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 { createSession, type Session } from './lib/auth';
import * as gitea from './lib/gitea';

const server = new Server(
  { name: 'gitea-browser', version: '1.0.0' },
  { capabilities: { tools: {} } }
);

async function withSession<T>(fn: (session: Session) => Promise<T>): Promise<T> {
  const session = await createSession();
  try {
    return await fn(session);
  } finally {
    await session.browser.close();
  }
}

const TOOLS = [
  {
    name: 'list_repos',
    description: 'List repositories accessible to the Gitea agent account.',
    inputSchema: { type: 'object', properties: {} },
  },
  {
    name: 'view_repo',
    description: 'View a Gitea repository: file list, default branch, and README excerpt.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo'],
      properties: {
        owner: { type: 'string', description: 'Repository owner (username or org)' },
        repo: { type: 'string', description: 'Repository name' },
      },
    },
  },
  {
    name: 'view_file',
    description: 'Get the raw content of a file in a Gitea repository.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo', 'branch', 'filepath'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        branch: { type: 'string', description: 'Branch name' },
        filepath: { type: 'string', description: 'Path to the file (e.g. src/main.js)' },
      },
    },
  },
  {
    name: 'list_prs',
    description: 'List pull requests for a Gitea repository.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        state: { type: 'string', enum: ['open', 'closed', 'all'], default: 'open' },
      },
    },
  },
  {
    name: 'create_pr',
    description: 'Create a new pull request in a Gitea repository.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo', 'head', 'base', 'title'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        head: { type: 'string', description: 'Source branch (the branch with changes)' },
        base: { type: 'string', description: 'Target branch to merge into' },
        title: { type: 'string' },
        body: { type: 'string', description: 'PR description (optional)' },
      },
    },
  },
  {
    name: 'view_pr',
    description: 'View details of a pull request including title, status, branches, and comments.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo', 'number'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        number: { type: 'number', description: 'PR number' },
      },
    },
  },
  {
    name: 'comment_pr',
    description: 'Add a comment to a pull request.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo', 'number', 'body'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        number: { type: 'number' },
        body: { type: 'string', description: 'Comment text' },
      },
    },
  },
  {
    name: 'merge_pr',
    description: 'Merge an open pull request.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo', 'number'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        number: { type: 'number' },
      },
    },
  },
  {
    name: 'close_pr',
    description: 'Close a pull request without merging.',
    inputSchema: {
      type: 'object',
      required: ['owner', 'repo', 'number'],
      properties: {
        owner: { type: 'string' },
        repo: { type: 'string' },
        number: { type: 'number' },
      },
    },
  },
] as const;

server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools: TOOLS }));

server.setRequestHandler(CallToolRequestSchema, async (request) => {
  const { name, arguments: args = {} } = request.params;
  const a = args as Record<string, unknown>;

  try {
    let result: unknown;

    switch (name) {
      case 'list_repos':
        result = await withSession(s => gitea.listRepos(s));
        break;
      case 'view_repo':
        result = await withSession(s => gitea.viewRepo(s, a.owner as string, a.repo as string));
        break;
      case 'view_file':
        result = await withSession(s => gitea.viewFile(s, a.owner as string, a.repo as string, a.branch as string, a.filepath as string));
        break;
      case 'list_prs':
        result = await withSession(s => gitea.listPRs(s, a.owner as string, a.repo as string, a.state as 'open' | 'closed' | 'all'));
        break;
      case 'create_pr':
        result = await withSession(s => gitea.createPR(s, a.owner as string, a.repo as string, a.head as string, a.base as string, a.title as string, a.body as string | undefined));
        break;
      case 'view_pr':
        result = await withSession(s => gitea.viewPR(s, a.owner as string, a.repo as string, a.number as number));
        break;
      case 'comment_pr':
        result = await withSession(s => gitea.commentPR(s, a.owner as string, a.repo as string, a.number as number, a.body as string));
        break;
      case 'merge_pr':
        result = await withSession(s => gitea.mergePR(s, a.owner as string, a.repo as string, a.number as number));
        break;
      case 'close_pr':
        result = await withSession(s => gitea.closePR(s, a.owner as string, a.repo as string, a.number as number));
        break;
      default:
        throw new Error(`Unknown tool: ${name}`);
    }

    return {
      content: [{ type: 'text' as const, text: JSON.stringify(result, null, 2) }],
    };
  } catch (err) {
    return {
      content: [{ type: 'text' as const, text: `Error: ${err instanceof Error ? err.message : String(err)}` }],
      isError: true,
    };
  }
});

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