chore: 年度リストを昇順に変更

backend/app/modules/trial_balance/router.py

@@ -2,9 +2,54 @@ from fastapi import APIRouter, HTTPException, Query
 from decimal import Decimal
 from typing import Dict, Any, List, Optional
 from app.modules.trial_balance.service import fetch_trial_balance
+from app.core.database import get_connection
 
 router = APIRouter(prefix="/trial-balance", tags=["試算表"])
 
+@router.get("/fiscal-years", summary="仕訳データから会計年度一覧取得（5月期）")
+def get_fiscal_years():
+    REIWA_OFFSET = 2018  # 令和元年 = 2019年
+
+    with get_connection() as conn, conn.cursor() as cur:
+        cur.execute("""
+            SELECT
+                MIN(entry_date)::date AS min_date,
+                MAX(entry_date)::date AS max_date
+            FROM journal_entries
+            WHERE is_deleted = false
+        """)
+        row = cur.fetchone()
+
+    if not row or not row["min_date"]:
+        return []
+
+    min_date = row["min_date"]
+    max_date = row["max_date"]
+
+    def fiscal_end_year(d):
+        return d.year + 1 if d.month >= 6 else d.year
+
+    start_fy = fiscal_end_year(min_date)
+    end_fy   = fiscal_end_year(max_date)
+
+    result = []
+    for fy in range(end_fy, start_fy - 1, -1):
+        reiwa = fy - REIWA_OFFSET
+        if reiwa > 0:
+            wareki = f"令和{reiwa}年"
+        elif reiwa == 0:
+            wareki = "平成31/令和元年"
+        else:
+            wareki = f"平成{fy - 1988}年"
+        label = f"{wareki}({fy}年)5月期"
+        result.append({
+            "label":     label,
+            "date_from": f"{fy - 1}-06-01",
+            "date_to":   f"{fy}-05-31",
+        })
+
+    return result
+
 @router.get("", summary="試算表（全科目）")
 def get_trial_balance(
     fiscal_year: Optional[int] = Query(None, description="会計年度（例: 2025）"),