import { Server } from '@modelcontextprotocol/sdk/server/index.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import {
  CallToolRequestSchema,
  ListToolsRequestSchema,
} from '@modelcontextprotocol/sdk/types.js';
import { readFileSync } from 'node:fs';
import { homedir, hostname } from 'node:os';
import { getPaths, loadAuth } from './lib/config.js';
import { resolveSourceProject } from './lib/domain-detector.js';
import { makeGiteaBackend } from './lib/gitea.js';
import { makeTasksTools } from './tools/tasks.js';
import { makeKnowledgeTools } from './tools/knowledge.js';
import { makeMetaTools } from './tools/meta.js';
import { makeWorkersTools } from './tools/workers.js';
import { makeOpsTools } from './tools/ops.js';

function getCwdArg(): string {
  const i = process.argv.indexOf('--cwd');
  if (i >= 0 && process.argv[i + 1]) return process.argv[i + 1];
  return process.cwd();
}

// Resolves to package.json regardless of run context: dist/server.js → ../package.json,
// or src/server.ts (tests / ts-node) → ../package.json. Keeps the MCP server-info
// version field in sync with package.json without a hardcoded literal.
function readPackageVersion(): string {
  const pkgUrl = new URL('../package.json', import.meta.url);
  const raw = readFileSync(pkgUrl, 'utf8');
  const pkg = JSON.parse(raw) as { version?: unknown };
  if (typeof pkg.version !== 'string' || pkg.version.length === 0) {
    throw new Error(`package.json at ${pkgUrl.pathname} missing string "version" field`);
  }
  return pkg.version;
}

async function main(): Promise<void> {
  const paths = getPaths(homedir());
  const cwd = getCwdArg();

  // Auth + backend are optional for read-only operation. Write tools surface
  // a clear error if these aren't available.
  const auth = await loadAuth(paths.authFile).catch(() => null);
  const backend = auth ? makeGiteaBackend({ baseUrl: auth.giteaUrl, token: auth.giteaToken }) : undefined;

  const { sourceProject, fellBack } = await resolveSourceProject(cwd);
  if (fellBack) {
    console.error(
      `[projects-meta] warning: cwd=${cwd} has no parseable git remote — ` +
        `identity-footer will use bare basename "${sourceProject}" instead of ` +
        `qualified <owner>/<repo>. Tasks/wiki created from here will not record their source repo.`,
    );
  }

  const tools = [
    ...makeTasksTools({
      cacheFile: paths.cacheFile,
      backend,
      giteaUser: auth?.giteaUser,
      agendaTasksRepo: auth?.agendaTasksRepo,
      agendaTasksOwner: auth?.agendaTasksOwner,
      aggregateSkipOwners: auth?.giteaAggregateSkipOwners,
      machine: hostname(),
      sourceProject,
    }),
    ...makeKnowledgeTools({
      wikiRoot: paths.sharedWikiClone,
      projectCwd: cwd,
      cacheFile: paths.cacheFile,
      backend,
      giteaUser: auth?.giteaUser,
      projectsWikiRepo: auth?.projectsWikiRepo,
      machine: hostname(),
      sourceProject,
    }),
    ...makeMetaTools({ paths }),
    ...makeWorkersTools(),
    ...makeOpsTools({ cacheFile: paths.cacheFile }),
  ];

  const byName = new Map<string, (typeof tools)[number]>();
  for (const t of tools) {
    if (byName.has(t.name)) throw new Error(`Duplicate tool name: ${t.name}`);
    byName.set(t.name, t);
  }

  const server = new Server(
    { name: 'projects-meta-mcp', version: readPackageVersion() },
    { capabilities: { tools: {} } },
  );

  server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools: tools.map((t) => ({
      name: t.name,
      description: t.description,
      inputSchema: t.inputSchema,
    })),
  }));

  server.setRequestHandler(CallToolRequestSchema, async (req) => {
    const tool = byName.get(req.params.name);
    if (!tool) {
      return {
        content: [{ type: 'text', text: `Unknown tool: ${req.params.name}` }],
        isError: true,
      };
    }
    return tool.handler(req.params.arguments ?? {});
  });

  const transport = new StdioServerTransport();
  await server.connect(transport);
}

await main();