init

frontend/src/pages/server/channel/index.vue

@@ -1,7 +1,6 @@
 <script lang="ts" setup>
 import 'highlight.js/styles/github-dark.css'
-import {computed, nextTick, onMounted, ref, watch} from 'vue';
-import {useRoute} from 'vue-router';
+import {computed, nextTick, ref, watch} from 'vue';
 import {storeToRefs} from 'pinia';
 import {useMessageStore} from '@/stores/message';
 import {useUserStore} from "@/stores/user.ts";
@@ -13,25 +12,129 @@ const props = defineProps<{
 }>();
 
 const channelId = computed(() => props.channelId);
-
-const route = useRoute();
 const messageStore = useMessageStore();
 const userStore = useUserStore();
 const {renderMarkdown} = useMarkdown()
 
-// Référence vers l'élément scrollable
 const messageContainer = ref<HTMLElement | null>(null);
-
-// "messages" ici est une référence réactive liée au store
-const {messages, loading} = storeToRefs(messageStore);
-
+const {messages, loading, loadingBefore, loadingAfter} = storeToRefs(messageStore);
 const newMessage = ref('');
 
+const SCROLL_LOAD_THRESHOLD = 120;
+const SCROLL_BOTTOM_TOLERANCE = 4;
+const paginationLock = ref<'before' | 'after' | null>(null);
+const paginationLockScrollTop = ref(0);
+const lastScrollTop = ref(0);
+
+interface ScrollAnchor {
+  id: string;
+  top: number;
+}
 
 const scrollToBottom = async () => {
   await nextTick();
   if (messageContainer.value) {
     messageContainer.value.scrollTop = messageContainer.value.scrollHeight;
+    messageStore.setAtBottom(true);
+  }
+};
+
+const getMessageElements = () => Array.from(
+  messageContainer.value?.querySelectorAll<HTMLElement>('[data-message-id]') ?? [],
+);
+
+const captureAnchor = (edge: 'top' | 'bottom'): ScrollAnchor | null => {
+  const container = messageContainer.value;
+  if (!container) return null;
+
+  const containerRect = container.getBoundingClientRect();
+  const visible = getMessageElements().filter(element => {
+    const rect = element.getBoundingClientRect();
+    return rect.bottom > containerRect.top && rect.top < containerRect.bottom;
+  });
+  const element = edge === 'top' ? visible[0] : visible[visible.length - 1];
+  if (!element?.dataset.messageId) return null;
+
+  return {
+    id: element.dataset.messageId,
+    top: element.getBoundingClientRect().top,
+  };
+};
+
+const restoreAnchor = async (anchor: ScrollAnchor | null) => {
+  if (!anchor || !messageContainer.value) return;
+  await nextTick();
+
+  const element = getMessageElements().find(item => item.dataset.messageId === anchor.id);
+  if (element) {
+    messageContainer.value.scrollTop += element.getBoundingClientRect().top - anchor.top;
+  }
+};
+
+const updateScrollState = () => {
+  const container = messageContainer.value;
+  if (!container) return;
+
+  const distanceFromBottom = container.scrollHeight - container.scrollTop - container.clientHeight;
+  messageStore.setAtBottom(distanceFromBottom <= SCROLL_BOTTOM_TOLERANCE);
+};
+
+const setPaginationLock = (direction: 'before' | 'after') => {
+  if (!messageContainer.value) return;
+  paginationLock.value = direction;
+  paginationLockScrollTop.value = messageContainer.value.scrollTop;
+  lastScrollTop.value = messageContainer.value.scrollTop;
+};
+
+const loadBefore = async () => {
+  const anchor = captureAnchor('top');
+  const change = await messageStore.fetchBefore(channelId.value);
+  if (change) {
+    await restoreAnchor(anchor);
+    setPaginationLock('before');
+  }
+};
+
+const loadAfter = async () => {
+  const anchor = captureAnchor('bottom');
+  const change = await messageStore.fetchAfter(channelId.value);
+  if (change) {
+    await restoreAnchor(anchor);
+    setPaginationLock('after');
+  }
+};
+
+const handleScroll = async () => {
+  const container = messageContainer.value;
+  if (!container) return;
+
+  const currentScrollTop = container.scrollTop;
+  const scrollDelta = currentScrollTop - lastScrollTop.value;
+  lastScrollTop.value = currentScrollTop;
+
+  if (paginationLock.value === 'after') {
+    if (scrollDelta < -1 || currentScrollTop > paginationLockScrollTop.value + 2) {
+      paginationLock.value = null;
+    } else {
+      return;
+    }
+  } else if (paginationLock.value === 'before') {
+    if (scrollDelta > 1 || currentScrollTop < paginationLockScrollTop.value - 2) {
+      paginationLock.value = null;
+    } else {
+      return;
+    }
+  }
+
+  updateScrollState();
+
+  if (container.scrollTop <= SCROLL_LOAD_THRESHOLD && !loadingBefore.value) {
+    await loadBefore();
+  } else {
+    const distanceFromBottom = container.scrollHeight - container.scrollTop - container.clientHeight;
+    if (distanceFromBottom <= SCROLL_LOAD_THRESHOLD && !loadingAfter.value) {
+      await loadAfter();
+    }
   }
 };
 
