#399

frontend/src/lib/postImportSourceValidation.ts

@@ -12,23 +12,14 @@ const bytesize = (value: string): number =>
     new TextEncoder ().encode (value).length
 
 
-const normaliseImportUrl = (value: string): string | null => {
+const parseImportUrl = (value: string): URL | null => {
     const trimmed = value.trim ()
     if (!(trimmed))
       return null
 
     try
     {
-      const url = new URL (trimmed)
-      if (!(url.protocol === 'http:' || url.protocol === 'https:'))
-        return null
-      if (!(url.host))
-        return null
-
-      url.hostname = url.hostname.toLowerCase ()
-      if (url.pathname.endsWith ('/'))
-        url.pathname = url.pathname.replace (/\/+$/, '')
-      return url.toString ()
+      return new URL (trimmed)
     }
     catch
     {
@@ -37,12 +28,23 @@ const normaliseImportUrl = (value: string): string | null => {
 }
 
 
-export const countImportSourceLines = (source: string): number =>
+const normaliseImportUrl = (url: URL): string => {
+  url.hostname = url.hostname.toLowerCase ()
+  if (url.pathname.endsWith ('/'))
+    url.pathname = url.pathname.replace (/\/+$/, '')
+  return url.toString ()
+}
+
+
+export const extractImportSourceUrls = (source: string): string[] =>
     source
         .split (/\r\n|\n|\r/)
         .map (line => line.trim ())
         .filter (line => line !== '')
-        .length
+
+
+export const countImportSourceLines = (source: string): number =>
+    extractImportSourceUrls (source).length
 
 
 export const validateImportSource = (
@@ -61,7 +63,6 @@ export const validateImportSource = (
       ++count
       const sourceRow = index + 1
       const displayUrl = truncateUrl (value)
-      const normalised = normaliseImportUrl (value)
       if (count > MAX_ROWS)
         {
           issues.push ({
@@ -70,14 +71,6 @@ export const validateImportSource = (
               url: displayUrl })
           return
         }
-      if (!(value.startsWith ('http://') || value.startsWith ('https://')))
-        {
-          issues.push ({
-              sourceRow,
-              message: 'HTTP または HTTPS の URL ではありません．',
-              url: displayUrl })
-          return
-        }
       if (bytesize (value) > MAX_URL_BYTES)
         {
           issues.push ({
@@ -86,7 +79,8 @@ export const validateImportSource = (
               url: displayUrl })
           return
         }
-      if (normalised == null)
+      const parsed = parseImportUrl (value)
+      if (parsed == null)
         {
           issues.push ({
               sourceRow,
@@ -94,6 +88,23 @@ export const validateImportSource = (
               url: displayUrl })
           return
         }
+      if (!(parsed.protocol === 'http:' || parsed.protocol === 'https:'))
+        {
+          issues.push ({
+              sourceRow,
+              message: 'HTTP または HTTPS の URL ではありません．',
+              url: displayUrl })
+          return
+        }
+      if (!(parsed.host))
+        {
+          issues.push ({
+              sourceRow,
+              message: 'URL の形式が不正です．',
+              url: displayUrl })
+          return
+        }
+      const normalised = normaliseImportUrl (parsed)
       const duplicateRow = seen.get (normalised)
       if (duplicateRow != null)
         {

frontend/src/lib/postImportStorage.ts

@@ -1,125 +1,24 @@
-import type { PostImportOrigin,
-	      PostImportDisplayTag,
-	      PostImportExistingPost,
-	      PostImportResetSnapshot,
-	      PostImportRow,
-	      PostImportSession,
-	      PostImportStatus,
-	      PostImportSkipReason,
-	      StorageErrorHandler } from '@/lib/postImportTypes'
+import type { StorageErrorHandler } from '@/lib/postImportTypes'
 
-const SESSION_VERSION = 3
-const SESSION_PREFIX = 'post-import-session:'
 const SOURCE_DRAFT_KEY = 'post-import-source-draft'
-const SESSION_MAX_AGE_MS = 24 * 60 * 60 * 1000
-const MAX_SESSION_JSON_BYTES = 262_144
-const MAX_SESSION_ROWS = 100
-const MAX_SOURCE_BYTES = 262_144
-const SESSION_ID_PATTERN =
-    /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i
-const ATTRIBUTE_KEYS = [
-    'title',
-    'thumbnailBase',
-    'originalCreatedFrom',
-    'originalCreatedBefore',
-    'duration',
-    'videoMs',
-    'tags',
-    'parentPostIds'] as const
-const PROVENANCE_KEYS = [...ATTRIBUTE_KEYS, 'url'] as const
-const TAG_SOURCE_KEYS = ['automatic', 'manual'] as const
-const WARNING_KEYS = [...ATTRIBUTE_KEYS, 'url'] as const
-const ROW_KEYS = [
-    'sourceRow',
-    'url',
-    'attributes',
-    'fieldWarnings',
-    'baseWarnings',
-    'validationErrors',
-    'importErrors',
-    'provenance',
-    'tagSources',
-    'status',
-    'skipReason',
-    'existingPostId',
-    'existingPost',
-    'metadataUrl',
-    'displayTags',
-    'resetSnapshot',
-    'createdPostId',
-    'importStatus',
-    'recoverable'] as const
-const SESSION_KEYS = [
-    'version',
-    'expiresAt',
-    'source',
-    'rows',
-    'repairMode'] as const
-const textEncoder = new TextEncoder ()
-
-
-const isPlainObject = (value: unknown): value is Record<string, unknown> =>
-    typeof value === 'object' && value != null && !(Array.isArray (value))
-
-const byteLength = (value: string): number =>
-    textEncoder.encode (value).byteLength
-
-
-export const validatePostImportSessionId = (value: unknown): string | null => {
-    if (typeof value !== 'string')
-      return null
-    if (value.length > 36 || !(SESSION_ID_PATTERN.test (value)))
-      return null
-
-    return value.toLowerCase ()
-}
-
-
-const generateUuidV4FromRandomValues = (): string => {
-    const bytes = new Uint8Array (16)
-    crypto.getRandomValues (bytes)
-    bytes[6] = (bytes[6] & 0x0f) | 0x40
-    bytes[8] = (bytes[8] & 0x3f) | 0x80
-
-    const hex = Array.from (
-	bytes,
-	byte => byte.toString (16).padStart (2, '0'))
-    return [
-	hex.slice (0, 4).join (''),
-	hex.slice (4, 6).join (''),
-	hex.slice (6, 8).join (''),
-	hex.slice (8, 10).join (''),
-	hex.slice (10, 16).join ('')].join ('-')
-}
-
-
-export const generatePostImportSessionId = (): string => {
-    if (typeof crypto.randomUUID === 'function')
-      return crypto.randomUUID ()
-
-    return generateUuidV4FromRandomValues ()
-}
-
-
-const sessionKey = (sessionId: string): string => `${ SESSION_PREFIX }${ sessionId }`
 
