// Derives the cable-sizing inputs that follow from the circuit itself, so the
// planner starts from the circuit's real values instead of fixed defaults.
import type {
  CircuitCategory,
  ExistingProtection,
} from "../../cable-sizing/domain/cable-sizing-calculation";
import type { CircuitTreeCircuitDto, CircuitTreeProtectionDeviceDto } from "../types";

/** Three-phase if the circuit group or any device row is three-phase. */
export function deriveCircuitPhase(
  circuit: CircuitTreeCircuitDto,
  circuitCategory?: CircuitCategory
): 1 | 3 {
  return circuitCategory === "three_phase" ||
    circuit.deviceRows.some((row) => row.phaseType === "three_phase")
    ? 3
    : 1;
}

/**
 * Power-weighted cos φ of the circuit: P / S with S = Σ P_row / cos φ_row.
 * Rows without cos φ count as 1; a circuit without load yields 1.
 */
export function deriveCircuitCosPhi(circuit: CircuitTreeCircuitDto): number {
  let activePowerKw = 0;
  let apparentPowerKva = 0;
  for (const row of circuit.deviceRows) {
    activePowerKw += row.rowTotalPower;
    apparentPowerKva += row.rowTotalPower / (row.cosPhi || 1);
  }
  if (activePowerKw <= 0 || apparentPowerKva <= 0) {
    return 1;
  }
  return Math.round((activePowerKw / apparentPowerKva) * 100) / 100;
}

/**
 * Maps the circuit's protective device to the overload-protection kind of the
 * calculation. Circuit-breakers (LS, FI/LS, AFDD) are "breaker", D0 and NH
 * fuse links "fuse"; a residual-current device without overcurrent release
 * (FI) provides no overload protection and is ignored.
 */
export function toExistingProtection(
  protection: CircuitTreeProtectionDeviceDto | undefined
): ExistingProtection | undefined {
  if (!protection || protection.type === "FI") {
    return undefined;
  }
  const kind =
    protection.type === "LS" || protection.type === "FI_LS" || protection.type === "AFDD"
      ? "breaker"
      : "fuse";
  return { ratedCurrentA: protection.ratedCurrentA, kind };
}