# SPDX-License-Identifier: AGPL-3.0-or-later
#
# This file is part of GNS3 Server.
#
# GNS3 Server is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
Message format converters for OpenAI-compatible message format.
Converts between LangChain messages and OpenAI-compatible format.
"""
import json
import uuid
from datetime import datetime
from typing import Dict, Any


def _ensure_string(content: Any) -> str:
    """Ensure content is a string, converting dicts/lists to JSON if needed."""
    if isinstance(content, str):
        return content
    elif isinstance(content, (dict, list)):
        return json.dumps(content, ensure_ascii=False, indent=2)
    else:
        return str(content)


def convert_langchain_to_openai(lc_message) -> Dict[str, Any]:
    """
    Convert LangChain message to OpenAI-compatible format.

    Args:
        lc_message: LangChain message (HumanMessage, AIMessage, SystemMessage, ToolMessage)

    Returns:
        Dictionary in OpenAI-compatible format
    """
    from langchain_core.messages import HumanMessage, AIMessage, SystemMessage, ToolMessage

    # Generate message ID
    msg_id = getattr(lc_message, 'id', None)
    if msg_id is None:
        msg_id = str(uuid.uuid4())

    # Get timestamp
    timestamp = getattr(lc_message, 'created_at', None)
    if timestamp is None:
        timestamp = datetime.utcnow().isoformat()
    elif hasattr(timestamp, 'isoformat'):
        timestamp = timestamp.isoformat()

    # Base message structure
    base_msg = {
        "id": msg_id,
        "created_at": timestamp,
        "metadata": {}
    }

    # Convert based on message type
    if isinstance(lc_message, HumanMessage):
        return {
            **base_msg,
            "role": "user",
            "content": lc_message.content
        }

    elif isinstance(lc_message, AIMessage):
        msg = {
            **base_msg,
            "role": "assistant",
            "content": lc_message.content
        }

        # Handle tool calls - convert to OpenAI format
        if hasattr(lc_message, 'tool_calls') and lc_message.tool_calls:
            tool_calls = []
            for tc in lc_message.tool_calls:
                # Convert to dict if it's an object
                tc_dict = tc if isinstance(tc, dict) else tc.model_dump()
                tool_calls.append({
                    "id": tc_dict.get("id", str(uuid.uuid4())),
                    "type": "function",
                    "function": {
                        "name": tc_dict.get("name", ""),
                        "arguments": tc_dict.get("args", {})
                    }
                })
            msg["tool_calls"] = tool_calls

        return msg

    elif isinstance(lc_message, ToolMessage):
        return {
            **base_msg,
            "role": "tool",
            "content": _ensure_string(lc_message.content),
            "name": getattr(lc_message, 'name', ''),
            "tool_call_id": getattr(lc_message, 'tool_call_id', '')
        }

    elif isinstance(lc_message, SystemMessage):
        return {
            **base_msg,
            "role": "system",
            "content": lc_message.content
        }

    else:
        # Fallback for unknown message types
        return {
            **base_msg,
            "role": "unknown",
            "content": str(lc_message)
        }


def convert_openai_to_langchain(msg: Dict[str, Any]):
    """
    Convert OpenAI-compatible format to LangChain message.

    Args:
        msg: Dictionary in OpenAI-compatible format

    Returns:
        LangChain message
    """
    from langchain_core.messages import HumanMessage, AIMessage, ToolMessage, SystemMessage

    role = msg.get("role", "user")
    content = msg.get("content", "")

    if role == "user":
        return HumanMessage(content=content, id=msg.get("id"))

    elif role == "assistant":
        ai_msg = AIMessage(content=content, id=msg.get("id"))

        # Restore tool calls if present
        if "tool_calls" in msg and msg["tool_calls"]:
            tool_calls = []
            for tc in msg["tool_calls"]:
                tool_calls.append({
                    "id": tc.get("id", str(uuid.uuid4())),
                    "name": tc.get("function", {}).get("name", ""),
                    "args": tc.get("function", {}).get("arguments", {})
                })
            ai_msg.tool_calls = tool_calls

        return ai_msg

    elif role == "tool":
        return ToolMessage(
            content=content,
            name=msg.get("name", ""),
            tool_call_id=msg.get("tool_call_id", "")
        )

    elif role == "system":
        return SystemMessage(content=content)

    else:
        # Fallback to HumanMessage for unknown roles
        return HumanMessage(content=content)


def convert_stream_event_to_openai(event: Dict[str, Any]) -> Dict[str, Any]:
    """
    Convert LangGraph streaming event to OpenAI-compatible format.

    Args:
        event: LangGraph streaming event

    Returns:
        Dictionary in OpenAI-compatible streaming response format
    """
    event_type = event.get("event", "")

    if event_type == "on_chat_model_stream":
        chunk = event.get("data", {}).get("chunk", {})
        content = getattr(chunk, 'content', '')

        if content:
            return {
                "type": "content",
                "content": content,
                "message_id": event.get("metadata", {}).get("msg_id")
            }

        # Check for tool call chunks
        if hasattr(chunk, 'tool_call_chunks') and chunk.tool_call_chunks:
            for tc_chunk in chunk.tool_call_chunks:
                tc_id = getattr(tc_chunk, 'id', None)
                tc_name = getattr(tc_chunk, 'name', None)
                tc_args = getattr(tc_chunk, 'args', None)

                if tc_id:
                    return {
                        "type": "tool_call",
                        "tool_call": {
                            "id": tc_id,
                            "type": "function",
                            "function": {
                                "name": tc_name or "",
                                "arguments": tc_args or ""
                            }
                        }
                    }

    elif event_type == "on_tool_start":
        return {
            "type": "tool_start",
            "tool_name": event.get("name", ""),
            "metadata": event.get("metadata", {})
        }

    elif event_type == "on_tool_end":
        tool_output = event.get("data", {}).get("output", "")
        # Convert dict or list output to JSON string for serialization
        if isinstance(tool_output, (dict, list)):
            tool_output = json.dumps(tool_output, ensure_ascii=False, indent=2)

        return {
            "type": "tool_end",
            "tool_output": tool_output,
            "tool_name": event.get("name", ""),
            "metadata": event.get("metadata", {})
        }

    # Default empty response
    return {"type": "unknown"}