fix message migration

BACKUP.md

@@ -0,0 +1,331 @@
+# Discord Reaper: Backup System Technical Specification
+
+This document provides a deep-dive into the architecture, data lifecycle, and resilience strategies of the Discord Reaper backup system.
+
+## 1. Architectural Overview
+
+The backup system is built on a decoupled architecture that separates the API communication layer from the business logic and I/O operations.
+
+-   **`DiscordReader` (API Provider)**: A high-level wrapper around the `discord.py` library. It handles authentication, rate limiting, and provides an asynchronous interface for fetching guild data, message history, and binary assets. It focuses on *fetching* rather than *processing*.
+-   **`DiscordExporter` (Orchestration & Serialization)**: The core engine that defines the export lifecycle. It consumes data from the `Reader`, transforms it into standardized schemas, and manages local filesystem operations.
+
+### Component Interaction Diagram
+
+```mermaid
+graph TD
+    A[UI / CLI] --> B[DiscordExporter]
+    B --> C[DiscordReader]
+    C --> D[Discord API]
+    B --> E[Local Filesystem]
+    B --> F[User Cache Object]
+```
+
+---
+
+## 2. Data Lifecycle & Serialization
+
+### 2.1 Incremental Synchronization Algorithm
+To achieve idempotency and efficiency, the system implements an incremental sync strategy using Discord's snowflake IDs.
+
+1.  **State Loading**: The `Exporter` reads the existing `{channel_id}.json` (if present).
+2.  **Snowflake Extraction**: It extracts the `lastMessageID` from the metadata.
+3.  **Filtered Fetch**: It calls `fetch_message_history(after_id=last_id)`.
+4.  **In-Memory Merge**: New messages are appended to the existing list.
+5.  **Atomic Write**: The updated JSON is written back to disk, ensuring that only new delta data is fetched from the API.
+
+### 2.2 User Profile Deduplication (`user_info.json`)
+The system avoids redundant storage of user metadata (usernames, roles, colors) by using a global `user_cache` map.
+-   **Key**: `userID` (Snowflake).
+-   **Policy**: Users are added to the cache only on their first appearance in any channel's history.
+-   **Avatar Persistence**: User avatars are stored in a centralized `user_avatars/` directory and referenced by relative paths in the JSON schemas.
+
+---
+
+## 3. Special Channel Type Specifications
+
+### 3.1 Forum Channels & Threads
+Forums present a hierarchical challenge where the "starter message" and the "conversation" exist in separate contexts.
+
+-   **Forum Index (`{channel_id}.json`)**: Contains an enriched list of "starter messages" representing each thread. These entries include thread titles, applied tags, and total attachment stats (summed from the entire thread).
+-   **Thread Persistence**:
+    -   **Regular Threads**: `message_backup/threads/{thread_id}.json`
+    -   **Forum Threads**: `message_backup/{forum_id}/{thread_id}.json`
+-   **Starter Identification**: The system uses `thread.history(limit=1, after=snowflake(thread_id - 1))` to reliably capture the first post even if it has been edited or pinned.
+
+---
+
+## 4. Resilience & Error Handling
+
+### 4.1 Permission Resilience (403 Forbidden)
+The system is designed to "fail-soft" when encountering restricted content:
+-   **Server Level**: If the bot lacks `view_channel` or `read_message_history` globally, the backup aborts with a clear error.
+-   **Channel Level**: If a specific channel is restricted, the error is logged, and the system proceeds to the next channel to ensure a partial backup is still completed.
+-   **Asset Level**: If an emoji or sticker cannot be downloaded due to permissions, the metadata is preserved with a `null` local path.
+
+### 4.2 Lottie Sticker Workaround
+Discord's Lottie stickers (format: 3) are not supported by standard `discord.py` save methods. The system implements a bypass:
+1.  Extracts the internal `aiohttp` session from the client: `client.http._HTTPClient__session`.
+2.  Performs a direct `GET` request to the sticker URL.
+3.  Streams the raw byte data directly to a `.json` file locally.
+
+---
+
+## 5. Technical Schemas
+
+### 5.1 Message Object (`_format_message`)
+The internal representation of a message focuses on portability:
+
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `messageID` | `String` | Original Discord Snowflake |
+| `type` | `String` | Normalized type (Text, ThreadStarter, Forward, etc.) |
+| `timestamp` | `ISO8601` | Created date/time |
+| `isPinned` | `Boolean` | Pin status |
+| `content` | `String` | Raw markdown content (or snapshot content for forwards) |
+| `userID` | `String` | Reference to `user_info.json` |
+| `attachments`| `Array` | List of local file references and metadata |
+| `embeds` | `Array` | Raw Dicord-formatted embed objects |
+| `stickers` | `Array` | List of Message Sticker objects (see below) |
+| `reactions` | `Array` | List of Reaction objects |
+
+#### Message Sticker Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `id` | `String` | Sticker Snowflake ID |
+| `name` | `String` | Sticker name |
+| `format` | `String` | File format (PNG, APNG, LOTTIE, GIF) |
+| `localPath` | `String` | Relative path to local file in `{channel_id}/` |
+
+#### Reaction Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `emoji` | `String` | String representation (`unicode` or `name:id`) |
+| `count` | `Integer` | Total count of this reaction |
+
+### 5.2 Asset Naming Logic
+To prevent filename collisions (e.g., multiple files named `image.png`), the system uses a suffixing strategy:
+`{filename_stem}-{snowflake_last_5}.{ext}`
+
+Example: `sunset-54321.png`
+
+### 5.3 `server_profile.json` Specification
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `name` | `String` | Original Discord guild name |
+| `id` | `String` | Guild Snowflake ID |
+| `icon` | `String` | Relative path to local guild icon in `server_media/` |
+| `banner` | `String` | Relative path to local guild banner in `server_media/` |
+| `last_backup` | `ISO8601` | Timestamp of the last successful backup run |
+| `ignore_channels` | `Array` | List of channel Snowflakes explicitly excluded from backup |
+
+### 5.4 `server_roles.json` Specification (Array of objects)
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `id` | `String` | Role Snowflake ID |
+| `name` | `String` | Role name |
+| `color` | `String` | Hex-string representation of role color (e.g. `"#ffffff"`) |
+| `position` | `Integer` | Vertical position in the hierarchy (0 is bottom) |
+| `permissions`| `Integer` | Bitwise integer representing the role's Discord permissions |
+| `hoist` | `Boolean` | Whether the role is displayed separately in the sidebar |
+| `mentionable`| `Boolean` | Whether the role can be mentioned |
+
+### 5.5 `server_assets.json` Specification
+Contains two primary arrays: `emojis` and `stickers`.
+#### Emoji Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `id` | `String` | Emoji Snowflake ID |
+| `name` | `String` | Emoji name (without colons) |
+| `animated` | `Boolean` | True if the emoji is a GIF |
+| `filename` | `String` | Filename within `server_media/` |
+
+#### Sticker Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `id` | `String` | Sticker Snowflake ID |
+| `name` | `String` | Sticker name |
+| `filename` | `String` | Filename within `server_media/` |
+
+### 5.6 `server_structure.json` Specification (Array of Category objects)
+#### Category Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `type` | `String` | Always `"category"` |
+| `id` | `String` | Category Snowflake ID (or `"uncategorized"`) |
+| `name` | `String` | Category name |
+| `position` | `Integer` | Vertical position in hierarchy |
+| `channels` | `Array` | List of Channel objects (see below) |
+
+#### Channel Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `id` | `String` | Channel Snowflake ID |
+| `name` | `String` | Channel name |
+| `type` | `String` | "text", "voice", "forum", "news", or "thread" |
+| `position` | `Integer` | Vertical position within the category |
+| `topic` | `String` | Channel description/topic (null if empty) |
+| `nsfw` | `Boolean` | True if marked Restricted/NSFW |
+| `available_tags` | `Array` | List of Forum Tag objects (see below) |
+
+#### Forum Tag Object
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `id` | `String` | Tag Snowflake ID |
+| `name` | `String` | Tag display name |
