/**
 * Environment Configuration & Utilities
 * Central config dictionary and environment discovery
 */

import { configureKeyValueStoreBackend, getProvider } from './storage.js';
import { api as apiClient } from './api.js';

// Private storage instance for config
const storage = getProvider('kv', 'config');

// Config dictionary - populated by loader
let config = {};
let consoleLoggerInstalled = false;
const lockedKeys = new Set();

const LOGGER_ICONS = {
  debug: '.',
  info: 'i',
  log: '>',
  warn: '!',
  error: 'x'
};

const NATIVE_CONSOLE = {
  log: console.log.bind(console),
  info: (console.info || console.log).bind(console),
  warn: console.warn.bind(console),
  error: console.error.bind(console),
  debug: (console.debug || console.log).bind(console)
};
const perfNow = () => {
  if (typeof performance !== 'undefined' && typeof performance.now === 'function') {
    return performance.now();
  }
  return Date.now();
};

function normalizeLogLevel(level = 'log') {
  if (level === 'info') return 'info';
  if (level === 'warn') return 'warn';
  if (level === 'error') return 'error';
  if (level === 'debug') return 'debug';
  return 'log';
}

function splitSourceAndMessage(args = []) {
  if (args.length === 0) {
    return {
      source: 'App',
      messageParts: []
    };
  }

  const [firstArg, ...restArgs] = args;
  if (typeof firstArg !== 'string') {
    return {
      source: 'App',
      messageParts: args
    };
  }

  const match = firstArg.match(/^\[([^\]]+)\]\s*(.*)$/s);
  if (!match) {
    return {
      source: 'App',
      messageParts: args
    };
  }

  const [, source, firstMessage] = match;
  const messageParts = firstMessage ? [firstMessage, ...restArgs] : restArgs;
  return {
    source,
    messageParts
  };
}

// Special config keys
export const CONFIG_KEYS = {
  APP_NAME: 'APP_NAME',
  APP_DISPLAY_NAME: 'APP_DISPLAY_NAME',
  APP_DESCRIPTION: 'APP_DESCRIPTION',
  FAVICON: 'FAVICON',
  BRAND_LOGO: 'BRAND_LOGO',
  THEME_COLOR: 'THEME_COLOR',
  BACKGROUND_COLOR: 'BACKGROUND_COLOR',
  UI_SHELL: 'UI_SHELL',
  STYLE_THEME: 'STYLE_THEME',
  INITIAL_ROUTE: 'INITIAL_ROUTE',
  STORAGE_BACKEND: 'STORAGE_BACKEND',
  API_BASE_URL: 'API_BASE_URL',
  MODULES: 'MODULES',
  SECURITY_CONFIG: 'SECURITY_CONFIG',
  LOCALE: 'LOCALE',
  /** Development host: extra dev UI, SW dev behavior, etc. Layered via getConfig (storage → profile → bundler). */
  DEV_HOST: 'DEV_HOST',
  /** Whether the app should register and use a service worker. */
  SERVICE_WORKER_ENABLED: 'SERVICE_WORKER_ENABLED'
};

// do not allow edits on these keys via setConfig - they are meant to be set from profile or env vars and not overridden at runtime
[
  CONFIG_KEYS.API_BASE_URL,
  CONFIG_KEYS.MODULES,
  CONFIG_KEYS.SECURITY_CONFIG
].forEach((key) => lockedKeys.add(key));

/**
 * Resolve dev-host flag from profile (explicit) or bundler hints.
 * Profile wins: `dev_host: true|false` or `runtime.dev: true|false`.
 * Otherwise Vite `import.meta.env.DEV`, else false.
 * @param {Object|null|undefined} appConfig
 * @returns {boolean}
 */
function resolveDevHostFlag(appConfig) {
  if (appConfig && typeof appConfig.dev_host === 'boolean') {
    return appConfig.dev_host;
  }
  if (appConfig?.runtime && typeof appConfig.runtime.dev === 'boolean') {
    return appConfig.runtime.dev;
  }
  if (typeof import.meta !== 'undefined' && import.meta.env) {
    return Boolean(import.meta.env.DEV);
  }
  return false;
}

