import type { IncomingMessage, ServerResponse } from 'node:http';
import type { HostApiContext } from '../context';
import { sendJson } from '../route-utils';
import { hasRendererCapability } from '../renderer-capability';
import { WORKS_SQUARE_CONFIG } from '../works-config';
import { getValidWorksSquareAccessToken } from '../../services/works-square-session';
import { proxyAwareFetch } from '../../utils/proxy-fetch';
import type { WorksCloudDeploymentRecord } from '../../../shared/works-cloud-deployment';
import type { DevicePreviewSnapshot } from '../../../shared/device-preview';

type RemoteProjectSnapshot = {
  appId: string | null;
  playable: boolean | null;
  runtimeUrl: string | null;
  runtimeVersionName: string | null;
  latestVersionId: string | null;
  latestVersionName: string | null;
  latestReleaseId: string | null;
  reviewStatus: string | null;
};

class DevicePreviewRequestError extends Error {
  readonly statusCode: number;

  constructor(message: string, statusCode: number) {
    super(message);
    this.name = 'DevicePreviewRequestError';
    this.statusCode = statusCode;
  }
}

const DEVICE_PREVIEW_ROUTE = /^\/api\/opencode\/projects\/([^/]+)\/device-preview$/;
const OWNER_STATUS_TIMEOUT_MS = 10_000;
const READY_REVIEW_STATUSES = new Set(['approved', 'published']);
const FAILED_REVIEW_STATUSES = new Set(['blocked', 'failed', 'rejected']);

function asRecord(value: unknown): Record<string, unknown> | null {
  return value && typeof value === 'object' && !Array.isArray(value)
    ? value as Record<string, unknown>
    : null;
}

function readString(value: unknown): string | null {
  return typeof value === 'string' && value.trim() ? value.trim() : null;
}

async function readResponsePayload(response: Response): Promise<unknown> {
  const text = await response.text();
  if (!text.trim()) return null;
  try {
    return JSON.parse(text) as unknown;
  } catch {
    return null;
  }
}

function projectFromPayload(payload: unknown): RemoteProjectSnapshot | null {
  const root = asRecord(payload);
  if (!root) return null;
  const wrappedStatus = asRecord(root.status);
  const project = asRecord(root.project)
    ?? asRecord(wrappedStatus?.project)
    ?? (readString(root.app_id) ? root : null);
  if (!project) return null;
  const latestVersion = asRecord(root.latest_version) ?? asRecord(wrappedStatus?.latest_version);
  return {
    appId: readString(project.app_id),
    playable: typeof project.playable === 'boolean' ? project.playable : null,
    runtimeUrl: readString(project.runtime_url) ?? readString(project.play_url),
    runtimeVersionName: readString(project.version_name),
    latestVersionId: readString(latestVersion?.id) ?? readString(latestVersion?.version_id),
    latestVersionName: readString(latestVersion?.version_name),
    latestReleaseId: readString(latestVersion?.release_id),
    reviewStatus: readString(latestVersion?.review_status),
  };
}

function normalizedWorksBaseUrl(): URL {
  const base = WORKS_SQUARE_CONFIG.apiBaseUrl.trim().replace(/\/+$/, '');
  return new URL(`${base}/`);
}

function isLoopbackHostname(hostname: string): boolean {
  const normalized = hostname.toLowerCase().replace(/^\[|\]$/g, '');
  return normalized === 'localhost'
    || normalized === '::1'
    || normalized === '0.0.0.0'
    || normalized.startsWith('127.');
}

function trustedLaunchUrl(value: string, worksBase: URL): string | null {
  try {
    const target = new URL(value, worksBase);
    const absoluteUrl = target.toString();
    if (
      absoluteUrl.length > 1_024
      || worksBase.protocol !== 'https:'
      || target.protocol !== 'https:'
      || target.origin !== worksBase.origin
      || Boolean(target.username || target.password)
      || isLoopbackHostname(target.hostname)
    ) {
      return null;
    }
    return absoluteUrl;
  } catch {
    return null;
  }
}

function trustedReleasePreviewUrl(
  value: string,
  worksBase: URL,
  releaseId: string,
): string | null {
  const trusted = trustedLaunchUrl(value, worksBase);
  if (!trusted) return null;
  const target = new URL(trusted);
  const expectedPrefix = `/previews/${encodeURIComponent(releaseId)}/`;
  return target.pathname.startsWith(expectedPrefix) ? trusted : null;
}

async function requireManagedAccessToken(): Promise<string> {
  const accessToken = await getValidWorksSquareAccessToken();
  if (!accessToken) {
    throw new DevicePreviewRequestError('请先登录，再核对当前项目的真机预览版本', 401);
  }
  return accessToken;
}

