fix(mods): remove pagination and fetch mods with sub fallback

Fixes #238

src/pages/mods/index.tsx

@@ -1,6 +1,5 @@
 import { ModFilter } from 'components/Filters/ModsFilter'
-import { Pagination } from 'components/Pagination'
-import React, { useCallback, useEffect, useRef, useState } from 'react'
+import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import {
   createSearchParams,
   useLoaderData,
@@ -8,7 +7,7 @@ import {
 } from 'react-router-dom'
 import { LoadingSpinner } from '../../components/LoadingSpinner'
 import { ModCard } from '../../components/ModCard'
-import { MOD_FILTER_LIMIT } from '../../constants'
+import { MOD_FILTER_LIMIT, T_TAG_VALUE } from '../../constants'
 import {
   useAppSelector,
   useFilteredMods,
@@ -20,77 +19,156 @@ import '../../styles/filters.css'
 import '../../styles/pagination.css'
 import '../../styles/search.css'
 import '../../styles/styles.css'
-import { FilterOptions, ModDetails } from '../../types'
-import { DEFAULT_FILTER_OPTIONS, scrollIntoView } from 'utils'
+import { FilterOptions, ModDetails, SortBy } from '../../types'
+import {
+  DEFAULT_FILTER_OPTIONS,
+  extractModData,
+  isModDataComplete
+} from 'utils'
 import { SearchInput } from 'components/SearchInput'
 import { ModsPageLoaderResult } from './loader'
+import { FetchModsOptions } from 'contexts/NDKContext'
+import {
+  NDKFilter,
+  NDKKind,
+  NDKSubscription,
+  NDKSubscriptionCacheUsage
+} from '@nostr-dev-kit/ndk'
 
 export const ModsPage = () => {
   const scrollTargetRef = useRef<HTMLDivElement>(null)
   const { repostList, muteLists, nsfwList } =
     useLoaderData() as ModsPageLoaderResult
-  const { fetchMods } = useNDKContext()
+  const { ndk, fetchMods } = useNDKContext()
   const [isFetching, setIsFetching] = useState(false)
   const [mods, setMods] = useState<ModDetails[]>([])
-
+  const [isLoadMoreVisible, setIsLoadMoreVisible] = useState(true)
   const [filterOptions] = useLocalStorage<FilterOptions>(
     'filter',
     DEFAULT_FILTER_OPTIONS
   )
 
-  const [page, setPage] = useState(1)
-
   const userState = useAppSelector((state) => state.user)
 
   useEffect(() => {
     setIsFetching(true)
     fetchMods({ source: filterOptions.source })
       .then((res) => {
-        setMods(res)
+        if (filterOptions.sort === SortBy.Latest) {
+          res.sort((a, b) => b.published_at - a.published_at)
+        } else if (filterOptions.sort === SortBy.Oldest) {
+          res.sort((a, b) => a.published_at - b.published_at)
+        }
+        setIsLoadMoreVisible(res.length >= MOD_FILTER_LIMIT)
+        setMods(res.slice(0, MOD_FILTER_LIMIT))
       })
       .finally(() => {
         setIsFetching(false)
       })
-  }, [filterOptions.source, fetchMods])
+  }, [filterOptions.source, fetchMods, filterOptions.sort])
 
