# NOTE:
# our .zprofile is expensive, so we keep track of what has been run already,
# and only set up what is necessary. additionally, we want to ensure that our
# environment is set up as early as possible, so we also source .zprofile in
# .zshenv for new non-login shells.
#
# these issues are handled by using these methods:
#   * the parent shell that starts the user's session after logging in to some
#     graphical environments may not be a login shell—due to misconfiguration
#     or otherwise—which means .zprofile is not ran and the environment is not
#     properly configured for any child processes.
#   * some desktop environments/graphical terminal emulators will start new
#     terminal windows with login shells, which runs .zprofile every time and
#     leads to noticably slow startup times.
#   * switching users without wiping the environment will result in paths and
#     variables intended for the old user being used for the new user. while
#     this may be considered an edge-case that should not be supported, there
#     are legitimate reasons to want to do this, and in any case the shell
#     should not choke or cause unexpected problems should it happen anyway.

### cleanup
# XXX: only call after relevant vars have been set up, defined early so that
#      below code can utilize it after they do so
function _sev_zcleanup {
    ## gpg forwarding
    if [[ -d $_sev_gpg_forward_dir && ( -z $1 || $1 == 'gpg-forward' ) ]] {
        # clean up forward dirs if its session is dead or we ask for it
        find $_sev_gpg_forward_dir -mindepth 1 -maxdepth 1 -type d |
          while {read -r x} {
            # NOTE: the only way we can get here is if we have not been
            #       forwarded before, if the user asks for it, or during
            #       logout. if our own pid already has a dir, it is most likely
            #       stale, the user wants it removed, or something is very
            #       broken—in all 3 of these cases the best choice is remove it.
            p=$(basename $x)
            if {[[ -v _sev_gpg_forward_clean || $$ == $p ]] ||
                ! kill -0 $p 2>/dev/null} {
                find $x -mindepth 1 -maxdepth 1 | while {read -r y} {
                    # XXX: real dirs will stop unlink, consider it a feature
                    unlink $y
                }
                # don't force in case something important is still there
                rmdir $x
            }
        }
        # reset GNUPGHOME if we removed our own dir
        if [[ $GNUPGHOME =~ '/.ssh_forward/\d+/*$' && ! -e $GNUPGHOME ]] {
            x=$GNUPGHOME
            [[ -o GLOB_ASSIGN ]]; y=$?
            setopt GLOB_ASSIGN
            GNUPGHOME=$GNUPGHOME/../..(:a)
            (( y != 0 )) && unsetopt GLOB_ASSIGN
        }
    }

    ## tmp
    # NOTE: _sev_tmp is not unset so session dirs will not be recreated
    # NOTE: XDG dirs that use our tmp are not unset here, they are in zlogout
    if [[ -d $_sev_tmp && ( -z $1 || $1 == 'tmp' ) ]] {
        # clean up tmp dirs if its session is dead or we ask for it
        find $_sev_tmp -mindepth 1 -maxdepth 1 -name '.session.*' -type d |
          while {read -r x} {
            # NOTE: same rationale as above
            p=${$(basename $x)#.session.}
            if {[[ -v _sev_tmp_clean || $$ == $p ]] ||
                ! kill -0 $p 2>/dev/null} {
                rm -rf $x
            }
        }
    }

    unset x p y
}

### lang
export CHARSET=${CHARSET:-UTF-8}
export LANG=${LANG:-en_US.UTF-8}
export LC_CTYPE=${LC_TYPE:-$LANG}

### path
# NOTE: we utilize the fact that unique arrays keep the first occurrence and
#       remove any further occurences to capture elements from the old PATH
#       that we did not anticipate and shift them to the front, since they are
#       probably important to the system
if [[ ! -v _sev_setup_path || -o login ]] {
    typeset -U path fpath
    # add as many generic paths as possible to keep the order we want
    # NOTE: /usr/{local,pkg,games} are unix/bsdisms
    # XXX: PREFIX not validated, non-posix but Termux uses it
    syspath=("$path[@]")
    path=({~,~/.local,{$PREFIX,}{,/opt,/usr{,/local,pkg}}}/sbin
          {~,~/.local,{$PREFIX,}{,/opt,/usr{,/local,pkg}}}/bin
          /usr/{X11R{7,6}/bin,games})
    ((len=$#path))
    path=("$path[@]" "$syspath[@]")
    # remove nonexistent and duplicate paths
    for (( i = 1; i <= $#path; i++ )) {
        if [[ ! -e $path[$i] ]] {
            path[$i]=()
            ((i <= len)) && ((len--))
            ((i--))
            continue
        }
    }
    # shift valid system paths to the front if there are any left
    ((len > 0 && len < $#path)) && path=("${(@)path[len + 1, -1]}" "${(@)path[1, len]}")
    unset syspath len i j
    # include our zsh dir in fpath. unlike above, we always prefer our paths
    fpath=(${ZDOTDIR:-~/.zsh}/functions/{*,Completions/*}(N) "$fpath[@]")
    # FPATH is not exported by default
    export FPATH
    typeset +U path fpath
    export _sev_setup_path=
}