function resolveDesktopApiBaseURL() {
  if (typeof window === 'undefined') {
    return null;
  }

  const bridgeBase = window.__bfaceDesktop?.apiBaseUrl;
  if (typeof bridgeBase === 'string' && bridgeBase.trim()) {
    return bridgeBase.trim();
  }

  return null;
}

/**
 * Resolve service-worker enablement from profile.
 * Defaults to true for backward compatibility with PWA templates.
 * @param {Object|null|undefined} appConfig
 * @returns {boolean}
 */
export function resolveServiceWorkerEnabled(appConfig = {}) {
  if (typeof appConfig?.service_worker?.enabled === 'boolean') {
    return appConfig.service_worker.enabled;
  }
  if (typeof appConfig?.serviceWorker?.enabled === 'boolean') {
    return appConfig.serviceWorker.enabled;
  }
  if (typeof appConfig?.pwa?.service_worker?.enabled === 'boolean') {
    return appConfig.pwa.service_worker.enabled;
  }
  return true;
}

/**
 * Initialize environment config
 * @param {Object} appConfig - Configuration from profile
 */
export function initEnv(appConfig) {
  const api = appConfig.api || {};
  const resolvedApiBaseURL =
    resolveDesktopApiBaseURL()
    || appConfig.backend?.base_url
    || api.base_url
    || api.baseURL
    || '/api';
  config = {
    APP_NAME: appConfig.id || appConfig.name,
    APP_DISPLAY_NAME: appConfig.displayName || appConfig.short_name || appConfig.name,
    APP_DESCRIPTION: appConfig.description || '',
    FAVICON: appConfig.favicon || appConfig.brand_logo || appConfig.brandLogo || appConfig.icons?.[0]?.src || '/favicon.svg',
    BRAND_LOGO: appConfig.brand_logo || appConfig.brandLogo || appConfig.icons?.[0]?.src || '/favicon.svg',
    THEME_COLOR: appConfig.theme_color || appConfig.themeColor || '#000000',
    BACKGROUND_COLOR: appConfig.background_color || appConfig.backgroundColor || '#ffffff',
    UI_SHELL: appConfig.ui_shell || appConfig.uiShell || 'EmptyShell',
    STYLE_THEME:
      appConfig.style_theme
      || appConfig.styleTheme
      || appConfig.ui?.style_theme
      || appConfig.ui?.styleTheme
      || null,
    INITIAL_ROUTE: appConfig.initial_route || appConfig.initialRoute || appConfig.ui?.initial_route || appConfig.ui?.initialRoute || '/home',
    STORAGE_BACKEND: appConfig.storage?.backend || 'localStorage',
    API_BASE_URL: resolvedApiBaseURL,
    MODULES: appConfig.modules || [],
    SECURITY_CONFIG: appConfig.security || {},
    LOCALE: appConfig.locale || null,
    [CONFIG_KEYS.DEV_HOST]: resolveDevHostFlag(appConfig),
    [CONFIG_KEYS.SERVICE_WORKER_ENABLED]: resolveServiceWorkerEnabled(appConfig),
    // Store full profile for advanced access
    _profile: appConfig
  };
  apiClient.setBaseURL(resolvedApiBaseURL);
  configureKeyValueStoreBackend(config.STORAGE_BACKEND);
}

function resolveSystemLocale() {
  if (typeof navigator !== 'undefined' && typeof navigator.language === 'string' && navigator.language.trim()) {
    return navigator.language.trim();
  }
  return 'en-US';
}