+| `moderated` | `Boolean` | True if restricted to moderators |
+| `emoji_id` | `String` | ID of the tag's emoji (null if unicode/none) |
+| `emoji_name` | `String` | Name of the tag's emoji |
+
+### 5.7 `user_info.json` Specification (Array of User objects)
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `userID` | `String` | User Snowflake ID |
+| `username` | `String` | Current global username |
+| `userNickname`| `String` | Server-specific nickname (display name) |
+| `userColor` | `String` | Role-derived color for the user |
+| `userIsBot` | `Boolean` | True if the account is a bot |
+| `userRoles` | `Array` | List of role snippets (name, id, color, position) |
+| `userAvatar` | `String` | Relative path to local avatar in `user_avatars/` |
+
+### 5.8 Channel History JSON Specification
+File: `message_backup/{channel_id}.json`
+
+This file contains the full history of a channel along with synchronization metadata.
+
+| Field | Type | Description |
+| :--- | :--- | :--- |
+| `channelName` | `String` | Human-readable name of the channel |
+| `channelID` | `String` | Channel Snowflake ID |
+| `channelType` | `String` | "Text", "Thread", "News", or "Forum" |
+| `messageCount` | `Integer` | Total number of messages stored in the `messages` array |
+| `threadCount` | `Integer` | (If Parent) Count of threads associated with this channel |
+| `lastMessageID`| `String` | ID of the most recent message (used for incremental sync) |
+| `totalAttachmentSizeBytes`| `Integer`| Summed size of all attachments for this channel |
+| `numberOfAttachments` | `Integer`| Total count of attachments |
+| `lastBackup` | `ISO8601` | Timestamp of last message fetch |
+| `messages` | `Array` | The message objects (see Section 5.1) |
+| `parentID` | `String` | (If Thread) Snowflake of the parent channel |
+
+---
+
+## 7. Backup Reader Implementation Guide
+
+This section is a technical manual for developers building third-party tools (viewers, search engines, or analytics) to consume Discord Reaper backups.
+
+### 7.1 Entry Point Discovery
+A reader should start by identifying the backup root directory (prefixed with `DISCORD_BACKUP-`).
+
+1.  **Parse `server_profile.json`**: Extract the server name, ID, and assets (icon/banner).
+2.  **Load `server_structure.json`**: This defines the navigation tree for your UI.
+    -   Iterate through categories.
+    -   Map channels to their respective types (text, voice, forum).
+    -   Store the `position` to preserve the original visual order.
+
+### 7.2 Relational Data Mapping
+The backup data is normalized to minimize duplication. A reader must implement the following resolve logic:
+
+-   **User Resolution**: When parsing a message in `{channel_id}.json`, the `userID` must be cross-referenced against the `userID` keys in `message_backup/user_info.json`.
+-   **Role Resolution**: Use the `userRoles` array (IDs) from the user object and resolve them against the role metadata in `server_roles.json` to get colors and names.
+-   **Static Asset Resolution**:
+    -   **Server Assets**: Prepend `server_media/` to filenames found in `server_assets.json`.
+    -   **User Avatars**: Resolve `userAvatar` paths found in `user_info.json` (pointing to `user_avatars/`).
+
+### 7.3 Message Rendering Logic
+When rendering the `messages` array from a channel JSON:
+
+| Feature | Reader Implementation Logic |
+| :--- | :--- |
+| **Markdown** | Content is raw Discord markdown. Use a library like `markdown-it` with discord-specific plugins. |
+| **Attachments** | Resolve `url` field (`{channel_id}/{filename}`) relative to the `message_backup/` directory. |
+| **Emojis/Stickers** | If a message contains custom emojis/stickers, resolve their metadata via `server_assets.json`. |
+| **Replies** | Use the `reference` object to find the target `messageId`. Note: The target might be in the same file or a different channel/thread. |
+
+### 7.4 Thread & Forum Reconstruction
+Reconstructing the hierarchy requires specific pointer logic:
+
+1.  **Forums**:
+    -   Read `message_backup/{forum_id}.json`.
+    -   Each message in this file is a `Thread_starter_message`.
+    -   The `messageID` of the starter message *is usually* the same as the `thread_id`.
