import type { IncomingMessage, ServerResponse } from 'node:http';
import {
  IMAGE_WORKSPACE_UNAVAILABLE_CODE,
  IMAGE_WORKSPACE_UNAVAILABLE_MESSAGE,
  type ImageWorkspaceGenerationSettings,
  type ImageWorkspaceReferenceUploadInput,
  type ImageWorkspaceSendMessageInput,
  type ImageWorkspaceSnapshot,
} from '../../../shared/image-workspace';
import { LocalImageWorkspaceError } from '../../image-workspace/local-workspace';
import type { HostApiContext } from '../context';
import { parseJsonBody, sendJson } from '../route-utils';

const IMAGE_WORKSPACE_ROUTE_PREFIX = '/api/works/image-workspace';

function sendWorkspace(res: ServerResponse, workspace: ImageWorkspaceSnapshot): void {
  sendJson(res, 200, { success: true, status: 200, workspace });
}

function decodedSegments(pathname: string): string[] | null {
  const suffix = pathname.slice(IMAGE_WORKSPACE_ROUTE_PREFIX.length).replace(/^\/+/, '');
  if (!suffix) return [];
  try {
    return suffix.split('/').map((segment) => decodeURIComponent(segment));
  } catch {
    return null;
  }
}

function asString(value: unknown): string {
  return typeof value === 'string' ? value : '';
}

function asStringArray(value: unknown): string[] {
  return Array.isArray(value) && value.every((item) => typeof item === 'string')
    ? value
    : [];
}

function asSettings(value: unknown): ImageWorkspaceGenerationSettings {
  if (typeof value !== 'object' || value === null || Array.isArray(value)) return {};
  const source = value as Record<string, unknown>;
  return {
    modeId: asString(source.modeId) || undefined,
    modelId: asString(source.modelId) || undefined,
    aspectRatioId: asString(source.aspectRatioId) || undefined,
    resolutionId: asString(source.resolutionId) || undefined,
    outputCountId: asString(source.outputCountId) || undefined,
  };
}

function sendRouteError(res: ServerResponse, error: unknown): void {
  if (error instanceof LocalImageWorkspaceError) {
    sendJson(res, error.status, {
      success: false,
      status: error.status,
      code: error.code,
      error: error.message,
    });
    return;
  }
  if (error instanceof SyntaxError) {
    sendJson(res, 400, {
      success: false,
      status: 400,
      code: 'IMAGE_WORKSPACE_INVALID_JSON',
      error: '请求内容不是有效 JSON',
    });
    return;
  }
  sendJson(res, 500, {
    success: false,
    status: 500,
    code: 'IMAGE_WORKSPACE_LOCAL_REQUEST_FAILED',
    error: error instanceof Error ? error.message : '创作空间请求失败',
  });
}

export async function handleImageWorkspaceRoutes(
  req: IncomingMessage,
  res: ServerResponse,
  url: URL,
  ctx: HostApiContext,
): Promise<boolean> {
  if (url.pathname !== IMAGE_WORKSPACE_ROUTE_PREFIX
    && !url.pathname.startsWith(`${IMAGE_WORKSPACE_ROUTE_PREFIX}/`)) {
    return false;
  }

  if (!ctx.imageWorkspace) {
    sendJson(res, 501, {
      success: false,
      status: 501,
      code: IMAGE_WORKSPACE_UNAVAILABLE_CODE,
      error: IMAGE_WORKSPACE_UNAVAILABLE_MESSAGE,
    });
    return true;
  }

  const segments = decodedSegments(url.pathname);
  if (!segments) {
    sendJson(res, 400, { success: false, status: 400, error: '无效的绘画空间路径' });
    return true;
  }

  try {
    if (segments.length === 0 && req.method === 'GET') {
      sendWorkspace(res, await ctx.imageWorkspace.getSnapshot());
      return true;
    }

    if (segments.length === 1 && segments[0] === 'projects' && req.method === 'POST') {
      const body = await parseJsonBody<{ name?: unknown }>(req);
      sendWorkspace(res, await ctx.imageWorkspace.createProject(asString(body.name)));
      return true;
    }

    if (segments.length === 1 && segments[0] === 'local-data' && req.method === 'DELETE') {
      sendWorkspace(res, await ctx.imageWorkspace.reset());
      return true;
    }

    if (segments.length === 3 && segments[0] === 'projects' && segments[2] === 'agents' && req.method === 'POST') {
      sendWorkspace(res, await ctx.imageWorkspace.addAgent(segments[1]));
      return true;
    }

    if (segments.length === 3 && segments[0] === 'projects' && segments[2] === 'messages' && req.method === 'POST') {
      const body = await parseJsonBody<Record<string, unknown>>(req);
      const input: ImageWorkspaceSendMessageInput = {
        projectId: segments[1],
        agentId: asString(body.agentId),
        prompt: asString(body.prompt),
        referenceImageIds: asStringArray(body.referenceImageIds),
        settings: asSettings(body.settings),
      };
      sendWorkspace(res, await ctx.imageWorkspace.sendMessage(input));
      return true;
    }

    if (segments.length === 3 && segments[0] === 'projects' && segments[2] === 'references' && req.method === 'POST') {
      const body = await parseJsonBody<Record<string, unknown>>(req);
      const input: ImageWorkspaceReferenceUploadInput = {
        projectId: segments[1],
        fileName: asString(body.fileName),
        mimeType: asString(body.mimeType),
        contentBase64: asString(body.contentBase64),
      };
      const result = await ctx.imageWorkspace.uploadReference(input);
      sendJson(res, 200, { success: true, status: 200, ...result });
      return true;
    }

    sendJson(res, 404, {
      success: false,
      status: 404,
      code: 'IMAGE_WORKSPACE_ROUTE_NOT_FOUND',
      error: `没有对应的绘画空间接口：${req.method ?? 'GET'} ${url.pathname}`,
    });
  } catch (error) {
    sendRouteError(res, error);
  }
  return true;
}