from fastapi import APIRouter, Query
from datetime import date
from typing import Optional
from app.core.database import get_connection

router = APIRouter(prefix="/trial-balance", tags=["试算表"])


@router.get("", summary="试算表（全科目）")
def get_trial_balance(
    fiscal_year: Optional[int] = Query(None, description="会计年度（可选）"),
    date_from: Optional[date] = Query(None, description="开始日期（可选）"),
    date_to: Optional[date] = Query(None, description="结束日期（可选）"),
):
    print("### trial-balance OPTIONAL PARAMS ACTIVE ###")

    with get_connection() as conn:
        # 检查 is_latest 字段是否存在（新的版本追踪系统）
        with conn.cursor() as check_cur:
            check_cur.execute("""
                SELECT COUNT(*) as cnt
                FROM information_schema.columns 
                WHERE table_name = 'journal_entries' AND column_name = 'is_latest'
            """)
            has_is_latest = check_cur.fetchone()[0] > 0

    # 构建查询语句
    if has_is_latest:
        # 新系统：只取最新版本（is_latest = true）
        sql = """
            SELECT
                a.account_id,
                a.account_code,
                a.account_name,
                a.account_type,
                COALESCE(SUM(l.debit), 0)  AS debit,
                COALESCE(SUM(l.credit), 0) AS credit
            FROM journal_lines l
            JOIN journal_entries e ON e.journal_entry_id = l.journal_entry_id
            JOIN accounts a ON a.account_id = l.account_id
            WHERE e.is_deleted = false
            AND e.is_latest = true
            AND a.account_code NOT IN ('512', '513', '516')
        """
    else:
        # 旧系统：排除已修正的记录（使用 parent_entry_id）
        sql = """
            SELECT
                a.account_id,
                a.account_code,
                a.account_name,
                a.account_type,
                COALESCE(SUM(l.debit), 0)  AS debit,
                COALESCE(SUM(l.credit), 0) AS credit
            FROM journal_lines l
            JOIN journal_entries e ON e.journal_entry_id = l.journal_entry_id
            JOIN accounts a ON a.account_id = l.account_id
            WHERE e.is_deleted = false
            AND a.account_code NOT IN ('512', '513', '516')
            AND e.journal_entry_id NOT IN (
                SELECT parent_entry_id 
                FROM journal_entries 
                WHERE parent_entry_id IS NOT NULL
            )
        """

    params = {}

    if fiscal_year is not None:
        sql += " AND e.fiscal_year = %(fiscal_year)s"
        params["fiscal_year"] = fiscal_year

    if date_from is not None:
        sql += " AND e.entry_date >= %(date_from)s"
        params["date_from"] = date_from

    if date_to is not None:
        sql += " AND e.entry_date <= %(date_to)s"
        params["date_to"] = date_to

    sql += """
        GROUP BY
            a.account_id,
            a.account_code,
            a.account_name,
            a.account_type
        ORDER BY
            CASE 
                WHEN a.account_code < '509' THEN a.account_code
                WHEN a.account_code IN ('510', '511') THEN '508.' || a.account_code
                ELSE a.account_code
            END
    """

    with get_connection() as conn, conn.cursor() as cur:
        cur.execute(sql, params)
        rows = cur.fetchall()

    return rows