@@ -39,47 +142,53 @@ const sendMessage = async () => {
   if (!newMessage.value.trim()) return;
 
   const content = newMessage.value;
+  const wasAtBottom = messageStore.isAtBottom;
 
   try {
     await messageStore.sendMessage(channelId.value, content);
-    newMessage.value = ''; // On vide le champ après succès
-    await scrollToBottom();
+    newMessage.value = '';
+    if (wasAtBottom) await scrollToBottom();
   } catch (e) {
-    // Gérer l'erreur (ex: notification toast)
+    console.error('Erreur lors de l\'envoi du message:', e);
   }
 };
 
-onMounted(() => {
-  if (channelId.value) {
-    messageStore.fetchMessages(channelId.value);
+// Only explicit initial loads and realtime messages received while at the
+// bottom request an automatic scroll. Pagination restores its own anchor.
+watch(messages, async () => {
+  if (messageStore.consumeScrollToBottomRequest()) {
+    await scrollToBottom();
   }
-});
+}, {deep: true, flush: 'post'});
 
-watch(channelId, (newChannelId) => {
+watch(channelId, async (newChannelId) => {
   if (newChannelId) {
-    messageStore.fetchMessages(newChannelId);
+    await messageStore.fetchMessages(newChannelId);
   }
 }, {immediate: true})
-
-// Scroll automatique quand la liste des messages change (nouveaux messages reçus)
-watch(messages, () => {
-  scrollToBottom();
-}, {deep: true});
 </script>
 
 <template>
-  <!-- Conteneur principal prenant toute la hauteur -->
   <v-container class="pa-0 fill-height d-flex flex-column" fluid>
-
-    <!-- Zone des messages (scrollable) -->
     <div
       ref="messageContainer"
       class="flex-grow-1 overflow-y-auto w-100 message-container"
+      @scroll.passive="handleScroll"
     >
+      <v-progress-linear v-if="loadingBefore" color="primary" indeterminate />
+
+      <v-progress-circular
+        v-if="loading && !messages.length"
+        class="d-block mx-auto mt-4"
+        color="primary"
+        indeterminate
+      />
+
       <v-list bg-color="transparent" lines="three">
         <v-list-item
           v-for="msg in messages"
           :key="msg.id"
+          :data-message-id="msg.id"
           class="px-4 py-1"
         >
           <template v-slot:prepend>
@@ -98,9 +207,10 @@ watch(messages, () => {
           </div>
         </v-list-item>
       </v-list>
+
+      <v-progress-linear v-if="loadingAfter" color="primary" indeterminate />
     </div>
 
-    <!-- Zone de saisie fixe en bas -->
     <v-sheet class="pa-4 flex-shrink-0" width="100%">
       <v-textarea
         v-model="newMessage"
@@ -126,13 +236,11 @@ watch(messages, () => {
         </template>
       </v-textarea>
     </v-sheet>
-
   </v-container>
 </template>
 
 <style scoped>
 .message-container {
-  /* Assure que la zone gère son scroll indépendamment */
   height: 0;
 }
 
@@ -155,4 +263,4 @@ watch(messages, () => {
   margin: 8px 0;
   overflow-x: auto;
 }
-</style>
+</style>

frontend/src/stores/message.ts

@@ -2,7 +2,12 @@ import {defineStore} from "pinia";
 import {useApi} from "@/composables/useApi.ts";
 import {onGatewayEvent} from "@/plugins/events.ts";
 
-interface Message {
+// Change this value to adjust the maximum number of messages kept in the DOM.
+// Directional loads automatically use half of this window.
+export const MESSAGE_WINDOW_SIZE = 50;
+export const MESSAGE_SHIFT_SIZE = Math.max(1, Math.floor(MESSAGE_WINDOW_SIZE / 2));
+
+export interface Message {
   id: string;
   channel_id: string;
   user_id: string;
@@ -12,78 +17,289 @@ interface Message {
   reply_to_id: string | null;
 }
 
