import shutil
from datetime import datetime
import tempfile
import zipfile
from flask import Blueprint, send_file, jsonify, request
import os
from api import require_auth
from db import get_db
from db.models.Markdown import Markdown
from db.models.Path import Path
import threading
import logging
logger = logging.getLogger(__name__)

backup_bp = Blueprint('backup', __name__, url_prefix='/api/backup')
backup_lock = threading.Lock()
@backup_bp.route('/', methods=['GET'])
@require_auth(roles=['admin'])
def get_backup():
    try:
        paths = {}
        with get_db() as session:
            pths = session.query(Path).all()
            paths = {p.id : p for p in pths}
        traverse(1, paths)
        timestamp = datetime.now().strftime('%Y-%m-%d_%H-%M-%S')
        archive = shutil.make_archive(base_name=timestamp, format='zip', root_dir='Root')

        shutil.rmtree('Root')
        return send_file(
            archive,
            as_attachment=True,
            download_name=timestamp + '.zip',
        )
    except Exception as e:
        logger.error(f"Failed to get backup: {e}")
        return jsonify({"error": "failed to get backup"}), 500


def create_and_cd(path_name):
    if not os.path.exists(path_name) or not os.path.isdir(path_name):
        os.makedirs(path_name)
    os.chdir(path_name)

def cd_back():
    os.chdir('..')

def traverse(path_id, paths):
    current_path = paths[path_id]
    if path_id == 1:
        create_and_cd("Root")
    else:
        create_and_cd(current_path.name)
    with open(".meta", "w") as meta_file:
        meta_file.write(f"order: {current_path.order}\n")
    with get_db() as session:
        mds = session.query(Markdown).filter(Markdown.path_id == path_id).all()
        for md in mds:
            with open(f"{md.title}.md", "w") as md_file:
                md_file.write(md.content)
            with open(f"{md.title}.mdmeta", "w") as meta_file:
                meta_file.write(f"created_at: {md.created_at}\n")
                meta_file.write(f"order: {md.order}\n")
                meta_file.write(f"shortcut: {md.shortcut}\n")
        children = [c for c in paths.values() if c.parent_id == path_id]
        for child in children:
            traverse(child.id, paths)
    cd_back()


@backup_bp.route('/load', methods=['POST'])
@require_auth(roles=['admin'])
def load_backup():
    if not backup_lock.acquire(blocking=False):
        return jsonify({"error": "Another backup restore is in progress. Please try again later."}), 429

    try:
        if 'file' not in request.files:
            return jsonify({"error": "No file provided"}), 400
        uploaded_file = request.files['file']

        temp_dir = tempfile.mkdtemp()
        zip_path = os.path.join(temp_dir, "backup.zip")
        uploaded_file.save(zip_path)

        with zipfile.ZipFile(zip_path, 'r') as zip_ref:
            zip_ref.extractall(temp_dir)

        root_dir = temp_dir
        if not os.path.exists(root_dir):
            return jsonify({"error": "Invalid backup format"}), 400

        with get_db() as session:
            path_mapping = {}
            restore_tree(root_dir, None, session, path_mapping)
            session.commit()

        shutil.rmtree(temp_dir)

        return jsonify({"success": True, "message": "Backup restored and merged successfully"})

    except Exception as e:
        logger.error(f"Failed to load backup: {e}")
        return jsonify({"error": f"Failed to load backup {e}"}), 500
    finally:
        backup_lock.release()


def restore_tree(dir_path, parent_id, session, path_mapping):

    dir_name = os.path.basename(dir_path)

    existing_path = session.query(Path).filter_by(parent_id=parent_id, name=dir_name).first()
    if parent_id is None:
        new_path_id = 1
    elif existing_path:
        new_path_id = existing_path.id
    else:
        order = ''
        meta_file_path = os.path.join(dir_path, ".meta")
        if os.path.exists(meta_file_path):
            with open(meta_file_path, "r") as meta_file:
                for line in meta_file:
                    key, value = line.strip().split(": ", 1)
                    if key == "order":
                        order = value

        new_path = Path(name=dir_name, parent_id=parent_id, order=order)
        session.add(new_path)
        session.flush()
        new_path_id = new_path.id

    path_mapping[dir_path] = new_path_id

    for file in os.listdir(dir_path):
        file_path = os.path.join(dir_path, file)
        if file.endswith(".md"):
            md_title = file[:-3]

            mdmeta_path = file_path + "meta"
            created_at = datetime.now()
            order = ''
            shortcut = ""

            if os.path.exists(mdmeta_path):
                with open(mdmeta_path, "r") as meta_file:
                    for line in meta_file:
                        key, value = line.strip().split(": ", 1)
                        if key == "created_at":
                            created_at = datetime.strptime(value, "%Y-%m-%d %H:%M:%S")
                        elif key == "order":
                            order = value
                        elif key == "shortcut":
                            shortcut = value

            with open(file_path, "r", encoding="utf-8") as md_file:
                content = md_file.read()

            unique_title = get_unique_markdown_title(session, md_title, new_path_id)

            new_md = Markdown(title=unique_title, content=content, path_id=new_path_id,
                              created_at=created_at, order=order, shortcut=shortcut)
            session.add(new_md)


    for item in os.listdir(dir_path):
        item_path = os.path.join(dir_path, item)
        if os.path.isdir(item_path):
            restore_tree(item_path, new_path_id, session, path_mapping)


def get_unique_markdown_title(session, title, path_id):
    existing_titles = {md.title for md in session.query(Markdown.title).filter_by(path_id=path_id).all()}
    unique_title = title
    while unique_title in existing_titles:
        unique_title += ".bp"
    return unique_title