/**
 * Bootstrap environment as early as possible from the selected profile.
 * This gives the app a single source of truth before full boot runs.
 * @param {Object} appConfig
 * @param {Object} options
 * @param {boolean} [options.installLoggerFirst=true]
 */
export function bootstrapEnv(appConfig, options = {}) {
  const { installLoggerFirst = true } = options;
  if (installLoggerFirst) {
    installConsoleLogger();
  }
  if (appConfig && typeof appConfig === 'object') {
    initEnv(appConfig);
  }
  return getConfigDict();
}

export function log(source = 'App', level = 'log', ...messageParts) {
  const normalizedLevel = normalizeLogLevel(level);
  const sink = NATIVE_CONSOLE[normalizedLevel] || NATIVE_CONSOLE.log;
  const timestamp = new Date().toISOString();
  const icon = LOGGER_ICONS[normalizedLevel] || LOGGER_ICONS.log;
  sink(`${timestamp} [${source}] ${icon}`, ...messageParts);
}

export function createLogger(source = 'App') {
  return {
    debug: (...messageParts) => log(source, 'debug', ...messageParts),
    info: (...messageParts) => log(source, 'info', ...messageParts),
    log: (...messageParts) => log(source, 'log', ...messageParts),
    warn: (...messageParts) => log(source, 'warn', ...messageParts),
    error: (...messageParts) => log(source, 'error', ...messageParts)
  };
}

export function startTrace(source = 'App', label = 'operation', metadata = null) {
  const startedAt = perfNow();
  if (metadata !== null && metadata !== undefined) {
    log(source, 'debug', `${label} started`, metadata);
  } else {
    log(source, 'debug', `${label} started`);
  }

  return {
    end(extra = null, level = 'log') {
      const durationMs = Math.round((perfNow() - startedAt) * 100) / 100;
      if (extra !== null && extra !== undefined) {
        log(source, level, `${label} finished in ${durationMs}ms`, extra);
      } else {
        log(source, level, `${label} finished in ${durationMs}ms`);
      }
      return durationMs;
    },
    fail(error = null) {
      const durationMs = Math.round((perfNow() - startedAt) * 100) / 100;
      log(source, 'error', `${label} failed in ${durationMs}ms`, error);
      return durationMs;
    }
  };
}

export async function traceAsync(source, label, fn, metadata = null) {
  const trace = startTrace(source, label, metadata);
  try {
    const result = await fn();
    trace.end();
    return result;
  } catch (error) {
    trace.fail(error);
    throw error;
  }
}

export function installConsoleLogger() {
  if (consoleLoggerInstalled || typeof console === 'undefined') {
    return;
  }

  consoleLoggerInstalled = true;

  console.log = (...args) => {
    const { source, messageParts } = splitSourceAndMessage(args);
    log(source, 'log', ...messageParts);
  };

  console.info = (...args) => {
    const { source, messageParts } = splitSourceAndMessage(args);
    log(source, 'info', ...messageParts);
  };

  console.warn = (...args) => {
    const { source, messageParts } = splitSourceAndMessage(args);
    log(source, 'warn', ...messageParts);
  };

  console.error = (...args) => {
    const { source, messageParts } = splitSourceAndMessage(args);
    log(source, 'error', ...messageParts);
  };

  console.debug = (...args) => {
    const { source, messageParts } = splitSourceAndMessage(args);
    log(source, 'debug', ...messageParts);
  };
}

export function lockConfigKey(key) {
  if (!key) {
    return false;
  }
  lockedKeys.add(key);
  return true;
}

export function unlockConfigKey(key) {
  if (!key) {
    return false;
  }
  return lockedKeys.delete(key);
}

export function isConfigKeyLocked(key) {
  return lockedKeys.has(key);
}

export function getLockedConfigKeys() {
  return Array.from(lockedKeys);
}

function setMetaTag(name, content) {
  if (typeof document === 'undefined') {
    return;
  }

  let element = document.querySelector(`meta[name="${name}"]`);
  if (!element) {
    element = document.createElement('meta');
    element.setAttribute('name', name);
    document.head.appendChild(element);
  }

  element.setAttribute('content', content);
}

export function setDocumentBackground(color) {
  if (typeof document === 'undefined' || !color) {
    return;
  }

  document.documentElement.style.backgroundColor = color;

