server.js

// OpenCode Bridge v5 - wraps opencode-cli as OpenAI-compatible API
// v5: built-in web search agent (CN Bing via curl, free, no API key)
const http = require('http');
const { spawnSync, execSync } = require('child_process');
const fs = require('fs');
const path = require('path');

const PORT = process.env.PORT || 4097;
const OPENCODE_CLI = process.env.OPENCODE_CLI || path.join(process.env.LOCALAPPDATA || '', 'OpenCode', 'opencode-cli.exe');
const LOG = path.join(__dirname, 'bridge.log');

function log(msg) {
  const line = `[${new Date().toISOString()}] ${msg}`;
  console.log(line);
  try { fs.appendFileSync(LOG, line + '\n'); } catch(e) {}
}

// ─── Web Search Agent (via system curl → Bing) ───
function webSearch(query, maxResults = 5) {
  try {
    const q = query.substring(0, 300).replace(/"/g,'');
    const url = `https://cn.bing.com/search?q=${encodeURIComponent(q)}&ensearch=0`;
    const html = execSync(
      `curl.exe -s --max-time 15 -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36" -H "Accept-Language: zh-CN,zh;q=0.9" "${url}"`,
      { encoding: 'utf-8', timeout: 16000, maxBuffer: 2*1024*1024, windowsHide: true }
    );
    const results = [];
    const blocks = html.split(/<li[^>]*class="[^"]*b_algo[^"]*"[^>]*>/i).slice(1);
    for (const block of blocks) {
      if (results.length >= maxResults) break;
      const endIdx = block.indexOf('<li');
      const part = endIdx > 0 ? block.substring(0, endIdx) : block;
      const titleM = /<h2[^>]*><a[^>]*href="([^"]*)"[^>]*>([\s\S]*?)<\/a>/i.exec(part);
      const snippetM = /<p[^>]*class="[^"]*b_lineclamp[^"]*"[^>]*>([\s\S]*?)<\/p>/i.exec(part) ||
                      /<div[^>]*class="[^"]*b_caption[^"]*"[^>]*>([\s\S]*?)<\/div>/i.exec(part) ||
                      /<p[^>]*>([\s\S]*?)<\/p>/i.exec(part);
      if (titleM) {
        const title = titleM[2].replace(/<[^>]*>/g, '').replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/g,'"').replace(/&#39;/g,"'").trim();
        const snippet = snippetM ? snippetM[1].replace(/<[^>]*>/g, '').replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>').replace(/&quot;/g,'"').replace(/&#39;/g,"'").trim() : '';
        const link = titleM[1].replace(/&amp;/g,'&');
        if (title && !title.includes('下一页') && !title.includes('Next')) {
          results.push({ title, snippet, url: link });
        }
      }
    }
    log(`SEARCH "${query.substring(0,60)}" → ${results.length} results`);
    return Promise.resolve(results);
  } catch(e) {
    log(`SEARCH_ERR: ${e.message}`);
    return Promise.resolve([]);
  }
}

// ─── Detect if search is needed ───
function needsSearch(messages) {
  const userText = messages
    .filter(m => m.role === 'user')
    .map(m => typeof m.content === 'string' ? m.content : '')
    .join(' ');
  
  // Time-sensitive keywords
  const timeRe = /今天|今日|最新|现在|搜索|search|news|trending|当前|实时|刚刚|近期|最新消息|头条|动态|热点/;
  // Explicit search request
  const explicitRe = /搜索一下|帮我搜|查一下|搜一搜|找一下|look.?up|find info|check (the )?latest/;
  
  return timeRe.test(userText) || explicitRe.test(userText);
}

// ─── Call OpenCode CLI ───
function callCLI(model, prompt) {
  log(`CALL model=${model} len=${prompt.length}`);

  const r = spawnSync(OPENCODE_CLI, ['run','--format','json','--dangerously-skip-permissions','-m',model,prompt], {
    encoding:'utf-8', timeout:180000, maxBuffer:20*1024*1024,
    windowsHide:true, env:{...process.env}
  });

  log(`STDOUT_LEN=${(r.stdout||'').length} STDERR_LEN=${(r.stderr||'').length} EXIT=${r.status} SIG=${r.signal||'none'}`);
  if (r.stderr) log(`STDERR: ${r.stderr.trim().substring(0,300)}`);

  const lines = (r.stdout||'').trim().split('\n');
  let text='', usage={prompt_tokens:0,completion_tokens:0,total_tokens:0};

  for (const line of lines) {
    if (!line.trim()) continue;
    try {
      const ev = JSON.parse(line);
      if (ev.type==='text' && ev.part?.text) text += ev.part.text;
      if (ev.type==='assistant' && ev.part?.text) text += ev.part.text;
      if (ev.type==='result' && ev.part?.text) text = ev.part.text;
      if (ev.type==='step_finish' && ev.part?.tokens) {
        usage = {prompt_tokens:ev.part.tokens.input||0,completion_tokens:ev.part.tokens.output||0,total_tokens:ev.part.tokens.total||0};
      }
    } catch(e) {
      log(`PARSE_ERR: ${e.message}`);
    }
  }

  if (!text && r.error) throw new Error(r.error.message||r.stderr||'unknown');
  return {text:text.trim(),usage};
}