+interface MessagePage {
+  messages: Message[];
+  oldest_id: string | null;
+  newest_id: string | null;
+  has_more_before: boolean;
+  has_more_after: boolean;
+}
+
+interface WindowChange {
+  addedIds: string[];
+  removedIds: string[];
+}
+
+function compareMessages(left: Message, right: Message): number {
+  if (left.id < right.id) return -1;
+  if (left.id > right.id) return 1;
+  return 0;
+}
+
+function mergeMessages(messages: Message[]): Message[] {
+  const byId = new Map<string, Message>();
+  for (const message of messages) {
+    byId.set(message.id, message);
+  }
+  return Array.from(byId.values()).sort(compareMessages);
+}
+
+async function requestPage(
+  channelId: string,
+  params: { limit: number; before_id?: string; after_id?: string },
+): Promise<MessagePage> {
+  const query = new URLSearchParams({
+    channel_id: channelId,
+    limit: String(params.limit),
+  });
+
+  if (params.before_id) query.set("before_id", params.before_id);
+  if (params.after_id) query.set("after_id", params.after_id);
+
+  const response = await useApi().get(`/messages?${query.toString()}`);
+  if (!response.ok) {
+    throw new Error(`Message loading failed (${response.status})`);
+  }
+
+  return response.json() as Promise<MessagePage>;
+}
+
 export const useMessageStore = defineStore("message", {
   state: () => ({
     messages: [] as Message[],
+    activeChannelId: null as string | null,
+    oldestId: null as string | null,
+    newestId: null as string | null,
+    hasMoreBefore: false,
+    hasMoreAfter: false,
     loading: false,
+    loadingBefore: false,
+    loadingAfter: false,
+    isAtBottom: true,
+    scrollToBottomRequested: false,
+    requestVersion: 0,
   }),
+
   actions: {
-    async fetchMessages(channel_id: string) {
+    updateBoundaries(page: MessagePage) {
+      this.oldestId = page.oldest_id ?? this.messages[0]?.id ?? null;
+      this.newestId = page.newest_id ?? this.messages[this.messages.length - 1]?.id ?? null;
+      this.hasMoreBefore = page.has_more_before;
+      this.hasMoreAfter = page.has_more_after;
+    },
+
+    updateLocalBoundaries() {
+      this.oldestId = this.messages[0]?.id ?? null;
+      this.newestId = this.messages[this.messages.length - 1]?.id ?? null;
+    },
+
+    async fetchMessages(channelId: string) {
+      const requestVersion = ++this.requestVersion;
+      this.activeChannelId = channelId;
+      this.messages = [];
+      this.oldestId = null;
+      this.newestId = null;
+      this.hasMoreBefore = false;
+      this.hasMoreAfter = false;
+      this.isAtBottom = true;
       this.loading = true;
 
-      // Query params
-      let params = new URLSearchParams();
-      params.append("channel_id", channel_id);
-      const queryString = params.toString();
-
       try {
-        const api = useApi();
-        // Utilisation du paramètre pour cibler le channel
-        const response = await api.get(`/messages${queryString ? `?${queryString}` : ""}`);
-        this.messages = await response.json();
+        const page = await requestPage(channelId, {limit: MESSAGE_WINDOW_SIZE});
+        if (requestVersion !== this.requestVersion || this.activeChannelId !== channelId) return;
+
+        this.messages = mergeMessages(page.messages).slice(-MESSAGE_WINDOW_SIZE);
+        this.updateBoundaries(page);
+        this.scrollToBottomRequested = true;
       } catch (error) {
-        console.error("Erreur lors du chargement des messages:", error);
+        if (requestVersion === this.requestVersion) {
+          console.error("Erreur lors du chargement des messages:", error);
+        }
       } finally {
-        this.loading = false;
+        if (requestVersion === this.requestVersion) {
+          this.loading = false;
+        }
       }
     },
-    async sendMessage(channelId: string, content: string) {
-      const api = useApi();
-      console.log("channelId", channelId);
-      try {
-        // Envoi au serveur pour persistance
-        const response = await api.post('/messages', {
-          channel_id: channelId,
-          content: content,
-          reply_to_id: null
-        });
-        const newMessage = await response.json();
 
