import json
import io
import sys


def forward(
    input_json,
    output_conf,
):
    with io.open(
        input_json,
        'r'
    ) as f:
        forward_nginx = json.load(f)

    with io.open(
        output_conf,
        'w'
    ) as f:
        names = [o['app_name'] for o in forward_nginx]

        if not '' in names:
            forward_nginx.append(
                dict(
                    app_name='',
                    redirect_url='https://product-development-service.blogspot.com',
                )
            )

        sections = []
        for entry in forward_nginx:
            location = None

            if entry['app_name'] != '':
                location = '/%s/' % entry['app_name']
            else:
                location = '/'

            if 'target_endpoint' in entry:
                section_body = r'''
          proxy_set_header Host $http_host;
          proxy_set_header X-Forwarded-For $t1;
          proxy_set_header X-Forwarded-Proto $scheme;
          proxy_set_header Upgrade $http_upgrade;
          proxy_set_header Connection $connection_upgrade;
          proxy_redirect off;
          proxy_buffering off;
          proxy_pass {target_endpoint};
                '''.replace(
                    '{target_endpoint}', entry['target_endpoint'],
                )
            elif 'redirect_url' in entry:
                section_body = r'''
          return 302 {redirect_url}$request_uri;
                '''.replace(
                    '{redirect_url}', entry['redirect_url'],
                )
            else:
                raise NotImplementedError

            sections.append(r'''
        location ^~ {location} {
            {section_body}
        }
            '''.replace(
                '{section_body}', section_body,
            ).replace(
                '{location}', location,
            ))
        f.write(r'''
    events {
      multi_accept on;
      worker_connections 64;
    }

    http {
      log_format main
        '[$time_local][$remote_addr:$remote_port, $http_x_forwarded_for, $t1, $http_host]'
        '[$request_length,$bytes_sent,$request_time]'
        '[$status][$request]'
        '[$http_user_agent][$http_referer]';

      access_log /dev/null combined;
      access_log /dev/stderr main;

      server {
        set $t1 $remote_addr;
        if ($http_x_forwarded_for)
        {
          set $t1 $http_x_forwarded_for;
        }


        listen 80;
        client_max_body_size 50M;

        {sections_config}
      }

      map $http_upgrade $connection_upgrade {
        default upgrade;
        '' close;
      }
    }
        '''.replace(
          '{sections_config}', '\n'.join(sections)
        ))

def ssl(input_json, output_conf):
    with io.open(
        input_json,
        'r'
    ) as f:
        ssl_nginx = json.load(f)

    servers = []

    for server in ssl_nginx['servers']:
        servers.append(
            r'''
server {
  set $t1 $remote_addr;
  if ($http_x_forwarded_for)
  {
    set $t1 $http_x_forwarded_for;
  }

  listen 443 ssl;
  server_name {server_names};

  client_max_body_size {client_max_body_size};

  ssl_certificate {signed_chain_cert};
  ssl_certificate_key {domain_key};

  location ^~ / {
    proxy_set_header Host $http_host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    proxy_redirect off;
    proxy_buffering off;
    proxy_pass http://app:80;
  }
}
            '''.replace(
                '{server_names}', ' '.join(server['server_names'])
              ).replace(
                  '{signed_chain_cert}', server['signed_chain_cert'],
              ).replace(
                  '{client_max_body_size}', server['client_max_body_size'],
              ).replace(
                  '{domain_key}', server['domain_key'],
              )
        )

    with io.open(
        output_conf,
        'w'
    ) as f:
        f.write(
            r'''
events {
  multi_accept on;
  worker_connections 64;
}

http {
  log_format main
  '[$time_local][$remote_addr:$remote_port, $http_x_forwarded_for, $t1, $http_host]'
  '[$request_length,$bytes_sent,$request_time]'
  '[$status][$request]'
  '[$http_user_agent][$http_referer]';

  access_log /dev/null combined;
  access_log /dev/stderr main;

  {servers}


  map $http_upgrade $connection_upgrade {
    default upgrade;
    '' close;
  }
}
            '''.replace('{servers}', '\n'.join(servers))
        )


if __name__ == '__main__':
    if len(sys.argv) >= 2 and sys.argv[1] == 'ssl':
        ssl(*sys.argv[2:])
    else:
        forward(*sys.argv[1:])