// ─── Main call: search if needed, then query CLI ───
async function call(model, messages) {
  let searchContext = '';
  let searchResults = [];

  if (needsSearch(messages)) {
    const userText = messages
      .filter(m => m.role === 'user')
      .map(m => typeof m.content === 'string' ? m.content : '')
      .join(' ');
    
    // Extract search query from user text (first 200 chars, or between quotes)
    let searchQuery = userText.substring(0, 200);
    const quoteMatch = userText.match(/"([^"]{10,200})"/);
    if (quoteMatch) searchQuery = quoteMatch[1];
    
    try {
      searchResults = await webSearch(searchQuery);
      if (searchResults.length > 0) {
        searchContext = '\n\n---\n[Web Search Results - for reference only, use this info]\n' +
          searchResults.map((r, i) =>
            `${i+1}. **${r.title}**\n   Link: ${r.url}\n   Snippet: ${r.snippet}`
          ).join('\n\n') +
          '\n---\n\nBased on the search results above, now answer: ';
        log(`SEARCH_INJECT ${searchResults.length} results, +${searchContext.length} chars`);
      }
    } catch(e) {
      log(`SEARCH_CALL_ERR: ${e.message}`);
    }
  }

  // Build prompt
  let prompt = messages.map(m => {
    if (m.role === 'system') return `System: ${m.content}`;
    if (m.role === 'assistant') return `Assistant: ${m.content}`;
    return `User: ${m.content}`;
  }).join('\n\n');

  if (searchContext) {
    prompt += '\n\n' + searchContext;
  } else {
    prompt += '\n\nAssistant:';
  }

  const result = callCLI(model, prompt);
  result.searchResults = searchResults;
  return result;
}

// ─── Server ───
const server = http.createServer((req,res)=>{
  res.setHeader('Access-Control-Allow-Origin','*');
  res.setHeader('Access-Control-Allow-Methods','POST,GET,OPTIONS');
  res.setHeader('Access-Control-Allow-Headers','Content-Type,Authorization');
  if (req.method==='OPTIONS') { res.writeHead(204); res.end(); return; }

  if (req.method==='GET' && req.url==='/v1/models') {
    res.writeHead(200,{'Content-Type':'application/json'});
    res.end(JSON.stringify({object:'list',data:[
      {id:'opencode/deepseek-v4-flash-free',object:'model',owned_by:'opencode'},
      {id:'opencode/mimo-v2.5-free',object:'model',owned_by:'opencode'},
      {id:'opencode/nemotron-3-super-free',object:'model',owned_by:'opencode'},
      {id:'opencode/big-pickle',object:'model',owned_by:'opencode'},
    ]})); return;
  }
  if (req.method==='GET' && req.url==='/health') {
    res.writeHead(200,{'Content-Type':'application/json'});
    res.end(JSON.stringify({status:'ok'})); return;
  }
  if (req.method==='POST' && req.url==='/v1/chat/completions') {
    let body='';
    req.on('data',c=>body+=c);
    req.on('end',async ()=>{
      try {
        const data=JSON.parse(body);
        let model=data.model||'opencode/deepseek-v4-flash-free';
        if (!model.includes('/')) model = 'opencode/' + model;
        const messages=data.messages||[{role:'user',content:'Hello'}];
        log(`REQ model=${model} msgs=${messages.length}`);

        // Handle content arrays
        const msgs = messages.map(m=>{
          const c=m.content;
          if (Array.isArray(c)) {
            const texts=c.filter(p=>p.type==='text').map(p=>p.text).join('\n');
            return {...m,content:texts||'(image)'};
          }
          return m;
        });

        const result = await call(model, msgs);
        const resp = {
          id:'chatcmpl-'+Date.now(), object:'chat.completion',
          created:Math.floor(Date.now()/1000), model,
          choices:[{index:0,message:{role:'assistant',content:result.text},finish_reason:'stop'}],
          usage:result.usage,
        };
        if (result.text.length===0) log('WARN: empty response!');
        log(`DONE text=${result.text.length} chars | searched=${result.searchResults.length}`);
        res.writeHead(200,{'Content-Type':'application/json'});
        res.end(JSON.stringify(resp));
      } catch(err) {
        log(`ERR ${err.message}`);
        res.writeHead(500,{'Content-Type':'application/json'});
        res.end(JSON.stringify({error:{message:err.message,type:'server_error'}}));
      }
    }); return;
  }
  res.writeHead(404); res.end('Not found');
});

server.listen(PORT,'127.0.0.1',()=>{
  log(`Bridge v5 (search agent) on :${PORT}, CLI: ${OPENCODE_CLI}`);
});