import type { ExtensionAPI, ToolDefinition as PiToolDefinition } from "@earendil-works/pi-coding-agent";

import { discoverProviders } from "./providers";
import type { Provider } from "./providers/base";
import { createHttpClient } from "./shared/http";
import { cacheManager, chunkingManager } from "./shared/instances";
import { createSearchLibraryDocsTool } from "./tools/search-library-docs";
import { createGetCacheInfoTool, createGetCacheEntriesTool } from "./tools/cache-admin";
import { createGetNextChunkTool } from "./tools/get-next-chunk";

/**
 * rtfd-pi — native pi extension port of the rtfd MCP server.
 *
 * Registers every provider tool (one per provider `getTools()` entry) plus the
 * server-level tools: `search_library_docs` (aggregator), `get_cache_info`,
 * `get_cache_entries`, `get_next_chunk`.
 *
 * Mirrors python `server._register_provider_tools()` + the server-level
 * `@mcp.tool(...)` registrations.
 *
 * No background resources are started at factory time (per pi extension guidance).
 */
export default function rtfdPi(pi: ExtensionAPI): void {
  const providerCtors = discoverProviders();

  // Instantiate all providers with the shared HTTP client factory.
  const providers: Record<string, Provider> = {};
  for (const [name, ProviderCtor] of Object.entries(providerCtors)) {
    try {
      providers[name] = new ProviderCtor(createHttpClient);
    } catch (error) {
      // Defensive init: log but don't crash (mirrors python `_get_provider_instances`).
      console.error(`Warning: Failed to initialize provider ${name}: ${error}`);
    }
  }

  // Register each provider's tools (mirror `_register_provider_tools`).
  for (const [providerName, provider] of Object.entries(providers)) {
    const metadata = provider.getMetadata();
    if (!metadata.exposeAsTool) continue;

    const tools = provider.getTools();
    for (const toolDef of Object.values(tools)) {
      // Our internal ToolDefinition uses `parameters: unknown` and a permissive execute
      // signature so providers stay decoupled from pi's exact types (easier to test).
      // The runtime values are Typebox schemas + compatible execute fns, so the cast at
      // this single boundary is safe. Verified by the parity + integration test suites.
      pi.registerTool(toolDef as unknown as PiToolDefinition<any, any, any>);
    }
    void providerName;
  }

  // Server-level tools (mirror the `@mcp.tool` registrations in server.py).
  pi.registerTool(createSearchLibraryDocsTool({ cacheManager, providers }) as unknown as PiToolDefinition<any, any, any>);
  pi.registerTool(createGetCacheInfoTool({ cacheManager }) as unknown as PiToolDefinition<any, any, any>);
  pi.registerTool(createGetCacheEntriesTool({ cacheManager }) as unknown as PiToolDefinition<any, any, any>);
  pi.registerTool(createGetNextChunkTool({ chunkingManager }) as unknown as PiToolDefinition<any, any, any>);
}

// Re-export singletons for tests and external use.
export { cacheManager, chunkingManager };