 
 const readStorage = (
     key:       string,
     onError?:  StorageErrorHandler,
 ): string | null => {
-    if (typeof window === 'undefined')
-      return null
+  if (typeof window === 'undefined')
+    return null
 
-    try
-    {
-      return sessionStorage.getItem (key)
-    }
-    catch
-    {
-      onError?.('保存済みデータを読み込めませんでした．')
-      return null
-    }
+  try
+  {
+    return sessionStorage.getItem (key)
+  }
+  catch
+  {
+    onError?.('保存済みデータを読み込めませんでした．')
+    return null
+  }
 }
 
 
@@ -128,19 +27,19 @@ const writeStorage = (
     value:     string,
     onError?:  StorageErrorHandler,
 ): boolean => {
-    if (typeof window === 'undefined')
-      return false
+  if (typeof window === 'undefined')
+    return false
 
-    try
-    {
-      sessionStorage.setItem (key, value)
-      return true
-    }
-    catch
-    {
-      onError?.('ブラウザへ保存できませんでした．')
-      return false
-    }
+  try
+  {
+    sessionStorage.setItem (key, value)
+    return true
+  }
+  catch
+  {
+    onError?.('ブラウザへ保存できませんでした．')
+    return false
+  }
 }
 
 
@@ -148,561 +47,36 @@ const removeStorage = (
     key:       string,
     onError?:  StorageErrorHandler,
 ) => {
-    if (typeof window === 'undefined')
-      return
+  if (typeof window === 'undefined')
+    return
 
