move backend source to src

backend/src/chat.py

@@ -0,0 +1,143 @@
+
+from sqlalchemy.orm import Session
+from sqlalchemy.sql.expression import select
+
+import database as db
+
+MESSAGE_PAGE_SIZE = 256
+
+class Message:
+    def __init__(self, id, content, sender, time=None, kind='message', subkind=None):
+        self.id = id
+        self.content = content
+        self.sender = sender
+        self.time = time
+        self.kind = kind
+        self.subkind = subkind
+    
+    def from_db_record(record):
+        return Message(record.id, record.content, record.sender, record.time)
+    
+    def __str__(self):
+        return f"Message(#{self.id} ({self.time if self.time != None else 'no-time'}) {self.sender}: {self.content.replace("\n", "\\n")})"
+
+class Thread:
+    def __init__(self, id, chat_id, name=None, description=None):
+        self.id = id
+        self.chat_id = chat_id
+        self.name = name
+        self.description = description
+
+        self.messages = []
+        self.notes = []
+        self.memories = []
+
+class ChatView:
+    def __init__(self, app, chat_id):
+        self.app = app
+        self.chat_id = chat_id
+
+        self.name = None
+        self.description = None
+
+        # Thread holding messages without a set thread id
+        self.default_thread = Thread(None, chat_id)
+        # Most recent thread objects, earliest to latest
+        self.threads = []
+        # Map of threads by their id
+        self.thread_map = {}
+        # Long term summary of this chat
+        self.summary = None
+        # Separate list for note messages from any thread
+        # Is it better to exclude them or include them from threads? atm they're included
+        self.notes = []
+
+        # Id of the thread currently in focus, by default the last thread appearing in the conversation
+        self.current_thread_id = None
+        
+        self._earliest_message_id = None
+
+        self._load_basic_data()
+        self._load_next_messages(MESSAGE_PAGE_SIZE)
+    
+    def _load_basic_data(self):
+        with self.app.sql_session() as session:
+            record = session.execute(
+                select(db.Chat).where(db.Chat.id == self.chat_id)
+            ).scalars().first()
+
+            if not record:
+                raise Exception(f"Chat not found with id {self.chat_id}")
+            
+            self.name = record.name
+            self.description = record.description
+
+    def _load_next_messages(self, load_count):
+        with self.app.sql_session() as session:
+            records_rev = session.execute(
+                select(db.Message).where(
+                    db.Message.chat_id == self.chat_id,
+                    self._earliest_message_id == None or db.Message.id <= self._earliest_message_id
+                ).order_by(db.Message.time.desc())
+            ).scalars().fetchmany(load_count)
+
+            # Update the earliest id for the next load operation
+            if records_rev:
+                self._earliest_message_id = records_rev[0].id
+                if not self.threads:
+                    # current thread is the latest known
+                    self.current_thread_id = records_rev[-1].thread_id
+
+            # Go over messages from newest to oldest
+            for record in records_rev:
+                if record.thread_id == None:
+                    thread = self.default_thread
+                else:
+                    thread = self.thread_map.get(record.thread_id)
+                    if not thread:
+                        thread = Thread(record.thread_id, self.chat_id)
+                        self.thread_map[thread.id] = thread
+                        self.threads.insert(0, thread)
+                # This is the oldest message so far, add it to the start of the chat
+                message = Message(record.id, record.content, record.sender, record.time, record.kind, record.subkind)
+
+                if message.kind == 'note':
+                    thread.notes.insert(0, message)
+                elif message.kind == 'memory':
+                    thread.memories.insert(0, message)
+                else:
+                    thread.messages.insert(0, message)
+    
+    def get_thread(self, thread_id):
+        if thread_id == None:
+            return self.default_thread
+        return self.thread_map.get(thread_id)
+    
+    def get_current_thread(self):
+        # TODO: if !thread
+        return self.get_thread(self.current_thread_id)
+    
+    def debug_string(self):
+        result_lines = []
+        def _print(line):
+            result_lines.append(line)
+
+        def print_thread(thread, title=None):
+            if title:
+                _print(title + ":")
+            elif thread.name:
+                _print(thread.name + ":")
+            else:
+                _print(f"Thread {thread.id}:")
+            for message in thread.messages:
+                _print("  " + str(message))
+        
+        print_thread(self.default_thread, "Default Thread")
+        for thread in self.threads:
+            print_thread(thread)
+
+        _print("Current thread id: " + str(self.current_thread_id))
+
+        return "\n".join(result_lines)
+
+