async function fetchOwnedRemoteProject(
  appId: string,
  accessToken: string,
): Promise<RemoteProjectSnapshot | null> {
  const worksBase = normalizedWorksBaseUrl();
  const abortController = new AbortController();
  const timeout = setTimeout(() => abortController.abort(), OWNER_STATUS_TIMEOUT_MS);
  let response: Response;
  try {
    response = await proxyAwareFetch(
      new URL(`/api/projects/mine/${encodeURIComponent(appId)}/status`, worksBase).toString(),
      {
        method: 'GET',
        headers: { Authorization: `Bearer ${accessToken}` },
        signal: abortController.signal,
      },
    );
  } catch (error) {
    if (abortController.signal.aborted) {
      throw new DevicePreviewRequestError('服务端预览状态读取超时，请稍后刷新', 502);
    }
    throw error;
  } finally {
    clearTimeout(timeout);
  }
  if (response.status === 404) return null;
  if (response.status === 401 || response.status === 403) {
    throw new DevicePreviewRequestError('登录状态已失效，请重新登录后刷新预览', response.status);
  }
  if (!response.ok) {
    throw new DevicePreviewRequestError(`服务端预览状态读取失败（${response.status}）`, 502);
  }

  const project = projectFromPayload(await readResponsePayload(response));
  if (!project) {
    throw new DevicePreviewRequestError('服务端返回了无法识别的预览状态', 502);
  }
  return project;
}

async function createOwnedReleasePreview(
  appId: string,
  releaseId: string,
  accessToken: string,
): Promise<string> {
  const worksBase = normalizedWorksBaseUrl();
  const abortController = new AbortController();
  const timeout = setTimeout(() => abortController.abort(), OWNER_STATUS_TIMEOUT_MS);
  let response: Response;
  try {
    response = await proxyAwareFetch(
      new URL(
        `/api/projects/${encodeURIComponent(appId)}/releases/${encodeURIComponent(releaseId)}/preview-url`,
        worksBase,
      ).toString(),
      {
        method: 'POST',
        headers: { Authorization: `Bearer ${accessToken}` },
        signal: abortController.signal,
      },
    );
  } catch (error) {
    if (abortController.signal.aborted) {
      throw new DevicePreviewRequestError('服务端预览地址生成超时，请稍后刷新', 502);
    }
    throw error;
  } finally {
    clearTimeout(timeout);
  }

  if (response.status === 401 || response.status === 403) {
    throw new DevicePreviewRequestError('登录状态已失效，请重新登录后刷新预览', response.status);
  }
  if (!response.ok) {
    throw new DevicePreviewRequestError(`服务端预览地址生成失败（${response.status}）`, 502);
  }
  const payload = asRecord(await readResponsePayload(response));
  const previewUrl = readString(payload?.url);
  if (!previewUrl) {
    throw new DevicePreviewRequestError('服务端返回了无法识别的预览地址', 502);
  }
  return previewUrl;
}

function localSnapshot(
  projectId: string,
  deployment: WorksCloudDeploymentRecord | null,
): Omit<DevicePreviewSnapshot, 'state' | 'message'> {
  return {
    projectId,
    ...(deployment?.app_id ? { appId: deployment.app_id } : {}),
    ...(deployment?.version_id ? { versionId: deployment.version_id } : {}),
    ...(deployment?.version_name ? { versionName: deployment.version_name } : {}),
    ...(deployment?.review_status ? { reviewStatus: deployment.review_status } : {}),
    ...(deployment?.updated_at ? { updatedAt: deployment.updated_at } : {}),
  };
}

function buildingMessage(status: WorksCloudDeploymentRecord['status']): string {
  if (status === 'waiting_for_login') return '正在等待登录状态恢复，恢复后会继续提交预览版本。';
  if (status === 'uploading') return '预览包正在上传到服务端。';
  return '正在等待新的预览包与安全检查完成。';
}

function normalizedReviewStatus(value: string | null): string | null {
  return value?.trim().toLowerCase() || null;
}

async function resolveDevicePreview(
  projectId: string,
  deployment: WorksCloudDeploymentRecord | null,
): Promise<DevicePreviewSnapshot> {
  if (!deployment) {
    return {
      projectId,
      state: 'not_deployed',
      message: '当前项目还没有与本机绑定的服务端预览版本。',
    };
  }

  if (deployment.project_id !== projectId) {
    return {
      projectId,
      state: 'unavailable',
      message: '本地预览记录不属于当前项目，请重新生成。',
    };
  }

  const base = localSnapshot(projectId, deployment);

  if (deployment.status === 'failed') {
    return {
      ...base,
      state: 'unavailable',
      message: deployment.error || '预览版本生成失败，请重新生成。',
    };
  }

  if (deployment.status !== 'submitted') {
    return {
      ...base,
      state: 'building',
      message: buildingMessage(deployment.status),
    };
  }

  if (!deployment.app_id || !deployment.version_id || !deployment.version_name) {
    return {
      ...base,
      state: 'unavailable',
      message: '本地预览记录缺少版本标识，请重新生成。',
    };
  }

