local optional(object, field) = std.get(object, field, {});

local dockerSocket = '/var/run/docker.sock:/var/run/docker.sock';

local mediaEnv = {
  PUID: 1000,
  PGID: 1000,
  TZ: 'America/New_York',
};

local formatHelper(fmt) = function(name, option) fmt % [name, option];
local toList(fmt) = function(object) std.objectValues(std.mapWithKey(formatHelper(fmt), object));
local toLabels = toList('%s=%s');
local toVolumes = toList('%s:%s');

local traefikLabels(name, host, port, extras) = toLabels({
  'traefik.enable': 'true',
  ['traefik.http.routers.%s.rule' % name]: 'Host(`%s.mat`)' % host,
  ['traefik.http.routers.%s.entrypoints' % name]: 'web',
  ['traefik.http.services.%s.loadbalancer.server.port' % name]: port,
  ['traefik.http.routers.%s.service' % name]: '%s' % name,
  'traefik.docker.network': 'traefik',
} + extras);

local mkService(name, svc) = svc {
  container_name: name,
  networks: ['traefik'],
  volumes: toVolumes(optional(svc, 'volumes'))
           + toVolumes(optional(svc, 'mounts'))
           + if std.get(svc, 'docker', false)
           then [dockerSocket]
           else [],
  labels: traefikLabels(name, std.get(svc, 'host', name), svc.webPort, optional(svc, 'traefik')),
  restart: 'always',
};

local extractVolumes(cfg) = {
  [name]: {
    // this is very ugly, a data driven approach would be better but very verbose
    external: std.length(std.findSubstr('_', name)) >= 2,
  }
  for name in std.flattenArrays([
    std.objectFields(optional(svc, 'volumes'))
    for svc in std.objectValues(cfg)
  ])
};

local mediaMounts(mounts) = {
  ['/media/mat/%s' % path]: mounts[path]
  for path in std.objectFields(mounts)
};

{
  Compose(cfg):: {
    services: std.mapWithKey(mkService, cfg),
    volumes: extractVolumes(cfg),
    networks: { traefik: { external: true } },
  },

  Port(port, src=port, kind='tcp')::
    local mapped = '%d:%d' % [port, src];
    '%s/%s' % [mapped, kind],

  Command:: toList('--%s=%s'),

  MediaMounts:: mediaMounts,

  MediaService(name, tag='latest', env={}, mounts={}, webPort, ports=[]):: {
    image: 'lscr.io/linuxserver/%s:%s' % [name, tag],
    environment: mediaEnv + env,
    volumes: { ['media_%s_config' % name]: '/config' },
    mounts:: mediaMounts(mounts),
    webPort:: webPort,
    ports: ports,
  },
}