-    try
-    {
-      sessionStorage.removeItem (key)
-    }
-    catch
-    {
-      onError?.('保存済みデータを削除できませんでした．')
-    }
-}
-
-
-const ensureStringListRecord = (value: unknown): Record<string, string[]> | null => {
-    if (!(isPlainObject (value)))
-      return null
-
-    const result: Record<string, string[]> = { }
-    for (const [key, entry] of Object.entries (value))
-      {
-        if (!(Array.isArray (entry)) || !(entry.every (item => typeof item === 'string')))
-          return null
-        result[key] = entry
-      }
-    return result
-}
-
-
-const isValidStatus = (
-    value: unknown,
-): value is PostImportRow['status'] =>
-    value === 'pending'
-    || value === 'ready'
-    || value === 'warning'
-    || value === 'error'
-
-
-const isValidImportStatus = (
-    value: unknown,
-): value is PostImportStatus =>
-    value === 'pending'
-    || value === 'created'
-    || value === 'skipped'
-    || value === 'failed'
-
-
-const isValidOrigin = (
-    value: unknown,
-): value is PostImportOrigin =>
-    value === 'automatic' || value === 'manual'
-
-
-const isValidSkipReason = (
-    value: unknown,
-): value is PostImportSkipReason =>
-    value === 'existing' || value === 'manual'
-
-const isPositiveInteger = (value: unknown): value is number =>
-    Number.isSafeInteger (value) && Number (value) > 0
-
-const isNonEmptyMessageRecord = (value: Record<string, string[]>): boolean =>
-    Object.values (value).some (messages => messages.length > 0)
-
-const hasOnlyKeys = (
-    value:        Record<string, unknown>,
-    allowedKeys:  readonly string[],
-): boolean =>
-    Object.keys (value).every (key => allowedKeys.includes (key))
-
-const sanitiseDisplayTag = (value: unknown): PostImportDisplayTag | null => {
-    if (!(isPlainObject (value)))
-      return null
-    if (!(hasOnlyKeys (value, ['name', 'category', 'sectionLiterals'])))
-      return null
-    if (typeof value.name !== 'string' || value.name === '')
-      return null
-    if (typeof value.category !== 'string')
-      return null
-    if (!(['deerjikist',
-	   'meme',
-	   'character',
-	   'general',
-	   'material',
-	   'meta',
-	   'nico'] as const).includes (value.category as never))
-      return null
-    if (value.sectionLiterals != null
-        && (!(Array.isArray (value.sectionLiterals))
-            || !(value.sectionLiterals.every (entry => typeof entry === 'string'))))
-      return null
-
-    return {
-        name: value.name,
-        category: value.category,
-        sectionLiterals:
-            value.sectionLiterals == null
-            ? undefined
-            : [...value.sectionLiterals] }
-}
-
-const sanitiseDisplayTags = (value: unknown): PostImportDisplayTag[] | null => {
-    if (value == null)
-      return []
-    if (!(Array.isArray (value)))
-      return null
-
-    const tags = value.map (sanitiseDisplayTag)
-    return tags.some (tag => tag == null) ? null : (tags as PostImportDisplayTag[])
-}
-
-const sanitiseResetSnapshot = (value: unknown): PostImportResetSnapshot | null => {
-    if (!(isPlainObject (value)))
-      return null
-    if (!(hasOnlyKeys (value, ['url',
-			       'attributes',
-			       'displayTags',
-			       'provenance',
-			       'tagSources',
-			       'fieldWarnings',
-			       'baseWarnings',
-			       'metadataUrl'])))
-      return null
-    if (typeof value.url !== 'string')
-      return null
-    if (!(isPlainObject (value.attributes)))
-      return null
-    if (!(hasOnlyKeys (value.attributes, ATTRIBUTE_KEYS)))
-      return null
-    if (!(Object.values (value.attributes).every (entry =>
-        typeof entry === 'string' || typeof entry === 'number')))
-      return null
-    if (!(isPlainObject (value.provenance)))
-      return null
-    if (!(hasOnlyKeys (value.provenance, PROVENANCE_KEYS)))
-      return null
-    if (!(Object.values (value.provenance).every (origin => isValidOrigin (origin))))
-      return null
-    if (!(isPlainObject (value.tagSources)))
-      return null
-    if (!(hasOnlyKeys (value.tagSources, TAG_SOURCE_KEYS)))
-      return null
-    if (!(Object.values (value.tagSources).every (entry => typeof entry === 'string')))
-      return null
-    const fieldWarnings = ensureStringListRecord (value.fieldWarnings)
-    if (fieldWarnings == null)
-      return null
-    if (!(hasOnlyKeys (fieldWarnings, WARNING_KEYS)))
-      return null
-    if (!(Array.isArray (value.baseWarnings))
-        || !(value.baseWarnings.every (warning => typeof warning === 'string')))
-      return null
-    if (value.metadataUrl != null && typeof value.metadataUrl !== 'string')
-      return null
-    const displayTags = sanitiseDisplayTags (value.displayTags)
-    if (displayTags == null)
-      return null
-
-    return {
-        url: value.url,
-        attributes: value.attributes as Record<string, string | number>,
-        displayTags,
-        provenance: value.provenance as Record<string, PostImportOrigin>,
-        tagSources: value.tagSources as Record<PostImportOrigin, string>,
-        fieldWarnings,
-        baseWarnings: value.baseWarnings,
-        metadataUrl: value.metadataUrl as string | undefined }
-}
-
-const sanitiseExistingPost = (value: unknown): PostImportExistingPost | undefined => {
-    if (value == null)
-      return undefined
-    if (!(isPlainObject (value)))
-      return undefined
-    if (!(isPositiveInteger (value.id)))
-      return undefined
-    if (typeof value.title !== 'string' || typeof value.url !== 'string')
-      return undefined
-    if (value.thumbnail !== undefined
-        && value.thumbnail !== null
-        && typeof value.thumbnail !== 'string')
-      return undefined
-    if (value.thumbnailBase !== undefined
-        && value.thumbnailBase !== null
-        && typeof value.thumbnailBase !== 'string')
-      return undefined
-    if (value.thumbnailUrl !== undefined
-        && value.thumbnailUrl !== null
-        && typeof value.thumbnailUrl !== 'string')
-      return undefined
-
-    return {
-        id: Number (value.id),
-        title: value.title,
-        url: value.url,
-        thumbnail:
