const json=(d,o={})=>{const h=new Headers(o.headers);h.set('Content-Type','application/json');return new Response(JSON.stringify(d),{...o,headers:h})};
const cookie=c=>(c.match(/auth_user=([^;]+)/)?.[1]||null);
const hash=c=>(c.match(/auth_hash=([^;]+)/)?.[1]||null);
const tsEq=(a,b)=>{if(!a||!b)return!1;let d=a.length^b.length;for(let i=0;i<a.length;i++)d|=a.charCodeAt(i)^b.charCodeAt(i);return d===0};
const auth=async(req,db)=>{const c=req.headers.get('Cookie')||'',u=cookie(c),h=hash(c);if(!u||!h)return null;const user=await db.prepare('SELECT id,username,role,pass_hash FROM users WHERE username=?').bind(u).first();return user&&tsEq(user.pass_hash,h)?user:null};

export async function onRequestGet({request,env}){
  try{
    const url=new URL(request.url),sub=url.searchParams.get('sub')||'free',sort=url.searchParams.get('sort')||'hot';
    const user=await auth(request,env.D1_SPCHCAP);
    const sub_row=await env.D1_SPCHCAP.prepare('SELECT id FROM subs WHERE name=?').bind(sub).first();
    if(!sub_row)return json({posts:[]});
    
    let order=sort==='new'?'ORDER BY p.created_at DESC':'ORDER BY (p.score/(CAST((julianday("now")-julianday(p.created_at))*24 AS REAL)+2)) DESC';
    const{results}=await env.D1_SPCHCAP.prepare(`SELECT p.id,p.title,p.link,p.content,p.score,p.comment_count,p.created_at,u.username${user?',v.direction as voted':''} FROM posts p JOIN users u ON p.user_id=u.id ${user?'LEFT JOIN votes v ON v.post_id=p.id AND v.user_id=?':''} WHERE p.sub_id=? ${order} LIMIT 30`).bind(...(user?[user.id,sub_row.id]:[sub_row.id])).all();
    return json({posts:results});
  }catch(e){return json({error:{message:e.message}},{status:500})}
}

export async function onRequestPost({request,env}){
  try{
    const user=await auth(request,env.D1_SPCHCAP);
    if(!user)return json({error:'Unauthorized'},{status:401});
    
    const{sub,title,link,content}=await request.json();
    if(!sub||!title)return json({error:'Missing fields'},{status:400});
    
    let sub_row=await env.D1_SPCHCAP.prepare('SELECT id FROM subs WHERE name=?').bind(sub).first();
    if(!sub_row){
      await env.D1_SPCHCAP.prepare('INSERT INTO subs(name)VALUES(?)').bind(sub).run();
      sub_row=await env.D1_SPCHCAP.prepare('SELECT id FROM subs WHERE name=?').bind(sub).first();
    }
    
    const{meta}=await env.D1_SPCHCAP.prepare('INSERT INTO posts(sub_id,user_id,title,link,content)VALUES(?,?,?,?,?)').bind(sub_row.id,user.id,title,link,content).run();
    return json({id:meta.last_row_id},{status:201});
  }catch(e){return json({error:{message:e.message}},{status:500})}
}