#!/usr/bin/env python3

import json
import os
import sys
import subprocess

try:
    import yaml
    # import clipboard
except:
    print("please install PyYAML/clipboard first", file=sys.stderr)
    print("sudo pip install PyYAML", file=sys.stderr)
    sys.exit(-1)


def halt_with_help():
    print("Usage: kc-import <YAML_FILE_PATH>", file=sys.stderr)
    print("   pipe from stdin is not supported because user input is needed", file=sys.stderr)
    print(file=sys.stderr)
    sys.exit(-1)


if len(sys.argv) < 2:
    halt_with_help()

# new_config_data = clipboard.paste()
yaml_path = sys.argv[1]
with open(yaml_path) as yaml_file:
    new_config_data = yaml_file.read()

if not new_config_data:
    halt_with_help()

try:
    new_config = yaml.load(new_config_data, Loader=yaml.Loader)
except:
    print("illegal yaml format", file=sys.stderr)

new_clusters = new_config.get('clusters')
new_contexts = new_config.get('contexts')
new_users = new_config.get('users')
if not new_clusters or not new_contexts or not new_users:
    print("configuration yaml must have clusers/contexts/users", file=sys.stderr)
    sys.exit(-1)

new_context_name = input("Enter context name:")
if not new_context_name:
    print("aborted!", file=sys.stderr)
    sys.exit(-1)

new_cluster_name = input("Enter cluster name:")
if not new_cluster_name:
    print("aborted!", file=sys.stderr)
    sys.exit(-1)

new_user_name = f'{new_cluster_name}-user'


# load config file
cfg_path = os.path.expanduser('~/.kube/config')
if os.path.exists(cfg_path):
    with open(cfg_path) as f:
        config = yaml.load(f, Loader=yaml.Loader) or {}
else:
    os.makedirs(os.path.dirname(cfg_path), exist_ok=True)
    config = {}
config['apiVersion'] = config.get('apiVersion', 'v1')
config['kind'] = config.get('kind', 'Config')
config['clusters'] = config.get('clusters', [])
config['contexts'] = config.get('contexts', [])
config['users'] =config.get('users', [])

# merge cluster into config
def append_or_replace(array, elem, cond):
    index = -1
    for i, c in enumerate(array):
        if cond(c):
            index = i
            break
    if index > -1:
        old_elem = array[index]
        array[index] = elem
        return old_elem
    else:
        array.append(elem)


def update_context_ref(old, new, ref_key):
    if old and old['name'] != new['name']:
        for ctx in config['contexts']:
            # import ipdb; ipdb.set_trace()
            if ctx['name'] == old['name']:
                ctx['context'][ref_key] = new['name']


new_context = new_contexts[0]
new_cluster = new_clusters[0]
new_user = new_users[0]

new_context['name'] = new_context_name
new_context['context']['cluster'] = new_cluster_name
new_context['context']['user'] = new_user_name
new_cluster['name'] = new_cluster_name
new_user['name'] = new_user_name

old_cluster = append_or_replace(
    config['clusters'],
    new_cluster,
    lambda c: (
        c['name'] == new_cluster_name or c['cluster'] == new_cluster['cluster']
    )
)
update_context_ref(old_cluster, new_cluster, 'cluster')

old_user = append_or_replace(
    config['users'],
    new_user,
    lambda u: (
        u['name'] == new_user['name'] or u['user'] == new_user['user']

    )
)
update_context_ref(old_user, new_user, 'user')

append_or_replace(
    config['contexts'],
    new_context,
    lambda c: (
        c['name'] == new_context_name
    )
)

# save config file
config['current-context'] = new_context_name
with open(cfg_path, 'w') as f:
    f.write(yaml.dump(config))