-            value.thumbnail === null
-            ? null
-            : typeof value.thumbnail === 'string'
-            ? value.thumbnail
-            : value.thumbnailUrl === null
-              ? null
-              : typeof value.thumbnailUrl === 'string'
-              ? value.thumbnailUrl
-              : undefined,
-        thumbnailBase:
-            value.thumbnailBase === null
-            ? null
-            : typeof value.thumbnailBase === 'string'
-            ? value.thumbnailBase
-            : undefined }
-}
-
-const canonicalisePersistedRow = (
-    row: PostImportRow,
-): PostImportRow | null => {
-    const sanitised = sanitiseRow (serialisePostImportRow (row))
-    return sanitised == null ? null : recalculateThumbnailWarning (sanitised)
-}
-
-const recalculateThumbnailWarning = (row: PostImportRow): PostImportRow => {
-    const others = (row.fieldWarnings.thumbnailBase ?? []).filter (
-	key => key !== 'サムネールなし')
-    const thumbnailBasePresent =
-	typeof row.attributes.thumbnailBase === 'string'
-	&& row.attributes.thumbnailBase.trim () !== ''
-
-    return {
-        ...row,
-        fieldWarnings: {
-	    ...row.fieldWarnings,
-	    thumbnailBase:
-		thumbnailBasePresent
-		? others
-		: [...new Set ([...others, 'サムネールなし'])] } }
-}
-
-const serialiseExistingPost = (value: PostImportExistingPost | undefined) =>
-    value == null
-    ? undefined
-    : {
-	 id: value.id,
-	 title: value.title,
-	 url: value.url,
-	 thumbnail: value.thumbnail,
-	 thumbnailBase: value.thumbnailBase }
-
-const serialiseResetSnapshot = (value: PostImportResetSnapshot) => ({
-    url: value.url,
-    attributes: Object.fromEntries (
-	Object.entries (value.attributes).map (([key, entry]) => [key, entry])),
-    displayTags: value.displayTags.map (tag => ({
-	name: tag.name,
-	category: tag.category,
-	sectionLiterals:
-	    tag.sectionLiterals == null ? undefined : [...tag.sectionLiterals] })),
-    provenance: Object.fromEntries (
-	Object.entries (value.provenance).map (([key, entry]) => [key, entry])),
-    tagSources: {
-	automatic: value.tagSources.automatic,
-	manual: value.tagSources.manual },
-    fieldWarnings: Object.fromEntries (
-	Object.entries (value.fieldWarnings).map (([key, entry]) => [key, [...entry]])),
-    baseWarnings: [...value.baseWarnings],
-    metadataUrl: value.metadataUrl })
-
-export const serialisePostImportRow = (row: PostImportRow) => {
-    const thumbnailBaseWarnings = (() => {
-      const others = (row.fieldWarnings.thumbnailBase ?? []).filter (
-	  message => message !== 'サムネールなし')
-      const thumbnailBasePresent =
-	  typeof row.attributes.thumbnailBase === 'string'
-	  && row.attributes.thumbnailBase.trim () !== ''
-      return thumbnailBasePresent
-	  ? others
-	  : [...new Set ([...others, 'サムネールなし'])]
-    }) ()
-
-    return {
-	sourceRow: row.sourceRow,
-	url: row.url,
-	attributes: Object.fromEntries (
-	    Object.entries (row.attributes).map (([key, entry]) => [key, entry])),
-	fieldWarnings: Object.fromEntries (
-	    Object.entries ({
-		...row.fieldWarnings,
-		thumbnailBase: thumbnailBaseWarnings }).map (([key, entry]) => [key, [...entry]])),
-	baseWarnings: [...row.baseWarnings],
-	validationErrors: Object.fromEntries (
-	    Object.entries (row.validationErrors).map (([key, entry]) => [key, [...entry]])),
-	importErrors:
-	    row.importErrors == null
-	    ? undefined
-	    : Object.fromEntries (
-		Object.entries (row.importErrors).map (([key, entry]) => [key, [...entry]])),
-	provenance: Object.fromEntries (
-	    Object.entries (row.provenance).map (([key, entry]) => [key, entry])),
-	displayTags:
-	    row.displayTags?.map (tag => ({
-		name: tag.name,
-		category: tag.category,
-		sectionLiterals:
-		    tag.sectionLiterals == null ? undefined : [...tag.sectionLiterals] })) ?? [],
-	tagSources:
-	    row.tagSources == null
-	    ? undefined
-	    : {
-		automatic: row.tagSources.automatic,
-		manual: row.tagSources.manual },
-	status: row.status,
-	skipReason: row.skipReason,
-	existingPostId: row.existingPostId,
-	existingPost: serialiseExistingPost (row.existingPost),
-	metadataUrl: row.metadataUrl,
-	resetSnapshot: serialiseResetSnapshot (row.resetSnapshot),
-	createdPostId: row.createdPostId,
-	importStatus: row.importStatus,
-	recoverable: row.recoverable }
-}
-
-export const serialisePostImportRows = (rows: PostImportRow[]) =>
-    rows.map (row => serialisePostImportRow (row))
-
-export const serialisedPostImportRowsEqual = (
-    left:  PostImportRow[],
-    right: PostImportRow[],
-): boolean => {
-    const canonicalLeft = left.map (canonicalisePersistedRow)
-    const canonicalRight = right.map (canonicalisePersistedRow)
-    if (canonicalLeft.some (row => row == null) || canonicalRight.some (row => row == null))
-      return false
-
-    return JSON.stringify (serialisePostImportRows (canonicalLeft as PostImportRow[]))
-        === JSON.stringify (serialisePostImportRows (canonicalRight as PostImportRow[]))
-}
-
-
-const sanitiseRow = (value: unknown): PostImportRow | null => {
-    if (!(isPlainObject (value)))
-      return null
-    if (!(hasOnlyKeys (value, ROW_KEYS)))
-      return null
-    if (!(Number.isInteger (value.sourceRow)) || Number (value.sourceRow) <= 0)
-      return null
-    if (typeof value.url !== 'string')
-      return null
-    if (byteLength (value.url) > 20_480)
-      return null
-    if (!(isPlainObject (value.attributes)))
-      return null
-    if (!(isPlainObject (value.provenance)))
-      return null
-    if (!(isValidStatus (value.status)))
-      return null
-    if (value.importStatus != null && !(isValidImportStatus (value.importStatus)))
-      return null
-    if (value.skipReason != null && !(isValidSkipReason (value.skipReason)))
-      return null
-    if (value.recoverable != null && value.recoverable !== true)
-      return null
-    if (value.skipReason === 'existing' && !(isPositiveInteger (value.existingPostId)))
-      return null
-    if (value.importStatus === 'created' && !(isPositiveInteger (value.createdPostId)))
-      return null
-    if (value.importStatus !== 'created' && value.createdPostId != null)