-        // Ajout local immédiat (optimistic update)
-        // this.messages.push(newMessage);
+    async fetchBefore(channelId: string): Promise<WindowChange | null> {
+      if (
+        this.activeChannelId !== channelId ||
+        !this.oldestId ||
+        !this.hasMoreBefore ||
+        this.loadingBefore ||
+        this.loadingAfter
+      ) return null;
+
+      const requestVersion = this.requestVersion;
+      const previousIds = new Set(this.messages.map(message => message.id));
+      this.loadingBefore = true;
+
+      try {
+        const page = await requestPage(channelId, {
+          limit: MESSAGE_SHIFT_SIZE,
+          before_id: this.oldestId,
+        });
+        if (requestVersion !== this.requestVersion || this.activeChannelId !== channelId) return null;
+
+        const incoming = mergeMessages(page.messages);
+        const merged = mergeMessages([...incoming, ...this.messages]);
+        this.messages = merged.slice(0, MESSAGE_WINDOW_SIZE);
+        this.updateBoundaries(page);
+        this.oldestId = this.messages[0]?.id ?? null;
+        this.newestId = this.messages[this.messages.length - 1]?.id ?? null;
+
+        return {
+          addedIds: incoming.filter(message => !previousIds.has(message.id)).map(message => message.id),
+          removedIds: merged.slice(0, -MESSAGE_WINDOW_SIZE).map(message => message.id),
+        };
+      } catch (error) {
+        console.error("Erreur lors du chargement des messages précédents:", error);
+        return null;
+      } finally {
+        if (requestVersion === this.requestVersion) {
+          this.loadingBefore = false;
+        }
+      }
+    },
+
+    async fetchAfter(channelId: string): Promise<WindowChange | null> {
+      if (
+        this.activeChannelId !== channelId ||
+        !this.newestId ||
+        !this.hasMoreAfter ||
+        this.loadingBefore ||
+        this.loadingAfter
+      ) return null;
+
+      const requestVersion = this.requestVersion;
+      const previousIds = new Set(this.messages.map(message => message.id));
+      this.loadingAfter = true;
+
+      try {
+        const page = await requestPage(channelId, {
+          limit: MESSAGE_SHIFT_SIZE,
+          after_id: this.newestId,
+        });
+        if (requestVersion !== this.requestVersion || this.activeChannelId !== channelId) return null;
+
+        const incoming = mergeMessages(page.messages);
+        const merged = mergeMessages([...this.messages, ...incoming]);
+        this.messages = merged.slice(-MESSAGE_WINDOW_SIZE);
+        this.updateBoundaries(page);
+        this.oldestId = this.messages[0]?.id ?? null;
+        this.newestId = this.messages[this.messages.length - 1]?.id ?? null;
+
+        return {
+          addedIds: incoming.filter(message => !previousIds.has(message.id)).map(message => message.id),
+          removedIds: merged.slice(0, Math.max(0, merged.length - MESSAGE_WINDOW_SIZE)).map(message => message.id),
+        };
+      } catch (error) {
+        console.error("Erreur lors du chargement des messages suivants:", error);
+        return null;
+      } finally {
+        if (requestVersion === this.requestVersion) {
+          this.loadingAfter = false;
+        }
+      }
+    },
+
+    async sendMessage(channelId: string, content: string) {
+      try {
+        const response = await useApi().post("/messages", {
+          channel_id: channelId,
+          content,
+          reply_to_id: null,
+        });
+        if (!response.ok) {
+          throw new Error(`Message sending failed (${response.status})`);
+        }
+
+        const newMessage = await response.json() as Message;
+        this.addRealtimeMessage(newMessage);
+        return newMessage;
       } catch (error) {
         console.error("Erreur lors de l'envoi du message:", error);
         throw error;
       }
     },
+
+    addRealtimeMessage(message: Message) {
+      if (message.channel_id !== this.activeChannelId) return;
+
+      const existingIndex = this.messages.findIndex(current => current.id === message.id);
+      if (existingIndex !== -1) {
+        this.messages[existingIndex] = message;
+        return;
+      }
+
+      if (!this.isAtBottom && this.newestId && message.id > this.newestId) {
+        this.hasMoreAfter = true;
+        return;
+      }
+
+      this.messages = mergeMessages([...this.messages, message]).slice(-MESSAGE_WINDOW_SIZE);
+      this.updateLocalBoundaries();
+      this.hasMoreAfter = false;
+      if (this.isAtBottom) {
+        this.scrollToBottomRequested = true;
+      }
+    },
+
+    updateMessage(message: Message) {
+      if (message.channel_id !== this.activeChannelId) return;
+      const index = this.messages.findIndex(current => current.id === message.id);
+      if (index !== -1) this.messages[index] = message;
+    },
+
+    removeMessage(id: string) {
+      const index = this.messages.findIndex(message => message.id === id);
+      if (index === -1) return;
+      this.messages.splice(index, 1);
+      this.updateLocalBoundaries();
+    },
+
+    setAtBottom(value: boolean) {
+      this.isAtBottom = value;
+    },
+
+    consumeScrollToBottomRequest() {
+      const requested = this.scrollToBottomRequested;
+      this.scrollToBottomRequested = false;
+      return requested;
+    },
+
     reset() {
+      this.requestVersion += 1;
       this.messages = [];
-    }
-  }
+      this.activeChannelId = null;
+      this.oldestId = null;
+      this.newestId = null;
+      this.hasMoreBefore = false;
+      this.hasMoreAfter = false;
+      this.loading = false;
+      this.loadingBefore = false;
+      this.loadingAfter = false;
+      this.isAtBottom = true;
+      this.scrollToBottomRequested = false;
+    },
+  },
 });
 
 onGatewayEvent("Message", (payload) => {
   const store = useMessageStore();
+
   switch (payload.action) {
     case "add":
-      const exists = store.messages.some(m => m.id === payload.content.id);
-      if (!exists) {
-        store.messages.push(payload.content);
-      }
+      store.addRealtimeMessage(payload.content as Message);
       break;
     case "update":
-      const updateIndex = store.messages.findIndex(m => m.id === payload.content.id);
-      if (updateIndex !== -1) {
-        store.messages[updateIndex] = payload.content;
-      }
+      store.updateMessage(payload.content as Message);
       break;
     case "remove":
-      const removeIndex = store.messages.findIndex(m => m.id === payload.content);
-      if (removeIndex !== -1) {
-        store.messages.splice(removeIndex, 1);
-      }
+      store.removeMessage(String(payload.content));
       break;
     default:
       console.warn("Action non gérée :", payload.action);
   }
-})
+});

migration/src/lib.rs

@@ -1,12 +1,16 @@
-pub use sea_orm_migration::prelude::*;
-
-mod m20220101_000001_create_table;
-
-pub struct Migrator;
-
-#[async_trait::async_trait]
-impl MigratorTrait for Migrator {
-    fn migrations() -> Vec<Box<dyn MigrationTrait>> {
-        vec![Box::new(m20220101_000001_create_table::Migration)]
-    }
-}
+pub use sea_orm_migration::prelude::*;
+
+mod m20220101_000001_create_table;
+mod m20260808_000002_add_message_channel_id_id_index;
+
+pub struct Migrator;
+
+#[async_trait::async_trait]
+impl MigratorTrait for Migrator {
+    fn migrations() -> Vec<Box<dyn MigrationTrait>> {
+        vec![
+            Box::new(m20220101_000001_create_table::Migration),
+            Box::new(m20260808_000002_add_message_channel_id_id_index::Migration),
+        ]
+    }
+}

