add FileSystemController API endpoint

komga/src/main/kotlin/org/gotson/komga/interfaces/web/rest/FileSystemController.kt

@@ -0,0 +1,67 @@
+package org.gotson.komga.interfaces.web.rest
+
+import com.fasterxml.jackson.annotation.JsonInclude
+import org.springframework.http.HttpStatus
+import org.springframework.http.MediaType
+import org.springframework.web.bind.annotation.GetMapping
+import org.springframework.web.bind.annotation.RequestMapping
+import org.springframework.web.bind.annotation.RequestParam
+import org.springframework.web.bind.annotation.RestController
+import org.springframework.web.server.ResponseStatusException
+import java.nio.file.FileSystems
+import java.nio.file.Files
+import java.nio.file.Path
+import kotlin.streams.toList
+
+@RestController
+@RequestMapping("api/v1/filesystem", produces = [MediaType.APPLICATION_JSON_VALUE])
+class FileSystemController {
+
+  private val fs = FileSystems.getDefault()
+
+  @GetMapping
+  fun getDirectoryListing(
+      @RequestParam(name = "path", required = false) path: String?
+  ): DirectoryListingDto =
+      if (path.isNullOrEmpty()) {
+        DirectoryListingDto(
+            directories = fs.rootDirectories.map { it.toDto() }
+        )
+      } else {
+        val p = fs.getPath(path)
+        if (!p.isAbsolute) throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Path must be absolute")
+        try {
+          DirectoryListingDto(
+              parent = (p.parent ?: "").toString(),
+              directories = Files.list(p).use { dirStream ->
+                dirStream
+                    .filter { Files.isDirectory(it) }
+                    .sorted()
+                    .map { it.toDto() }
+                    .toList()
+              }
+          )
+        } catch (e: Exception) {
+          throw ResponseStatusException(HttpStatus.BAD_REQUEST, "Path does not exist")
+        }
+      }
+}
+
+@JsonInclude(JsonInclude.Include.NON_NULL)
+data class DirectoryListingDto(
+    val parent: String? = null,
+    val directories: List<PathDto>
+)
+
+data class PathDto(
+    val type: String,
+    val name: String,
+    val path: String
+)
+
+fun Path.toDto(): PathDto =
+    PathDto(
+        type = if (Files.isDirectory(this)) "directory" else "file",
+        name = (fileName ?: this).toString(),
+        path = toString()
+    )

komga/src/test/kotlin/org/gotson/komga/interfaces/web/rest/FileSystemControllerTest.kt

@@ -0,0 +1,49 @@
+package org.gotson.komga.interfaces.web.rest
+
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.security.test.context.support.WithAnonymousUser
+import org.springframework.security.test.context.support.WithMockUser
+import org.springframework.test.context.junit.jupiter.SpringExtension
+import org.springframework.test.web.servlet.MockMvc
+import org.springframework.test.web.servlet.request.MockMvcRequestBuilders
+import org.springframework.test.web.servlet.result.MockMvcResultMatchers
+import java.nio.file.Files
+
+@ExtendWith(SpringExtension::class)
+@SpringBootTest
+@AutoConfigureMockMvc(printOnlyOnFailure = false)
+class FileSystemControllerTest(
+    @Autowired private val mockMvc: MockMvc
+) {
+  private val route = "/api/v1/filesystem"
+
+  @Test
+  @WithAnonymousUser
+  fun `given anonymous user when getDirectoryListing then return unauthorized`() {
+    mockMvc.perform(MockMvcRequestBuilders.get(route))
+        .andExpect(MockMvcResultMatchers.status().isUnauthorized)
+  }
+
+  @Test
+  @WithMockUser(roles = ["USER"])
+  fun `given relative path param when getDirectoryListing then return bad request`() {
+    mockMvc.perform(MockMvcRequestBuilders.get(route)
+        .param("path", "."))
+        .andExpect(MockMvcResultMatchers.status().isBadRequest)
+  }
+
+  @Test
+  @WithMockUser(roles = ["USER"])
+  fun `given non-existent path param when getDirectoryListing then return bad request`() {
+    val parent = Files.createTempDirectory(null)
+    Files.delete(parent)
+
+    mockMvc.perform(MockMvcRequestBuilders.get(route)
+        .param("path", parent.toString()))
+        .andExpect(MockMvcResultMatchers.status().isBadRequest)
+  }
+}