import { canActorReadAssetContent } from "../services/asset-content-access.js";
import { Router, type Request, type Response } from "express";
import multer from "multer";
import createDOMPurify from "dompurify";
import { JSDOM } from "jsdom";
import type { Db } from "@paperclipai/db";
import { ASSET_NAMESPACE_RULE, createAssetImageMetadataSchema } from "@paperclipai/shared";
import type { StorageService } from "../storage/types.js";
import { assetService, logActivity } from "../services/index.js";
import {
  formatAttachmentSize,
  isAllowedContentType,
  isInlineAttachmentContentType,
  MAX_ATTACHMENT_BYTES,
} from "../attachment-types.js";
import { assertCompanyAccess, getAccessibleResource, getActorInfo } from "./authz.js";
const SVG_CONTENT_TYPE = "image/svg+xml";
const ALLOWED_COMPANY_LOGO_CONTENT_TYPES = new Set([
  "image/png",
  "image/jpeg",
  "image/jpg",
  "image/webp",
  "image/gif",
  SVG_CONTENT_TYPE,
]);

function sanitizeSvgBuffer(input: Buffer): Buffer | null {
  const raw = input.toString("utf8").trim();
  if (!raw) return null;

  const baseDom = new JSDOM("");
  const domPurify = createDOMPurify(
    baseDom.window as unknown as Parameters<typeof createDOMPurify>[0],
  );
  domPurify.addHook("uponSanitizeAttribute", (_node, data) => {
    const attrName = data.attrName.toLowerCase();
    const attrValue = (data.attrValue ?? "").trim();

    if (attrName.startsWith("on")) {
      data.keepAttr = false;
      return;
    }

    if ((attrName === "href" || attrName === "xlink:href") && attrValue && !attrValue.startsWith("#")) {
      data.keepAttr = false;
    }
  });

  let parsedDom: JSDOM | null = null;
  try {
    const sanitized = domPurify.sanitize(raw, {
      USE_PROFILES: { svg: true, svgFilters: true, html: false },
      FORBID_TAGS: ["script", "foreignObject"],
      FORBID_CONTENTS: ["script", "foreignObject"],
      RETURN_TRUSTED_TYPE: false,
    });

    parsedDom = new JSDOM(sanitized, { contentType: SVG_CONTENT_TYPE });
    const document = parsedDom.window.document;
    const root = document.documentElement;
    if (!root || root.tagName.toLowerCase() !== "svg") return null;

    for (const el of Array.from(root.querySelectorAll("script, foreignObject"))) {
      el.remove();
    }
    for (const el of Array.from(root.querySelectorAll("*"))) {
      for (const attr of Array.from(el.attributes)) {
        const attrName = attr.name.toLowerCase();
        const attrValue = attr.value.trim();
        if (attrName.startsWith("on")) {
          el.removeAttribute(attr.name);
          continue;
        }
        if ((attrName === "href" || attrName === "xlink:href") && attrValue && !attrValue.startsWith("#")) {
          el.removeAttribute(attr.name);
        }
      }
    }

    const output = root.outerHTML.trim();
    if (!output || !/^<svg[\s>]/i.test(output)) return null;
    return Buffer.from(output, "utf8");
  } catch {
    return null;
  } finally {
    parsedDom?.window.close();
    baseDom.window.close();
  }
}

export function assetRoutes(db: Db, storage: StorageService) {
  const router = Router();
  const svc = assetService(db);
  const assetUpload = multer({
    storage: multer.memoryStorage(),
    limits: { fileSize: MAX_ATTACHMENT_BYTES, files: 1 },
  });
  const companyLogoUpload = multer({
    storage: multer.memoryStorage(),
    limits: { fileSize: MAX_ATTACHMENT_BYTES, files: 1 },
  });

  async function runSingleFileUpload(
    upload: ReturnType<typeof multer>,
    req: Request,
    res: Response,
  ) {
    await new Promise<void>((resolve, reject) => {
      upload.single("file")(req, res, (err: unknown) => {
        if (err) reject(err);
        else resolve();
      });
    });
  }

  router.post("/companies/:companyId/assets/images", async (req, res) => {
    const companyId = req.params.companyId as string;
    assertCompanyAccess(req, companyId);

    try {
      await runSingleFileUpload(assetUpload, req, res);
    } catch (err) {
      if (err instanceof multer.MulterError) {
        if (err.code === "LIMIT_FILE_SIZE") {
          res.status(422).json({
            error: `File is larger than the ${formatAttachmentSize(MAX_ATTACHMENT_BYTES)} limit`,
          });
          return;
        }
        res.status(400).json({ error: err.message });
        return;
      }
      throw err;
    }

