"""REST API – analýza energetických toků (modelované toky z audit_interval)."""

from __future__ import annotations

import json
from datetime import date
from typing import Annotated, Any

import asyncpg
from fastapi import APIRouter, Depends, HTTPException, Query
from pydantic import BaseModel

from app.db_json import fetch_json
from app.deps import get_pg_pool

router = APIRouter(
    prefix="/sites/{site_id}/energy-flows",
    tags=["energy-flows"],
)


class DailyEnergyFlows(BaseModel):
    day: date
    interval_count: int
    pv_production_kwh: float
    grid_import_kwh: float
    grid_export_kwh: float
    batt_charge_kwh: float
    batt_discharge_kwh: float
    load_kwh: float
    pv_to_load_kwh: float
    pv_to_batt_kwh: float
    pv_to_grid_kwh: float
    batt_to_load_kwh: float
    batt_to_grid_kwh: float
    grid_to_load_kwh: float
    grid_to_batt_kwh: float
    grid_import_cashflow_czk: float
    grid_export_revenue_czk: float
    grid_to_load_cost_czk: float
    grid_to_batt_cost_czk: float


class DailyEnergyFlowsResponse(BaseModel):
    days: list[DailyEnergyFlows]


class IntervalEnergyFlows(BaseModel):
    interval_start: str
    pv_production_kwh: float | None
    grid_import_kwh: float | None
    grid_export_kwh: float | None
    batt_charge_kwh: float | None
    batt_discharge_kwh: float | None
    load_kwh: float | None
    pv_to_load_kwh: float | None
    pv_to_batt_kwh: float | None
    pv_to_grid_kwh: float | None
    batt_to_load_kwh: float | None
    batt_to_grid_kwh: float | None
    grid_to_load_kwh: float | None
    grid_to_batt_kwh: float | None


def _num(val: Any) -> float:
    if val is None:
        return 0.0
    return float(val)


async def _check_site(conn: asyncpg.Connection, site_id: int) -> None:
    ok = await conn.fetchval(
        "SELECT EXISTS(SELECT 1 FROM ems.site WHERE id = $1)", site_id
    )
    if not ok:
        raise HTTPException(status_code=404, detail="Site not found")


def _parse_day(val: Any) -> date:
    from datetime import datetime as _dt

    if isinstance(val, _dt):
        return val.date()
    if isinstance(val, date):
        return val
    if isinstance(val, str):
        return date.fromisoformat(val[:10])
    raise ValueError(val)


@router.get("/daily", response_model=DailyEnergyFlowsResponse)
async def get_energy_flows_daily(
    site_id: int,
    db: Annotated[asyncpg.Pool, Depends(get_pg_pool)],
    month: str = Query(
        ...,
        description="YYYY-MM",
        pattern=r"^\d{4}-\d{2}$",
    ),
) -> DailyEnergyFlowsResponse:
    try:
        year, mon = month.split("-")
        month_start = date(int(year), int(mon), 1)
        if int(mon) == 12:
            month_end = date(int(year) + 1, 1, 1)
        else:
            month_end = date(int(year), int(mon) + 1, 1)
    except (ValueError, IndexError):
        raise HTTPException(status_code=400, detail="Invalid month, expected YYYY-MM")

    async with db.acquire() as conn:
        await _check_site(conn, site_id)
        raw = await fetch_json(
            conn,
            "select ems.fn_energy_flows_daily_month($1::int, $2::date, $3::date)",
            site_id,
            month_start,
            month_end,
        )
    if not isinstance(raw, dict):
        raw = json.loads(raw)
    rows = raw.get("days") or []
    days: list[DailyEnergyFlows] = []
    for r in rows:
        if not isinstance(r, dict):
            continue
        days.append(
            DailyEnergyFlows(
                day=_parse_day(r.get("day")),
                interval_count=int(r.get("interval_count") or 0),
                pv_production_kwh=_num(r.get("pv_production_kwh")),
                grid_import_kwh=_num(r.get("grid_import_kwh")),
                grid_export_kwh=_num(r.get("grid_export_kwh")),
                batt_charge_kwh=_num(r.get("batt_charge_kwh")),
                batt_discharge_kwh=_num(r.get("batt_discharge_kwh")),
                load_kwh=_num(r.get("load_kwh")),
                pv_to_load_kwh=_num(r.get("pv_to_load_kwh")),
                pv_to_batt_kwh=_num(r.get("pv_to_batt_kwh")),
                pv_to_grid_kwh=_num(r.get("pv_to_grid_kwh")),
                batt_to_load_kwh=_num(r.get("batt_to_load_kwh")),
                batt_to_grid_kwh=_num(r.get("batt_to_grid_kwh")),
                grid_to_load_kwh=_num(r.get("grid_to_load_kwh")),
                grid_to_batt_kwh=_num(r.get("grid_to_batt_kwh")),
                grid_import_cashflow_czk=_num(r.get("grid_import_cashflow_czk")),
                grid_export_revenue_czk=_num(r.get("grid_export_revenue_czk")),
                grid_to_load_cost_czk=_num(r.get("grid_to_load_cost_czk")),
                grid_to_batt_cost_czk=_num(r.get("grid_to_batt_cost_czk")),
            )
        )
    return DailyEnergyFlowsResponse(days=days)


@router.get("/daily/{day}/intervals", response_model=list[IntervalEnergyFlows])
async def get_energy_flows_intervals(
    site_id: int,
    day: date,
    db: Annotated[asyncpg.Pool, Depends(get_pg_pool)],
) -> list[IntervalEnergyFlows]:
    async with db.acquire() as conn:
        await _check_site(conn, site_id)
        rows = await fetch_json(
            conn,
            "select ems.fn_energy_flows_intervals_day($1::int, $2::date)",
            site_id,
            day,
        )
    if not isinstance(rows, list):
        rows = json.loads(rows) if isinstance(rows, str) else []
    out: list[IntervalEnergyFlows] = []
    for r in rows:
        if not isinstance(r, dict):
            continue
        ist = r.get("interval_start")
        out.append(
            IntervalEnergyFlows(
                interval_start=ist if isinstance(ist, str) else str(ist),
                pv_production_kwh=r.get("pv_production_kwh"),
                grid_import_kwh=r.get("grid_import_kwh"),
                grid_export_kwh=r.get("grid_export_kwh"),
                batt_charge_kwh=r.get("batt_charge_kwh"),
                batt_discharge_kwh=r.get("batt_discharge_kwh"),
                load_kwh=r.get("load_kwh"),
                pv_to_load_kwh=r.get("pv_to_load_kwh"),
                pv_to_batt_kwh=r.get("pv_to_batt_kwh"),
                pv_to_grid_kwh=r.get("pv_to_grid_kwh"),
                batt_to_load_kwh=r.get("batt_to_load_kwh"),
                batt_to_grid_kwh=r.get("batt_to_grid_kwh"),
                grid_to_load_kwh=r.get("grid_to_load_kwh"),
                grid_to_batt_kwh=r.get("grid_to_batt_kwh"),
            )
        )
    return out