import json
import logging
from pathlib import Path
import sys
import threading

from flask import Blueprint, Flask, Response, jsonify, render_template, request, send_from_directory

ROOT = Path(__file__).resolve().parent.parent
if str(ROOT) not in sys.path:
    sys.path.insert(0, str(ROOT))

from upload.backend.upload_refs import create_upload_refs_blueprint
from upload.backend.session import get_files, file_count, cleanup

logging.basicConfig(level=logging.INFO, format="%(asctime)s [%(levelname)s] %(name)s: %(message)s")
log = logging.getLogger("upload-platform")

# Конфигурация стенда: разрешённые расширения, буфер и лимиты
DEFAULT_CONFIG = {
    "allowedExt": [".pdf", ".doc", ".docx", ".txt", ".md"],
    "vmUploadUrl": "/mock-buffer/",
    "vmUploadPrefix": "/mock-buffer/",
}
try:
    with (ROOT / "config.json").open(encoding="utf-8") as config_file:
        CONFIG = {**DEFAULT_CONFIG, **json.load(config_file)}
except (OSError, json.JSONDecodeError):
    CONFIG = DEFAULT_CONFIG

VERSION = "0.2.2"

app = Flask(
    __name__,
    template_folder=str(ROOT / "site" / "templates"),
    static_folder=str(ROOT / "site" / "static"),
)

# -----------------------------------------------------------------------------
# In-memory Mock Buffer (эмуляция WebDAV буфера на ВМ для локальных тестов)
# -----------------------------------------------------------------------------
_mock_storage = {}
_mock_storage_lock = threading.Lock()
mock_buffer_bp = Blueprint("mock_buffer", __name__)


@mock_buffer_bp.route("/mock-buffer/<path:key>", methods=["PUT"])
def mock_put(key):
    """Принимает файл от браузера в RAM mock-буфера."""
    data = request.get_data()
    with _mock_storage_lock:
        _mock_storage[key] = data
    log.info("MockBuffer: stored key=%s (%d bytes)", key, len(data))
    return "", 201


@mock_buffer_bp.route("/mock-buffer/<path:key>", methods=["GET"])
def mock_get(key):
    """Отдаёт файл по GET-запросу бэкенда (исходящий pull)."""
    with _mock_storage_lock:
        data = _mock_storage.get(key)
    if data is None:
        log.warning("MockBuffer: key not found key=%s", key)
        return "Not found", 404
    return Response(data, mimetype="application/octet-stream")


@mock_buffer_bp.route("/mock-buffer/<path:key>", methods=["DELETE"])
def mock_delete(key):
    """Удаляет файл из RAM mock-буфера после успешного pull."""
    with _mock_storage_lock:
        existed = _mock_storage.pop(key, None) is not None
    log.info("MockBuffer: deleted key=%s (existed=%s)", key, existed)
    return "", 204


@mock_buffer_bp.route("/mock-buffer/status", methods=["GET"])
def mock_status():
    """Диагностика mock-буфера: количество и размер находящихся в нём файлов."""
    with _mock_storage_lock:
        items = [{"key": k, "size": len(v)} for k, v in _mock_storage.items()]
    return jsonify({"count": len(items), "items": items})


# -----------------------------------------------------------------------------
# Регистрация Слоя 2 (upload_refs) с эмуляцией передачи в Слой 3
# -----------------------------------------------------------------------------
def on_file_received_for_layer3(sid: str, name: str, content: bytes):
    """Эмуляция отдачи файла в Слой 3 бизнес-логики (обфускация/парсинг)."""
    log.info("[Layer 3 Emulation] Ready to process file in session %s: name=%s, size=%d bytes",
             sid, name, len(content))


upload_refs_bp = create_upload_refs_blueprint({
    "apiPrefix": "/api",
    "vmUploadPrefix": CONFIG.get("vmUploadPrefix", "/mock-buffer/"),
    "maxFileBytes": CONFIG.get("maxFileBytes", 50 * 1024 * 1024),
    "maxSessionBytes": CONFIG.get("maxSessionBytes", 500 * 1024 * 1024),
    "ttlSeconds": CONFIG.get("ttlSeconds", 30 * 60),
    "pullRetries": 2,
    "pullRetryDelay": 0.3,
    "onFileReceived": on_file_received_for_layer3,
})

app.register_blueprint(mock_buffer_bp)
app.register_blueprint(upload_refs_bp)


# -----------------------------------------------------------------------------
# Роуты тестового стенда
# -----------------------------------------------------------------------------
@app.route("/")
def index():
    """Возвращает demo-страницу со Слой 1 (picker) и Слой 2 (transit upload)."""
    return render_template("index.html", version=VERSION, config=CONFIG)


@app.route("/health")
def health():
    """Liveness-проверка платформы."""
    return "ok", 200


@app.route("/api/session/<sid>/files", methods=["GET"])
def session_files(sid):
    """Проверка содержимого сессии в RAM бэкенда (для тестов и UI)."""
    files = get_files(sid)
    if files is None:
        return jsonify({"ok": False, "error": "Session not found"}), 404
    return jsonify({
        "ok": True,
        "session": sid,
        "files": [{"name": name, "size": len(content)} for name, content in files]
    })


@app.get("/upload-frontend/<path:filename>")
def upload_frontend(filename):
    """Отдаёт исходные модули фронтенда из каталога upload/frontend."""
    return send_from_directory(ROOT / "upload" / "frontend", filename)


@app.get("/file-picker/<path:filename>")
def file_picker_dist(filename):
    """Отдаёт собранный бандл из каталога dist."""
    return send_from_directory(ROOT / "dist", filename)


if __name__ == "__main__":
    app.run(debug=False, host="0.0.0.0", port=5000)