migration/src/m20260808_000002_add_message_channel_id_id_index.rs

@@ -0,0 +1,31 @@
+use sea_orm_migration::prelude::*;
+
+#[derive(DeriveMigrationName)]
+pub struct Migration;
+
+#[async_trait::async_trait]
+impl MigrationTrait for Migration {
+    async fn up(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .create_index(
+                Index::create()
+                    .name("idx_message_channel_id_id")
+                    .table(Alias::new("message"))
+                    .col(Alias::new("channel_id"))
+                    .col(Alias::new("id"))
+                    .to_owned(),
+            )
+            .await
+    }
+
+    async fn down(&self, manager: &SchemaManager) -> Result<(), DbErr> {
+        manager
+            .drop_index(
+                Index::drop()
+                    .name("idx_message_channel_id_id")
+                    .table(Alias::new("message"))
+                    .to_owned(),
+            )
+            .await
+    }
+}

scripts/generate_messages.py

@@ -0,0 +1,215 @@
+#!/usr/bin/env python3
+"""Generate test messages directly in the project's SQLite database."""
+
+from __future__ import annotations
+
+import argparse
+import random
+import sqlite3
+import time
+import uuid
+from datetime import datetime, timezone
+from pathlib import Path
+
+
+WORD_POOL = (
+    "message", "canal", "serveur", "utilisateur", "test", "donnee", "histoire",
+    "discussion", "contenu", "generation", "curseur", "fenetre", "lecture",
+    "chargement", "conversation", "exemple", "texte", "systeme", "application",
+    "client", "serveur", "base", "requete", "resultat", "information", "session",
+    "connexion", "fonction", "version", "contenu", "rapide", "simple", "aleatoire",
+    "important", "nouveau", "ancien", "prochain", "precedent", "visible", "local",
+    "distant", "stable", "chronologique", "variable", "longueur", "performance",
+    "validation", "operation", "transaction", "historique", "position", "defilement",
+)
+MESSAGE_MARKER_FORMAT = "[{number:04d}]"
+
+
+def positive_int(value: str) -> int:
+    parsed = int(value)
+    if parsed <= 0:
+        raise argparse.ArgumentTypeError("must be greater than zero")
+    return parsed
+
+
+def parse_uuid(value: str, option_name: str) -> uuid.UUID:
+    try:
+        return uuid.UUID(value)
+    except ValueError as error:
+        raise argparse.ArgumentTypeError(f"{option_name} is not a valid UUID: {value}") from error
+
+
+def next_uuid(previous: uuid.UUID | None) -> uuid.UUID:
+    """Return a UUID v7 strictly greater than the previous generated ID."""
+    generated = uuid.uuid7()
+    if previous is not None and generated.int <= previous.int:
+        generated = uuid.UUID(int=previous.int + 1)
+    return generated
+
+
+def random_message(
+    rng: random.Random,
+    min_words: int,
+    max_words: int,
+    marker: str,
+) -> str:
+    # The marker itself counts as one word in the requested range.
+    body_count = rng.randint(max(0, min_words - 1), max_words - 1)
+    body = " ".join(rng.choices(WORD_POOL, k=body_count))
+    return f"{marker} {body}".rstrip()
+
+
+def build_parser() -> argparse.ArgumentParser:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        "--db",
+        type=Path,
+        default=Path("oxspeak.db"),
+        help="SQLite database path (default: oxspeak.db)",
+    )
+    parser.add_argument("--channel-id", required=True, help="target channel UUID")
+    parser.add_argument("--user-id", required=True, help="author user UUID")
+    parser.add_argument(
+        "--count",
+        required=True,
+        type=positive_int,
+        help="number of messages to insert",
+    )
+    parser.add_argument(
+        "--min-words",
+        type=positive_int,
+        default=10,
+        help="minimum number of words per message (default: 10)",
+    )
+    parser.add_argument(
+        "--max-words",
+        type=positive_int,
+        default=500,
+        help="maximum number of words per message (default: 500)",
+    )
+    parser.add_argument(
+        "--seed",
+        type=int,
+        default=None,
+        help="optional seed to reproduce generated contents",
+    )
+    parser.add_argument(
+        "--batch-size",
+        type=positive_int,
+        default=500,
+        help="number of rows inserted per batch (default: 500)",
+    )
+    return parser
+
+
+def ensure_target_exists(
+    connection: sqlite3.Connection,
+    table: str,
+    identifier: bytes,
+    label: str,
+) -> None:
+    row = connection.execute(
+        f'SELECT 1 FROM "{table}" WHERE id = ? LIMIT 1',
+        (identifier,),
+    ).fetchone()
+    if row is None:
+        raise ValueError(f"{label} does not exist in the database")
+
+
+def generate_messages(
+    database: Path,
+    channel_id: uuid.UUID,
+    user_id: uuid.UUID,
+    count: int,
+    batch_size: int,
+    min_words: int,
+    max_words: int,
+    seed: int | None,
+) -> None:
+    started_at = time.monotonic()
+    connection = sqlite3.connect(database)
+    connection.execute("PRAGMA foreign_keys = ON")
+    connection.execute("PRAGMA busy_timeout = 5000")
+
+    try:
+        ensure_target_exists(connection, "channel", channel_id.bytes, "channel")
+        ensure_target_exists(connection, "user", user_id.bytes, "user")
+
+        previous_id: uuid.UUID | None = None
+        inserted = 0
+        rng = random.Random(seed)
+
+        connection.execute("BEGIN")
+        try:
+            while inserted < count:
+                current_batch_size = min(batch_size, count - inserted)
+                rows = []
+
+                for offset in range(current_batch_size):
+                    message_id = next_uuid(previous_id)
+                    previous_id = message_id
+                    message_number = inserted + offset + 1
+                    marker = MESSAGE_MARKER_FORMAT.format(number=message_number)
+                    content = random_message(rng, min_words, max_words, marker)
+                    created_at = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M:%S")
+                    rows.append(
+                        (
+                            message_id.bytes,
+                            channel_id.bytes,
+                            user_id.bytes,
+                            content,
+                            created_at,
+                            None,
+                            None,
+                        )
+                    )
+
+                connection.executemany(
+                    """
+                    INSERT INTO message
+                        (id, channel_id, user_id, content, created_at, updated_at, reply_to_id)
+                    VALUES (?, ?, ?, ?, ?, ?, ?)
+                    """,
+                    rows,
+                )
+                inserted += current_batch_size
+
+            connection.commit()
+        except Exception:
+            connection.rollback()
+            raise
+    finally:
+        connection.close()
+
+    elapsed = time.monotonic() - started_at
+    print(f"Inserted {count} messages into {database} in {elapsed:.2f}s")
+
+
+def main() -> int:
+    parser = build_parser()
+    args = parser.parse_args()
+
+    if args.max_words < args.min_words:
+        parser.error("--max-words must be greater than or equal to --min-words")
+
+    try:
+        channel_id = parse_uuid(args.channel_id, "--channel-id")
+        user_id = parse_uuid(args.user_id, "--user-id")
+        generate_messages(
+            database=args.db,
+            channel_id=channel_id,
+            user_id=user_id,
+            count=args.count,
+            batch_size=args.batch_size,
+            min_words=args.min_words,
+            max_words=args.max_words,
+            seed=args.seed,
+        )
+    except (OSError, sqlite3.Error, ValueError) as error:
+        parser.error(str(error))
+
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

