export type ConversationChannel='say'|'whisper';

export type ConversationRequest={
 id:string;
 createdAt:string;
 speakerName:string;
 message:string;
 channel:ConversationChannel;
 zoneName:string;
 receiver:string;
 selectedPlayer:string;
 nearbyBots:string[];
 status:'pending'|'processing'|'awaiting_delivery'|'completed'|'failed';
 attempts:number;
};

async function ensure(db:D1Database){
 await db.prepare(`CREATE TABLE IF NOT EXISTS conversation_requests (
  id TEXT PRIMARY KEY NOT NULL,
  created_at TEXT NOT NULL,
  speaker_name TEXT NOT NULL,
  message TEXT NOT NULL,
  channel TEXT NOT NULL,
  zone_name TEXT NOT NULL,
  receiver TEXT NOT NULL,
  selected_player TEXT NOT NULL,
  nearby_bots TEXT NOT NULL,
  status TEXT NOT NULL,
  attempts INTEGER NOT NULL DEFAULT 0,
  started_at TEXT,
  completed_at TEXT,
  result TEXT,
  error TEXT
 )`).run();
 await db.prepare(`CREATE INDEX IF NOT EXISTS idx_conversation_requests_status_created
  ON conversation_requests(status,created_at)`).run();
}

function text(payload:Record<string,unknown>,key:string,max:number){
 const value=payload[key];
 return typeof value==='string'?value.trim().slice(0,max):'';
}

export async function queueConversationEvent(db:D1Database,kind:string,payload:Record<string,unknown>){
 if(payload.isBot===true)return null;
 if(kind!=='player.chat'&&kind!=='player.whisper')return null;

 const speakerName=text(payload,'name',40);
 const message=text(payload,'message',500);
 if(!speakerName||!message)return null;
 if(message.startsWith('.')||message.startsWith('!'))return null;

 if(kind==='player.whisper'&&payload.receiverIsBot!==true)return null;
 if(kind==='player.chat'&&!text(payload,'selectedPlayer',40)&&!text(payload,'nearbyBots',1000))return null;

 await ensure(db);
 const id=crypto.randomUUID();
 const createdAt=new Date().toISOString();
 const channel:ConversationChannel=kind==='player.whisper'?'whisper':'say';
 await db.prepare(`INSERT INTO conversation_requests
  (id,created_at,speaker_name,message,channel,zone_name,receiver,selected_player,nearby_bots,status,attempts)
  VALUES (?,?,?,?,?,?,?,?,?,'pending',0)`)
  .bind(
   id,createdAt,speakerName,message,channel,
   text(payload,'zoneName',120),
   text(payload,'receiver',40),
   text(payload,'selectedPlayer',40),
   text(payload,'nearbyBots',1000)
  ).run();
 return {id,createdAt};
}

export async function leaseConversation(db:D1Database):Promise<ConversationRequest|null>{
 await ensure(db);
 const staleBefore=new Date(Date.now()-90_000).toISOString();
 await db.prepare(`UPDATE conversation_requests
  SET status='pending',started_at=NULL
  WHERE status='processing' AND started_at IS NOT NULL AND started_at<?`)
  .bind(staleBefore).run();

 const row=await db.prepare(`SELECT id,created_at,speaker_name,message,channel,zone_name,receiver,selected_player,nearby_bots,status,attempts
  FROM conversation_requests WHERE status='pending' ORDER BY created_at LIMIT 1`).first<any>();
 if(!row)return null;

 const startedAt=new Date().toISOString();
 const updated=await db.prepare(`UPDATE conversation_requests
  SET status='processing',started_at=?,attempts=attempts+1
  WHERE id=? AND status='pending'`).bind(startedAt,row.id).run();
 if(updated.meta.changes!==1)return null;

 return {
  id:row.id,
  createdAt:row.created_at,
  speakerName:row.speaker_name,
  message:row.message,
  channel:row.channel==='whisper'?'whisper':'say',
  zoneName:row.zone_name,
  receiver:row.receiver,
  selectedPlayer:row.selected_player,
  nearbyBots:String(row.nearby_bots||'').split(',').map((x:string)=>x.trim()).filter(Boolean),
  status:'processing',
  attempts:Number(row.attempts||0)+1
 };
}

export async function completeConversation(db:D1Database,id:string,result:string){
 await ensure(db);
 await db.prepare(`UPDATE conversation_requests
  SET status='completed',result=?,error=NULL,completed_at=?
  WHERE id=?`).bind(result.slice(0,2000),new Date().toISOString(),id).run();
}

export async function failConversation(db:D1Database,id:string,error:string){
 await ensure(db);
 await db.prepare(`UPDATE conversation_requests
  SET status='failed',error=?,completed_at=?
  WHERE id=?`).bind(error.slice(0,2000),new Date().toISOString(),id).run();
}

export async function cleanupConversations(db:D1Database){
 await ensure(db);
 const before=new Date(Date.now()-24*60*60_000).toISOString();
 await db.prepare(`DELETE FROM conversation_requests
  WHERE status IN ('completed','failed') AND completed_at IS NOT NULL AND completed_at<?`)
  .bind(before).run();
}

export async function awaitDelivery(db:D1Database,request:ConversationRequest,botId:string,reply:string,commandId:string){
 await db.prepare("UPDATE conversation_requests SET status='awaiting_delivery',result=? WHERE id=?")
  .bind(JSON.stringify({request,botId,reply,commandId}),request.id).run();
}

export async function pendingDeliveries(db:D1Database){
 await ensure(db);
 const rows=await db.prepare("SELECT result FROM conversation_requests WHERE status='awaiting_delivery' ORDER BY created_at LIMIT 50").all<{result:string}>();
 const deliveries=[];
 for(const row of rows.results){
  const delivery=JSON.parse(row.result) as {request:ConversationRequest;botId:string;reply:string;commandId:string};
  const command=await db.prepare('SELECT status,error FROM ale_commands WHERE id=?').bind(delivery.commandId).first<{status:string;error:string|null}>();
  deliveries.push({...delivery,status:command?.status??'pending',error:command?.error});
 }
 return deliveries;
}