    const file = (req as Request & { file?: { mimetype: string; buffer: Buffer; originalname: string } }).file;
    if (!file) {
      res.status(400).json({ error: "Missing file field 'file'" });
      return;
    }

    const parsedMeta = createAssetImageMetadataSchema.safeParse(req.body ?? {});
    if (!parsedMeta.success) {
      res.status(400).json({
        error: `Invalid image metadata: ${ASSET_NAMESPACE_RULE}`,
        details: parsedMeta.error.issues,
      });
      return;
    }

    const namespaceSuffix = parsedMeta.data.namespace ?? "general";
    const contentType = (file.mimetype || "").toLowerCase();
    if (contentType !== SVG_CONTENT_TYPE && !isAllowedContentType(contentType)) {
      res.status(422).json({ error: `Unsupported file type: ${contentType || "unknown"}` });
      return;
    }
    let fileBody = file.buffer;
    if (contentType === SVG_CONTENT_TYPE) {
      const sanitized = sanitizeSvgBuffer(file.buffer);
      if (!sanitized || sanitized.length <= 0) {
        res.status(422).json({ error: "SVG could not be sanitized" });
        return;
      }
      fileBody = sanitized;
    }
    if (fileBody.length <= 0) {
      res.status(422).json({ error: "Image is empty" });
      return;
    }

    const actor = getActorInfo(req);
    const stored = await storage.putFile({
      companyId,
      namespace: `assets/${namespaceSuffix}`,
      originalFilename: file.originalname || null,
      contentType,
      body: fileBody,
    });

    const asset = await svc.create(companyId, {
      provider: stored.provider,
      objectKey: stored.objectKey,
      contentType: stored.contentType,
      byteSize: stored.byteSize,
      sha256: stored.sha256,
      originalFilename: stored.originalFilename,
      createdByAgentId: actor.agentId,
      createdByUserId: actor.actorType === "user" ? actor.actorId : req.actor.onBehalfOfUserId ?? null,
    });

    await logActivity(db, {
      companyId,
      actorType: actor.actorType,
      actorId: actor.actorId,
      agentId: actor.agentId,
      runId: actor.runId,
      agentApiKeyId: actor.agentApiKeyId,
      action: "asset.created",
      entityType: "asset",
      entityId: asset.id,
      details: {
        ...(namespaceSuffix.startsWith("issues/") ? {} : { originalFilename: asset.originalFilename }),
        contentType: asset.contentType,
        byteSize: asset.byteSize,
      },
    });

    res.status(201).json({
      assetId: asset.id,
      companyId: asset.companyId,
      provider: asset.provider,
      objectKey: asset.objectKey,
      contentType: asset.contentType,
      byteSize: asset.byteSize,
      sha256: asset.sha256,
      originalFilename: asset.originalFilename,
      createdByAgentId: asset.createdByAgentId,
      createdByUserId: asset.createdByUserId,
      createdAt: asset.createdAt,
      updatedAt: asset.updatedAt,
      contentPath: `/api/assets/${asset.id}/content`,
    });
  });

  router.post("/companies/:companyId/logo", async (req, res) => {
    const companyId = req.params.companyId as string;
    assertCompanyAccess(req, companyId);

    try {
      await runSingleFileUpload(companyLogoUpload, req, res);
    } catch (err) {
      if (err instanceof multer.MulterError) {
        if (err.code === "LIMIT_FILE_SIZE") {
          res.status(422).json({
            error: `Image is larger than the ${formatAttachmentSize(MAX_ATTACHMENT_BYTES)} limit`,
          });
          return;
        }
        res.status(400).json({ error: err.message });
        return;
      }
      throw err;
    }

    const file = (req as Request & { file?: { mimetype: string; buffer: Buffer; originalname: string } }).file;
    if (!file) {
      res.status(400).json({ error: "Missing file field 'file'" });
      return;
    }

    const contentType = (file.mimetype || "").toLowerCase();
    if (!ALLOWED_COMPANY_LOGO_CONTENT_TYPES.has(contentType)) {
      res.status(422).json({ error: `Unsupported image type: ${contentType || "unknown"}` });
      return;
    }

    let fileBody = file.buffer;
    if (contentType === SVG_CONTENT_TYPE) {
      const sanitized = sanitizeSvgBuffer(file.buffer);
      if (!sanitized || sanitized.length <= 0) {
        res.status(422).json({ error: "SVG could not be sanitized" });
        return;
      }
      fileBody = sanitized;
    }

