import re
import os
import subprocess
import argparse
import shutil
import time

import gitlab_api

SUBMODULE_PATTERN = re.compile(r"\[submodule \"([^\"]+)\"]")
PATH_PATTERN = re.compile(r"path\s+=\s+(\S+)")
URL_PATTERN = re.compile(r"url\s+=\s+(\S+)")

SUBMODULE_ARCHIVE_TEMP_FOLDER = "submodule_archive"


class SubModule(object):
    # We don't need to support recursive submodule clone now

    GIT_LS_TREE_OUTPUT_PATTERN = re.compile(r"\d+\s+commit\s+([0-9a-f]+)\s+")

    def __init__(self, gitlab_inst, path, url):
        self.path = path
        self.gitlab_inst = gitlab_inst
        self.project_id = self._get_project_id(url)
        self.commit_id = self._get_commit_id(path)

    def _get_commit_id(self, path):
        output = subprocess.check_output(["git", "ls-tree", "HEAD", path])
        output = output.decode()
        # example output: 160000 commit d88a262fbdf35e5abb372280eb08008749c3faa0	components/esp_wifi/lib
        match = self.GIT_LS_TREE_OUTPUT_PATTERN.search(output)
        return match.group(1)

    def _get_project_id(self, url):
        base_name = os.path.basename(url)
        project_id = self.gitlab_inst.get_project_id(os.path.splitext(base_name)[0],  # remove .git
                                                     namespace="espressif")
        return project_id

    def download_archive(self):
        print("Update submodule: {}: {}".format(self.path, self.commit_id))
        path_name = self.gitlab_inst.download_archive(self.commit_id, SUBMODULE_ARCHIVE_TEMP_FOLDER,
                                                      self.project_id)
        renamed_path = os.path.join(os.path.dirname(path_name), os.path.basename(self.path))
        os.rename(path_name, renamed_path)
        shutil.rmtree(self.path, ignore_errors=True)
        shutil.move(renamed_path, os.path.dirname(self.path))


def update_submodule(git_module_file, submodules_to_update):
    gitlab_inst = gitlab_api.Gitlab()
    submodules = []
    with open(git_module_file, "r") as f:
        data = f.read()
    match = SUBMODULE_PATTERN.search(data)
    while True:
        next_match = SUBMODULE_PATTERN.search(data, pos=match.end())
        if next_match:
            end_pos = next_match.start()
        else:
            end_pos = len(data)
        path_match = PATH_PATTERN.search(data, pos=match.end(), endpos=end_pos)
        url_match = URL_PATTERN.search(data, pos=match.end(), endpos=end_pos)
        path = path_match.group(1)
        url = url_match.group(1)

        filter_result = True
        if submodules_to_update:
            if path not in submodules_to_update:
                filter_result = False
        if filter_result:
            submodules.append(SubModule(gitlab_inst, path, url))

        match = next_match
        if not match:
            break

    shutil.rmtree(SUBMODULE_ARCHIVE_TEMP_FOLDER, ignore_errors=True)

    for submodule in submodules:
        submodule.download_archive()


if __name__ == '__main__':
    start_time = time.time()
    parser = argparse.ArgumentParser()
    parser.add_argument("--repo_path", "-p", default=".", help="repo path")
    parser.add_argument("--submodule", "-s", default="all",
                        help="Submodules to update. By default update all submodules. "
                             "For multiple submodules, separate them with `;`. "
                             "`all` and `none` are special values that indicates we fetch all / none submodules")
    args = parser.parse_args()
    if args.submodule == "none":
        print("don't need to update submodules")
        exit(0)
    if args.submodule == "all":
        _submodules = []
    else:
        _submodules = args.submodule.split(";")
    update_submodule(os.path.join(args.repo_path, ".gitmodules"), _submodules)
    print("total time spent on update submodule: {:.02f}s".format(time.time() - start_time))