/**
 * Composable Security Plugin for Federated Wiki
 * 
 * Combines authentication providers with authorization enhancers
 * while maintaining compatibility with the existing security interface.
 */

// Register CoffeeScript to allow requiring .coffee files. Needed for wiki-security-passportjs
require('coffeescript/register');

const _ = require('lodash');
const coffee = require('coffeescript');

module.exports = (log, loga, argv) => {
  const security = {};
  
  // Parse security configuration
  const authProvider = argv.auth_provider;
  let authzEnhancers = argv.authz_enhancers || [];
  
  // Ensure authzEnhancers is always an array
  if (typeof authzEnhancers === 'string') {
    authzEnhancers = [authzEnhancers];
  }
  
  // Require explicit auth provider configuration
  if (!authProvider) {
    const errorMsg = 'Composable Security: auth_provider must be specified. Example: wiki --security_type composable --auth_provider wiki-security-friends';
    log(errorMsg);
    throw new Error(errorMsg);
  }
  
  log(`Composable Security: Loading auth provider: ${authProvider}`);
  if (authzEnhancers.length > 0) {
    log(`Composable Security: Loading authz enhancers: ${authzEnhancers.join(', ')}`);
  }
  
  // Load the base authentication provider
  let baseHandler;
  try {
    // Check if auth provider is already a function (for testing)
    if (typeof authProvider === 'function') {
      baseHandler = authProvider(log, loga, argv);
    } else {
      const AuthProvider = require(authProvider);
      baseHandler = AuthProvider(log, loga, argv);
    }
  } catch (error) {
    log(`Failed to load auth provider ${authProvider}: ${error.message}`);
    throw new Error(`Cannot load authentication provider: ${authProvider}`);
  }
  
  
  // Load authorization enhancers from regular plugins
  const enhancers = [];
  for (const enhancerName of authzEnhancers) {
    try {
      // Check if enhancer is already a function (for testing)
      let enhancer;
      if (typeof enhancerName === 'function') {
        enhancer = enhancerName(log, loga, argv, baseHandler);
      } else {
        // Load as a regular plugin
        let Plugin;
        try {
          // First try direct require (for global modules)
          Plugin = require(enhancerName);
        } catch (firstError) {
          // Try resolving from the main wiki's package directory
          const path = require('path');
          const enhancerPath = path.join(argv.packageDir, enhancerName);
          Plugin = require(enhancerPath);
        }
        
        // Check if the plugin exports a security enhancer
        if (Plugin.securityEnhancer && typeof Plugin.securityEnhancer === 'function') {
          enhancer = Plugin.securityEnhancer(log, loga, argv, baseHandler);
          log(`Loaded security enhancer from plugin: ${enhancerName}`);
        } else {
          log(`Warning: Plugin ${enhancerName} does not export a securityEnhancer function`);
          continue;
        }
      }
      
      enhancers.push({
        name: typeof enhancerName === 'string' ? enhancerName : enhancerName.name || 'anonymous',
        handler: enhancer
      });
      log(`Loaded authorization enhancer: ${typeof enhancerName === 'string' ? enhancerName : enhancerName.name || 'anonymous'}`);
    } catch (error) {
      log(`Warning: Failed to load authz enhancer ${enhancerName}: ${error.message}`);
      // Continue loading other enhancers
    }
  }
  
  // Compose the security interface
  
  // Owner management - delegate to base auth provider
  security.retrieveOwner = (cb) => {
    return baseHandler.retrieveOwner(cb);
  };
  
  security.getOwner = () => {
    return baseHandler.getOwner();
  };
  
  security.setOwner = (id, cb) => {
    return baseHandler.setOwner(id, cb);
  };
  
  // User identification - allow enhancers to modify
  security.getUser = (req) => {
    let baseGetUser = () => baseHandler.getUser(req);
    
    // Let each enhancer potentially modify user identification
    for (const enhancer of enhancers) {
      if (enhancer.handler.getUser) {
        const previousGetUser = baseGetUser;
        baseGetUser = () => enhancer.handler.getUser(req, previousGetUser);
      }
    }
    
    return baseGetUser();
  };
  
  // Authorization - compose base auth with enhancers
  security.isAuthorized = (req) => {
    let baseIsAuthorized = () => baseHandler.isAuthorized(req);
    
