#!/usr/bin/env node

/**
 * This script generates a app-config.js file with environment variables
 * starting with CLIENT_ for both development and production environments.
 *
 * It works in both local development and production environments,
 * eliminating the need for a separate Docker entrypoint script.
 */

import fs from "fs";
import path from "path";
import dotenv from "dotenv";
import { fileURLToPath } from "url";

// Get the directory name in ESM
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

// Determine if we're in production or development mode
const isProduction = process.env.NODE_ENV === "production";

// Load environment variables from .env files
// In production, we prioritize .env.production and .env
// In development, we use the standard Vite hierarchy
if (isProduction) {
  dotenv.config({ path: path.resolve(process.cwd(), ".env.production") });
  dotenv.config({ path: path.resolve(process.cwd(), ".env") });
} else {
  // Development mode - follow Vite's loading order
  dotenv.config({ path: path.resolve(process.cwd(), ".env") });
  dotenv.config({ path: path.resolve(process.cwd(), ".env.development") });
  dotenv.config({ path: path.resolve(process.cwd(), ".env.local") });
  dotenv.config({
    path: path.resolve(process.cwd(), ".env.development.local"),
  });
}

// Determine the target directory based on environment
// In production, we use the dist directory (or a specified output directory)
// In development, we use the public directory
const targetDir = isProduction
  ? process.env.OUTPUT_DIR || path.resolve(process.cwd(), "dist")
  : path.resolve(process.cwd(), "public");

// Ensure the target directory exists
if (!fs.existsSync(targetDir)) {
  fs.mkdirSync(targetDir, { recursive: true });
  console.log(`Created directory: ${targetDir}`);
}

// Function to convert SNAKE_CASE to camelCase
function toCamelCase(str) {
  return str
    .toLowerCase()
    .replace(/_([a-z])/g, (_, letter) => letter.toUpperCase());
}

// Create the app-config.js file
const configFilePath = path.join(targetDir, "app-config.js");
let configContent =
  "// Runtime environment variables - Generated by generate-app-config.js\n";
configContent += "window.appConfig = {\n";

// Get all environment variables starting with CLIENT_
const clientEnvVars = Object.entries(process.env).filter(([key]) =>
  key.startsWith("CLIENT_"),
);

// Add each environment variable to the config
clientEnvVars.forEach(([key, value]) => {
  // Remove CLIENT_ prefix
  const keyWithoutPrefix = key.replace(/^CLIENT_/, "");

  // Convert to camelCase
  const camelKey = toCamelCase(keyWithoutPrefix);

  // Add the key-value pair to the config
  // If the value is 'true', 'false', 'null', or a number, don't add quotes
  if (
    value === "true" ||
    value === "false" ||
    value === "null" ||
    /^[0-9]+$/.test(value)
  ) {
    configContent += `  ${camelKey}: ${value},\n`;
  } else {
    configContent += `  ${camelKey}: "${value}",\n`;
  }
});

// Add default values for essential variables if they don't exist
if (!process.env.CLIENT_BASE_PATH) {
  configContent += '  basePath: "/",\n';
}
if (!process.env.CLIENT_APP_NAME) {
  configContent += '  appName: "App",\n';
}
if (!process.env.CLIENT_DEBUG) {
  configContent += "  debug: " + (isProduction ? "false" : "true") + ",\n";
}

// Close the object
configContent += "};";

// Helper function for colorized logging like Vite
function formatLog(label, message, color = "\x1b[36m ") {
  // Default to cyan color
  const reset = "\x1b[0m";
  const dim = "\x1b[2m";
  const arrow = `${dim}${color}➜${reset}`;
  const formattedLabel = `${color}${label}:${reset}`;
  return ` ${arrow} ${formattedLabel} ${message}`;
}

// Write the config file
fs.writeFileSync(configFilePath, configContent);
console.log(formatLog("Generated", `app-config.js at ${configFilePath}`));

// Check if index.html exists in the target directory
const indexHtmlPath = path.join(targetDir, "index.html");
if (fs.existsSync(indexHtmlPath)) {
  let indexHtmlContent = fs.readFileSync(indexHtmlPath, "utf8");

  // Check if the script tag already exists
  if (!indexHtmlContent.includes("app-config.js")) {
    // Insert the script tag after the opening head tag
    indexHtmlContent = indexHtmlContent.replace(
      "<head>",
      '<head>\n    <script src="./app-config.js"></script>',
    );

    // Write the updated index.html
    fs.writeFileSync(indexHtmlPath, indexHtmlContent);
    console.log(
      formatLog(
        "Updated",
        `injected script tag into ${path.basename(indexHtmlPath)}`,
      ),
    );
  } else {
    console.log(
      formatLog(
        "Note",
        `app-config.js script already exists in ${path.basename(indexHtmlPath)}`,
        "\x1b[33m ",
      ),
    ); // Yellow
  }
} else {
  console.log(
    formatLog("Note", `index.html not found in ${targetDir}`, "\x1b[34m "),
  ); // Blue
  if (!isProduction) {
    console.log(
      formatLog(
        "Vite",
        "script will be injected during development",
        "\x1b[34m ",
      ),
    ); // Blue
  } else {
    console.log(
      formatLog(
        "Warning",
        "index.html not found in production build directory!",
        "\x1b[33m ",
      ),
    ); // Yellow
  }
}

console.log(
  formatLog(
    "Ready",
    `app-config generated for ${isProduction ? "production" : "development"} environment`,
    "\x1b[32m ",
  ),
); // Green