"""
This module implements data models and functions for retrieving and sending
Telegram messages, managing chats, and working with contacts. 

The module connects to a SQLite database that stores all Telegram messages and chat data,
which is maintained by the Telegram Bridge. It also provides an HTTP client for sending
messages via the Bridge's API endpoint.

Main features:
- Data models for messages, chats, contacts, and message context
- Database access functions for retrieving messages, chats, and contacts
- HTTP client for sending messages through the Telegram Bridge
- Helper functions for displaying formatted messages and chats

All database operations use parameterized queries to prevent SQL injection.
"""

import sqlite3
import requests
import json
import os.path
from datetime import datetime
from dataclasses import dataclass
from typing import Optional, List, Tuple, Dict, Any

# Database path
MESSAGES_DB_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'telegram-bridge', 'store', 'messages.db')
TELEGRAM_API_BASE_URL = "http://localhost:8081/api"

@dataclass
class Message:
    """
    Represents a Telegram message with all its metadata.
    
    Attributes:
        id: Unique message identifier
        chat_id: ID of the chat the message belongs to
        chat_title: Title of the chat (user name, group name, etc.)
        sender_name: Name of the message sender
        content: Text content of the message
        timestamp: Date and time when the message was sent
        is_from_me: Boolean indicating if the message was sent by the user
        sender_id: ID of the message sender
    """
    id: int
    chat_id: int
    chat_title: str
    sender_name: str
    content: str
    timestamp: datetime
    is_from_me: bool
    sender_id: int

@dataclass
class Chat:
    """
    Represents a Telegram chat (direct message, group, channel, etc.).
    
    Attributes:
        id: Unique chat identifier
        title: Name of the chat (user name, group name, etc.)
        username: Optional Telegram username (without @)
        type: Type of chat ('user', 'group', 'channel', 'supergroup')
        last_message_time: Timestamp of the most recent message in the chat
    """
    id: int
    title: str
    username: Optional[str]
    type: str
    last_message_time: Optional[datetime]

@dataclass
class Contact:
    """
    Represents a Telegram contact.
    
    Attributes:
        id: Unique contact identifier
        username: Optional Telegram username (without @)
        name: Display name of the contact
    """
    id: int
    username: Optional[str]
    name: str

@dataclass
class MessageContext:
    """
    Provides context around a specific message.
    
    Attributes:
        message: The target message
        before: List of messages that came before the target message
        after: List of messages that came after the target message
    """
    message: Message
    before: List[Message]
    after: List[Message]

def print_message(message: Message, show_chat_info: bool = True) -> None:
    """Print a single message with consistent formatting."""
    direction = "→" if message.is_from_me else "←"
    
    if show_chat_info:
        print(f"[{message.timestamp:%Y-%m-%d %H:%M:%S}] {direction} Chat: {message.chat_title} (ID: {message.chat_id})")
    else:
        print(f"[{message.timestamp:%Y-%m-%d %H:%M:%S}] {direction}")
        
    print(f"From: {'Me' if message.is_from_me else message.sender_name}")
    print(f"Message: {message.content}")
    print("-" * 100)

def print_messages_list(messages: List[Message], title: str = "", show_chat_info: bool = True) -> None:
    """Print a list of messages with a title and consistent formatting."""
    if not messages:
        print("No messages to display.")
        return
        
    if title:
        print(f"\n{title}")
        print("-" * 100)
    
    for message in messages:
        print_message(message, show_chat_info)

def print_chat(chat: Chat) -> None:
    """Print a single chat with consistent formatting."""
    print(f"Chat: {chat.title} (ID: {chat.id})")
    print(f"Type: {chat.type}")
    if chat.username:
        print(f"Username: @{chat.username}")
    if chat.last_message_time:
        print(f"Last active: {chat.last_message_time:%Y-%m-%d %H:%M:%S}")
    print("-" * 100)

def print_chats_list(chats: List[Chat], title: str = "") -> None:
    """Print a list of chats with a title and consistent formatting."""
    if not chats:
        print("No chats to display.")
        return
        
    if title:
        print(f"\n{title}")
        print("-" * 100)
    
    for chat in chats:
        print_chat(chat)

