from __future__ import annotations

from .shared import *

from .budgets_write_services import create_ledger_budget
from .transactions_write_services import create_ledger_transaction, delete_ledger_transaction, update_ledger_transaction

def list_ledger_transactions(start_date: str = "", end_date: str = "", type: str = "", category: str = "", person: str = "", account_id: str = "", include_deleted: bool = False, limit: int = 100, db_path: str | None = None) -> dict[str, Any]:
    clauses=[]; params=[]
    if not include_deleted:
        clauses.append("status='active'")
    for field, value in [("type", type), ("category", category), ("person", person), ("account_id", account_id)]:
        if value:
            clauses.append(f"{field}=?"); params.append(value)
    if start_date:
        clauses.append("transaction_date>=?"); params.append(normalize_date(start_date))
    if end_date:
        clauses.append("transaction_date<=?"); params.append(normalize_date(end_date))
    where = " WHERE " + " AND ".join(clauses) if clauses else ""
    sql = f"SELECT * FROM transactions{where} ORDER BY transaction_date DESC, created_at DESC LIMIT ?"
    params.append(max(1, min(int(limit), 1000)))
    with db(db_path) as conn:
        rows = conn.execute(sql, params).fetchall()
    return ok(transactions=[row_to_dict(r) for r in rows], count=len(rows))


def _transaction_signed_amount(tx_type: str, amount: int) -> int:
    if tx_type in {"income", "refund", "adjustment"}:
        return int(amount)
    if tx_type in {"expense", "transfer"}:
        return -int(amount)
    return 0


def _account_balance_row(conn: sqlite3.Connection, account_id: str, baseline_at: str) -> dict[str, Any]:
    date_cutoff = normalize_date(baseline_at[:10])
    rows = conn.execute(
        """SELECT type, amount, balance_after, transaction_date, transaction_datetime, created_at
             FROM transactions
            WHERE status='active' AND account_id=? AND transaction_date<=?
            ORDER BY transaction_date ASC, transaction_datetime ASC, created_at ASC""",
        (account_id, date_cutoff),
    ).fetchall()
    signed_total = sum(_transaction_signed_amount(row["type"], int(row["amount"] or 0)) for row in rows)
    latest_balance_row = next((row for row in reversed(rows) if row["balance_after"] is not None), None)
    if latest_balance_row is not None:
        calculated_balance = int(latest_balance_row["balance_after"])
        basis = "latest_transaction_balance_after"
        basis_at = latest_balance_row["transaction_datetime"] or latest_balance_row["transaction_date"]
    else:
        calculated_balance = int(signed_total)
        basis = "net_transaction_delta_without_opening_balance"
        basis_at = baseline_at
    return {
        "calculated_balance": calculated_balance,
        "calculation_basis": basis,
        "calculation_basis_at": basis_at,
        "transaction_count": len(rows),
        "signed_transaction_total": int(signed_total),
    }