    if (fileBody.length <= 0) {
      res.status(422).json({ error: "Image is empty" });
      return;
    }

    const actor = getActorInfo(req);
    const stored = await storage.putFile({
      companyId,
      namespace: "assets/companies",
      originalFilename: file.originalname || null,
      contentType,
      body: fileBody,
    });

    const asset = await svc.create(companyId, {
      provider: stored.provider,
      objectKey: stored.objectKey,
      contentType: stored.contentType,
      byteSize: stored.byteSize,
      sha256: stored.sha256,
      originalFilename: stored.originalFilename,
      createdByAgentId: actor.agentId,
      createdByUserId: actor.actorType === "user" ? actor.actorId : null,
    });

    await logActivity(db, {
      companyId,
      actorType: actor.actorType,
      actorId: actor.actorId,
      agentId: actor.agentId,
      runId: actor.runId,
      agentApiKeyId: actor.agentApiKeyId,
      action: "asset.created",
      entityType: "asset",
      entityId: asset.id,
      details: {
        originalFilename: asset.originalFilename,
        contentType: asset.contentType,
        byteSize: asset.byteSize,
        namespace: "assets/companies",
      },
    });

    res.status(201).json({
      assetId: asset.id,
      companyId: asset.companyId,
      provider: asset.provider,
      objectKey: asset.objectKey,
      contentType: asset.contentType,
      byteSize: asset.byteSize,
      sha256: asset.sha256,
      originalFilename: asset.originalFilename,
      createdByAgentId: asset.createdByAgentId,
      createdByUserId: asset.createdByUserId,
      createdAt: asset.createdAt,
      updatedAt: asset.updatedAt,
      contentPath: `/api/assets/${asset.id}/content`,
    });
  });

  router.get("/assets/:assetId/content", async (req, res, next) => {
    const assetId = req.params.assetId as string;
    const asset = await getAccessibleResource(req, res, svc.getById(assetId), "Asset not found");
    if (!asset) return;
    if (!(await canActorReadAssetContent(db, req.actor, asset))) {
      res.status(404).json({ error: "Asset not found" }); return;
    }

    // Use the persisted size only after resource authorization. Single ranges
    // keep saved API text pages bounded all the way to disk or object storage.
    const rawRange = req.headers.range;
    const rangeSyntax = rawRange && /^bytes=(\d*)-(\d*)$/i.exec(rawRange);
    const emptyRead = asset.byteSize === 0 && rangeSyntax?.[1] === "0";
    const ranges = rawRange && !emptyRead ? req.range(asset.byteSize) : undefined;
    res.setHeader("Accept-Ranges", "bytes");
    if (/^[a-f0-9]{64}$/.test(asset.sha256)) res.setHeader("ETag", `"${asset.sha256}"`);
    if (rawRange && (!rangeSyntax || (!rangeSyntax[1] && !rangeSyntax[2])
      || (!emptyRead && (!Array.isArray(ranges) || ranges.length !== 1)))) {
      res.setHeader("Content-Range", `bytes */${asset.byteSize}`);
      res.status(416).end();
      return;
    }
    const range = Array.isArray(ranges) ? ranges[0] : undefined;
    const object = await storage.getObject(asset.companyId, asset.objectKey, range ? { range } : undefined);
    const responseContentType = asset.contentType || object.contentType || "application/octet-stream";
    const mediaType = responseContentType.split(";", 1)[0]?.trim().toLowerCase() ?? "";
    const inlineSafe = mediaType !== SVG_CONTENT_TYPE
      && isInlineAttachmentContentType(mediaType);
    res.setHeader("Content-Type", responseContentType);
    res.setHeader("Content-Length", String(range ? range.end - range.start + 1 : asset.byteSize || object.contentLength || 0));
    if (range) {
      res.status(206);
      res.setHeader("Content-Range", `bytes ${range.start}-${range.end}/${asset.byteSize}`);
    }
    res.setHeader("Cache-Control", "private, no-store");
    res.setHeader("X-Content-Type-Options", "nosniff");
    if (!inlineSafe) {
      res.setHeader("Content-Security-Policy", "sandbox; default-src 'none'");
    }
    const filename = asset.originalFilename ?? "asset";
    const disposition = inlineSafe
      ? "inline"
      : "attachment";
    res.setHeader("Content-Disposition", `${disposition}; filename=\"${filename.replaceAll("\"", "")}\"`);

    object.stream.on("error", (err) => {
      next(err);
    });
    res.on("close", () => object.stream.destroy());
    object.stream.pipe(res);
  });

  return router;
}