def search_contacts(query: str) -> List[Contact]:
    """Search contacts by name or username."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        # Search in chats where type is 'user'
        cursor.execute("""
            SELECT id, username, title
            FROM chats
            WHERE type = 'user' AND (title LIKE ? OR username LIKE ?)
            ORDER BY title
            LIMIT 50
        """, (f"%{query}%", f"%{query}%"))
        
        contacts = cursor.fetchall()
        
        result = []
        for contact_data in contacts:
            contact = Contact(
                id=contact_data[0],
                username=contact_data[1],
                name=contact_data[2]
            )
            result.append(contact)
            
        return result
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return []
    finally:
        if 'conn' in locals():
            conn.close()

def list_messages(
    date_range: Optional[Tuple[datetime, datetime]] = None,
    sender_id: Optional[int] = None,
    chat_id: Optional[int] = None,
    query: Optional[str] = None,
    limit: int = 20,
    page: int = 0,
    include_context: bool = True,
    context_before: int = 1,
    context_after: int = 1
) -> List[Message]:
    """Get messages matching the specified criteria with optional context."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        # Build base query
        query_parts = ["""
            SELECT 
                m.id, 
                m.chat_id, 
                c.title, 
                m.sender_name, 
                m.content, 
                m.timestamp, 
                m.is_from_me, 
                m.sender_id
            FROM messages m
        """]
        query_parts.append("JOIN chats c ON m.chat_id = c.id")
        where_clauses = []
        params = []
        
        # Add filters
        if date_range:
            where_clauses.append("m.timestamp BETWEEN ? AND ?")
            params.extend([date_range[0].isoformat(), date_range[1].isoformat()])
            
        if sender_id:
            where_clauses.append("m.sender_id = ?")
            params.append(sender_id)
            
        if chat_id:
            where_clauses.append("m.chat_id = ?")
            params.append(chat_id)
            
        if query:
            where_clauses.append("LOWER(m.content) LIKE LOWER(?)")
            params.append(f"%{query}%")
            
        if where_clauses:
            query_parts.append("WHERE " + " AND ".join(where_clauses))
            
        # Add pagination
        offset = page * limit
        query_parts.append("ORDER BY m.timestamp DESC")
        query_parts.append("LIMIT ? OFFSET ?")
        params.extend([limit, offset])
        
        cursor.execute(" ".join(query_parts), tuple(params))
        messages = cursor.fetchall()
        
        result = []
        for msg in messages:
            message = Message(
                id=msg[0],
                chat_id=msg[1],
                chat_title=msg[2],
                sender_name=msg[3],
                content=msg[4],
                timestamp=datetime.fromisoformat(msg[5]),
                is_from_me=bool(msg[6]),
                sender_id=msg[7]
            )
            result.append(message)
            
        if include_context and result:
            # Add context for each message
            messages_with_context = []
            for msg in result:
                context = get_message_context(msg.id, msg.chat_id, context_before, context_after)
                messages_with_context.extend(context.before)
                messages_with_context.append(context.message)
                messages_with_context.extend(context.after)
            return messages_with_context
            
        return result
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return []
    finally:
        if 'conn' in locals():
            conn.close()

def get_message_context(
    message_id: int,
    chat_id: int,
    before: int = 5,
    after: int = 5
) -> MessageContext:
    """Get context around a specific message."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        # Get the target message first
        cursor.execute("""
            SELECT m.id, m.chat_id, c.title, m.sender_name, m.content, m.timestamp, m.is_from_me, m.sender_id
            FROM messages m
            JOIN chats c ON m.chat_id = c.id
            WHERE m.id = ? AND m.chat_id = ?
        """, (message_id, chat_id))
        msg_data = cursor.fetchone()
        
        if not msg_data:
            raise ValueError(f"Message with ID {message_id} in chat {chat_id} not found")
            
        target_message = Message(
            id=msg_data[0],
            chat_id=msg_data[1],
            chat_title=msg_data[2],
            sender_name=msg_data[3],
            content=msg_data[4],
            timestamp=datetime.fromisoformat(msg_data[5]),
            is_from_me=bool(msg_data[6]),
            sender_id=msg_data[7]
        )
        
        # Get messages before
        cursor.execute("""
            SELECT m.id, m.chat_id, c.title, m.sender_name, m.content, m.timestamp, m.is_from_me, m.sender_id
            FROM messages m
            JOIN chats c ON m.chat_id = c.id
            WHERE m.chat_id = ? AND m.timestamp < ?
            ORDER BY m.timestamp DESC
            LIMIT ?
        """, (chat_id, target_message.timestamp.isoformat(), before))
        
        before_messages = []
        for msg in cursor.fetchall():
            before_messages.append(Message(
                id=msg[0],
                chat_id=msg[1],
                chat_title=msg[2],
                sender_name=msg[3],
                content=msg[4],
                timestamp=datetime.fromisoformat(msg[5]),
                is_from_me=bool(msg[6]),
                sender_id=msg[7]
            ))
        
        # Get messages after
        cursor.execute("""
            SELECT m.id, m.chat_id, c.title, m.sender_name, m.content, m.timestamp, m.is_from_me, m.sender_id
            FROM messages m
            JOIN chats c ON m.chat_id = c.id
            WHERE m.chat_id = ? AND m.timestamp > ?
            ORDER BY m.timestamp ASC
            LIMIT ?
        """, (chat_id, target_message.timestamp.isoformat(), after))
        
        after_messages = []
        for msg in cursor.fetchall():
            after_messages.append(Message(
                id=msg[0],
                chat_id=msg[1],
                chat_title=msg[2],
                sender_name=msg[3],
                content=msg[4],
                timestamp=datetime.fromisoformat(msg[5]),
                is_from_me=bool(msg[6]),
                sender_id=msg[7]
            ))
        
        return MessageContext(
            message=target_message,
            before=before_messages,
            after=after_messages
        )
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        raise
    finally:
        if 'conn' in locals():
            conn.close()

def list_chats(
    query: Optional[str] = None,
    limit: int = 20,
    page: int = 0,
    chat_type: Optional[str] = None,
    sort_by: str = "last_active"
) -> List[Chat]:
    """Get chats matching the specified criteria."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        # Build base query
        query_parts = ["SELECT id, title, username, type, last_message_time FROM chats"]
        
        where_clauses = []
        params = []
        
        if query:
            where_clauses.append("(LOWER(title) LIKE LOWER(?) OR LOWER(username) LIKE LOWER(?))")
            params.extend([f"%{query}%", f"%{query}%"])
        
        if chat_type:
            where_clauses.append("type = ?")
            params.append(chat_type)
            
        if where_clauses:
            query_parts.append("WHERE " + " AND ".join(where_clauses))
            
        # Add sorting
        order_by = "last_message_time DESC" if sort_by == "last_active" else "title"
        query_parts.append(f"ORDER BY {order_by}")
        
        # Add pagination
        offset = (page) * limit
        query_parts.append("LIMIT ? OFFSET ?")
        params.extend([limit, offset])
        
        cursor.execute(" ".join(query_parts), tuple(params))
        chats = cursor.fetchall()
        
        result = []
        for chat_data in chats:
            last_message_time = datetime.fromisoformat(chat_data[4]) if chat_data[4] else None
            chat = Chat(
                id=chat_data[0],
                title=chat_data[1],
                username=chat_data[2],
                type=chat_data[3],
                last_message_time=last_message_time
            )
            result.append(chat)
            
        return result
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return []
    finally:
        if 'conn' in locals():
            conn.close()

def get_chat(chat_id: int) -> Optional[Chat]:
    """Get chat metadata by ID."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        cursor.execute("""
            SELECT id, title, username, type, last_message_time
            FROM chats
            WHERE id = ?
        """, (chat_id,))
        
        chat_data = cursor.fetchone()
        
        if not chat_data:
            return None
            
        last_message_time = datetime.fromisoformat(chat_data[4]) if chat_data[4] else None
        return Chat(
            id=chat_data[0],
            title=chat_data[1],
            username=chat_data[2],
            type=chat_data[3],
            last_message_time=last_message_time
        )
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return None
    finally:
        if 'conn' in locals():
            conn.close()