  if (document.body) {
    document.body.style.backgroundColor = color;
  }
}

function setFavicon(href) {
  if (typeof document === 'undefined' || !href) {
    return;
  }

  let element = document.querySelector('link[rel="icon"]');
  if (!element) {
    element = document.createElement('link');
    element.setAttribute('rel', 'icon');
    document.head.appendChild(element);
  }

  element.setAttribute('href', href);
  if (!element.getAttribute('type')) {
    element.setAttribute('type', 'image/svg+xml');
  }
}

export async function syncDocumentHeadFromConfig(options = {}) {
  if (typeof document === 'undefined') {
    return null;
  }

  const {
    titleFallback = 'PWA Template',
    descriptionFallback = '',
    themeColorFallback = '#000000',
    backgroundColorFallback = '#ffffff'
  } = options;

  const [favicon, title, description, themeColor, backgroundColor, brandLogo] = await Promise.all([
    getConfig(CONFIG_KEYS.FAVICON, '/favicon.svg'),
    getConfig(CONFIG_KEYS.APP_DISPLAY_NAME, titleFallback),
    getConfig(CONFIG_KEYS.APP_DESCRIPTION, descriptionFallback),
    getConfig(CONFIG_KEYS.THEME_COLOR, themeColorFallback),
    getConfig(CONFIG_KEYS.BACKGROUND_COLOR, backgroundColorFallback),
    getConfig(CONFIG_KEYS.BRAND_LOGO, '/favicon.svg')
  ]);

  document.title = title || titleFallback;
  setMetaTag('description', description || descriptionFallback);
  setMetaTag('theme-color', themeColor || themeColorFallback);
  setDocumentBackground(backgroundColor || backgroundColorFallback);
  setFavicon(favicon || '/favicon.svg');

  return {
    title: title || titleFallback,
    description: description || descriptionFallback,
    themeColor: themeColor || themeColorFallback,
    backgroundColor: backgroundColor || backgroundColorFallback,
    favicon: favicon || '/favicon.svg',
    brandLogo: brandLogo || '/favicon.svg'
  };
}

/**
 * Get config value by key
 * Checks in order: storage (if key exists) → config dictionary → environment variables → altValue
 * Uses storage.hasKey() as a guard to skip unnecessary storage.get() calls for profile config keys
 * @param {string} key - Config key
 * @param {any} altValue - Alternative value if not found
 * @returns {Promise<any>} Config value or altValue
 */
export function getConfigSync(key, altValue = null) {
  if (config.hasOwnProperty(key)) {
    return config[key];
  }

  if (typeof import.meta !== 'undefined' && import.meta.env) {
    const envKey = `VITE_${key}`;
    const envValue = import.meta.env[envKey];
    if (envValue !== undefined) {
      return envValue;
    }
  }

  return altValue;
}

export async function getConfig(key, altValue = null) {
  // Locked profile keys cannot be overridden by persisted storage values.
  if (isConfigKeyLocked(key) && config.hasOwnProperty(key)) {
    return config[key];
  }

  // 1. Check if key exists in storage first (quick check to avoid unnecessary get)
  try {
    const exists = await storage.hasKey(key);
    if (exists) {
      // Only do full storage.get() if key exists
      const storedValue = await storage.get(key, null);
      if (storedValue !== null && storedValue !== undefined) {
        return storedValue;
      }
    }
    // If key doesn't exist in storage, skip to config dictionary (faster path)
  } catch (error) {
    // Storage might not be available, continue to next check
    console.warn(`[Env] Failed to check storage for "${key}":`, error);
  }
  
  // 2. Check config dictionary (in-memory config from profile)
  if (config.hasOwnProperty(key)) {
    return config[key];
  }
  
