#!/usr/bin/env python

from __future__ import print_function

description = """
Upload all the ExternalData files to the Midas server.

The files corresponding to all the ExternalData content links
in the source tree are archived on the Midas server using the
local ExternalData object store.

Requires pydas: https://github.com/midasplatform/pydas
"""

import argparse
import fnmatch
import os
import sys

import pydas

def connect_to_midas(email=None, api_key=None, midas_url='https://midas3.kitware.com/midas/'):
    if not api_key:
        print('Please enter your login information for ' + midas_url)
        pydas.login(url=midas_url, email=email)
    else:
        pydas.login(url=midas_url, email=email, api_key=api_key)
    session = pydas.session
    communicator = session.communicator
    return session, communicator


def upload_to_midas(content_link, externaldata_object_store,
        repository_dir,
        session, communicator):
    # get the MD5 checksum
    print('Uploading ' + content_link + ' ...')
    with open(content_link, 'r') as fp:
        md5hash = fp.readline().strip()
    print('Checksum: ' + md5hash)

    # upload to Midas
    def get_child_folder(parent, child_name):
        children = communicator.folder_children(session.token, parent['folder_id'])
        for folder in children['folders']:
            if folder['name'] == child_name:
                return folder
        return None
    itk_community = communicator.get_community_by_name('ITK')
    itk_public = get_child_folder(itk_community, 'Public')
    itk_folder = get_child_folder(itk_public, 'ITK')

    # Where to place the file in Midas.  Mirror the source tree location.
    folders = os.path.dirname(content_link)
    if repository_dir != '':
        folders = folders[folders.find(repository_dir)+len(repository_dir)+1:]
    folders = folders.split(os.path.sep)

    current_folder = itk_folder
    for folder in folders:
        child_folder = get_child_folder(current_folder, folder)
        if child_folder is None:
            print('Creating folder: ' + folder)
            current_folder = communicator.create_folder(session.token,
                    folder,
                    current_folder['folder_id'])
        else:
            current_folder = child_folder

    # get the existing or create a new item to hold the file
    item_name = os.path.basename(content_link[:-4])
    item_id = None
    current_folder_children = communicator.folder_children(session.token,
            current_folder['folder_id'])
    if current_folder_children.has_key('items'):
        for item in current_folder_children['items']:
            if item['name'] == item_name:
                item_id = item['item_id']
                break

    if item_id is None:
        new_item = communicator.create_item(session.token, item_name,
                current_folder['folder_id'])
        item_id = new_item['item_id']

    object_store = os.path.join(externaldata_object_store, 'MD5', md5hash)
    if not os.path.exists(object_store):
        sys.stderr.write('Could not find the expected object store.\n')
        sys.exit(1)

    upload_token = communicator.generate_upload_token(session.token,
            item_id,
            item_name,
            md5hash)
    if upload_token != "":
        communicator.perform_upload(upload_token,
                item_name,
                item_id=item_id,
                revision='head',
                filepath=object_store)


def run(itk_source_dir, externaldata_object_store,
        email=None, api_key=None, midas_url='https://midas3.kitware.com/midas/'):
    session, communicator = connect_to_midas(email, api_key, midas_url)

    md5files = []
    for root, dirnames, filenames in os.walk(itk_source_dir):
        for filename in fnmatch.filter(filenames, '*.md5'):
            md5files.append(os.path.join(root, filename))

    # Find the location of top level directory in the repository.
    repository_dir = None
    example_path = os.path.normpath(os.path.dirname(md5files[0]))
    potential_path = example_path
    previous_path = None
    while previous_path != '':
        dir = os.path.join(potential_path, '.git')
        if os.path.exists(dir):
            repository_dir = potential_path
            break
        previous_path = potential_path
        potential_path = os.path.split(potential_path)[0]
    if repository_dir == None:
        sys.stderr.write('Could not find ITK repository directory.\n')
        sys.exit(1)

    for content_link in md5files:
        src_examples = os.path.join('src', 'Examples')
        if content_link.find(src_examples) == -1:
            uncategorized = True
        else:
            uncategorized = False

        if uncategorized:
            folders = ['Uncategorized']
        else:
            group_module_path = content_link.split(src_examples)[1][1:]
            hiercharchy = group_module_path.split(os.path.sep)
            group = hiercharchy[0]
            module = hiercharchy[1]
            folders = [group, module]

        upload_to_midas(content_link, externaldata_object_store, repository_dir,
                session, communicator)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description=description)
    parser.add_argument('--api-key-file', '-k', type=argparse.FileType('r'),
            help="A file that contains your Midas user's API key.")
    parser.add_argument('--email', '-e',
            help="Email address associated with your Midas account.")
    parser.add_argument('itk_source_dir',
            help='Path to the ITK source tree.')
    parser.add_argument('externaldata_object_store',
            help='Path to the ExternalData object store, e.g. ' \
            + 'ExternalData/Objects/ in a build tree.')
    parser.add_argument('--midas-url', '-u',
            help='URL of the Midas server.',
            default='https://midas3.kitware.com/midas/')
    args = parser.parse_args()

    if args.api_key_file:
        api_key = args.api_key_file.readline()
        api_key = api_key.strip()
    else:
        api_key = None

    run(args.itk_source_dir, args.externaldata_object_store,
        email=args.email, api_key=api_key, midas_url=args.midas_url)