-      return null
-    if (value.recoverable === true
-        && value.importStatus !== 'failed'
-        && value.importStatus !== 'pending')
-      return null
-    if ((value.importStatus === 'created' || value.importStatus === 'skipped')
-        && value.recoverable != null)
-      return null
-
-    const validationErrors = ensureStringListRecord (value.validationErrors)
-    const fieldWarnings = ensureStringListRecord (value.fieldWarnings)
-    const resetSnapshot = sanitiseResetSnapshot (value.resetSnapshot)
-    if (validationErrors == null || fieldWarnings == null)
-      return null
-    if (resetSnapshot == null)
-      return null
-
-    const importErrors =
-        value.importErrors == null
-        ? undefined
-        : ensureStringListRecord (value.importErrors)
-    if (importErrors === null)
-      return null
-    if (!(Array.isArray (value.baseWarnings))
-        || !(value.baseWarnings.every (warning => typeof warning === 'string')))
-      return null
-
-    const provenanceEntries = Object.entries (value.provenance)
-    if (!(hasOnlyKeys (value.attributes, ATTRIBUTE_KEYS)))
-      return null
-    if (!(Object.values (value.attributes).every (entry =>
-        typeof entry === 'string' || typeof entry === 'number')))
-      return null
-    if (!(hasOnlyKeys (value.provenance, PROVENANCE_KEYS)))
-      return null
-    if (!(provenanceEntries.every (([, origin]) => isValidOrigin (origin))))
-      return null
-
-    if (value.tagSources != null)
-      {
-        if (!(isPlainObject (value.tagSources)))
-          return null
-        if (!(hasOnlyKeys (value.tagSources, TAG_SOURCE_KEYS)))
-          return null
-        if (!(Object.values (value.tagSources).every (entry => typeof entry === 'string')))
-          return null
-      }
-    const displayTags = sanitiseDisplayTags (value.displayTags)
-    if (displayTags == null)
-      return null
-
-    const existingPost = sanitiseExistingPost (value.existingPost)
-    const existingPostId =
-        isPositiveInteger (value.existingPostId) ? Number (value.existingPostId) : undefined
-    if (existingPost != null && existingPostId == null)
-      return null
-    if (existingPost != null && existingPost.id !== existingPostId)
-      return null
-
-    return {
-        sourceRow: Number (value.sourceRow),
-        url: value.url,
-        attributes: value.attributes as Record<string, string | number>,
-        fieldWarnings: isNonEmptyMessageRecord (fieldWarnings) ? fieldWarnings : { },
-        baseWarnings: value.baseWarnings,
-        validationErrors: isNonEmptyMessageRecord (validationErrors) ? validationErrors : { },
-        importErrors:
-            importErrors != null && isNonEmptyMessageRecord (importErrors)
-            ? importErrors
-            : undefined,
-        provenance: value.provenance as Record<string, PostImportOrigin>,
-        displayTags,
-        tagSources: value.tagSources as Record<PostImportOrigin, string> | undefined,
-        status: value.status,
-        skipReason: value.skipReason ?? undefined,
-        existingPostId,
-        existingPost,
-        metadataUrl: typeof value.metadataUrl === 'string' ? value.metadataUrl : undefined,
-        resetSnapshot,
-        createdPostId:
-            isPositiveInteger (value.createdPostId) ? Number (value.createdPostId) : undefined,
-        importStatus: value.importStatus ?? undefined,
-        recoverable: value.recoverable === true ? true : undefined }
-}
-
-const sanitiseSession = (value: unknown): PostImportSession | null => {
-    if (!(isPlainObject (value)))
-      return null
-    if (!(hasOnlyKeys (value, SESSION_KEYS)))
-      return null
-    if (value.version !== SESSION_VERSION || !(Array.isArray (value.rows)))
-      return null
-    if (value.rows.length === 0 || value.rows.length > MAX_SESSION_ROWS)
-      return null
-    if (typeof value.expiresAt !== 'string' || isExpiredSession (value.expiresAt))
-      return null
-    if (typeof value.source !== 'string' || byteLength (value.source) > MAX_SOURCE_BYTES)
-      return null
-
-    const rows = value.rows.map (sanitiseRow)
-    if (rows.some (row => row == null))
-      return null
-    if ((new Set (rows.map (row => row?.sourceRow))).size !== rows.length)
-      return null
-
-    return {
-        version: SESSION_VERSION,
-        expiresAt: value.expiresAt,
-        source: value.source,
-        rows: (rows as PostImportRow[]).map (row => recalculateThumbnailWarning (row)),
-        repairMode: value.repairMode === 'failed' ? 'failed' : 'all' }
-}
-
-
-const isExpiredSession = (expiresAt: string): boolean => {
-    const value = Date.parse (expiresAt)
-    return Number.isNaN (value) || value <= Date.now ()
-}
-
-
-export const cleanupExpiredPostImportSessions = (
-    onError?: StorageErrorHandler,
-) => {
-    if (typeof window === 'undefined')
-      return
-
-    try
-    {
-      for (let i = 0; i < sessionStorage.length; ++i)
-        {
-          const key = sessionStorage.key (i)
-          if (key == null || !(key.startsWith (SESSION_PREFIX)))
-            continue
-
-          const sessionId = validatePostImportSessionId (key.slice (SESSION_PREFIX.length))
-          if (sessionId == null)
-            {
-              sessionStorage.removeItem (key)
-              --i
-              continue
-            }
-
-          const raw = sessionStorage.getItem (key)
-          if (raw == null)
-            continue
-          if (byteLength (raw) > MAX_SESSION_JSON_BYTES)
-            {
-              sessionStorage.removeItem (key)
-              --i
-              continue
-            }
-
-          try
-          {
-            if (sanitiseSession (JSON.parse (raw)) == null)
-              {
-                sessionStorage.removeItem (key)
-                --i
-              }
-          }
-          catch
-          {
-            sessionStorage.removeItem (key)
-            --i
-          }
-        }
-    }
-    catch
-    {
-      onError?.('保存済みデータを整理できませんでした．')
-    }
+  try
+  {
+    sessionStorage.removeItem (key)
+  }
+  catch
+  {
+    onError?.('保存済みデータを削除できませんでした．')
+  }
 }
 
