import { randomUUID } from "node:crypto";
import { makeEvent, type Viewer } from "@lxc/protocol";
import type { WheelDatabase, SongCatalog, ViewerRow } from "./db.js";
import type { EventHub } from "./hub.js";
import type { ReplyPort } from "./reply.js";
import type { IncomingLiveMessage } from "./live.js";

export const WHEEL_COST = 150;
const normal = (text: string) => text.trim().replace(/\s+/g, " ");
const toViewerRow = (viewer: Viewer): ViewerRow => ({ uid: viewer.uid, displayName: viewer.name, points: 0 });

export class WheelService {
  constructor(private readonly database: WheelDatabase, private readonly songs: SongCatalog, private readonly hub: EventHub, private readonly reply: ReplyPort, private readonly roomId: string) {}
  async handle(message: IncomingLiveMessage, scope = "live") {
    const viewer = message.viewer; await this.database.ensureViewer(scope, this.roomId, toViewerRow(viewer));
    if (message.kind === "enter") { this.hub.publish(makeEvent(this.roomId, "live.enter", { viewer })); return; }
    if (message.kind === "gift") return this.gift(message, scope);
    this.hub.publish(makeEvent(this.roomId, "live.danmaku", { viewer, text: message.text })); return this.command(viewer, message.text, scope);
  }
  private async gift(message: Extract<IncomingLiveMessage, { kind: "gift" }>, scope: string) {
    const amount = Math.max(0, Math.floor(message.battery)) * Math.max(1, Math.floor(message.quantity));
    const result = await this.database.withTransaction(async client => {
      await this.database.ensureViewer(scope, this.roomId, toViewerRow(message.viewer), client);
      const inserted = await client.query("INSERT INTO point_ledger(id,scope,room_id,uid,delta,reason,source_event_id,metadata) VALUES($1,$2,$3,$4,$5,'gift',$6,$7) ON CONFLICT(source_event_id) DO NOTHING RETURNING id", [randomUUID(), scope, this.roomId, message.viewer.uid, amount, message.sourceEventId, JSON.stringify({ giftName: message.giftName, battery: message.battery, quantity: message.quantity })]);
      if (!inserted.rowCount) return undefined;
      const updated = await client.query<{ points: number }>("UPDATE viewer_accounts SET points=points+$1,updated_at=now() WHERE scope=$2 AND room_id=$3 AND uid=$4 RETURNING points", [amount, scope, this.roomId, message.viewer.uid]); return updated.rows[0]?.points;
    });
    this.hub.publish(makeEvent(this.roomId, "live.gift", { viewer: message.viewer, giftName: message.giftName, battery: message.battery, quantity: message.quantity, sourceEventId: message.sourceEventId }));
    if (result !== undefined) this.hub.publish(makeEvent(this.roomId, "viewer.points.updated", { viewer: message.viewer, delta: amount, balance: result, reason: "gift" }));
  }
  private async command(viewer: Viewer, raw: string, scope: string) {
    const text = normal(raw); if (text === "转盘查询") { const account = await this.database.getViewer(scope, this.roomId, viewer.uid); const balance = account?.points ?? 0; const event = makeEvent(this.roomId, "viewer.points.updated", { viewer, delta: 0, balance, reason: "gift" }); this.hub.publish(event); await this.reply.send(`${viewer.name} 当前转盘点数：${balance}`); return; }
    if (text === "转盘") return this.invalid(viewer, "用法：转盘 [类别]");
    const match = /^转盘\s+(.+)$/.exec(text); if (!match) return;
    const category = match[1]!; const choice = await this.songs.random(category); if (!choice) return this.invalid(viewer, "歌单暂时没有可抽取的歌曲");
    const result = await this.database.withTransaction(async client => {
      const current = await this.database.getViewer(scope, this.roomId, viewer.uid, client); const balance = current?.points ?? 0; if (balance < WHEEL_COST) return { insufficient: true as const, balance };
      const update = await client.query<{ points: number }>("UPDATE viewer_accounts SET points=points-$1,updated_at=now() WHERE scope=$2 AND room_id=$3 AND uid=$4 AND points >= $1 RETURNING points", [WHEEL_COST, scope, this.roomId, viewer.uid]); if (!update.rowCount) return { insufficient: true as const, balance: 0 };
      const balanceAfter = update.rows[0]!.points; await client.query("INSERT INTO point_ledger(id,scope,room_id,uid,delta,reason,metadata) VALUES($1,$2,$3,$4,$5,'wheel',$6)", [randomUUID(), scope, this.roomId, viewer.uid, -WHEEL_COST, JSON.stringify({ category, songId: choice.song.id })]); await client.query("INSERT INTO wheel_spins(id,scope,room_id,uid,category,song_id,song_title,fallback,cost,balance_after) VALUES($1,$2,$3,$4,$5,$6,$7,$8,$9,$10)", [randomUUID(), scope, this.roomId, viewer.uid, category, choice.song.id, choice.song.title, choice.fallback, WHEEL_COST, balanceAfter]); return { insufficient: false as const, balance: balanceAfter };
    });
    if (result.insufficient) { this.hub.publish(makeEvent(this.roomId, "wheel.insufficient-balance", { viewer, balance: result.balance, cost: WHEEL_COST })); await this.reply.send(`${viewer.name} 点数不足（需要 ${WHEEL_COST}，当前 ${result.balance}）`); return; }
    this.hub.publish(makeEvent(this.roomId, "viewer.points.updated", { viewer, delta: -WHEEL_COST, balance: result.balance, reason: "wheel" })); this.hub.publish(makeEvent(this.roomId, "wheel.result", { viewer, category, fallback: choice.fallback, song: choice.song, cost: WHEEL_COST, balance: result.balance })); await this.reply.send(`${viewer.name} 抽中了《${choice.song.title}》`);
  }
  private async invalid(viewer: Viewer, message: string) { this.hub.publish(makeEvent(this.roomId, "wheel.invalid-command", { viewer, message })); await this.reply.send(`${viewer.name}：${message}`); }
}