from flask import Blueprint, request, jsonify
import difflib
from util.logger import logger
from auth.token import verify_token

textdiff_blueprint = Blueprint('textdiff_tool', __name__)


@textdiff_blueprint.route('/api/text/diff', methods=['POST'])
def text_diff():
    user = verify_token()
    if not user:
        return jsonify({"message": "Nicht autorisiert"}), 401
    try:
        data = request.get_json()
        text1 = data.get("text1", "")
        text2 = data.get("text2", "")

        lines1 = text1.splitlines(keepends=True)
        lines2 = text2.splitlines(keepends=True)

        result = []
        for line in difflib.unified_diff(lines1, lines2, lineterm=''):
            if line.startswith('+++') or line.startswith('---') or line.startswith('@@'):
                continue
            if line.startswith('+'):
                result.append({"type": "added", "text": line[1:]})
            elif line.startswith('-'):
                result.append({"type": "removed", "text": line[1:]})
            else:
                result.append({"type": "unchanged", "text": line[1:] if line.startswith(' ') else line})

        logger.info(f"Text-Diff erstellt von {user['username']}")
        return jsonify({"diff": result})
    except Exception as e:
        logger.error(f"Fehler Text-Diff: {e}")
        return jsonify({"message": "Fehler beim Vergleich"}), 500