 
 export const loadPostImportSourceDraft = (
     onError?: StorageErrorHandler,
 ): { source: string } => {
-    const raw = readStorage (SOURCE_DRAFT_KEY, onError)
-    if (raw == null)
-      return { source: '' }
+  const raw = readStorage (SOURCE_DRAFT_KEY, onError)
+  if (raw == null)
+    return { source: '' }
 
-    try
-    {
-      const value = JSON.parse (raw) as { source?: string }
-      return { source: typeof value.source === 'string' ? value.source : '' }
-    }
-    catch
-    {
-      return { source: '' }
-    }
+  try
+  {
+    const value = JSON.parse (raw) as { source?: string }
+    return { source: typeof value.source === 'string' ? value.source : '' }
+  }
+  catch
+  {
+    return { source: '' }
+  }
 }
 
 
@@ -716,73 +90,5 @@ export const savePostImportSourceDraft = (
 export const clearPostImportSourceDraft = (
     onError?: StorageErrorHandler,
 ) => {
-    removeStorage (SOURCE_DRAFT_KEY, onError)
-}
-
-
-export const savePostImportSession = (
-    sessionId: string,
-    session: Omit<PostImportSession, 'version' | 'expiresAt'>,
-    onError?:  StorageErrorHandler,
-): boolean => {
-    const validatedId = validatePostImportSessionId (sessionId)
-    if (validatedId == null)
-      return false
-
-    return writeStorage (
-        sessionKey (validatedId),
-        JSON.stringify ({
-            source: session.source,
-            rows: serialisePostImportRows (session.rows),
-            repairMode: session.repairMode,
-            version: SESSION_VERSION,
-            expiresAt: new Date (Date.now () + SESSION_MAX_AGE_MS).toISOString () }),
-        onError)
-}
-
-
-export const loadPostImportSession = (
-    sessionId: string,
-    onError?: StorageErrorHandler,
-): PostImportSession | null => {
-    const validatedId = validatePostImportSessionId (sessionId)
-    if (validatedId == null)
-      return null
-
-    const raw = readStorage (sessionKey (validatedId), onError)
-    if (raw == null)
-      return null
-    if (byteLength (raw) > MAX_SESSION_JSON_BYTES)
-      {
-        removeStorage (sessionKey (validatedId), onError)
-        return null
-      }
-
-    try
-    {
-      const session = sanitiseSession (JSON.parse (raw))
-      if (session == null)
-        {
-          removeStorage (sessionKey (validatedId), onError)
-          return null
-        }
-      return session
-    }
-    catch
-    {
-      removeStorage (sessionKey (validatedId), onError)
-      return null
-    }
-}
-
-
-export const clearPostImportSession = (
-    sessionId: string,
-    onError?: StorageErrorHandler,
-) => {
-    const validatedId = validatePostImportSessionId (sessionId)
-    if (validatedId == null)
-      return
-
-    removeStorage (sessionKey (validatedId), onError)
+  removeStorage (SOURCE_DRAFT_KEY, onError)
 }

frontend/src/lib/postImportTypes.ts

@@ -79,13 +79,6 @@ export type PostImportResultRow =
 	errors?:   Record<string, string[]>
 	recoverable?: boolean }
 
-export type PostImportSession = {
-    version:     number
-    expiresAt:   string
-    source:      string
-    rows:        PostImportRow[]
-    repairMode:  PostImportRepairMode }
-
 export type PostImportSourceIssue = {
     sourceRow: number
     message:   string

frontend/src/lib/useUnsavedChangesGuard.tsx

@@ -1,6 +1,15 @@
-import { createContext, useCallback, useContext, useMemo, useState } from 'react'
+import {
+    createContext,
+    useCallback,
+    useContext,
+    useEffect,
+    useMemo,
+    useRef,
+    useState,
+} from 'react'
+import { useBlocker, useLocation } from 'react-router-dom'
 
-import { useDialogue } from '@/components/dialogues/DialogueProvider'
+import { useDialogue } from '@/lib/dialogues/useDialogue'
 
 import type { FC, PropsWithChildren } from 'react'
 
@@ -8,12 +17,17 @@ type UnsavedChangesSource = {
     dirty:    boolean
     discard:  () => void | Promise<void> }
 
+type UseUnsavedChangesGuardOptions = {
+    dirty:      boolean
+    onDiscard?: () => void | Promise<void> }
+
 type UnsavedChangesGuardContextValue = {
     hasUnsavedChanges:             boolean
     registerUnsavedChangesSource:  (
 	source: UnsavedChangesSource | null,
     ) => void
-    confirmDiscardNavigation:      () => Promise<boolean> }
+    confirmDiscardNavigation:      () => Promise<boolean>
+    allowNextNavigation:           () => void }
 
 const UnsavedChangesGuardContext =
     createContext<UnsavedChangesGuardContextValue | null> (null)
@@ -21,7 +35,9 @@ const UnsavedChangesGuardContext =
 
 export const UnsavedChangesGuardProvider: FC<PropsWithChildren> = ({ children }) => {
   const dialogue = useDialogue ()
+  const location = useLocation ()
   const [source, setSource] = useState<UnsavedChangesSource | null> (null)
+  const bypassNextNavigationRef = useRef (false)
 
   const registerUnsavedChangesSource = useCallback ((
       nextSource: UnsavedChangesSource | null,
@@ -29,28 +45,81 @@ export const UnsavedChangesGuardProvider: FC<PropsWithChildren> = ({ children })
     setSource (nextSource)
   }, [])
 
