import { existsSync, readFileSync } from "node:fs";
import { dirname, resolve } from "node:path";
import { fileURLToPath } from "node:url";

function resolveWorkspaceRoot() {
  return resolve(dirname(fileURLToPath(import.meta.url)), "..");
}

export function resolveWorkspaceEnvPath(options = {}) {
  const { workspaceRoot = resolveWorkspaceRoot() } = options;
  return resolve(workspaceRoot, ".env");
}

export function resolveWorkspaceEnvPaths(options = {}) {
  const { workspaceRoot = resolveWorkspaceRoot(), nodeEnv = process.env.NODE_ENV } = options;
  const candidates = [".env"];

  if (nodeEnv) {
    candidates.push(`.env.${nodeEnv}`);
  }

  candidates.push(".env.local");

  if (nodeEnv) {
    candidates.push(`.env.${nodeEnv}.local`);
  }

  return [...new Set(candidates.map((candidate) => resolve(workspaceRoot, candidate)))];
}

export function loadWorkspaceEnv(options = {}) {
  const envPaths = resolveWorkspaceEnvPaths(options);
  const originalKeys = new Set(Object.keys(process.env));
  const loadedPaths = [];

  for (const envPath of envPaths) {
    if (!existsSync(envPath)) {
      continue;
    }

    const contents = readFileSync(envPath, "utf8");
    for (const rawLine of contents.split(/\r?\n/u)) {
      const line = rawLine.trim();
      if (!line || line.startsWith("#")) {
        continue;
      }

      const separatorIndex = line.indexOf("=");
      if (separatorIndex <= 0) {
        continue;
      }

      const key = line.slice(0, separatorIndex).trim();
      const rawValue = line.slice(separatorIndex + 1).trim();
      const quoted =
        (rawValue.startsWith("\"") && rawValue.endsWith("\""))
        || (rawValue.startsWith("'") && rawValue.endsWith("'"));
      const value = quoted ? rawValue.slice(1, -1) : rawValue;

      if (!originalKeys.has(key)) {
        process.env[key] = value;
      }
    }

    loadedPaths.push(envPath);
  }

  return loadedPaths;
}