+    -   To load the full thread, open `message_backup/{forum_id}/{thread_id}.json`.
+2.  **Regular Threads**:
+    -   Discoverable via the `parentID` field in any message or by scanning `message_backup/threads/`.
+    -   Match the `thread.id` in a `ThreadStarter` message to the respective JSON in the `threads/` folder.
+
+---
+
+## 8. Discord.py Model Hydration Guide
+
+If you are building a `discord.py` API-compatible wrapper to read these backups directly into familiar Discord objects, here is the explicit property mapping from the schema to the standard `discord.py` object attributes.
+
+### 8.1 Base Server (Guild)
+File: `server_profile.json` & `server_roles.json` & `server_structure.json`
+-   **`discord.Guild`**:
+    -   `id`: Cast `id` (str) to `int`.
+    -   `name`: Mapped directly from `name`.
+    -   `icon` / `banner`: Represented as `discord.Asset` objects. Use the local file paths from `icon` / `banner` as the asset URL/filepath.
+    -   `roles`: Hydrated from `server_roles.json`.
+    -   `channels` / `categories`: Hydrated from `server_structure.json`.
+
+### 8.2 Roles (`discord.Role`)
+File: `server_roles.json`
+-   `id`: Cast `id` to `int`.
+-   `name`: Mapped directly.
+-   `color`: Parse the hex string to `discord.Color(value)`.
+-   `position`: Mapped directly.
+-   `permissions`: Initialize `discord.Permissions(value=int(permissions))`.
+-   `hoist`: Mapped directly to boolean.
+-   `mentionable`: Mapped directly to boolean.
+
+### 8.3 Users & Members (`discord.Member` / `discord.User`)
+File: `message_backup/user_info.json`
+-   `id`: Cast `userID` to `int`.
+-   `name`: Mapped from `username`.
+-   `display_name`: Mapped from `userNickname`.
+-   `bot`: Mapped from `userIsBot`.
+-   `color`: Parse `userColor` string to `discord.Color`.
+-   `roles`: List of hydrated `discord.Role` objects via matching `id`s from the `userRoles` array.
+-   `avatar`: Mocked `discord.Asset` using the `userAvatar` local path.
+
+### 8.4 Channels (`discord.TextChannel`, `discord.CategoryChannel`, `discord.ForumChannel`)
+File: `server_structure.json`
+-   Iterate over the top-level array (Categories):
+    -   **`discord.CategoryChannel`**:
+        -   `id`: Cast `id` to `int`.
+        -   `name`: Mapped directly.
+        -   `position`: Mapped directly.
+-   Iterate over the nested `channels` array:
+    -   **`discord.abc.GuildChannel` classes**:
+        -   `id`: Cast `id` to `int`.
+        -   `name`: Mapped directly.
+        -   `position`: Mapped directly.
+        -   `type`: Match the `type` string back to the `discord.ChannelType` enum.
+        -   `category_id`: Inherited from the parent category block.
+        -   `topic`: Mapped directly (if applicable).
+        -   `nsfw`: Mapped directly to boolean.
+
+### 8.5 Messages (`discord.Message`)
+File: `message_backup/{channel_id}.json` (Iterating the `messages` array)
+-   `id`: Cast `messageID` to `int`.
+-   `type`: Map the string `type` (e.g., "Default", "Reply") to `discord.MessageType`.
+-   `created_at`: Parse `timestamp` (ISO-8601 string) into a timezone-aware `datetime` object.
+-   `pinned`: Mapped from `isPinned`.
+-   `content`: Mapped from `content`.
+-   `author`: Resolve the `userID` against the loaded `discord.Member` mocks.
+-   `embeds`: Instantiate using `discord.Embed.from_dict(embed_dict)` directly on the elements of the `embeds` array.
+-   **Reference (Replies)**:
+    -   If `reference` exists, hydrate a `discord.MessageReference`.
+    -   `message_id`: Cast `reference.messageId` to `int`.
+    -   `channel_id`: Cast `reference.channelId` to `int`.
+
+### 8.6 Attachments (`discord.Attachment`)
+Nested within Message objects.
+-   `id`: Cast `id` to `int`.
+-   `filename`: Mapped from `fileName`.
+-   `size`: Mapped from `fileSizeBytes`.
+-   `url` / `proxy_url`: Point to the local relative path (`{channel_id}/{resolved_filename}`).
+
+### 8.7 Reactions (`discord.Reaction` & `discord.PartialEmoji`)
+Nested within Message objects.
+-   `count`: Mapped from `count`.
+-   `emoji`: Iterate the `emoji` string. If custom (contains a `:`), split it to mock a `discord.PartialEmoji(name=..., id=...)`. Otherwise, mock standard unicode strings.

