#!/usr/bin/env node
// claude-sub-proxy.js — OpenAI-compatible proxy routing through Claude Code CLI (Pro subscription)
// Accepts OpenAI chat completions format, routes through claude CLI, returns OpenAI format
// Usage: CLAUDE_CODE_OAUTH_TOKEN=<token> node claude-sub-proxy.js

import { createServer } from 'http';
import { spawn } from 'child_process';

const PORT = 8782;
const CLAUDE_BIN = '/home/openclaw/.npm-global/bin/claude';

// Build a plain-text prompt from OpenAI messages array
function buildPrompt(messages, system) {
  const parts = [];
  if (system) parts.push(`[SYSTEM]\n${system}\n[/SYSTEM]`);
  for (const msg of messages) {
    const role = msg.role === 'assistant' ? 'Assistant' : 'Human';
    const content = Array.isArray(msg.content)
      ? msg.content.map(b => typeof b === 'string' ? b : (b.text || '')).join('')
      : String(msg.content || '');
    parts.push(`${role}: ${content}`);
  }
  return parts.join('\n\n');
}

// Strip provider prefix e.g. "sub-claude/claude-sonnet-4-5" → "claude-sonnet-4-5"
function cleanModel(model) {
  return (model || 'claude-sonnet-4-5').replace(/^[^/]+\//, '');
}

function runClaude(prompt, model) {
  return new Promise((resolve, reject) => {
    const env = { ...process.env };
    delete env.ANTHROPIC_API_KEY; // force CLAUDE_CODE_OAUTH_TOKEN auth
    const child = spawn(CLAUDE_BIN, [
      '-p', prompt,
      '--output-format', 'json',
      '--model', model,
      '--dangerously-skip-permissions',
      '--no-session-persistence',
    ], { env, timeout: 120000, stdio: ['ignore', 'pipe', 'pipe'] });

    let stdout = '', stderr = '';
    child.stdout.on('data', d => stdout += d);
    child.stderr.on('data', d => stderr += d);
    child.on('close', code => {
      if (code !== 0) return reject(new Error(`claude exit ${code}: ${stderr.slice(0, 300)}`));
      if (!stdout.trim()) return reject(new Error(`empty output. stderr: ${stderr.slice(0, 200)}`));
      try { resolve(JSON.parse(stdout)); }
      catch { reject(new Error(`bad JSON: ${stdout.slice(0, 200)}`)); }
    });
    child.on('error', reject);
  });
}

const server = createServer(async (req, res) => {
  // Health check
  if (req.method === 'GET' && req.url === '/health') {
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({ ok: true, proxy: 'claude-sub-proxy' }));
    return;
  }

  if (req.method !== 'POST') { res.writeHead(405); res.end(); return; }

  let body = '';
  req.on('data', d => body += d);
  req.on('end', async () => {
    try {
      const parsed = JSON.parse(body);
      const model = cleanModel(parsed.model);
      const messages = parsed.messages || [];
      const system = typeof parsed.system === 'string' ? parsed.system : undefined;
      const prompt = buildPrompt(messages, system);
      console.log(`[${new Date().toISOString()}] → ${model} (${prompt.length} chars)`);

      const result = await runClaude(prompt, model);
      if (result.is_error) throw new Error(result.result || 'Claude error');

      console.log(`[${new Date().toISOString()}] ✅ cost=$${result.total_cost_usd?.toFixed(5) || '?'}`);

      // Return OpenAI chat completions format
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({
        id: `chatcmpl_proxy_${Date.now()}`,
        object: 'chat.completion',
        created: Math.floor(Date.now() / 1000),
        model: parsed.model || model,
        choices: [{
          index: 0,
          message: { role: 'assistant', content: result.result },
          finish_reason: 'stop',
        }],
        usage: {
          prompt_tokens: result.usage?.input_tokens || 0,
          completion_tokens: result.usage?.output_tokens || 0,
          total_tokens: (result.usage?.input_tokens || 0) + (result.usage?.output_tokens || 0),
        },
      }));
    } catch (err) {
      console.error(`[${new Date().toISOString()}] ❌`, err.message);
      res.writeHead(500, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ error: { message: err.message, type: 'proxy_error' } }));
    }
  });
});

server.listen(PORT, '127.0.0.1', () => {
  console.log(`✅ claude-sub-proxy on http://127.0.0.1:${PORT} (OpenAI-compatible)`);
  console.log(`   Routes → Claude Code CLI (${CLAUDE_BIN}) using Pro subscription`);
});