    // Let each enhancer potentially modify authorization
    for (const enhancer of enhancers) {
      if (enhancer.handler.isAuthorized) {
        const previousIsAuthorized = baseIsAuthorized;
        baseIsAuthorized = () => enhancer.handler.isAuthorized(req, previousIsAuthorized);
      }
    }
    
    return baseIsAuthorized();
  };
  
  // Admin check - compose base auth with enhancers
  security.isAdmin = (req) => {
    let baseIsAdmin = () => baseHandler.isAdmin(req);
    
    // Let each enhancer potentially modify admin check
    for (const enhancer of enhancers) {
      if (enhancer.handler.isAdmin) {
        const previousIsAdmin = baseIsAdmin;
        baseIsAdmin = () => enhancer.handler.isAdmin(req, previousIsAdmin);
      }
    }
    
    return baseIsAdmin();
  };
  
  // Clean and setup client assets from base provider
  const setupClientAssets = () => {
    if (typeof authProvider === 'string') {
      try {
        const path = require('path');
        const fs = require('fs');
        
        // Get base provider's client path
        const packagePath = require.resolve(`${authProvider}/package.json`);
        const baseProviderClientPath = path.join(path.dirname(packagePath), 'client');
        
        if (fs.existsSync(baseProviderClientPath)) {
          // Get our client path
          const ourClientPath = path.join(__dirname, '..', 'client');
          
          // Clean existing client directory to avoid stale files from previous providers
          if (fs.existsSync(ourClientPath)) {
            log(`Composable Security: Cleaning existing client directory`);
            fs.rmSync(ourClientPath, { recursive: true, force: true });
          }
          
          // Copy files from base provider to our client directory
          const copyFiles = (source, target) => {
            if (!fs.existsSync(target)) {
              fs.mkdirSync(target, { recursive: true });
            }
            
            const files = fs.readdirSync(source);
            for (const file of files) {
              const sourcePath = path.join(source, file);
              const targetPath = path.join(target, file);
              
              if (fs.statSync(sourcePath).isDirectory()) {
                copyFiles(sourcePath, targetPath);
              } else {
                if (path.extname(sourcePath) === '.coffee') {
                  const coffeeScript = fs.readFileSync(sourcePath, 'utf8');
                  const javascript = coffee.compile(coffeeScript);
                  const jsPath = targetPath.replace(/\.coffee$/, '.js');
                  fs.writeFileSync(jsPath, javascript);
                  log(`Compiled and copied ${file} as ${path.basename(jsPath)}`);
                } else {
                  fs.copyFileSync(sourcePath, targetPath);
                }
              }
            }
          };
          
          copyFiles(baseProviderClientPath, ourClientPath);
          log(`Composable Security: Copied client assets from ${authProvider}`);
        } else {
          log(`Warning: No client directory found for ${authProvider}, client-side functionality may not work`);
        }
      } catch (error) {
        log(`Warning: Failed to setup client assets: ${error.message}`);
      }
    }
  };
  
  // Set up client assets before defining routes
  setupClientAssets();

  // Route definition - combine base routes with enhancer routes
  security.defineRoutes = (app, cors, updateOwner) => {
    // Note: Static route for /security is automatically set up by wiki-server
    // based on argv.security_type, so we don't need to set it up here.
    
    // First, let the base auth provider define its routes
    baseHandler.defineRoutes(app, cors, updateOwner);
    
    // Apply middleware from enhancers
    for (const enhancer of enhancers) {
      if (enhancer.handler.middleware) {
        log(`Adding middleware from ${enhancer.name}`);
        app.use(enhancer.handler.middleware);
      }
    }
    
    // Then, let each enhancer add additional routes
    for (const enhancer of enhancers) {
      if (enhancer.handler.defineRoutes) {
        log(`Adding routes from ${enhancer.name}`);
        enhancer.handler.defineRoutes(app, cors, updateOwner);
      }
    }
  };
  
  // Expose loaded components for debugging/introspection
  security._debug = {
    authProvider: authProvider,
    authzEnhancers: authzEnhancers,
    loadedEnhancers: enhancers.map(e => e.name),
    baseHandler: baseHandler
  };
  
  // Expose the base provider's client path for the server to use
  security.getClientPath = () => {
    const path = require('path');
    try {
      if (typeof authProvider === 'string') {
        // For npm packages, resolve the package directory
        const packagePath = require.resolve(`${authProvider}/package.json`);
        return path.join(path.dirname(packagePath), 'client');
      }
    } catch (error) {
      log(`Warning: Could not resolve client path for ${authProvider}: ${error.message}`);
    }
    return null;
  };
  
  return security;
};