from datetime import date

from fastapi import APIRouter, Query

from app.analytics import service
from app.dependencies import Context, Db

router = APIRouter(prefix="/analytics", tags=["analytics"])


@router.get("/category-spend")
def category_spend(
    date_from: date = Query(alias="from"),
    date_to: date = Query(alias="to"),
    *,
    db: Db,
    context: Context,
) -> list[dict]:
    rows = service.category_spend(
        db, space_id=context.space.id, date_from=date_from, date_to=date_to
    )
    return [
        {
            "categoryId": row["category_id"],
            "name": row["name"],
            "nameKey": row["name_key"],
            "amountKopecks": row["amount_kopecks"],
        }
        for row in rows
    ]


@router.get("/cash-flow")
def cash_flow(
    date_from: date = Query(alias="from"),
    date_to: date = Query(alias="to"),
    *,
    db: Db,
    context: Context,
) -> list[dict]:
    rows = service.cash_flow(db, space_id=context.space.id, date_from=date_from, date_to=date_to)
    months: dict[str, dict[str, int | str]] = {}
    for row in rows:
        month = row["date"].strftime("%Y-%m")
        bucket = months.setdefault(
            month,
            {
                "month": month,
                "incomeKopecks": 0,
                "expenseKopecks": 0,
                "refundsKopecks": 0,
                "netKopecks": 0,
            },
        )
        amount = int(row["amount_kopecks"])
        key = {
            "income": "incomeKopecks",
            "expense": "expenseKopecks",
            "refund": "refundsKopecks",
        }[row["type"]]
        bucket[key] = int(bucket[key]) + abs(amount)
        bucket["netKopecks"] = int(bucket["netKopecks"]) + amount
    return list(months.values())


@router.get("/plan-fact")
def plan_fact(month: str, db: Db, context: Context) -> dict:
    from app.budgeting.router import parse_month

    year, month_number = parse_month(month)
    state = service.plan_fact(db, space_id=context.space.id, year=year, month=month_number)
    categories = state.get("monthly_categories", [])
    return {
        "month": month,
        "items": [
            {
                "categoryId": row["category_id"],
                "name": row.get("name"),
                "nameKey": row.get("name_key"),
                "plannedKopecks": row["planned"],
                "actualKopecks": row["spent"],
            }
            for row in categories
        ],
    }


@router.get("/balances")
def balances(db: Db, context: Context) -> dict:
    from datetime import UTC, datetime

    rows = service.balances(db, space_id=context.space.id)
    assets = sum(max(row["balance_kopecks"], 0) for row in rows if row["kind"] != "credit")
    liabilities = sum(row["debt_kopecks"] for row in rows)
    return {
        "asOf": datetime.now(UTC).date(),
        "assetsKopecks": assets,
        "liabilitiesKopecks": liabilities,
        "netKopecks": assets - liabilities,
        "items": [
            {
                "accountId": row["account_id"],
                "name": row["account"],
                "type": row["kind"],
                "balanceKopecks": row["balance_kopecks"],
            }
            for row in rows
        ],
    }