/**
 * PrintDot 本地桥接器（Wails 客户端）WebSocket 协议封装。
 * 默认地址 ws://127.0.0.1:1122/ws ，与 PrintDot-Client 中 Bridge 默认端口一致。
 */

const LS_WS_URL = 'qhmes_print_dot_ws_url';
const LS_KEY = 'qhmes_print_dot_key';

export type PrintDotPrinter = { name: string; isDefault?: boolean };

export function getPrintDotBridgeConfig() {
  return {
    wsUrl: localStorage.getItem(LS_WS_URL) || 'ws://127.0.0.1:1122/ws',
    key: localStorage.getItem(LS_KEY) || '',
  };
}

export function setPrintDotBridgeConfig(wsUrl: string, key: string) {
  localStorage.setItem(LS_WS_URL, (wsUrl || '').trim());
  localStorage.setItem(LS_KEY, key ?? '');
}

function buildWsUrl(wsUrl: string, key: string) {
  const base = (wsUrl || '').trim();
  const k = (key || '').trim();
  if (!k) {
    return base;
  }
  const sep = base.includes('?') ? '&' : '?';
  return `${base}${sep}key=${encodeURIComponent(k)}`;
}

/** 连接后服务端会先推送 printer_list，本方法读取该列表后关闭连接 */
export function fetchPrintDotPrinters(timeoutMs = 8000): Promise<PrintDotPrinter[]> {
  const { wsUrl, key } = getPrintDotBridgeConfig();
  return new Promise((resolve, reject) => {
    let done = false;
    const ws = new WebSocket(buildWsUrl(wsUrl, key));
    const timer = window.setTimeout(() => {
      if (done) {
        return;
      }
      done = true;
      try {
        ws.close();
      } catch {
        // ignore
      }
      reject(new Error('连接 PrintDot 超时，请确认客户端已启动且 WebSocket 地址正确'));
    }, timeoutMs);

    const finish = (fn: () => void) => {
      if (done) {
        return;
      }
      done = true;
      window.clearTimeout(timer);
      try {
        ws.close();
      } catch {
        // ignore
      }
      fn();
    };

    ws.onmessage = (ev) => {
      try {
        const data = JSON.parse(ev.data as string);
        if (data?.type === 'printer_list' && Array.isArray(data.data)) {
          const list = data.data
            .map((p: any) => ({
              name: String(p?.name || '').trim(),
              isDefault: p?.isDefault === true,
            }))
            .filter((p: PrintDotPrinter) => !!p.name);
          finish(() => resolve(list));
        }
      } catch {
        // ignore
      }
    };

    ws.onerror = () => {
      finish(() => reject(new Error('无法连接 PrintDot WebSocket，请检查地址与客户端是否运行')));
    };
  });
}

/** 将 PrintDot 返回的英文错误转为带处理步骤的提示（便于运维排查） */
function enhancePrintDotErrorMessage(raw: string): string {
  const m = String(raw || '').trim();
  if (/SumatraPDF\.exe not found/i.test(m) || /SUMATRAPDF_PATH/i.test(m)) {
    return `${m}。本地处理：PrintDot 依赖 SumatraPDF 静默打印 PDF。请安装 Sumatra PDF 后任选其一：将 SumatraPDF.exe 放在 PrintDot 客户端 exe 同目录；或将 Sumatra 安装目录加入系统 PATH；或设置用户/系统环境变量 SUMATRAPDF_PATH 指向 SumatraPDF.exe 的完整路径，然后重启 PrintDot。`;
  }
  return m;
}

/**
 * 发送 PDF 打印任务（content 为 Base64 PDF，可为纯 Base64 或 data:application/pdf;base64, 前缀）
 * 连接建立后服务端可能先推送 printer_list，需忽略直至收到 status。
 */
export function printDotSendPdf(params: {
  printer: string;
  pdfBase64: string;
  jobName?: string;
  copies?: number;
  timeoutMs?: number;
}): Promise<{ ok: boolean; message: string }> {
  const { wsUrl, key } = getPrintDotBridgeConfig();
  const timeout = params.timeoutMs ?? 180000;

  return new Promise((resolve, reject) => {
    let settled = false;
    const ws = new WebSocket(buildWsUrl(wsUrl, key));
    const timer = window.setTimeout(() => {
      if (settled) {
        return;
      }
      settled = true;
      try {
        ws.close();
      } catch {
        // ignore
      }
      reject(new Error('PrintDot 打印等待结果超时'));
    }, timeout);

    const finishOk = (ok: boolean, message: string) => {
      if (settled) {
        return;
      }
      settled = true;
      window.clearTimeout(timer);
      try {
        ws.close();
      } catch {
        // ignore
      }
      resolve({ ok, message });
    };

    ws.onopen = () => {
      let content = String(params.pdfBase64 || '').trim();
      if (content.startsWith('data:')) {
        const idx = content.indexOf(',');
        if (idx !== -1) {
          content = content.slice(idx + 1);
        }
      }
      const payload: Record<string, unknown> = {
        printer: String(params.printer || '').trim(),
        content,
        job: {
          name: String(params.jobName || 'QH-MES').trim() || 'QH-MES',
          copies: Math.max(1, Number(params.copies) || 1),
        },
      };
      ws.send(JSON.stringify(payload));
    };

    ws.onmessage = (ev) => {
      try {
        const data = JSON.parse(ev.data as string);
        if (data?.type === 'printer_list') {
          return;
        }
        if (data?.status) {
          const ok = data.status === 'success';
          const rawMsg = String(data.message || '');
          finishOk(ok, ok ? rawMsg : enhancePrintDotErrorMessage(rawMsg));
        }
      } catch {
        finishOk(false, 'PrintDot 返回无法解析');
      }
    };

    ws.onerror = () => {
      if (settled) {
        return;
      }
      settled = true;
      window.clearTimeout(timer);
      try {
        ws.close();
      } catch {
        // ignore
      }
      reject(new Error('PrintDot WebSocket 错误'));
    };
  });
}

/** 将列表页的「系统默认」或空选择解析为桥接器返回的默认打印机名称 */
export function resolvePrintDotPrinterName(selectedValue: string, printers: PrintDotPrinter[]): string {
  const s = String(selectedValue || '').trim();
  if (s && s !== '__system_default__') {
    return s;
  }
  const def = printers.find((p) => p.isDefault);
  return def?.name || printers[0]?.name || '';
}