def get_balance_reconciliation_report(account_id: str = "", baseline_balance: int | None = None, baseline_at: str = "", source_note: str = "", memo: str = "", tolerance: int = BALANCE_RECONCILIATION_TOLERANCE_KRW, db_path: str | None = None) -> dict[str, Any]:
    """Preview manual/partial-import account balance reconciliation without mutating transactions."""
    try:
        baseline_at_norm = normalize_snapshot_at(baseline_at.strip(), default_now=False) if baseline_at and baseline_at.strip() else None
        tolerance_int = int(tolerance)
        if tolerance_int < 0:
            raise ValueError("tolerance must be non-negative")
        baseline_balance_int = int(baseline_balance) if baseline_balance is not None else None
    except Exception as e:
        return fail("validation_error", str(e))
    with db(db_path) as conn:
        clauses = ["active=1"]
        params: list[Any] = []
        if account_id:
            clauses.append("id=?")
            params.append(account_id)
        else:
            placeholders = ",".join("?" for _ in RECONCILIATION_TARGET_STATUSES)
            clauses.append(f"statement_status IN ({placeholders})")
            params.extend(sorted(RECONCILIATION_TARGET_STATUSES))
        accounts = conn.execute(f"SELECT * FROM accounts WHERE {' AND '.join(clauses)} ORDER BY name", params).fetchall()
        items: list[dict[str, Any]] = []
        for account in accounts:
            effective_baseline = baseline_balance_int if baseline_balance_int is not None else account["last_balance"]
            effective_at = baseline_at_norm or account["last_synced_at"] or now_iso()
            calc = _account_balance_row(conn, account["id"], effective_at)
            if effective_baseline is None:
                difference = None
                ratio = None
                status = "BASELINE_REQUIRED"
            else:
                difference = int(effective_baseline) - int(calc["calculated_balance"])
                ratio = abs(difference) / abs(int(effective_baseline)) if int(effective_baseline) else None
                status = "OK" if abs(difference) <= tolerance_int else "REVIEW_NEEDED"
            items.append({
                "account_id": account["id"],
                "account_name": account["name"],
                "statement_status": account["statement_status"],
                "is_reconciliation_target": account["statement_status"] in RECONCILIATION_TARGET_STATUSES,
                "baseline_balance": effective_baseline,
                "baseline_at": effective_at,
                "calculated_balance": calc["calculated_balance"],
                "difference": difference,
                "tolerance": tolerance_int,
                "reference_ratio_threshold": BALANCE_RECONCILIATION_REFERENCE_RATIO,
                "difference_ratio": ratio,
                "status": status,
                "recommended_decisions": ["계좌이동", "실지출", "실수입", "투자이동", "분석제외", "확인필요"] if status == "REVIEW_NEEDED" else [],
                "source_note": source_note,
                "memo": memo,
                **calc,
            })
    return ok(items=items, count=len(items), tolerance=tolerance_int, baseline_at=baseline_at_norm, routing="preview_only_manual_confirmation_required")



def list_ledger_budgets(month: str = "", db_path: str | None = None) -> dict[str, Any]:
    clauses=[]; params=[]
    if month:
        clauses.append("month=?"); params.append(normalize_month(month))
    where = " WHERE " + " AND ".join(clauses) if clauses else ""
    with db(db_path) as conn:
        rows = conn.execute(f"SELECT * FROM budgets{where} ORDER BY month DESC, category", params).fetchall()
    return ok(budgets=[row_to_dict(r) for r in rows], count=len(rows))

def _month_range(month: str) -> tuple[str, str]:
    m = normalize_month(month)
    y, mo = map(int, m.split("-"))
    start = date(y, mo, 1)
    end = date(y + (mo == 12), 1 if mo == 12 else mo + 1, 1)
    return start.isoformat(), end.isoformat()

def get_monthly_cashflow_report(month: str = "", db_path: str | None = None) -> dict[str, Any]:
    month_norm = normalize_month(month); start, next_month = _month_range(month_norm)
    with db(db_path) as conn:
        type_rows = conn.execute("""SELECT type, SUM(amount) AS total FROM transactions
                                   WHERE status='active' AND transaction_date>=? AND transaction_date<?
                                   GROUP BY type""", (start, next_month)).fetchall()
        cashflow_rows = conn.execute(f"""SELECT {CASHFLOW_KIND_SQL} AS cashflow_kind, SUM(t.amount) AS total
                                       FROM transactions t
                                       LEFT JOIN ledger_categories lc
                                         ON lc.active=1 AND t.category=lc.category AND t.subcategory=lc.subcategory
                                      WHERE t.status='active' AND t.transaction_date>=? AND t.transaction_date<?
                                      GROUP BY {CASHFLOW_KIND_SQL}""", (start, next_month)).fetchall()
    type_totals = {r["type"]: int(r["total"] or 0) for r in type_rows}
    cashflow_totals = {r["cashflow_kind"]: int(r["total"] or 0) for r in cashflow_rows}
    income = cashflow_totals.get("income", 0)
    expenses = cashflow_totals.get("expense", 0)
    net_cashflow = income - expenses
    savings_rate = round(net_cashflow / income, 4) if income else None
    return ok(month=month_norm, income=income, expenses=expenses, net_cashflow=net_cashflow, savings_rate=savings_rate, by_type=type_totals, by_cashflow_kind=cashflow_totals)

