effective_user.id
-    await update.message.reply_text("正在为您生成订阅统计图表，请稍候...")
+    await update.message.reply_text("正在为您生成更美观的统计图，请稍候...")
 
     font_prop = get_chinese_font()
     main_currency = get_user_main_currency(user_id)
@@ -453,41 +453,102 @@ async def stats(update: Update, context: CallbackContext):
         await update.message.reply_text("您的订阅没有有效的费用信息。")
         return
 
-    plt.style.use('seaborn-v0_8-darkgrid')
-    fig, ax = plt.subplots(figsize=(12, 12))
+    max_categories = 8
+    if len(category_costs) > max_categories:
+        top = category_costs.iloc[:max_categories]
+        others_sum = category_costs.iloc[max_categories:].sum()
+        if others_sum > 0:
+            category_costs = pd.concat([top, pd.Series({'其他': others_sum})])
+        else:
+            category_costs = top
+
+    total_monthly = category_costs.sum()
+    currency_symbols = {'USD': '$', 'CNY': '¥', 'EUR': '€', 'GBP': '£', 'JPY': '¥'}
+    symbol = currency_symbols.get(main_currency.upper(), f'{main_currency.upper()} ')
+
+    def autopct_if_large(pct):
+        if pct < 4:
+            return ''
+        value = total_monthly * pct / 100
+        return f'{pct:.1f}%\n{symbol}{value:.2f}'
+
+    fig = plt.figure(figsize=(14, 8), facecolor='#f8fafc')
+    gs = fig.add_gridspec(1, 2, width_ratios=[1.2, 1], wspace=0.12)
+    ax_pie = fig.add_subplot(gs[0, 0])
+    ax_bar = fig.add_subplot(gs[0, 1])
     image_path = None
 
     try:
-        autopct_function = make_autopct(category_costs.values, main_currency)
+        colors = list(plt.get_cmap('tab20').colors)[:len(category_costs)]
 
-        wedges, texts, autotexts = ax.pie(category_costs.values,
-                                          labels=category_costs.index,
-                                          autopct=autopct_function,
-                                          startangle=140,
-                                          pctdistance=0.7,
-                                          labeldistance=1.05)
+        _, texts, autotexts = ax_pie.pie(
+            category_costs.values,
+            labels=category_costs.index,
+            autopct=autopct_if_large,
+            startangle=120,
+            counterclock=False,
+            pctdistance=0.78,
+            labeldistance=1.08,
+            colors=colors,
+            wedgeprops={'width': 0.42, 'edgecolor': 'white', 'linewidth': 1.2}
+        )
 
-        ax.set_title('每月订阅支出分类统计', fontproperties=font_prop, fontsize=32, pad=20)
+        for t in texts:
+            t.set_fontproperties(font_prop)
+            t.set_fontsize(12)
+            t.set_color('#1f2937')
+        for t in autotexts:
+            t.set_fontproperties(font_prop)
+            t.set_fontsize(10)
+            t.set_color('#111827')
 
-        for text in texts:
-            text.set_fontproperties(font_prop)
-            text.set_fontsize(22)
+        ax_pie.text(
+            0, 0,
+            f"月总支出\n{symbol}{total_monthly:.2f}",
+            ha='center', va='center',
+            fontproperties=font_prop,
+            fontsize=16,
+            color='#111827',
+            weight='bold'
+        )
+        ax_pie.set_title('订阅支出结构（按类别）', fontproperties=font_prop, fontsize=16, pad=14, color='#111827')
+        ax_pie.axis('equal')
 
-        for autotext in autotexts:
-            autotext.set_fontproperties(font_prop)
-            autotext.set_fontsize(20)
-            autotext.set_color('white')
+        bar_series = category_costs.sort_values(ascending=True)
+        bars = ax_bar.barh(bar_series.index, bar_series.values, color=colors[:len(bar_series)], alpha=0.9)
+        ax_bar.set_title('类别月支出对比', fontproperties=font_prop, fontsize=16, pad=14, color='#111827')
+        ax_bar.set_xlabel(f'金额（{main_currency.upper()}）', fontproperties=font_prop, fontsize=11, color='#374151')
+        ax_bar.tick_params(axis='x', colors='#6b7280')
+        ax_bar.tick_params(axis='y', colors='#111827')
+        ax_bar.grid(axis='x', linestyle='--', alpha=0.25)
+        for label in ax_bar.get_yticklabels():
+            label.set_fontproperties(font_prop)
+            label.set_fontsize(11)
 
-        ax.axis('equal')
-        fig.tight_layout()
+        max_val = bar_series.max() if len(bar_series) else 0
+        offset = max_val * 0.015 if max_val > 0 else 0.1
+        for rect, value in zip(bars, bar_series.values):
+            ax_bar.text(
+                rect.get_width() + offset,
+                rect.get_y() + rect.get_height() / 2,
+                f"{symbol}{value:.2f}",
+                va='center',
+                ha='left',
+                fontproperties=font_prop,
+                fontsize=10,
+                color='#1f2937'
+            )
+
+        fig.suptitle('每月订阅支出统计', fontproperties=font_prop, fontsize=20, color='#0f172a', y=0.98)
+        fig.tight_layout(rect=[0, 0, 1, 0.96])
 
         with tempfile.NamedTemporaryFile(prefix=f'stats_{user_id}_', suffix='.png', delete=False) as tmp:
             image_path = tmp.name
 
-        plt.savefig(image_path)
+        plt.savefig(image_path, dpi=220, bbox_inches='tight', facecolor=fig.get_facecolor())
 
         with open(image_path, 'rb') as photo:
-            await update.message.reply_photo(photo, caption="这是您按类别统计的每月订阅总支出。")
+            await update.message.reply_photo(photo, caption="这是优化后的订阅月支出统计图（结构 + 对比）。")
     finally:
         plt.close(fig)
         if image_path and os.path.exists(image_path):