use std::borrow::Cow;
use std::path::Path;
use std::path::PathBuf;

use command_runner::{CommandRunner, SetuidCommandRunner};
use storage::{SimpleStorage, Storage};
use symbols::acme::{newAcmeUser, AcmeCert, AcmeCertChain};
use symbols::cron::Cron;
use symbols::file::File;
use symbols::git::checkout::GitCheckout;
use symbols::hook::Hook;
use symbols::list::List;
use symbols::mariadb::{DatabaseDump, MariaDBDatabase, MariaDBUser};
use symbols::nginx::server::{server_config, NginxServer};
use symbols::owner::Owner;
use symbols::stored_directory::{StorageDirection, StoredDirectory};
use symbols::systemd::reload::ReloadService;
use symbols::systemd::user_service::UserService;
use symbols::tls::SelfSignedTlsCert;
use symbols::{Symbol, SymbolRunner};

pub trait Policy {
  fn user_name_for_host(&self, host_name: &'static str) -> String {
    host_name.split('.').rev().fold(String::new(), |result, part| if result.is_empty() { result } else { result + "_" } + part)
  }
  fn home_for_user(&self, user_name: &str) -> PathBuf {
    format!("/home/{}", user_name).into()
  }
  fn socket_path(&self, user_name: &str, service_name: &str) -> PathBuf {
    format!("/var/tmp/{}-{}.socket", user_name, service_name).into()
  }
}

pub struct DefaultPolicy;

impl Policy for DefaultPolicy {}

pub struct SymbolFactory<'a, C: 'a + CommandRunner, R: 'a + SymbolRunner, P: 'a + Policy> {
  command_runner: &'a C,
  acme_command_runner: SetuidCommandRunner<'a, Cow<'a, str>, C>,
  symbol_runner: &'a R,
  policy: &'a P,
}

impl<'b, C: 'b + CommandRunner, R: 'b + SymbolRunner, P: 'b + Policy> SymbolFactory<'b, C, R, P> {
  pub fn new(command_runner: &'b C, symbol_runner: &'b R, policy: &'b P) -> Self {
    let acme_user = "acme"; // FIXME: CONFIG

    let acme_command_runner = SetuidCommandRunner::new(acme_user.into(), command_runner);
    SymbolFactory {
      command_runner,
      acme_command_runner,
      symbol_runner,
      policy,
    }
  }

  pub fn get_nginx_acme_server<'a, 'c: 'a, S: 'a + Symbol>(
    &'c self,
    host: &'static str,
    nginx_server_symbol: S,
  ) -> impl Symbol + 'a {
    List::from((
      SelfSignedTlsCert::new(host, self.command_runner),
      Hook::new(
        nginx_server_symbol,
        ReloadService::new("nginx", self.command_runner),
      ),
      AcmeCert::new(host, &self.acme_command_runner),
      Hook::new(
        AcmeCertChain::new(host, &self.acme_command_runner),
        ReloadService::new("nginx", self.command_runner),
      ),
    ))
  }
  pub fn get_nginx_acme_challenge_config<'a>(&'a self) -> impl Symbol + 'a {
    File::new(
      "/etc/nginx/snippets/acme-challenge.conf",
      "location ^~ /.well-known/acme-challenge/ {
  alias /home/acme/challenges/;
  try_files $uri =404;
}",
    )
  }

  fn get_php_fpm_pool_socket_path<'a>(&'a self, user_name: &str) -> PathBuf {
    format!("/run/php/{}.sock", user_name).into()
  }

  fn get_php_fpm_pool<'a>(&'a self, user_name: &str) -> impl Symbol + 'a {
    let socket = self.get_php_fpm_pool_socket_path(user_name);
    Hook::new(
      File::new(
        format!("/etc/php/7.0/fpm/pool.d/{}.conf", user_name),
        format!(
          "[{0}]

user = {0}
group = www-data
listen = {1}
listen.owner = www-data
pm = ondemand
pm.max_children = 10
catch_workers_output = yes
env[PATH] = /usr/local/bin:/usr/bin:/bin
",
          user_name,
          socket.to_str().unwrap()
        ),
      ),
      ReloadService::new("php7.0-fpm", self.command_runner),
    )
  }

  pub fn serve_php<'a, ROOT: AsRef<Path>>(
    &'a self,
    host_name: &'static str,
    root_dir: ROOT,
    additional_config: &'a str,
  ) -> impl Symbol + 'a {
    let user_name = self.policy.user_name_for_host(host_name);
    let socket = self.get_php_fpm_pool_socket_path(&user_name);
    List::from((
      self.get_php_fpm_pool(&user_name),
      self.get_nginx_acme_server(
        host_name,
        NginxServer::new_php(
          host_name,
          socket,
          root_dir,
          self.command_runner,
          additional_config,
        ),
      ),
    ))
  }

  pub fn serve_wordpress<'a, ROOT: 'a + AsRef<Path>>(
    &'a self,
    host_name: &'static str,
    root_dir: ROOT,
  ) -> impl Symbol + 'a {
    self.serve_php(
      host_name,
      root_dir,
      "
        location / {{
          try_files         $uri $uri/ /index.php?$args;
        }}
      ",
    )
  }

  pub fn serve_dokuwiki<'a>(
    &'a self,
    host_name: &'static str,
    root_dir: &'static str,
  ) -> impl Symbol + 'a {
    let user_name = self.policy.user_name_for_host(host_name);
    let socket = self.get_php_fpm_pool_socket_path(&user_name);
    List::from((
      self.get_php_fpm_pool(&user_name),
      self.get_nginx_acme_server(host_name,
        NginxServer::new(
          host_name,
          server_config(host_name, &format!("
      root                {};
      index               doku.php;
      location ~ [^/]\\.php(/|$) {{
        fastcgi_pass      unix:{};
        include           \"snippets/fastcgi-php.conf\";
      }}

      location ~ /(data/|conf/|bin/|inc/|install.php) {{ deny all; }}

      location / {{ try_files $uri $uri/ @dokuwiki; }}

      location @dokuwiki {{
          # rewrites \"doku.php/\" out of the URLs if you set the userewrite setting to .htaccess in dokuwiki config page
          rewrite ^/_media/(.*) /lib/exe/fetch.php?media=$1 last;
          rewrite ^/_detail/(.*) /lib/exe/detail.php?media=$1 last;
          rewrite ^/_export/([^/]+)/(.*) /doku.php?do=export_$1&id=$2 last;
          rewrite ^/(.*) /doku.php?id=$1&$args last;
      }}
  ",
        root_dir,
        socket.to_str().unwrap())),
        self.command_runner
      ))
    ))
  }

  pub fn serve_nextcloud<'a, ROOT: 'a + AsRef<Path>>(
    &'a self,
    host_name: &'static str,
    root_dir: ROOT,
  ) -> impl Symbol + 'a {
    self.serve_php(
      host_name,
      root_dir,
      "
              client_max_body_size 500M;

              # Disable gzip to avoid the removal of the ETag header
              gzip off;

              rewrite ^/caldav(.*)$ /remote.php/caldav$1 redirect;
              rewrite ^/carddav(.*)$ /remote.php/carddav$1 redirect;
              rewrite ^/webdav(.*)$ /remote.php/webdav$1 redirect;

              error_page 403 /core/templates/403.php;
              error_page 404 /core/templates/404.php;

              location = /robots.txt {
                allow all;
                log_not_found off;
                access_log off;
              }

              location ~ ^/(?:\\.htaccess|data|config|db_structure\\.xml|README) {
                deny all;
              }

              location / {
                # The following 2 rules are only needed with webfinger
                rewrite ^/.well-known/host-meta /public.php?service=host-meta last;
                rewrite ^/.well-known/host-meta.json /public.php?service=host-meta-json last;

                rewrite ^/.well-known/carddav /remote.php/carddav/ redirect;
                rewrite ^/.well-known/caldav /remote.php/caldav/ redirect;

                rewrite ^(/core/doc/[^\\/]+/)$ $1/index.html;

                try_files $uri $uri/ /index.php;
              }

              # Adding the cache control header for js and css files
              # Make sure it is BELOW the location ~ \\.php(?:$|/) { block
              location ~* \\.(?:css|js)$ {
                add_header Cache-Control \"public, max-age=7200\";
                # Optional: Don't log access to assets
                access_log off;
              }

              # Optional: Don't log access to other assets
              location ~* \\.(?:jpg|jpeg|gif|bmp|ico|png|swf)$ {
                access_log off;
              }
          ",
    )
  }

  pub fn serve_redir<'a>(
    &'a self,
    host_name: &'static str,
    target: &'static str,
  ) -> impl Symbol + 'a {
    self.get_nginx_acme_server(
      host_name,
      NginxServer::new_redir(host_name, target, self.command_runner),
    )
  }

  pub fn serve_static<'a>(&'a self, host_name: &'static str, dir: &'a str) -> impl Symbol + 'a {
    self.get_nginx_acme_server(
      host_name,
      NginxServer::new_static(host_name, dir, self.command_runner),
    )
  }