-  const handleNext = useCallback(() => {
+  const lastMod: ModDetails | undefined = useMemo(() => {
+    // For the latest sort find oldest mod
+    // for the oldest sort find newest mod
+    return mods.reduce((prev, current) => {
+      if (!prev) return current
+      if (filterOptions.sort === SortBy.Latest) {
+        return current.edited_at < prev.edited_at ? current : prev
+      } else if (filterOptions.sort === SortBy.Oldest) {
+        return current.edited_at > prev.edited_at ? current : prev
+      }
+      return prev
+    }, undefined as ModDetails | undefined)
+  }, [mods, filterOptions.sort])
+
+  // Add missing mods to the list
+  useEffect(() => {
+    let sub: NDKSubscription
+    if (lastMod) {
+      const filter: NDKFilter = {
+        kinds: [NDKKind.Classified],
+        '#t': [T_TAG_VALUE]
+      }
+      if (filterOptions.sort === SortBy.Latest) {
+        filter.since = lastMod.edited_at + 1
+      } else if (filterOptions.sort === SortBy.Oldest) {
+        filter.until = lastMod.edited_at - 1
+      }
+      if (filterOptions.source === window.location.host) {
+        filter['#r'] = [window.location.host]
+      }
+      sub = ndk.subscribe(
+        filter,
+        {
+          closeOnEose: false,
+          cacheUsage: NDKSubscriptionCacheUsage.PARALLEL
+        },
+        undefined,
+        {
+          onEvent: (ndkEvent) => {
+            setMods((prevMods) => {
+              // Skip if not valid
+              if (!isModDataComplete(ndkEvent)) {
+                return prevMods
+              }
+
+              // Skip existing
+              if (
+                prevMods.find(
+                  (e) =>
+                    e.id === ndkEvent.id ||
+                    prevMods.findIndex((n) => n.id === ndkEvent.id) !== -1
+                )
+              ) {
+                return prevMods
+              }
+              const newMod = extractModData(ndkEvent)
+              return [...prevMods, newMod]
+            })
+          }
+        }
+      )
+    }
+    return () => {
+      if (sub) sub.stop()
+    }
+  }, [filterOptions.sort, filterOptions.source, lastMod, ndk])
+
+  const handleLoadMore = useCallback(() => {
     setIsFetching(true)
 
-    const until =
-      mods.length > 0 ? mods[mods.length - 1].published_at - 1 : undefined
+    const fetchModsOptions: FetchModsOptions = {
+      source: filterOptions.source
+    }
 
-    fetchMods({
-      source: filterOptions.source,
-      until
-    })
+    if (lastMod) {
+      if (filterOptions.sort === SortBy.Latest) {
+        fetchModsOptions.until = lastMod.edited_at - 1
+      } else if (filterOptions.sort === SortBy.Oldest) {
+        fetchModsOptions.since = lastMod.edited_at + 1
+      }
+    }
+
+    fetchMods(fetchModsOptions)
       .then((res) => {
-        setMods(res)
-        setPage((prev) => prev + 1)
-        scrollIntoView(scrollTargetRef.current)
+        setMods((prevMods) => {
+          const newMods = res
+          const combinedMods = [...prevMods, ...newMods]
+          const uniqueMods = Array.from(
+            new Set(combinedMods.map((mod) => mod.id))
+          )
+            .map((id) => combinedMods.find((mod) => mod.id === id))
+            .filter((mod): mod is ModDetails => mod !== undefined)
+
+          setIsLoadMoreVisible(newMods.length >= MOD_FILTER_LIMIT)
+
+          return uniqueMods
+        })
       })
       .finally(() => {
         setIsFetching(false)
       })
-  }, [filterOptions.source, mods, fetchMods])
-
-  const handlePrev = useCallback(() => {
-    setIsFetching(true)
-
-    const since = mods.length > 0 ? mods[0].published_at + 1 : undefined
-
-    fetchMods({
-      source: filterOptions.source,
-      since
-    })
-      .then((res) => {
-        setMods(res)
-        setPage((prev) => prev - 1)
-        scrollIntoView(scrollTargetRef.current)
-      })
-      .finally(() => {
-        setIsFetching(false)
-      })
-  }, [filterOptions.source, mods, fetchMods])
+  }, [fetchMods, filterOptions, lastMod])
 
   const filteredModList = useFilteredMods(
     mods,
@@ -121,12 +199,17 @@ export const ModsPage = () => {
               </div>
             </div>
 
-            <Pagination
-              page={page}
-              disabledNext={mods.length < MOD_FILTER_LIMIT}
-              handlePrev={handlePrev}
-              handleNext={handleNext}
-            />
+            {!isFetching && isLoadMoreVisible && filteredModList.length > 0 && (
+              <div className='IBMSMListFeedLoadMore'>
+                <button
+                  className='btn btnMain IBMSMListFeedLoadMoreBtn'
+                  type='button'
+                  onClick={handleLoadMore}
+                >
+                  Load More
+                </button>
+              </div>
+            )}
           </div>
         </div>
       </div>