src/stoat/migrate_message.py

@@ -68,7 +68,13 @@ async def analyze_migration(context: MigrationContext, source_channel_id: int, a
     """
     Scans channel history to count messages, threads, and attachments.
     """
-    stats = {"messages": 0, "threads": 0, "attachments": 0}
+    stats = {
+        "messages": 0, 
+        "threads": 0, 
+        "attachments": 0,
+        "first_message_url": "",
+        "last_message_url": ""
+    }
     
     async for msg in context.discord_reader.fetch_message_history(source_channel_id, after_id=after_message_id):
         if not context.is_running:
@@ -97,7 +103,13 @@ async def analyze_migration(context: MigrationContext, source_channel_id: int, a
 
 async def migrate_messages(context: MigrationContext, source_channel_id: int, target_channel_id: str, after_message_id: int | None = None, progress_callback: Callable[[Dict[str, Any]], Awaitable[None]] | None = None) -> Dict[str, Any]:
     """Migrate messages for a specific channel using Stoat masquerade for author impersonation."""
-    stats = {"messages": 0, "threads": 0, "attachments": 0}
+    stats = {
+        "messages": 0, 
+        "threads": 0, 
+        "attachments": 0,
+        "first_message_url": "",
+        "last_message_url": ""
+    }
     
     logger.info(f"Starting message migration: Discord #{source_channel_id} -> Stoat #{target_channel_id}")
     if after_message_id:

src/stoat/roles_permissions.py

@@ -181,6 +181,11 @@ async def migrate_roles(context: MigrationContext, progress_callback: Callable[[
     except Exception as e:
         logger.error(f"Failed to sync default permissions: {e}")
 
+    # 2. Fetch and filter roles
+    roles = await context.discord_reader.get_roles()
+    if not force:
+        roles = [r for r in roles if not context.state.get_target_role_id(str(r.id))]
+
     total = len(roles)
     cloned_role_names = []
     

src/ui/shuttle_ops.py

@@ -9,6 +9,7 @@ import logging
 import re
 import time
 import aiohttp
+import traceback
 from pathlib import Path
 
 from textual.app import ComposeResult
@@ -39,6 +40,8 @@ import src.stoat.migrate_message as stoat_migrate
 global_rate_limit_msg = ""
 global_rate_limit_expires = 0.0
 
+logger = logging.getLogger(__name__)
+
 
 class RateLimitHandler(logging.Handler):
     """Intercepts library logs to capture rate-limit messages."""
@@ -412,6 +415,7 @@ class ShuttlePane(Container):
             report = self._format_clone_report(results)
             modal.write(report)
         except Exception as e:
+            logger.error(f"Batch Cloning Error: {e}\n{traceback.format_exc()}")
             modal.write(f"[bold red]Error: {e}[/bold red]")
             modal.phase_report("Batch Operation", "error")
         finally:
@@ -464,6 +468,7 @@ class ShuttlePane(Container):
             report = self._format_sync_report(results)
             modal.write(report)
         except Exception as e:
+            logger.error(f"Batch Sync Error: {e}\n{traceback.format_exc()}")
             modal.write(f"[bold red]Error: {e}[/bold red]")
             modal.phase_report("Batch Operation", "error")
         finally: