import json
import logging
import os

import splunk.clilib.bundle_paths as bundle_paths
import splunk.clilib.cli_common as comm
from splunk.appbuilder import PACKAGE_PATH

logger = logging.getLogger('splunk.spl2')

FILELOCK_SERVICE_FAILED = "Service temporarily unavailable. Retry in 30 seconds."

DOWNLOAD_MODULES_ENDPOINT = "/spl2/modules/download?app={app_name}"


def sync_spl2_objects(handler_args, object_type, session_key, app_name):
    if object_type == "spl2-modules":
        dest = handler_args.get('dest', ["default"])[0]

        module_filter = []
        arg_data = handler_args.data
        if 'filter' in arg_data and arg_data['filter'][0] is not None:
            for entry in arg_data['filter'][0].split(','):
                entry = entry.strip()
                if entry:
                    module_filter.append(entry)

        app_modules = _get_all_modules(app_name, session_key)
        if not app_modules:
            logger.debug("No SPL2 modules found for app '{}'".format(app_name))
            return

        bundle_paths.maybe_makedirs(PACKAGE_PATH, throw_exceptions=True)
        # TODO: Add concurrency mechanism - SCP-69093
        create_module_files(app_name, dest, app_modules, module_filter)
    else:
        raise NotImplementedError("No handler for object_type {}".format(object_type))


def create_module_files(app, dest, modules, module_filter):
    app_path = bundle_paths.get_bundle(app).location()

    temp_path = os.path.join(PACKAGE_PATH, 'SPL2_DELETEME_' + app)
    spl2_path = os.path.join(app_path, dest, "data", "spl2")

    # delete stale temp_path if exists from previous CLI invoke and re-create dirs
    bundle_paths.safe_remove(temp_path)
    bundle_paths.maybe_makedirs(temp_path)

    # if ..app/{dest}/data/spl2 exists, copy all contents to temp_path
    if os.path.lexists(spl2_path):
        comm.mergeDirs(spl2_path, temp_path)

    # delete all .spl2 files from temp_path
    _delete_spl2_modules(temp_path)
    # write module files to the temp_path
    _write_module_files(temp_path, modules, module_filter)

    # remove ..app/{dest}/data/spl2 and mv temp_path contents to /data/spl2
    bundle_paths.safe_remove(spl2_path)
    comm.moveItem(temp_path, spl2_path)
    logger.info("Moved downloaded modules to {}".format(spl2_path))


def _write_module_files(des, modules, module_filter):
    modules_written = []

    for module in modules:
        name = module['name']
        dirs = module['namespace'].split('.')[2:]  # remove apps.<app_name.
        content = module['definition']
        mod_resource_name = module['namespace'] + '.' + module['name']
        folder_path = os.path.join(des, *dirs)
        file_path = os.path.join(folder_path, name + ".spl2")

        file_ns_name = ".".join(dirs + [name])

        if module_filter:
            if file_ns_name in module_filter:
                _write_module(content, file_path, folder_path)
                modules_written.append(mod_resource_name)
            else:
                logger.debug("Skipped writing module {}. Applied filter: {}".format(file_ns_name, module_filter))
                continue
        else:
            _write_module(content, file_path, folder_path)
            modules_written.append(mod_resource_name)

    if modules_written:
        logger.info("Wrote {} module(s) to {}. Modules: {}".format(len(modules_written), des, modules_written))


def _write_module(content, file_path, folder_path):
    os.makedirs(folder_path, exist_ok=True)
    with open(file_path, "w") as file:
        file.write(content)


def _get_all_modules(app, auth):
    from splunk import rest
    download_path = DOWNLOAD_MODULES_ENDPOINT.format(app_name=app)
    response, content = rest.simpleRequest(download_path, sessionKey=auth, raiseAllErrors=True)
    if content:
        modules = json.loads(content)
        logger.debug("Downloaded {} modules from app: {} using REST".format(len(modules), app))
        return modules


def _delete_spl2_modules(path, extension=".spl2"):
    for root, dirs, files in os.walk(path, topdown=False):
        for file in files:
            if file.endswith(extension):
                file_path = os.path.join(root, file)
                os.remove(file_path)

    # Now check and delete empty directories
    for root, dirs, files in os.walk(path, topdown=False):
        for dir_name in dirs:
            dir_path = os.path.join(root, dir_name)
            if not os.listdir(dir_path):
                os.rmdir(dir_path)