  pub fn get_stored_directory<'a, T: Into<String>>(
    &'a self,
    storage_name: &'static str,
    target: T,
  ) -> (impl Symbol + 'a, impl Symbol + 'a) {
    let data = SimpleStorage::new("/root/data".to_string(), storage_name.to_string());
    let string_target = target.into();
    (
      StoredDirectory::new(
        string_target.clone(),
        data.clone(),
        StorageDirection::Save,
        self.command_runner,
      ),
      StoredDirectory::new(
        string_target,
        data.clone(),
        StorageDirection::Load,
        self.command_runner,
      ),
    )
  }

  pub fn get_mariadb_database<'a>(&'a self, name: &'static str) -> impl Symbol + 'a {
    let db_dump = SimpleStorage::new("/root/data".to_string(), format!("{}.sql", name));
    List::from((
      MariaDBDatabase::new(
        name,
        db_dump.read_filename().expect("Initial db dump missing"),
        self.command_runner,
      ),
      DatabaseDump::new(name, db_dump, self.command_runner),
    ))
  }

  pub fn get_mariadb_user<'a>(&'a self, user_name: &'static str) -> impl Symbol + 'a {
    MariaDBUser::new(user_name, self.command_runner)
  }

  pub fn get_git_checkout<'a, T: 'a + AsRef<Path>>(
    &'a self,
    target: T,
    source: &'a str,
    branch: &'a str,
  ) -> impl Symbol + 'a {
    GitCheckout::new(target, source, branch, self.command_runner)
  }

  pub fn get_owner<'a, U: 'a + AsRef<str>, F: 'a + AsRef<Path>>(
    &'a self,
    file: F,
    user: U,
  ) -> impl Symbol + 'a {
    Owner::new(file, user, self.command_runner)
  }

  pub fn get_file<'a, F: 'a + AsRef<str>, Q: 'a + AsRef<Path>>(
    &'a self,
    path: Q,
    content: F,
  ) -> impl Symbol + 'a {
    File::new(path, content)
  }

  pub fn get_cron<'a, T: 'a + AsRef<str>, U: 'a + AsRef<str>>(
    &'a self,
    user: U,
    content: T,
  ) -> impl Symbol + 'a {
    Cron::new(user, content, self.command_runner)
  }

  pub fn get_acme_user<'a, S: 'a + AsRef<str> + Clone, D: 'a + AsRef<str>>(
    &'a self,
    cert: D,
    user_name: S,
  ) -> impl Symbol + 'a {
    let home = self.policy.home_for_user(user_name.as_ref());
    newAcmeUser(self.command_runner, cert, user_name.clone(), home)
  }

  pub fn get_systemd_user_service<'a>(
    &'a self,
    user_name: Cow<'a, str>,
    service_name: &'a str,
    config: Cow<'a, str>,
  ) -> impl Symbol + 'a {
    let socket_path = self.policy.socket_path(&user_name, service_name);
    let home = self.policy.home_for_user(&user_name);
    UserService::new(
      socket_path.into(),
      home.into(),
      user_name,
      service_name,
      self.command_runner,
      config.into(),
    )
  }

  fn get_nodejs_systemd_user_service<'a, T: Into<Cow<'a, Path>>>(
    &'a self,
    user_name: Cow<'a, str>,
    service_name: &'a str,
    path: T,
  ) -> impl Symbol + 'a {
    let socket_path = self.policy.socket_path(&user_name, service_name);
    let home = self.policy.home_for_user(&user_name);
    UserService::new_nodejs(
      home.into(),
      user_name,
      service_name,
      path.into(),
      self.command_runner,
      socket_path.into(),
    )
  }

  pub fn proxy_socket<'a, T: Into<Cow<'a, Path>>>(
    &'a self,
    host_name: &'static str,
    service_name: &'a str,
    root_dir: T,
  ) -> impl Symbol + 'a {
    let user_name = self.policy.user_name_for_host(host_name);
    let socket_path = self.policy.socket_path(&user_name, service_name);
    self.get_nginx_acme_server(
      host_name,
      NginxServer::new_proxy(host_name, socket_path, root_dir.into(), self.command_runner),
    )
  }

  pub fn serve_nodejs<
    'a,
    'c: 'a,
    S: 'a + Symbol,
    T: 'a + Into<Cow<'a, Path>>,
    SP: 'a + Into<Cow<'a, Path>>,
  >(
    &'c self,
    host: &'static str,
    service_name: &'a str,
    path: T,
    static_path: SP,
    nodejs_symbol: S,
  ) -> impl Symbol + 'a {
    let user_name = self.policy.user_name_for_host(host);
    List::from((
      Hook::new(
        nodejs_symbol,
        self.get_nodejs_systemd_user_service(user_name.into(), service_name, path),
      ),
      self.proxy_socket(host, service_name, static_path),
    ))
  }
}