src/domain/dto/message.rs

@@ -14,6 +14,15 @@ pub struct MessageResponse {
     pub reply_to_id: Option<Uuid>,
 }
 
+#[derive(Debug, Serialize, ToSchema)]
+pub struct MessagePageResponse {
+    pub messages: Vec<MessageResponse>,
+    pub oldest_id: Option<Uuid>,
+    pub newest_id: Option<Uuid>,
+    pub has_more_before: bool,
+    pub has_more_after: bool,
+}
+
 #[derive(Debug, Serialize, Deserialize, ToSchema)]
 pub struct CreateMessageRequest {
     pub channel_id: Uuid,
@@ -26,19 +35,10 @@ pub struct UpdateMessageRequest {
     pub content: String,
 }
 
-#[derive(serde::Deserialize, utoipa::IntoParams)]
+#[derive(Debug, serde::Deserialize, utoipa::IntoParams)]
 pub struct MessageQueryParams {
-    pub channel_id: Option<uuid::Uuid>,
+    pub channel_id: Uuid,
     pub before_id: Option<Uuid>,
+    pub after_id: Option<Uuid>,
     pub limit: Option<u64>,
 }
-
-impl Default for MessageQueryParams {
-    fn default() -> Self {
-        Self {
-            channel_id: None,
-            before_id: None,
-            limit: Some(50),
-        }
-    }
-}

src/models/mod.rs

@@ -1,20 +1,20 @@
-//! `SeaORM` Entity, @generated by sea-orm-codegen 1.1.19
-
-pub mod prelude;
-
-pub mod attachment;
-pub mod category;
-pub mod channel;
-pub mod channel_role_permission;
-pub mod channel_user;
-pub mod channel_user_permission;
-pub mod computed_permission;
-pub mod message;
-pub mod role;
-pub mod role_user;
-pub mod server;
-pub mod server_item_order;
-pub mod server_role_permission;
-pub mod server_user;
-pub mod server_user_permission;
-pub mod user;
+//! `SeaORM` Entity, @generated by sea-orm-codegen 1.1.19
+
+pub mod prelude;
+
+pub mod attachment;
+pub mod category;
+pub mod channel;
+pub mod channel_role_permission;
+pub mod channel_user;
+pub mod channel_user_permission;
+pub mod computed_permission;
+pub mod message;
+pub mod role;
+pub mod role_user;
+pub mod server;
+pub mod server_item_order;
+pub mod server_role_permission;
+pub mod server_user;
+pub mod server_user_permission;
+pub mod user;