+  const allowNextNavigation = useCallback (() => {
+    bypassNextNavigationRef.current = true
+  }, [])
+
   const confirmDiscardNavigation = useCallback (async (): Promise<boolean> => {
     if (!(source?.dirty))
       return true
 
     const confirmed = await dialogue.confirm ({
-	title: '未保存の変更があります',
-	description: 'このまま移動すると、保存していない変更は失われます。',
-	cancelText: 'このページに残る',
+	title: '変更が破棄してページ移動しますか?',
 	confirmText: '変更を破棄して移動',
 	variant: 'danger' })
     if (!(confirmed))
       return false
 
+    bypassNextNavigationRef.current = true
     await source.discard ()
     return true
   }, [dialogue, source])
 
+  const blocker = useBlocker (() =>
+      source?.dirty === true && !(bypassNextNavigationRef.current))
+
+  useEffect (() => {
+    if (blocker.state !== 'blocked')
+      return
+
+    let cancelled = false
+
+    void (async () => {
+      const confirmed = await confirmDiscardNavigation ()
+      if (cancelled)
+	return
+
+      if (confirmed)
+	blocker.proceed ()
+      else
+	blocker.reset ()
+    }) ()
+
+    return () => {
+      cancelled = true
+    }
+  }, [blocker, confirmDiscardNavigation])
+
+  useEffect (() => {
+    bypassNextNavigationRef.current = false
+  }, [location.hash, location.pathname, location.search])
+
+  useEffect (() => {
+    if (!(source?.dirty))
+      return
+
+    const handleBeforeUnload = (event: BeforeUnloadEvent) => {
+      event.preventDefault ()
+      event.returnValue = ''
+    }
+
+    window.addEventListener ('beforeunload', handleBeforeUnload)
+    return () => {
+      window.removeEventListener ('beforeunload', handleBeforeUnload)
+    }
+  }, [source?.dirty])
+
   const value = useMemo<UnsavedChangesGuardContextValue> (() => ({
       hasUnsavedChanges: source?.dirty === true,
       registerUnsavedChangesSource,
       confirmDiscardNavigation,
-  }), [confirmDiscardNavigation, registerUnsavedChangesSource, source?.dirty])
+      allowNextNavigation,
+  }), [
+      allowNextNavigation,
+      confirmDiscardNavigation,
+      registerUnsavedChangesSource,
+      source?.dirty,
+  ])
 
   return (
       <UnsavedChangesGuardContext.Provider value={value}>
@@ -59,11 +128,26 @@ export const UnsavedChangesGuardProvider: FC<PropsWithChildren> = ({ children })
 }
 
 
-export const useUnsavedChangesGuard = (): UnsavedChangesGuardContextValue => {
+export const useUnsavedChangesGuard = (
+    options?: UseUnsavedChangesGuardOptions,
+): UnsavedChangesGuardContextValue => {
   const context = useContext (UnsavedChangesGuardContext)
 
   if (context == null)
     throw new Error ('UnsavedChangesGuardProvider が必要です．')
 
+  useEffect (() => {
+    if (options == null)
+      return
+
+    context.registerUnsavedChangesSource ({
+	dirty: options.dirty,
+	discard: options.onDiscard ?? (() => undefined) })
+
+    return () => {
+      context.registerUnsavedChangesSource (null)
+    }
+  }, [context, options?.dirty, options?.onDiscard])
+
   return context
 }

frontend/src/pages/posts/PostImportSourcePage.tsx

@@ -12,26 +12,23 @@ import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { SITE_TITLE } from '@/config'
 import {
-    appendPostNewSessionId,
-    serialisePostNewState,
+    buildPostNewReviewPath,
+    isPostNewReviewPathWithinLimit,
 } from '@/lib/postNewQueryState'
+import {
+    countImportSourceLines,
+    extractImportSourceUrls,
+    validateImportSource,
+} from '@/lib/postImportSourceValidation'
+import {
+    loadPostImportSourceDraft,
+    savePostImportSourceDraft,
+} from '@/lib/postImportStorage'
 import { canEditContent } from '@/lib/users'
-import { countImportSourceLines,
-	 generatePostImportSessionId,
-	 cleanupExpiredPostImportSessions,
-	 initialisePreviewRows,
-	 loadPostImportSession,
-	 loadPostImportSourceDraft,
-	 resultRepairMode,
-	 serialisedPostImportRowsEqual,
-	 savePostImportSession,
-	 savePostImportSourceDraft,
-	 validateImportSource } from '@/lib/postImportSession'
 import Forbidden from '@/pages/Forbidden'
 
 import type { FC } from 'react'
 
-import type { PostImportRow } from '@/lib/postImportSession'
 import type { User } from '@/types'
 
 type Props = { user: User | null }
@@ -40,71 +37,6 @@ const MAX_ROWS = 100
 const SOURCE_ERROR_ID = 'post-import-source-error'
 const SOURCE_ISSUES_ID = 'post-import-source-issues'
 
