import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js';
import { z } from 'zod';

const CORE_URL = process.env['TOKENVAULT_URL'] ?? 'http://localhost:3300';

async function fetchCore<T>(path: string): Promise<T> {
  const res = await fetch(`${CORE_URL}${path}`);
  if (!res.ok) throw new Error(`TokenVault API error: ${res.status}`);
  return res.json() as Promise<T>;
}

const server = new McpServer({
  name: 'tokenvault',
  version: '0.1.0',
});

// ─── tv_ticket: View and search tickets ──────────────────────────────────────
server.tool(
  'tv_ticket',
  'View, search, and manage TokenVault tickets. Every LLM request = 1 ticket.',
  {
    action: z.enum(['list', 'get', 'stats']).describe('Action to perform'),
    id: z.string().optional().describe('Ticket ID (for get action)'),
    provider: z.string().optional().describe('Filter by provider'),
    project: z.string().optional().describe('Filter by project'),
    period: z.string().optional().describe('Stats period: today, week, month, all'),
    limit: z.number().optional().describe('Max results (default 20)'),
  },
  async ({ action, id, provider, project, period, limit }) => {
    if (action === 'get' && id) {
      const ticket = await fetchCore(`/v1/tickets/${id}`);
      return { content: [{ type: 'text' as const, text: JSON.stringify(ticket, null, 2) }] };
    }

    if (action === 'stats') {
      const stats = await fetchCore(`/v1/tickets/stats?period=${period ?? 'today'}`);
      return { content: [{ type: 'text' as const, text: JSON.stringify(stats, null, 2) }] };
    }

    const params = new URLSearchParams();
    if (provider) params.set('provider', provider);
    if (project) params.set('project', project);
    params.set('limit', String(limit ?? 20));
    const data = await fetchCore(`/v1/tickets?${params}`);
    return { content: [{ type: 'text' as const, text: JSON.stringify(data, null, 2) }] };
  },
);

// ─── tv_cost: Cost dashboard ─────────────────────────────────────────────────
server.tool(
  'tv_cost',
  'Show cost dashboard: spend, savings, forecasts. Tracks every token across all LLM providers.',
  {
    period: z.enum(['today', 'week', 'month', 'all']).optional().describe('Time period'),
    group_by: z.enum(['provider', 'model', 'project', 'team']).optional().describe('Group breakdown by'),
  },
  async ({ period, group_by }) => {
    const [summary, breakdown] = await Promise.all([
      fetchCore(`/v1/cost?period=${period ?? 'month'}`),
      group_by ? fetchCore(`/v1/cost/breakdown?group_by=${group_by}`) : Promise.resolve(null),
    ]);

    const parts = [`# Cost Summary (${period ?? 'month'})\n${JSON.stringify(summary, null, 2)}`];
    if (breakdown) {
      parts.push(`\n# Breakdown by ${group_by}\n${JSON.stringify(breakdown, null, 2)}`);
    }
    return { content: [{ type: 'text' as const, text: parts.join('\n') }] };
  },
);

// ─── tv_health: Service health ───────────────────────────────────────────────
server.tool(
  'tv_health',
  'Check TokenVault service health and configured providers.',
  {},
  async () => {
    const health = await fetchCore('/health');
    return { content: [{ type: 'text' as const, text: JSON.stringify(health, null, 2) }] };
  },
);

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