def get_category_spending_report(month: str = "", start_date: str = "", end_date: str = "", person: str = "", db_path: str | None = None) -> dict[str, Any]:
    if month:
        start_date, next_month = _month_range(month); end_op = "<"; end_value = next_month
    else:
        start_date = normalize_date(start_date, default_today=False) if start_date else "0001-01-01"
        end_value = normalize_date(end_date, default_today=False) if end_date else "9999-12-31"; end_op = "<="
    params=[start_date, end_value]; person_clause=""
    if person:
        person_clause=" AND t.person=?"; params.append(person)
    sql=f"""SELECT t.category, t.subcategory, SUM(t.amount) AS total, COUNT(*) AS count FROM transactions t
             LEFT JOIN ledger_categories lc ON lc.active=1 AND t.category=lc.category AND t.subcategory=lc.subcategory
             WHERE t.status='active' AND {CASHFLOW_KIND_SQL}='expense' AND t.transaction_date>=? AND t.transaction_date{end_op}?{person_clause}
             GROUP BY t.category, t.subcategory ORDER BY total DESC"""
    with db(db_path) as conn:
        rows=conn.execute(sql, params).fetchall()
    total=sum(int(r["total"] or 0) for r in rows)
    items=[{"category": r["category"], "subcategory": r["subcategory"], "amount": int(r["total"] or 0), "count": r["count"], "share": round((int(r["total"] or 0)/total),4) if total else 0} for r in rows]
    return ok(total_expense=total, items=items, count=len(items))

def get_fixed_cost_report(month: str = "", db_path: str | None = None) -> dict[str, Any]:
    month_norm=normalize_month(month); start,next_month=_month_range(month_norm)
    with db(db_path) as conn:
        rows=conn.execute(f"""SELECT t.category, t.merchant, t.amount, t.transaction_date, t.person, t.memo FROM transactions t
                             LEFT JOIN ledger_categories lc ON lc.active=1 AND t.category=lc.category AND t.subcategory=lc.subcategory
                             WHERE t.status='active' AND {CASHFLOW_KIND_SQL}='expense' AND t.is_fixed=1 AND t.transaction_date>=? AND t.transaction_date<?
                             ORDER BY t.amount DESC""", (start,next_month)).fetchall()
    items=[row_to_dict(r) for r in rows]
    return ok(month=month_norm, total_fixed_cost=sum(i["amount"] for i in items), items=items, count=len(items))

def get_budget_vs_actual_report(month: str = "", db_path: str | None = None) -> dict[str, Any]:
    month_norm=normalize_month(month); start,next_month=_month_range(month_norm)
    with db(db_path) as conn:
        budgets=conn.execute("SELECT * FROM budgets WHERE month=?", (month_norm,)).fetchall()
        actuals=conn.execute(f"""SELECT t.category, t.subcategory, t.person, SUM(t.amount) AS amount FROM transactions t
                                LEFT JOIN ledger_categories lc ON lc.active=1 AND t.category=lc.category AND t.subcategory=lc.subcategory
                                WHERE t.status='active' AND {CASHFLOW_KIND_SQL}='expense' AND t.transaction_date>=? AND t.transaction_date<?
                                GROUP BY t.category, t.subcategory, t.person""", (start,next_month)).fetchall()
    actual_map={(r["category"], r["subcategory"], r["person"]): int(r["amount"] or 0) for r in actuals}
    items=[]
    for b in budgets:
        key=(b["category"], b["subcategory"], b["person"]); actual=actual_map.get(key,0); budget=int(b["amount"])
        items.append({"category": b["category"], "subcategory": b["subcategory"], "person": b["person"], "budget": budget, "actual": actual, "remaining": budget-actual, "usage_rate": round(actual/budget,4) if budget else None, "status": "over" if actual>budget else "ok"})
    return ok(month=month_norm, items=items, total_budget=sum(i["budget"] for i in items), total_actual=sum(i["actual"] for i in items))

def get_investable_cashflow_report(month: str = "", minimum_cash_buffer: int = 0, planned_extra_expense: int = 0, db_path: str | None = None) -> dict[str, Any]:
    cashflow=get_monthly_cashflow_report(month, db_path)
    if not cashflow.get("success"):
        return cashflow
    investable=max(0, int(cashflow["net_cashflow"]) - int(minimum_cash_buffer) - int(planned_extra_expense))
    return ok(month=cashflow["month"], income=cashflow["income"], expenses=cashflow["expenses"], net_cashflow=cashflow["net_cashflow"], minimum_cash_buffer=int(minimum_cash_buffer), planned_extra_expense=int(planned_extra_expense), investable_cashflow=investable)