introduce file proxies (#24)

* introduce file proxies

* format

Author: seveibar

lib/db/db-client.ts

@@ -1,7 +1,12 @@
 import { createStore } from "zustand/vanilla"
 import { hoist } from "zustand-hoist"
 import { combine } from "zustand/middleware"
-import { databaseSchema, type File, type FileServerEvent } from "./schema.ts"
+import {
+  databaseSchema,
+  type File,
+  type FileProxy,
+  type FileServerEvent,
+} from "./schema.ts"
 import { normalizePath } from "../utils/normalize-path"
 
 export const createDatabase = () => {
@@ -203,4 +208,56 @@ const initializer = combine(databaseSchema.parse({}), (set, get) => ({
       events: [],
     }))
   },
+
+  createFileProxy: (
+    proxy: Omit<FileProxy, "file_proxy_id" | "created_at">,
+  ): FileProxy => {
+    let newProxy: FileProxy
+    set((state) => {
+      newProxy = {
+        ...proxy,
+        file_proxy_id: state.idCounter.toString(),
+        created_at: new Date().toISOString(),
+      } as FileProxy
+      return {
+        file_proxies: [...state.file_proxies, newProxy],
+        idCounter: state.idCounter + 1,
+      }
+    })
+    return newProxy!
+  },
+
+  getFileProxy: (query: {
+    file_proxy_id?: string
+    matching_pattern?: string
+  }): FileProxy | undefined => {
+    const state = get()
+    return state.file_proxies.find(
+      (p) =>
+        (query.file_proxy_id && p.file_proxy_id === query.file_proxy_id) ||
+        (query.matching_pattern &&
+          p.matching_pattern === query.matching_pattern),
+    )
+  },
+
+  listFileProxies: (): FileProxy[] => {
+    return get().file_proxies
+  },
+
+  matchFileProxy: (file_path: string): FileProxy | undefined => {
+    const state = get()
+    const normalizedPath = normalizePath(file_path)
+
+    for (const proxy of state.file_proxies) {
+      const pattern = proxy.matching_pattern
+      // Pattern format: "prefix/*" - match anything starting with "prefix/"
+      if (pattern.endsWith("/*")) {
+        const prefix = pattern.slice(0, -1) // Remove the "*" to get "prefix/"
+        if (normalizedPath.startsWith(prefix)) {
+          return proxy
+        }
+      }
+    }
+    return undefined
+  },
 }))

lib/db/schema.ts

@@ -32,9 +32,28 @@ export const eventSchema = z.object({
 })
 export type FileServerEvent = z.infer<typeof eventSchema>
 
+export const fileProxySchema = z.discriminatedUnion("proxy_type", [
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("disk"),
+    disk_path: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("http"),
+    http_target_url: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+])
+export type FileProxy = z.infer<typeof fileProxySchema>
+
 export const databaseSchema = z.object({
   idCounter: z.number().default(0),
   files: z.array(fileSchema).default([]),
   events: z.array(eventSchema).default([]),
+  file_proxies: z.array(fileProxySchema).default([]),
 })
 export type DatabaseSchema = z.infer<typeof databaseSchema>

lib/utils/resolve-file-proxy.ts

@@ -0,0 +1,112 @@
+import type { FileProxy } from "../db/schema"
+import { readFile } from "node:fs/promises"
+import { join } from "node:path"
+import { normalizePath } from "./normalize-path"
+
+export async function resolveFileProxy(
+  proxy: FileProxy,
+  file_path: string,
+): Promise<Response> {
+  const normalizedPath = normalizePath(file_path)
+  const pattern = proxy.matching_pattern
+
+  // Extract the relative path after the pattern prefix
+  // Pattern: "prefix/*" -> prefix is "prefix/"
+  const prefix = pattern.slice(0, -1) // Remove "*" to get "prefix/"
+  const relativePath = normalizedPath.slice(prefix.length)
+
+  if (proxy.proxy_type === "disk") {
+    return resolveDiskProxy(proxy.disk_path, relativePath)
+  } else {
+    return resolveHttpProxy(proxy.http_target_url, relativePath)
+  }
+}
+
+async function resolveDiskProxy(
+  diskPath: string,
+  relativePath: string,
+): Promise<Response> {
+  const fullPath = join(diskPath, relativePath)
+
+  try {
+    const content = await readFile(fullPath)
+    const fileName = relativePath.split("/").pop() || "file"
+    const contentType = getContentType(fileName)
+
+    return new Response(content, {
+      headers: {
+        "Content-Type": contentType,
+        "Content-Disposition": `attachment; filename="${fileName}"`,
+        "Content-Length": content.byteLength.toString(),
+      },
+    })
+  } catch (error: any) {
+    if (error.code === "ENOENT") {
+      return new Response("File not found", { status: 404 })
+    }
+    console.error("Disk proxy error:", error)
+    return new Response("Failed to read file from disk", { status: 500 })
+  }
+}
+
+async function resolveHttpProxy(
+  httpTargetUrl: string,
+  relativePath: string,
+): Promise<Response> {
+  // Ensure the URL doesn't have double slashes
+  const baseUrl = httpTargetUrl.endsWith("/")
+    ? httpTargetUrl.slice(0, -1)
+    : httpTargetUrl
+  const targetUrl = `${baseUrl}/${relativePath}`
+
+  try {
+    const response = await fetch(targetUrl)
+
+    if (!response.ok) {
+      return new Response(`HTTP proxy returned status ${response.status}`, {
+        status: response.status,
+      })
+    }
+
+    // Pass through the response body and relevant headers
+    const headers = new Headers()
+    const contentType = response.headers.get("Content-Type")
+    if (contentType) {
+      headers.set("Content-Type", contentType)
+    }
+    const contentLength = response.headers.get("Content-Length")
+    if (contentLength) {
+      headers.set("Content-Length", contentLength)
+    }
+    const fileName = relativePath.split("/").pop() || "file"
+    headers.set("Content-Disposition", `attachment; filename="${fileName}"`)
+
+    return new Response(response.body, {
+      status: response.status,
+      headers,
+    })
+  } catch (error) {
+    console.error("HTTP proxy error:", error)
+    return new Response("Failed to fetch file from HTTP proxy", { status: 502 })
+  }
+}
+
+function getContentType(fileName: string): string {
+  const ext = fileName.split(".").pop()?.toLowerCase()
+  const mimeTypes: Record<string, string> = {
+    txt: "text/plain",
+    html: "text/html",
+    css: "text/css",
+    js: "application/javascript",
+    json: "application/json",
+    xml: "application/xml",
+    png: "image/png",
+    jpg: "image/jpeg",
+    jpeg: "image/jpeg",
+    gif: "image/gif",
+    svg: "image/svg+xml",
+    pdf: "application/pdf",
+    zip: "application/zip",
+  }
+  return mimeTypes[ext || ""] || "application/octet-stream"
+}