  const accessToken = await requireManagedAccessToken();
  const remote = await fetchOwnedRemoteProject(deployment.app_id, accessToken);
  if (!remote) {
    return {
      ...base,
      state: 'building',
      message: '服务端正在接收或构建本次预览版本。',
    };
  }

  if (remote.appId !== deployment.app_id) {
    return {
      ...base,
      state: 'unavailable',
      message: '服务端返回的项目标识不匹配，已停止展示预览。',
    };
  }

  const reviewStatus = normalizedReviewStatus(remote.reviewStatus);
  const remoteBase = {
    ...base,
    ...(remote.reviewStatus ? { reviewStatus: remote.reviewStatus } : {}),
  };
  const targetVersionMatches = remote.latestVersionId === deployment.version_id
    && remote.latestVersionName === deployment.version_name;
  const launchUrl = remote.runtimeUrl
    ? trustedLaunchUrl(remote.runtimeUrl, normalizedWorksBaseUrl())
    : null;

  if (!targetVersionMatches) {
    return {
      ...remoteBase,
      state: 'unavailable',
      message: '服务端最新版本已与本地绑定版本不一致，请重新同步项目状态。',
    };
  }

  if (reviewStatus && FAILED_REVIEW_STATUSES.has(reviewStatus)) {
    return {
      ...remoteBase,
      state: 'unavailable',
      message: '本次预览版本未通过服务端检查，请修改后重新生成。',
    };
  }

  if (reviewStatus === 'building' || reviewStatus === 'queued' || reviewStatus === 'reviewing') {
    return {
      ...remoteBase,
      state: 'building',
      message: '本次预览版本仍在构建或审核，暂不展示旧版本。',
    };
  }

  if (reviewStatus === 'pending_review') {
    if (!remote.latestReleaseId) {
      return {
        ...remoteBase,
        state: 'building',
        message: '本次版本已构建完成，正在准备审核前预览。',
      };
    }
    const rawPreviewUrl = await createOwnedReleasePreview(
      deployment.app_id,
      remote.latestReleaseId,
      accessToken,
    );
    const previewUrl = trustedReleasePreviewUrl(
      rawPreviewUrl,
      normalizedWorksBaseUrl(),
      remote.latestReleaseId,
    );
    if (!previewUrl) {
      return {
        ...remoteBase,
        state: 'unavailable',
        message: '服务端返回的审核前预览地址未通过安全校验。',
      };
    }
    return {
      ...remoteBase,
      state: 'ready',
      launchUrl: previewUrl,
      message: '审核前真机预览已就绪。',
    };
  }

  if (remote.runtimeUrl && !launchUrl) {
    return {
      ...remoteBase,
      state: 'unavailable',
      message: '服务端返回的预览地址未通过安全校验。',
    };
  }

  if (
    remote.playable === true
    && launchUrl
    && remote.runtimeVersionName === deployment.version_name
    && reviewStatus !== null
    && READY_REVIEW_STATUSES.has(reviewStatus)
  ) {
    return {
      ...remoteBase,
      state: 'ready',
      launchUrl,
      message: '真机预览已就绪。',
    };
  }

  if (
    reviewStatus !== null
    && READY_REVIEW_STATUSES.has(reviewStatus)
    && remote.runtimeVersionName !== deployment.version_name
  ) {
    return {
      ...remoteBase,
      state: 'building',
      message: '本次版本已通过审核，服务端运行地址仍在切换中。',
    };
  }

  return {
    ...remoteBase,
    state: 'unavailable',
    message: '服务端尚未确认本次版本可供真机访问。',
  };
}

export async function handleDevicePreviewRoutes(
  req: IncomingMessage,
  res: ServerResponse,
  url: URL,
  ctx: HostApiContext,
): Promise<boolean> {
  const match = url.pathname.match(DEVICE_PREVIEW_ROUTE);
  if (!match) return false;

  res.setHeader('Cache-Control', 'no-store');
  if (req.method !== 'GET') {
    res.setHeader('Allow', 'GET');
    sendJson(res, 405, { success: false, error: 'Method not allowed' });
    return true;
  }
  if (!hasRendererCapability(req)) {
    sendJson(res, 403, { success: false, error: 'Renderer capability required' });
    return true;
  }

  try {
    const projectId = decodeURIComponent(match[1] ?? '').trim();
    const activeProject = await ctx.opencodeProjectStore.getActiveProject();
    if (!projectId || !activeProject || activeProject.id !== projectId) {
      sendJson(res, 409, { success: false, error: 'Select this project before opening device preview' });
      return true;
    }

    const deployment = ctx.worksCloudDeployment
      ? await ctx.worksCloudDeployment.get(projectId)
      : null;
    const preview = await resolveDevicePreview(projectId, deployment);
    sendJson(res, 200, { success: true, preview });
  } catch (error) {
    sendJson(res, error instanceof DevicePreviewRequestError ? error.statusCode : 502, {
      success: false,
      error: error instanceof Error ? error.message : String(error),
    });
  }
  return true;
}