def get_direct_chat_by_contact(contact_id: int) -> Optional[Chat]:
    """Get direct chat metadata by contact ID."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        cursor.execute("""
            SELECT id, title, username, type, last_message_time
            FROM chats
            WHERE id = ? AND type = 'user'
        """, (contact_id,))
        
        chat_data = cursor.fetchone()
        
        if not chat_data:
            return None
            
        last_message_time = datetime.fromisoformat(chat_data[4]) if chat_data[4] else None
        return Chat(
            id=chat_data[0],
            title=chat_data[1],
            username=chat_data[2],
            type=chat_data[3],
            last_message_time=last_message_time
        )
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return None
    finally:
        if 'conn' in locals():
            conn.close()

def get_contact_chats(contact_id: int, limit: int = 20, page: int = 0) -> List[Chat]:
    """Get all chats involving the contact.
    
    Args:
        contact_id: The contact's ID to search for
        limit: Maximum number of chats to return (default 20)
        page: Page number for pagination (default 0)
    """
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        cursor.execute("""
            SELECT DISTINCT
                c.id, c.title, c.username, c.type, c.last_message_time
            FROM chats c
            JOIN messages m ON c.id = m.chat_id
            WHERE m.sender_id = ? OR c.id = ?
            ORDER BY c.last_message_time DESC
            LIMIT ? OFFSET ?
        """, (contact_id, contact_id, limit, page * limit))
        
        chats = cursor.fetchall()
        
        result = []
        for chat_data in chats:
            last_message_time = datetime.fromisoformat(chat_data[4]) if chat_data[4] else None
            chat = Chat(
                id=chat_data[0],
                title=chat_data[1],
                username=chat_data[2],
                type=chat_data[3],
                last_message_time=last_message_time
            )
            result.append(chat)
            
        return result
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return []
    finally:
        if 'conn' in locals():
            conn.close()

def get_last_interaction(contact_id: int) -> Optional[Message]:
    """Get most recent message involving the contact."""
    try:
        conn = sqlite3.connect(MESSAGES_DB_PATH)
        cursor = conn.cursor()
        
        cursor.execute("""
            SELECT 
                m.id, m.chat_id, c.title, m.sender_name, m.content, m.timestamp, m.is_from_me, m.sender_id
            FROM messages m
            JOIN chats c ON m.chat_id = c.id
            WHERE m.sender_id = ? OR c.id = ?
            ORDER BY m.timestamp DESC
            LIMIT 1
        """, (contact_id, contact_id))
        
        msg_data = cursor.fetchone()
        
        if not msg_data:
            return None
            
        return Message(
            id=msg_data[0],
            chat_id=msg_data[1],
            chat_title=msg_data[2],
            sender_name=msg_data[3],
            content=msg_data[4],
            timestamp=datetime.fromisoformat(msg_data[5]),
            is_from_me=bool(msg_data[6]),
            sender_id=msg_data[7]
        )
        
    except sqlite3.Error as e:
        print(f"Database error: {e}")
        return None
    finally:
        if 'conn' in locals():
            conn.close()

def send_message(recipient: str, message: str) -> Tuple[bool, str]:
    """Send a Telegram message to the specified recipient.
    
    Args:
        recipient: The recipient - either a username (with or without @), 
                  or a chat ID as a string or integer
        message: The message text to send
        
    Returns:
        Tuple[bool, str]: A tuple containing success status and a status message
    """
    try:
        # Validate input
        if not recipient:
            return False, "Recipient must be provided"
        
        url = f"{TELEGRAM_API_BASE_URL}/send"
        payload = {
            "recipient": recipient,
            "message": message
        }
        
        response = requests.post(url, json=payload)
        
        # Check if the request was successful
        if response.status_code == 200:
            result = response.json()
            return result.get("success", False), result.get("message", "Unknown response")
        else:
            return False, f"Error: HTTP {response.status_code} - {response.text}"
            
    except requests.RequestException as e:
        return False, f"Request error: {str(e)}"
    except json.JSONDecodeError:
        return False, f"Error parsing response: Unknown"
    except Exception as e:
        return False, f"Unexpected error: {str(e)}"