routes/file_proxies/create.ts

@@ -0,0 +1,71 @@
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+const fileProxyInputSchema = z.discriminatedUnion("proxy_type", [
+  z.object({
+    proxy_type: z.literal("disk"),
+    disk_path: z.string(),
+    matching_pattern: z.string().regex(/^.+\/\*$/, {
+      message: "matching_pattern must end with /*",
+    }),
+  }),
+  z.object({
+    proxy_type: z.literal("http"),
+    http_target_url: z.string().url(),
+    matching_pattern: z.string().regex(/^.+\/\*$/, {
+      message: "matching_pattern must end with /*",
+    }),
+  }),
+])
+
+const fileProxyOutputSchema = z.discriminatedUnion("proxy_type", [
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("disk"),
+    disk_path: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("http"),
+    http_target_url: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+])
+
+export default withRouteSpec({
+  methods: ["POST"],
+  jsonBody: fileProxyInputSchema,
+  jsonResponse: z.union([
+    z.object({
+      file_proxy: fileProxyOutputSchema,
+    }),
+    z.object({
+      error: z.object({
+        message: z.string(),
+      }),
+    }),
+  ]),
+})((req, ctx) => {
+  const proxyInput = req.jsonBody
+
+  // Check if a proxy with the same matching_pattern already exists
+  const existingProxy = ctx.db.getFileProxy({
+    matching_pattern: proxyInput.matching_pattern,
+  })
+  if (existingProxy) {
+    return ctx.json(
+      {
+        error: {
+          message: `A file proxy with matching_pattern "${proxyInput.matching_pattern}" already exists`,
+        },
+      },
+      { status: 400 },
+    )
+  }
+
+  const file_proxy = ctx.db.createFileProxy(proxyInput)
+  return ctx.json({ file_proxy })
+})

routes/file_proxies/get.ts

@@ -0,0 +1,35 @@
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+const fileProxyOutputSchema = z.discriminatedUnion("proxy_type", [
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("disk"),
+    disk_path: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("http"),
+    http_target_url: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+])
+
+export default withRouteSpec({
+  methods: ["GET"],
+  queryParams: z.object({
+    file_proxy_id: z.string().optional(),
+    matching_pattern: z.string().optional(),
+  }),
+  jsonResponse: z.object({
+    file_proxy: fileProxyOutputSchema.nullable(),
+  }),
+})((req, ctx) => {
+  const { file_proxy_id, matching_pattern } = req.query
+  const file_proxy =
+    ctx.db.getFileProxy({ file_proxy_id, matching_pattern }) ?? null
+  return ctx.json({ file_proxy })
+})

routes/file_proxies/list.ts

@@ -0,0 +1,30 @@
+import { withRouteSpec } from "lib/middleware/with-winter-spec"
+import { z } from "zod"
+
+const fileProxyOutputSchema = z.discriminatedUnion("proxy_type", [
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("disk"),
+    disk_path: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+  z.object({
+    file_proxy_id: z.string(),
+    proxy_type: z.literal("http"),
+    http_target_url: z.string(),
+    matching_pattern: z.string(),
+    created_at: z.string(),
+  }),
+])
+
+export default withRouteSpec({
+  methods: ["GET"],
+  jsonResponse: z.object({
+    file_proxies: z.array(fileProxyOutputSchema),
+  }),
+})((req, ctx) => {
+  return ctx.json({
+    file_proxies: ctx.db.listFileProxies(),
+  })
+})

routes/files/download.ts

@@ -4,18 +4,26 @@ import {
   decodeBase64ToUint8Array,
   uint8ArrayToArrayBuffer,
 } from "lib/utils/decode-base64"
+import { resolveFileProxy } from "lib/utils/resolve-file-proxy"
 
 export default withRouteSpec({
   methods: ["GET"],
   queryParams: z.object({
     file_id: z.string().optional(),
     file_path: z.string().optional(),
   }),
-})((req, ctx) => {
+})(async (req, ctx) => {
   const { file_id, file_path } = req.query
   const file = ctx.db.getFile({ file_id, file_path })
 
   if (!file) {
+    // Check if there's a matching proxy (only for file_path queries)
+    if (file_path) {
+      const proxy = ctx.db.matchFileProxy(file_path)
+      if (proxy) {
+        return resolveFileProxy(proxy, file_path)
+      }
+    }
     return new Response("File not found", { status: 404 })
   }