src/models/prelude.rs

@@ -1,16 +1,16 @@
-//! `SeaORM` Entity, @generated by sea-orm-codegen 1.1.19
-
-pub use super::attachment::Entity as Attachment;
-pub use super::category::Entity as Category;
-pub use super::channel::Entity as Channel;
-pub use super::channel_user::Entity as ChannelUser;
-pub use super::computed_permission::Entity as ComputedPermission;
-pub use super::message::Entity as Message;
-pub use super::role::Entity as Group;
-pub use super::role_user::Entity as GroupMember;
-pub use super::server::Entity as Server;
-pub use super::server_item_order::Entity as ServerItemOrder;
-pub use super::server_role_permission::Entity as ServerRolePermission;
-pub use super::server_user::Entity as ServerUser;
-pub use super::server_user_permission::Entity as ServerUserPermission;
-pub use super::user::Entity as User;
+//! `SeaORM` Entity, @generated by sea-orm-codegen 1.1.19
+
+pub use super::attachment::Entity as Attachment;
+pub use super::category::Entity as Category;
+pub use super::channel::Entity as Channel;
+pub use super::channel_user::Entity as ChannelUser;
+pub use super::computed_permission::Entity as ComputedPermission;
+pub use super::message::Entity as Message;
+pub use super::role::Entity as Group;
+pub use super::role_user::Entity as GroupMember;
+pub use super::server::Entity as Server;
+pub use super::server_item_order::Entity as ServerItemOrder;
+pub use super::server_role_permission::Entity as ServerRolePermission;
+pub use super::server_user::Entity as ServerUser;
+pub use super::server_user_permission::Entity as ServerUserPermission;
+pub use super::user::Entity as User;

src/repositories/message.rs

@@ -1,9 +1,18 @@
 use super::types::MessageFilter;
-use crate::models::{channel, message};
+use crate::models::message;
 use crate::repositories::{AnyResult, RepositoryContext};
-use event_bus::Scope;
 use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, QueryFilter, QueryOrder, QuerySelect};
 use std::sync::Arc;
+use uuid::Uuid;
+
+const DEFAULT_MESSAGE_LIMIT: u64 = 20;
+pub const MAX_MESSAGE_LIMIT: u64 = 100;
+
+pub struct MessagePage {
+    pub messages: Vec<message::Model>,
+    pub has_more_before: bool,
+    pub has_more_after: bool,
+}
 
 #[derive(Clone, Debug)]
 pub struct MessageRepository {
@@ -21,7 +30,11 @@ impl MessageRepository {
             .await?)
     }
 
-    pub async fn filter(&self, filter: MessageFilter) -> AnyResult<Vec<message::Model>> {
+    pub async fn filter(&self, filter: MessageFilter) -> AnyResult<MessagePage> {
+        let limit = filter
+            .limit
+            .unwrap_or(DEFAULT_MESSAGE_LIMIT)
+            .clamp(1, MAX_MESSAGE_LIMIT);
         let mut query = message::Entity::find();
 
         if let Some(channel_id) = filter.channel_id {
@@ -32,11 +45,80 @@ impl MessageRepository {
             query = query.filter(message::Column::Id.lt(before_id));
         }
 
-        if let Some(limit) = filter.limit {
-            query = query.order_by_desc(message::Column::Id).limit(limit);
+        if let Some(after_id) = filter.after_id {
+            query = query
+                .filter(message::Column::Id.gt(after_id))
+                .order_by_asc(message::Column::Id);
+        } else {
+            query = query.order_by_desc(message::Column::Id);
         }
 
-        Ok(query.all(&self.context.db).await?)
+        let mut messages = query.limit(limit + 1).all(&self.context.db).await?;
+        let has_more_in_direction = messages.len() > limit as usize;
+        messages.truncate(limit as usize);
+
+        // Queries that walk backwards are executed in descending order so the
+        // database can stop as soon as it has found the requested rows. The UI
+        // always receives chronological order.
+        if filter.after_id.is_none() {
+            messages.reverse();
+        }
+
+        let (has_more_before, has_more_after) = if filter.after_id.is_some() {
+            let has_messages_before = self
+                .exists_on_or_before(filter.channel_id, filter.after_id.unwrap())
+                .await?;
+            (has_messages_before, has_more_in_direction)
+        } else if filter.before_id.is_some() {
+            let has_messages_after = self
+                .exists_on_or_after(filter.channel_id, filter.before_id.unwrap())
+                .await?;
+            (has_more_in_direction, has_messages_after)
+        } else {
+            (has_more_in_direction, false)
+        };
+
+        Ok(MessagePage {
+            messages,
+            has_more_before,
+            has_more_after,
+        })
+    }
+
+    async fn exists_on_or_before(&self, channel_id: Option<Uuid>, id: Uuid) -> AnyResult<bool> {
+        let mut query = message::Entity::find()
+            .select_only()
+            .column(message::Column::Id)
+            .filter(message::Column::Id.lte(id));
+
+        if let Some(channel_id) = channel_id {
+            query = query.filter(message::Column::ChannelId.eq(channel_id));
+        }
+
+        Ok(query
+            .limit(1)
+            .into_tuple::<Uuid>()
+            .one(&self.context.db)
+            .await?
+            .is_some())
+    }
+
+    async fn exists_on_or_after(&self, channel_id: Option<Uuid>, id: Uuid) -> AnyResult<bool> {
+        let mut query = message::Entity::find()
+            .select_only()
+            .column(message::Column::Id)
+            .filter(message::Column::Id.gte(id));
+
+        if let Some(channel_id) = channel_id {
+            query = query.filter(message::Column::ChannelId.eq(channel_id));
+        }
+
+        Ok(query
+            .limit(1)
+            .into_tuple::<Uuid>()
+            .one(&self.context.db)
+            .await?
+            .is_some())
     }
 