  // 3. Fall back to environment variables (Vite env vars)
  // Check if import.meta.env exists (available in Vite, not in Node)
  if (typeof import.meta !== 'undefined' && import.meta.env) {
    const envKey = `VITE_${key}`;
    const envValue = import.meta.env[envKey];
    
    if (envValue !== undefined) {
      return envValue;
    }
  }
  
  // 4. Return alternative value
  return altValue;
}

/**
 * Set config value
 * If key exists in config dictionary, update it there (in-memory).
 * Otherwise, save to storage (for persistence).
 * @param {string} key - Config key
 * @param {any} value - Value to set
 * @returns {Promise<boolean>}
 */
export async function setConfig(key, value) {
  if (isConfigKeyLocked(key)) {
    console.warn(`[Env] Refusing to set locked config key "${key}". Unlock it explicitly first if this override is intentional.`);
    return false;
  }

  // If key exists in config dictionary, update it there (in-memory config)
  if (config.hasOwnProperty(key)) {
    config[key] = value;
    return true;
  } else {
    // Otherwise, save to storage (for state/settings persistence)
    try {
      await storage.set(key, value);
      return true;
    } catch (error) {
      console.warn(`[Env] Failed to set "${key}" in storage:`, error);
      // Fallback: store in config dictionary if storage fails
      config[key] = value;
      return true;
    }
  }
}

/**
 * Get full config object (read-only copy)
 * @returns {Object} Config dictionary
 */
export function getConfigDict() {
  return { ...config };
}

export async function getLocale(altValue = null) {
  const savedLocale = await getConfig(CONFIG_KEYS.LOCALE, null);
  if (savedLocale && typeof savedLocale === 'string') {
    config[CONFIG_KEYS.LOCALE] = savedLocale;
    return savedLocale;
  }

  return altValue || resolveSystemLocale();
}

export function getLocaleSync(altValue = null) {
  return config[CONFIG_KEYS.LOCALE] || altValue || resolveSystemLocale();
}

export async function setLocale(locale) {
  const normalizedLocale = typeof locale === 'string' && locale.trim() ? locale.trim() : null;
  config[CONFIG_KEYS.LOCALE] = normalizedLocale;

  try {
    if (normalizedLocale) {
      await storage.set(CONFIG_KEYS.LOCALE, normalizedLocale);
    } else {
      await storage.remove(CONFIG_KEYS.LOCALE);
    }
  } catch (error) {
    console.warn('[Env] Failed to persist locale:', error);
  }

  return normalizedLocale || resolveSystemLocale();
}

/**
 * Whether the app is treated as a development host (dev tooling, SW policy, etc.).
 * Synchronous: uses in-memory config after {@link initEnv} / {@link bootstrapEnv}.
 * For persisted overrides, use {@link getConfig} with {@link CONFIG_KEYS.DEV_HOST} in async code.
 */
export function isDevelopment() {
  if (config && Object.prototype.hasOwnProperty.call(config, CONFIG_KEYS.DEV_HOST)) {
    return Boolean(config[CONFIG_KEYS.DEV_HOST]);
  }
  if (typeof import.meta !== 'undefined' && import.meta.env) {
    return Boolean(import.meta.env.DEV);
  }
  return false;
}

/**
 * Whether service worker registration is enabled for this app.
 * Synchronous: uses in-memory config after {@link initEnv} / {@link bootstrapEnv}.
 */
export function isServiceWorkerEnabledSync(altValue = true) {
  if (config && Object.prototype.hasOwnProperty.call(config, CONFIG_KEYS.SERVICE_WORKER_ENABLED)) {
    return Boolean(config[CONFIG_KEYS.SERVICE_WORKER_ENABLED]);
  }
  return altValue;
}

/**
 * Async profile-aware service worker enablement check.
 */
export async function isServiceWorkerEnabled(altValue = true) {
  const configured = await getConfig(CONFIG_KEYS.SERVICE_WORKER_ENABLED, null);
  if (typeof configured === 'boolean') {
    return configured;
  }
  return isServiceWorkerEnabledSync(altValue);
}

/**
 * Inverse of {@link isDevelopment} when no explicit production flag exists.
 */
export function isProduction() {
  if (typeof import.meta !== 'undefined' && import.meta.env && typeof import.meta.env.PROD === 'boolean') {
    return import.meta.env.PROD;
  }
  return !isDevelopment();
}