import QRCode from 'qrcode';
import { resolveRpcAuthority } from '../../rpc-authority.mjs';
import { publicWorkspaceError, SET_WORKSPACE_ENDPOINT, validWorkspacePayload } from '../shared/workspace-rpc.mjs';
import {
  connectionTestTargetUnavailable,
  publicConnectionTestResult,
} from '../../../../src/channels/shared/connection-test.mjs';

export const DINGTALK_RPC_CHANNEL = '/dingtalk';
export const DINGTALK_ENDPOINTS = Object.freeze({
  status: 'connection.status',
  beginProvisioning: 'provision.begin',
  pollProvisioning: 'provision.poll',
  cancelProvisioning: 'provision.cancel',
  bindCredentials: 'bot.bind-credentials',
  reconnectBot: 'bot.reconnect',
  deleteBot: 'bot.delete',
  setWorkspace: SET_WORKSPACE_ENDPOINT,
  approveSender: 'bot.sender.approve',
  revokeSender: 'bot.sender.revoke',
});
export const DINGTALK_RPC_ENDPOINTS = Object.freeze(Object.values(DINGTALK_ENDPOINTS));

const FORBIDDEN_PUBLIC_KEYS = new Set([
  'clientSecret',
  'client_secret',
  'deviceCode',
  'device_code',
  'secretRef',
  'staffId',
  'senderStaffId',
  'verificationUrl',
  'verificationUri',
  'userCode',
]);

function isRecord(value) {
  return value !== null && typeof value === 'object' && !Array.isArray(value);
}

function exactKeys(value, allowed) {
  return isRecord(value) && Object.keys(value).every((key) => allowed.includes(key));
}

function validId(value) {
  return typeof value === 'string' && /^[A-Za-z0-9_-]{1,128}$/.test(value);
}

function validCredential(value, maxLength) {
  return typeof value === 'string' && value.trim().length > 0 && value.length <= maxLength;
}

function payloadFailure(endpoint, payload) {
  if (!isRecord(payload)) return 'Payload must be an object.';
  if (endpoint === DINGTALK_ENDPOINTS.status) {
    return exactKeys(payload, []) ? null : 'connection.status does not accept fields.';
  }
  if (endpoint === DINGTALK_ENDPOINTS.beginProvisioning) {
    return exactKeys(payload, ['locale']) && (payload.locale === undefined || payload.locale === 'zh-CN')
      ? null
      : 'provision.begin received unsupported fields.';
  }
  if ([DINGTALK_ENDPOINTS.pollProvisioning, DINGTALK_ENDPOINTS.cancelProvisioning].includes(endpoint)) {
    return exactKeys(payload, ['attemptId']) && validId(payload.attemptId)
      ? null
      : `${endpoint} requires an attemptId.`;
  }
  if (endpoint === DINGTALK_ENDPOINTS.bindCredentials) {
    return exactKeys(payload, ['clientId', 'clientSecret'])
      && validCredential(payload.clientId, 256)
      && validCredential(payload.clientSecret, 1024)
      ? null
      : 'bot.bind-credentials requires Client ID and Client Secret.';
  }
  if (endpoint === DINGTALK_ENDPOINTS.reconnectBot) {
    return exactKeys(payload, ['botId', 'sendTest'])
      && validId(payload.botId)
      && (payload.sendTest === undefined || payload.sendTest === true)
      ? null
      : 'bot.reconnect requires a botId and optional sendTest=true.';
  }
  if (endpoint === DINGTALK_ENDPOINTS.deleteBot) {
    return exactKeys(payload, ['botId', 'confirm']) && validId(payload.botId) && payload.confirm === true
      ? null
      : 'bot.delete requires a botId and confirm=true.';
  }
  if (endpoint === DINGTALK_ENDPOINTS.setWorkspace) {
    return validWorkspacePayload(payload)
      ? null : '请输入工作区绝对路径。';
  }
  if (endpoint === DINGTALK_ENDPOINTS.approveSender) {
    return exactKeys(payload, ['botId', 'requestId', 'confirm'])
      && validId(payload.botId)
      && validId(payload.requestId)
      && payload.confirm === true
      ? null
      : 'bot.sender.approve requires botId, requestId, and confirm=true.';
  }
  if (endpoint === DINGTALK_ENDPOINTS.revokeSender) {
    return exactKeys(payload, ['botId', 'senderKey', 'confirm'])
      && validId(payload.botId)
      && validId(payload.senderKey)
      && payload.confirm === true
      ? null
      : 'bot.sender.revoke requires botId, senderKey, and confirm=true.';
  }
  return 'Unknown DingTalk endpoint.';
}

function badRequest(message) {
  return { ok: false, error: { code: 'bad-request', message } };
}

function cancelled() {
  return { ok: false, error: { code: 'cancelled', message: 'The request was cancelled.' } };
}

function internalFailure() {
  return {
    ok: false,
    error: { code: 'dingtalk-operation-failed', message: '钉钉操作失败，请稍后重试。' },
  };
}

function sanitizePublic(value) {
  if (Array.isArray(value)) return value.map(sanitizePublic);
  if (!isRecord(value)) return value;
  const safe = {};
  for (const [key, child] of Object.entries(value)) {
    if (!FORBIDDEN_PUBLIC_KEYS.has(key)) safe[key] = sanitizePublic(child);
  }
  return safe;
}