     pub async fn get_by_channel(&self, channel_id: uuid::Uuid) -> AnyResult<Vec<message::Model>> {

src/repositories/types.rs

@@ -24,6 +24,7 @@ pub struct ServerTree {
 pub struct MessageFilter {
     pub channel_id: Option<uuid::Uuid>,
     pub before_id: Option<uuid::Uuid>,
+    pub after_id: Option<uuid::Uuid>,
     pub limit: Option<u64>,
 }
 

src/routes/message/handlers.rs

@@ -1,21 +1,25 @@
-use crate::domain::dto::message::{CreateMessageRequest, MessageQueryParams, MessageResponse, UpdateMessageRequest};
 use crate::core::state::AppState;
+use crate::domain::dto::message::{
+    CreateMessageRequest, MessagePageResponse, MessageQueryParams, MessageResponse,
+    UpdateMessageRequest,
+};
 use crate::http::context::CurrentUser;
 use crate::http::error::HTTPError;
 use crate::routes::message::mapper;
 use axum::{
+    Json,
     extract::{Path, Query, State},
     http::StatusCode,
-    Json,
 };
 use uuid::Uuid;
 
-/// Liste tous les messages
+/// Liste une fenêtre paginée de messages
 #[utoipa::path(
     get,
     path = "/messages",
     responses(
-        (status = 200, description = "Liste des messages récupérée avec succès", body = [MessageResponse]),
+        (status = 200, description = "Fenêtre de messages récupérée avec succès", body = MessagePageResponse),
+        (status = 400, description = "Curseurs incompatibles ou canal manquant"),
         (status = 500, description = "Erreur interne du serveur")
     ),
     params(
@@ -26,15 +30,29 @@ use uuid::Uuid;
 pub async fn get_all(
     State(state): State<AppState>,
     Query(filters): Query<MessageQueryParams>,
-) -> Result<Json<Vec<MessageResponse>>, HTTPError> {
+) -> Result<Json<MessagePageResponse>, HTTPError> {
+    if filters.before_id.is_some() && filters.after_id.is_some() {
+        return Err(HTTPError::BadRequest(
+            "before_id and after_id cannot be used together".to_string(),
+        ));
+    }
+
     let params = mapper::query_params_to_message_filter(filters);
-    let messages = state.repositories.message.filter(params).await?;
-    Ok(Json(
-        messages
+    let page = state.repositories.message.filter(params).await?;
+    let oldest_id = page.messages.first().map(|message| message.id);
+    let newest_id = page.messages.last().map(|message| message.id);
+
+    Ok(Json(MessagePageResponse {
+        messages: page
+            .messages
             .into_iter()
             .map(mapper::message_model_to_message_response)
             .collect(),
-    ))
+        oldest_id,
+        newest_id,
+        has_more_before: page.has_more_before,
+        has_more_after: page.has_more_after,
+    }))
 }
 
 /// Récupère un message par son ID
@@ -105,7 +123,11 @@ pub async fn create(
             ))?;
     }
 
-    let message = state.services.message.create_message(payload.channel_id, user.id, payload.content).await?;
+    let message = state
+        .services
+        .message
+        .create_message(payload.channel_id, user.id, payload.content)
+        .await?;
     Ok((
         StatusCode::CREATED,
         Json(mapper::message_model_to_message_response(message)),
@@ -150,7 +172,11 @@ pub async fn update(
         return Err(HTTPError::Forbidden);
     }
 
-    let message = state.services.message.update_message(id, payload.content).await?;
+    let message = state
+        .services
+        .message
+        .update_message(id, payload.content)
+        .await?;
 
     Ok(Json(mapper::message_model_to_message_response(message)))
 }

src/routes/message/mapper.rs

@@ -1,8 +1,8 @@
-use crate::models::message;
-use crate::repositories::types::MessageFilter;
 use crate::domain::dto::message::{
     CreateMessageRequest, MessageQueryParams, MessageResponse, UpdateMessageRequest,
 };
+use crate::models::message;
+use crate::repositories::types::MessageFilter;
 use chrono::Utc;
 use sea_orm::Set;
 use uuid::Uuid;
@@ -48,8 +48,9 @@ pub fn update_request_to_am(
 
 pub fn query_params_to_message_filter(params: MessageQueryParams) -> MessageFilter {
     MessageFilter {
-        channel_id: params.channel_id,
+        channel_id: Some(params.channel_id),
         before_id: params.before_id,
+        after_id: params.after_id,
         limit: params.limit,
     }
 }