{ lib, pkgs, config, ... }:
let
    cfg = config.myServices.databases.postgresql;
in {
  options.myServices.databases = {
    postgresql = {
      enable = lib.mkOption {
        default = false;
        example = true;
        description = "Whether to enable postgresql database";
        type = lib.types.bool;
      };
      package = lib.mkOption {
        type = lib.types.package;
        default = pkgs.postgresql;
        description = ''
          Postgresql package to use.
          '';
      };
      ldapConfig = lib.mkOption {
        description = "LDAP configuration to allow PAM identification via LDAP";
        type = lib.types.submodule {
          options = {
            host = lib.mkOption { type = lib.types.str; };
            base = lib.mkOption { type = lib.types.str; };
            dn = lib.mkOption { type = lib.types.str; };
            password = lib.mkOption { type = lib.types.str; };
            filter = lib.mkOption { type = lib.types.str; };
          };
        };
      };
      replicationLdapConfig = lib.mkOption {
        description = "LDAP configuration to allow replication";
        type = lib.types.submodule {
          options = {
            host = lib.mkOption { type = lib.types.str; };
            base = lib.mkOption { type = lib.types.str; };
            dn = lib.mkOption { type = lib.types.str; };
            password = lib.mkOption { type = lib.types.str; };
          };
        };
      };
      authorizedHosts = lib.mkOption {
        default = {};
        description = "Hosts to allow connections from";
        type = lib.types.attrsOf (lib.types.listOf (lib.types.submodule {
          options = {
            method = lib.mkOption {
              default = "md5";
              type = lib.types.str;
            };
            username = lib.mkOption {
              default = "all";
              type = lib.types.str;
            };
            database = lib.mkOption {
              default = "all";
              type = lib.types.str;
            };
            ip4 = lib.mkOption {
              default = [];
              type = lib.types.listOf lib.types.str;
            };
            ip6 = lib.mkOption {
              default = [];
              type = lib.types.listOf lib.types.str;
            };
          };
        }));
      };
      replicationHosts = lib.mkOption {
        default = {};
        description = "Hosts to allow replication from";
        type = lib.types.attrsOf (lib.types.submodule {
          options = {
            ip4 = lib.mkOption {
              type = lib.types.listOf lib.types.str;
            };
            ip6 = lib.mkOption {
              type = lib.types.listOf lib.types.str;
            };
          };
        });
      };
      # Output variables
      socketsDir = lib.mkOption {
        type = lib.types.path;
        default = "/run/postgresql";
        description = ''
          The directory where Postgresql puts sockets.
          '';
        readOnly = true;
      };
      systemdRuntimeDirectory = lib.mkOption {
        type = lib.types.str;
        # Use ReadWritePaths= instead if socketsDir is outside of /run
        default = assert lib.strings.hasPrefix "/run/" cfg.socketsDir;
          lib.strings.removePrefix "/run/" cfg.socketsDir;
        description = ''
        Adjusted Postgresql sockets directory for systemd
        '';
        readOnly = true;
      };
    };
  };

  config = lib.mkIf cfg.enable {
    networking.firewall.allowedTCPPorts = [ 5432 ];

    security.acme.certs."postgresql" = config.myServices.databasesCerts // {
      user = "postgres";
      group = "postgres";
      plugins = [ "fullchain.pem" "key.pem" "account_key.json" ];
      domain = "db-1.immae.eu";
      postRun = ''
        systemctl reload postgresql.service
      '';
    };

    systemd.services.postgresql.serviceConfig = {
      SupplementaryGroups = "keys";
      RuntimeDirectory = cfg.systemdRuntimeDirectory;
    };
    services.postgresql = {
      enable = true;
      package = cfg.package;
      enableTCPIP = true;
      extraConfig = ''
        max_connections = 100
        wal_level = logical
        shared_buffers = 512MB
        work_mem = 10MB
        max_wal_size = 1GB
        min_wal_size = 80MB
        log_timezone = 'Europe/Paris'
        datestyle = 'iso, mdy'
        timezone = 'Europe/Paris'
        lc_messages = 'en_US.UTF-8'
        lc_monetary = 'en_US.UTF-8'
        lc_numeric = 'en_US.UTF-8'
        lc_time = 'en_US.UTF-8'
        default_text_search_config = 'pg_catalog.english'
        ssl = on
        ssl_cert_file = '${config.security.acme.directory}/postgresql/fullchain.pem'
        ssl_key_file = '${config.security.acme.directory}/postgresql/key.pem'
        '';
      authentication = let
        hosts = builtins.concatStringsSep "\n" (
          lib.lists.flatten (lib.mapAttrsToList (k: vs: map (v:
            map (ip6: "hostssl	${v.database}	${v.username}	${ip6}/128	${v.method}") v.ip6
            ++ map (ip4: "hostssl	${v.database}	${v.username}	${ip4}/32		${v.method}") v.ip4
          ) vs) cfg.authorizedHosts
        ));
        replication = builtins.concatStringsSep "\n" (
          lib.lists.flatten (lib.mapAttrsToList (k: v:
          map (ip6: "hostssl	replication	${k}	${ip6}/128	pam pamservice=postgresql_replication") v.ip6
          ++ map (ip4: "hostssl	replication	${k}	${ip4}/32		pam pamservice=postgresql_replication") v.ip4
          ) cfg.replicationHosts
        ));
      in ''
        local	all	postgres				ident
        local	all	all					md5
        ${hosts}
        hostssl	all	all	all				pam
        ${replication}
      '';
    };

    secrets.keys = [
      {
        dest = "postgresql/pam";
        permissions = "0400";
        group = "postgres";
        user = "postgres";
        text =  with cfg.ldapConfig; ''
          host ${host}
          base ${base}
          binddn ${dn}
          bindpw ${password}
          pam_filter ${filter}
          ssl start_tls
        '';
      }
      {
        dest = "postgresql/pam_replication";
        permissions = "0400";
        group = "postgres";
        user = "postgres";
        text = with cfg.replicationLdapConfig; ''
          host ${host}
          base ${base}
          binddn ${dn}
          bindpw ${password}
          pam_login_attribute cn
          ssl start_tls
        '';
      }
    ];

    security.pam.services = let
      pam_ldap = "${pkgs.pam_ldap}/lib/security/pam_ldap.so";
    in [
      {
        name = "postgresql";
        text = ''
          auth    required ${pam_ldap} config=${config.secrets.location}/postgresql/pam
          account required ${pam_ldap} config=${config.secrets.location}/postgresql/pam
          '';
      }
      {
        name = "postgresql_replication";
        text = ''
          auth    required ${pam_ldap} config=${config.secrets.location}/postgresql/pam_replication
          account required ${pam_ldap} config=${config.secrets.location}/postgresql/pam_replication
          '';
      }
    ];
  };
}