"""
Chat REST API: conversations, messages, recall.
"""
from flask import Blueprint, request, jsonify
from flask_jwt_extended import jwt_required, get_jwt_identity
from app.services.chat_engine import ChatEngineService
from app.socket_events import broadcast_new_message

chat_bp = Blueprint("chat", __name__)


@chat_bp.route("/conversations", methods=["GET"])
@jwt_required()
def list_conversations():
    skip = request.args.get("skip", 0, type=int)
    limit = min(request.args.get("limit", 20, type=int), 100)
    user_id = get_jwt_identity()
    convs = ChatEngineService.list_conversations(user_id, skip=skip, limit=limit)
    return jsonify({
        "items": [
            {
                "id": c.id,
                "title": c.title,
                "last_message_at": c.last_message_at.isoformat() if c.last_message_at else None,
                "created_at": c.created_at.isoformat() if c.created_at else None,
            }
            for c in convs
        ]
    })


@chat_bp.route("/conversations", methods=["POST"])
@jwt_required()
def create_conversation():
    data = request.get_json() or {}
    title = (data.get("title") or "新对话").strip() or "新对话"
    user_id = get_jwt_identity()
    conv = ChatEngineService.get_or_create_conversation(user_id, title=title)
    return jsonify({
        "id": conv.id,
        "title": conv.title,
        "last_message_at": conv.last_message_at.isoformat() if conv.last_message_at else None,
        "created_at": conv.created_at.isoformat() if conv.created_at else None,
    }), 201


@chat_bp.route("/conversations/<conversation_id>/messages", methods=["GET"])
@jwt_required()
def get_messages(conversation_id):
    before_id = request.args.get("before_id")
    limit = min(request.args.get("limit", 50, type=int), 100)
    user_id = get_jwt_identity()
    messages = ChatEngineService.get_messages(conversation_id, user_id, before_id=before_id, limit=limit)
    return jsonify({"items": [m.to_dict() for m in reversed(messages)]})


@chat_bp.route("/conversations/<conversation_id>/messages", methods=["POST"])
@jwt_required()
def send_message(conversation_id):
    data = request.get_json() or {}
    content = (data.get("content") or "").strip()
    content_type = data.get("content_type") or "text"
    attachment_url = data.get("attachment_url")
    attachment_name = data.get("attachment_name")
    if not content and not attachment_url:
        return jsonify({"error": "content or attachment required"}), 400
    user_id = get_jwt_identity()
    msg = ChatEngineService.send_message(
        conversation_id, user_id, content or "(附件)",
        content_type=content_type,
        attachment_url=attachment_url,
        attachment_name=attachment_name,
    )
    if not msg:
        return jsonify({"error": "Conversation not found or access denied"}), 404
    broadcast_new_message(msg)
    return jsonify(msg.to_dict()), 201


@chat_bp.route("/messages/<message_id>/recall", methods=["POST"])
@jwt_required()
def recall_message(message_id):
    user_id = get_jwt_identity()
    ok = ChatEngineService.recall_message(message_id, user_id)
    if not ok:
        return jsonify({"error": "Message not found or recall not allowed"}), 400
    return jsonify({"status": "recalled"})