// Application configuration
export interface AppConfig {
  adminDid: string;
  adminHandle: string;
  aiDid: string;
  aiHandle: string;
  aiDisplayName: string;
  aiAvatar: string;
  aiDescription: string;
  collections: {
    base: string;  // Base collection like "ai.syui.log"
  };
  host: string;
  rkey?: string; // Current post rkey if on post page
  aiEnabled: boolean;
  aiAskAi: boolean;
  aiProvider: string;
  aiModel: string;
  aiHost: string;
  aiSystemPrompt: string;
  allowedHandles: string[]; // Handles allowed for OAuth authentication
  atprotoPds: string; // Configured PDS for admin/ai handles
  // Legacy - prefer per-user PDS detection
  bskyPublicApi: string;
  atprotoApi: string;
}

// Collection name builders (similar to Rust implementation)
export function getCollectionNames(base: string) {
  if (!base) {
    // Fallback to default
    base = 'ai.syui.log';
  }
  
  const collections = {
    comment: base,
    user: `${base}.user`,
    chat: `${base}.chat`,
    chatLang: `${base}.chat.lang`,
    chatComment: `${base}.chat.comment`,
  };
  
  return collections;
}

// Generate collection names from host
// Format: ${reg}.${name}.${sub}
// Example: log.syui.ai -> ai.syui.log
function generateBaseCollectionFromHost(host: string): string {
  try {
    // Remove protocol if present
    const cleanHost = host.replace(/^https?:\/\//, '');
    
    // Split host into parts
    const parts = cleanHost.split('.');
    
    if (parts.length < 2) {
      throw new Error('Invalid host format');
    }
    
    // Reverse the parts for collection naming
    // log.syui.ai -> ai.syui.log
    const reversedParts = parts.reverse();
    const result = reversedParts.join('.');
    return result;
  } catch (error) {
    // Fallback to default
    return 'ai.syui.log';
  }
}

// Extract rkey from current URL
// /posts/xxx -> xxx (remove .html if present)
function extractRkeyFromUrl(): string | undefined {
  const pathname = window.location.pathname;
  const match = pathname.match(/\/posts\/([^/]+)\/?$/);
  if (match) {
    // Remove .html extension if present
    return match[1].replace(/\.html$/, '');
  }
  return undefined;
}

// Get application configuration from environment variables
export function getAppConfig(): AppConfig {
  const host = import.meta.env.VITE_APP_HOST || 'https://log.syui.ai';
  const adminDid = import.meta.env.VITE_ADMIN_DID || 'did:plc:uqzpqmrjnptsxezjx4xuh2mn';
  const adminHandle = import.meta.env.VITE_ADMIN_HANDLE || 'syui.ai';
  const aiDid = import.meta.env.VITE_AI_DID || 'did:plc:4hqjfn7m6n5hno3doamuhgef';
  const aiHandle = import.meta.env.VITE_AI_HANDLE || 'yui.syui.ai';
  const aiDisplayName = import.meta.env.VITE_AI_DISPLAY_NAME || 'ai';
  const aiAvatar = import.meta.env.VITE_AI_AVATAR || '';
  const aiDescription = import.meta.env.VITE_AI_DESCRIPTION || '';
  
  // Priority: Environment variables > Auto-generated from host
  const autoGeneratedBase = generateBaseCollectionFromHost(host);
  let baseCollection = import.meta.env.VITE_OAUTH_COLLECTION || autoGeneratedBase;
  
  // Ensure base collection is never undefined
  if (!baseCollection) {
    baseCollection = 'ai.syui.log';
  }
  
  const collections = {
    base: baseCollection,
  };
  
  const rkey = extractRkeyFromUrl();
  
  // AI configuration
  const aiEnabled = import.meta.env.VITE_AI_ENABLED === 'true';
  const aiAskAi = import.meta.env.VITE_AI_ASK_AI === 'true';
  const aiProvider = import.meta.env.VITE_AI_PROVIDER || 'ollama';
  const aiModel = import.meta.env.VITE_AI_MODEL || 'gemma2:2b';
  const aiHost = import.meta.env.VITE_AI_HOST || 'https://ollama.syui.ai';
  const aiSystemPrompt = import.meta.env.VITE_AI_SYSTEM_PROMPT || 'You are a helpful AI assistant trained on this blog\'s content.';
  const atprotoPds = import.meta.env.VITE_ATPROTO_PDS || 'syu.is';
  const bskyPublicApi = import.meta.env.VITE_BSKY_PUBLIC_API || 'https://public.api.bsky.app';
  const atprotoApi = import.meta.env.VITE_ATPROTO_API || 'https://bsky.social';
  
  // Parse allowed handles list
  const allowedHandlesStr = import.meta.env.VITE_ATPROTO_HANDLE_LIST || '[]';
  let allowedHandles: string[] = [];
  try {
    allowedHandles = JSON.parse(allowedHandlesStr);
  } catch {
    // If parsing fails, allow all handles (empty array means no restriction)
    allowedHandles = [];
  }
  
  return {
    adminDid,
    adminHandle,
    aiDid,
    aiHandle,
    aiDisplayName,
    aiAvatar,
    aiDescription,
    collections,
    host,
    rkey,
    aiEnabled,
    aiAskAi,
    aiProvider,
    aiModel,
    aiHost,
    aiSystemPrompt,
    allowedHandles,
    atprotoPds,
    bskyPublicApi,
    atprotoApi
  };
}

// Export singleton instance
export const appConfig = getAppConfig();