import { config as loadDotenv } from "dotenv";
import { fileURLToPath } from "node:url";
import { dirname, join } from "node:path";
import { z } from "zod";

// In production (docker-compose) env vars are already injected via env_file;
// this only fills gaps for local `npm run dev`, and is a no-op if the file is absent.
loadDotenv({ path: join(dirname(fileURLToPath(import.meta.url)), "../../.env") });

const envSchema = z.object({
  PORT: z.coerce.number().default(3000),
  INFLUX_URL: z.string().url(),
  INFLUX_TOKEN: z.string().min(1),
  INFLUX_ORG: z.string().min(1),
  INFLUX_BUCKET: z.string().min(1),
  INFLUX_MEASUREMENT: z.string().default("power"),
  INFLUX_DOMAIN: z.string(),
  INFLUX_ENTITY_ID: z.string(),
  INFLUX_FIELD: z.string().default("value"),
  INFLUX_FIELD_UNIT: z.enum(["W", "kW"]).default("W"),
  HA_URL: z.string().url(),
  HA_TOKEN: z.string().min(1),
  TARGET_KW: z.coerce.number().positive(),
  DB_PATH: z.string().default("./data/energy.db"),
  CONTROL_LOOP_INTERVAL_MS: z.coerce.number().default(10_000),
});

export type Env = z.infer<typeof envSchema>;

export function loadEnv(): Env {
  const parsed = envSchema.safeParse(process.env);
  if (!parsed.success) {
    console.error("Invalid environment configuration:", parsed.error.flatten().fieldErrors);
    process.exit(1);
  }
  return parsed.data;
}