async function qrDataUrl(value) {
  return QRCode.toDataURL(value, {
    type: 'image/png',
    errorCorrectionLevel: 'M',
    margin: 2,
    width: 320,
  });
}

async function withEncodedQr(value, encodeQr) {
  if (!value || typeof value.verificationUrl !== 'string') return sanitizePublic(value);
  return sanitizePublic({
    ...value,
    qrCodeDataUrl: await encodeQr(value.verificationUrl),
  });
}

async function publicStatus(status, encodeQr) {
  const value = structuredClone(status);
  if (value?.provisioning) {
    value.provisioning = await withEncodedQr(value.provisioning, encodeQr);
  }
  return sanitizePublic(value);
}

function assertController(controller) {
  for (const method of [
    'status',
    'startProvisioning',
    'registrationStatus',
    'cancelProvisioning',
    'bindCredentials',
    'reconnectBot',
    'deleteBot',
    'approveSender',
    'revokeSender',
  ]) {
    if (typeof controller?.[method] !== 'function') {
      throw new TypeError(`A complete DingTalk controller is required (${method})`);
    }
  }
}

export function createDingtalkRpcHandler(controller, { encodeQr = qrDataUrl } = {}) {
  assertController(controller);
  const qrCache = new Map();
  const cachedEncode = (url) => {
    let encoded = qrCache.get(url);
    if (!encoded) {
      if (qrCache.size >= 16) qrCache.delete(qrCache.keys().next().value);
      encoded = Promise.resolve().then(() => encodeQr(url));
      qrCache.set(url, encoded);
    }
    return encoded;
  };

  return async (endpoint, payload, signal) => {
    if (signal?.aborted) return cancelled();
    if (!DINGTALK_RPC_ENDPOINTS.includes(endpoint)) return badRequest('Unknown DingTalk endpoint.');
    const invalid = payloadFailure(endpoint, payload);
    if (invalid) return badRequest(invalid);

    try {
      let value;
      if (endpoint === DINGTALK_ENDPOINTS.status) {
        value = await publicStatus(await controller.status(), cachedEncode);
      } else if (endpoint === DINGTALK_ENDPOINTS.beginProvisioning) {
        const started = await controller.startProvisioning({ signal });
        if (signal?.aborted) {
          await controller.cancelProvisioning(started.attemptId);
          return cancelled();
        }
        value = await withEncodedQr(started, cachedEncode);
      } else if (endpoint === DINGTALK_ENDPOINTS.pollProvisioning) {
        const current = await controller.registrationStatus(payload.attemptId);
        if (!current) return badRequest('The provisioning attempt no longer exists.');
        value = await withEncodedQr(current, cachedEncode);
      } else if (endpoint === DINGTALK_ENDPOINTS.cancelProvisioning) {
        value = await controller.cancelProvisioning(payload.attemptId);
        if (!value) return badRequest('The provisioning attempt no longer exists.');
        value = sanitizePublic(value);
      } else if (endpoint === DINGTALK_ENDPOINTS.bindCredentials) {
        value = await publicStatus(await controller.bindCredentials(payload), cachedEncode);
      } else if (endpoint === DINGTALK_ENDPOINTS.reconnectBot) {
        const snapshot = await controller.reconnectBot(payload.botId);
        if (signal?.aborted) return cancelled();
        let testMessage;
        if (payload.sendTest === true) {
          const connected = snapshot?.bots?.some(
            (bot) => bot?.botId === payload.botId && bot?.connected === true,
          );
          if (!connected || typeof controller.sendConnectionTest !== 'function') {
            testMessage = publicConnectionTestResult(
              connectionTestTargetUnavailable('钉钉机器人'),
            );
          } else {
            try {
              await controller.sendConnectionTest(payload.botId);
              testMessage = publicConnectionTestResult();
            } catch (error) {
              testMessage = publicConnectionTestResult(error);
            }
          }
        }
        value = await publicStatus({ ...snapshot, ...(testMessage ? { testMessage } : {}) }, cachedEncode);
      } else if (endpoint === DINGTALK_ENDPOINTS.deleteBot) {
        value = await publicStatus(await controller.deleteBot(payload.botId), cachedEncode);
      } else if (endpoint === DINGTALK_ENDPOINTS.setWorkspace) {
        if (typeof controller.updateWorkspace !== 'function') throw new Error('Workspace update is unavailable');
        value = await publicStatus(
          await controller.updateWorkspace(payload.botId, payload.workspace),
          cachedEncode,
        );
      } else if (endpoint === DINGTALK_ENDPOINTS.approveSender) {
        value = await publicStatus(
          await controller.approveSender(payload.botId, payload.requestId),
          cachedEncode,
        );
      } else {
        value = await publicStatus(
          await controller.revokeSender(payload.botId, payload.senderKey),
          cachedEncode,
        );
      }
      return signal?.aborted ? cancelled() : { ok: true, value };
    } catch (error) {
      const workspaceError = publicWorkspaceError(error);
      return signal?.aborted ? cancelled() : workspaceError
        ? { ok: false, error: workspaceError }
        : internalFailure();
    }
  };
}

export function installDingtalkRpc(ctx, controller, options, authority) {
  if (!ctx?.connection?.rpc || typeof ctx.connection.rpc.handle !== 'function') {
    throw new TypeError('DSH Host Connection RPC is required');
  }
  return ctx.connection.rpc.handle(
    DINGTALK_RPC_CHANNEL,
    createDingtalkRpcHandler(controller, options),
    { authority: resolveRpcAuthority(authority) },
  );
}