-const buildInitialRows = (source: string): PostImportRow[] =>
-    source
-        .split (/\r\n|\n|\r/)
-        .map ((line, index) => ({
-            sourceRow: index + 1,
-            url: line.trim () }))
-        .filter (row => row.url !== '')
-        .map (row => ({
-            sourceRow: row.sourceRow,
-            url: row.url,
-            attributes: {
-                title: '',
-                thumbnailBase: '',
-                originalCreatedFrom: '',
-                originalCreatedBefore: '',
-                duration: '',
-                videoMs: '',
-                tags: '',
-                parentPostIds: '' },
-            fieldWarnings: { },
-            baseWarnings: [],
-            validationErrors: { },
-            provenance: {
-                url: 'manual',
-                title: 'automatic',
-                thumbnailBase: 'automatic',
-                originalCreatedFrom: 'automatic',
-                originalCreatedBefore: 'automatic',
-                duration: 'automatic',
-                videoMs: 'automatic',
-                tags: 'automatic',
-                parentPostIds: 'automatic' },
-            tagSources: {
-                automatic: '',
-                manual: '' },
-            status: 'pending' as const,
-            displayTags: [],
-            resetSnapshot: {
-                url: row.url,
-                attributes: {
-                    title: '',
-                    thumbnailBase: '',
-                    originalCreatedFrom: '',
-                    originalCreatedBefore: '',
-                    duration: '',
-                    videoMs: '',
-                    tags: '',
-                    parentPostIds: '' },
-                provenance: {
-                    url: 'manual',
-                    title: 'automatic',
-                    thumbnailBase: 'automatic',
-                    originalCreatedFrom: 'automatic',
-                    originalCreatedBefore: 'automatic',
-                    duration: 'automatic',
-                    videoMs: 'automatic',
-                    tags: 'automatic',
-                    parentPostIds: 'automatic' },
-                tagSources: {
-                    automatic: '',
-                    manual: '' },
-                displayTags: [],
-                fieldWarnings: { },
-                baseWarnings: [] } }))
-
 
 const PostImportSourcePage: FC<Props> = ({ user }) => {
   const editable = canEditContent (user)
@@ -117,6 +49,8 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
   const editedRef = useRef (false)
 
   const lineCount = countImportSourceLines (source)
+  const sourceUrls = extractImportSourceUrls (source)
+  const withinPathLimit = isPostNewReviewPathWithinLimit (sourceUrls)
   const messages = sourceError != null ? [sourceError] : []
   const sourceDescribedBy =
       [sourceError != null ? SOURCE_ERROR_ID : null,
@@ -124,13 +58,7 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
       .filter (value => value != null)
       .join (' ')
 
-  const showStorageError = (message: string) =>
-      toast ({ description: message })
-
   useEffect (() => {
-    cleanupExpiredPostImportSessions (message =>
-	toast ({ title: '保存済みデータを整理できませんでした', description: message }))
-
     const draft = loadPostImportSourceDraft (message =>
 	toast ({ title: '保存済み入力を復元できませんでした', description: message }))
 
@@ -173,73 +101,15 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
 	setSourceError (null)
 	return
       }
+    if (!(withinPathLimit))
+      return
 
     setLoading (true)
     setSourceIssues ([])
     setSourceError (null)
     try
     {
-      const nextRows = initialisePreviewRows (buildInitialRows (source))
-      const serialised = await serialisePostNewState (nextRows)
-      const sessionId = (() => {
-	try
-	{
-	  return generatePostImportSessionId ()
-	}
-	catch
-	{
-	  return null
-	}
-      }) ()
-      const session = {
-	  source,
-	  rows: nextRows,
-	  repairMode: resultRepairMode (nextRows) }
-      const saved =
-	  sessionId == null
-	  ? false
-	  : savePostImportSession (sessionId, session, showStorageError)
-      const loadedSession =
-	  sessionId == null
-	  ? null
-	  : loadPostImportSession (sessionId, showStorageError)
-      const sessionRoundTripSucceeded =
-	  saved
-	  && serialisedPostImportRowsEqual (
-	      loadedSession?.rows ?? [],
-	      nextRows)
-      const canNavigate =
-	  serialised?.complete === true
-	  || sessionRoundTripSucceeded
-      if (!(canNavigate))
-	{
-	  showStorageError ('ブラウザへ保存できませんでした．')
-	  return
-	}
-
-      const nextPath = (() => {
-	if (serialised != null)
-	  {
-	    return sessionId == null
-		? serialised.path
-		: appendPostNewSessionId (serialised.path, sessionId)
-	  }
-	if (sessionRoundTripSucceeded && sessionId != null)
-	  return `/posts/new?session_id=${ sessionId }`
-	return null
-      }) ()
-      if (nextPath == null)
-	{
-	  showStorageError ('ブラウザへ保存できませんでした．')
-	  return
-	}
-
-      navigate (nextPath)
-    }
-    catch (error)
-    {
-      console.error (error)
-      showStorageError ('ブラウザへ保存できませんでした．')
+      navigate (buildPostNewReviewPath (sourceUrls))
     }
     finally
     {
@@ -268,8 +138,9 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
 		    className="h-80 font-mono text-sm"
 		    onBlur={() => {
 		      savePostImportSourceDraft (source, message =>
-			  toast ({ title: '入力内容を保存できませんでした',
-				   description: message }))
+			  toast ({
+			      title: '入力内容を保存できませんでした',
+			      description: message }))
 		    }}
 		    onChange={ev => {
 		      editedRef.current = true
@@ -299,7 +170,7 @@ const PostImportSourcePage: FC<Props> = ({ user }) => {
 		type="button"
 		className="pointer-events-auto shrink-0"
 		onClick={preview}
-		disabled={loading}>
+		disabled={loading || !(withinPathLimit)}>
 	      次へ
 	    </Button>
 	  </div>