### tmp
# NOTE: specs say that POSIX tmp and XDG runtime directories should exist
#       until the last session is logged out (POSIX can exist for longer).
#       since we can't reliably keep track of sessions in a cross-platform
#       manner, the current implementation should use a separate directory per
#       toplevel session (i.e. SHLVL=1). this should placate most applications,
#       though it is not expressly spec compliant.
if [[ ! -v _sev_tmp ]] {
    _sev_tmp=~/tmp
    # create personal tmp dir
    t=${TMPDIR:-${TEMP:-${TMP:-/tmp}}}/.home-$LOGNAME
    [[ ! -e $t ]] && mkdir -m700 $t 2>/dev/null
    if [[ ! -d $t ]] {
        [[ -o interactive ]] &&
          print -P "%F{red}!!! Can't create tmpdir $t%f"
        # fallback bare directories
        [[ -h $_sev_tmp ]] && unlink $_sev_tmp 2>/dev/null
        [[ ! -e $_sev_tmp ]] && mkdir -m700 $_sev_tmp 2>/dev/null
    }
    # link home tmp for convenience if there isn't anything meaningful there
    [[ -h $_sev_tmp || ! -e $_sev_tmp ]] && ln -sfn $t $_sev_tmp 2>/dev/null
    export _sev_tmp=$(realpath $_sev_tmp)
    # ensure dir is clean
    _sev_zcleanup tmp
    # finally create our subdir for this session
    h=$_sev_tmp/.session.$$
    mkdir -m700 $h 2>/dev/null
    export TMPDIR=$h TEMP=$h TMP=$h
    unset t h
}

### xdg
if [[ ! -v _sev_setup_xdg ]] {
    # merge with any existing dirs and remove duplicates using unique arrays
    # NOTE: include and then remove CONFIG_HOME and DATA_HOME to ensure they
    #       are not present in the array if it was added before we got to it
    typeset -UT XDG_CONFIG_DIRS xdg_config_dirs
    export XDG_CONFIG_HOME=~/etc
    mkdir $XDG_CONFIG_HOME 2>/dev/null
    xdg_config_dirs=($XDG_CONFIG_HOME ~/.config
      {/opt,/usr/local,/usr/pkg,}/etc/xdg
      "${XDG_CONFIG_DIRS:+${xdg_config_dirs[@]}}")
    export XDG_CONFIG_DIRS=${XDG_CONFIG_DIRS#$XDG_CONFIG_HOME}

    typeset -UT XDG_DATA_DIRS xdg_data_dirs
    export XDG_DATA_HOME=~/share
    mkdir $XDG_DATA_HOME 2>/dev/null
    xdg_data_dirs=($XDG_DATA_HOME ~/.local/share
      /{opt,usr/local,usr/pkg,usr}/share
      "${XDG_DATA_DIRS:+${xdg_data_dirs[@]}}")
    export XDG_DATA_DIRS=${XDG_DATA_DIRS#$XDG_DATA_HOME}

    mkdir ~/var 2>/dev/null
    export XDG_STATE_HOME=~/var/lib
    mkdir $XDG_STATE_HOME 2>/dev/null

    if [[ -v _sev_tmp ]] {
        export XDG_CACHE_HOME=$_sev_tmp/.xdg.cache
        mkdir $XDG_CACHE_HOME 2>/dev/null

        export XDG_RUNTIME_DIR=$TMPDIR/.xdg.runtime
        # same as in tmpdir creation, ensure it doesn't exist
        if [[ -h $XDG_RUNTIME_DIR ]]; then
            unlink $XDG_RUNTIME_DIR 2>/dev/null
        elif [[ -e $XDG_RUNTIME_DIR ]]; then
            rm -rf $XDG_RUNTIME_DIR 2>/dev/null
        fi
        mkdir -m700 $XDG_RUNTIME_DIR 2>/dev/null
    }

    # source user dirs after other vars
    [[ -e $XDG_CONFIG_HOME/user-dirs.dirs ]] &&
      emulate sh -c "source $XDG_CONFIG_HOME/user-dirs.dirs"
    export _sev_setup_xdg=
}

### dbus
if [[ ! -v DBUS_SESSION_BUS_ADDRESS && -v commands[dbus-launch] ]] {
    eval $(dbus-launch)
    export DBUS_SESSION_BUS_ADDRESS DBUS_SESSION_BUS_PID
}

### gpg home
if [[ ! -v GNUPGHOME ]] {
    export GNUPGHOME=~/etc/gnupg
    if [[ -d ~/.gnupg ]] {
        mv ~/.gnupg ~/etc/gnupg
    }
}

### gpg agent + forwarding
# NOTE: while ssh manages its auth sock in its protocol when ForwardSsh is
#       enabled, GPG must be forwarded manually over Unix socket. to support
#       this, we forward the restricted gpg-agent extra socket to the remote
#       host with a RemoteForward rule in ~/.ssh/config that uses the
#       _GNUPG_SOCK_* env vars. to avoid conflicts with other ssh sessions
#       where the same user is connecting to the same host from different
#       machines, gpg in each environment should utilize its own forwarded
#       socket, rather than replace the sockets in GNUPGHOME which will be
#       overridden on the next connection. previously, you could provide a path
#       to the agent socket in GPG_AGENT_INFO, but that was deprecated in GPG
#       v2.1. instead, we must clone GNUPGHOME with links and replace the agent
#       sockets there with the forwarded one.
# NOTE: since Unix sockets are not supported under Windows, this will not work
#       under msys, cygwin, mingw, etc., but may work under wsl2.
# HACK: without SendEnv, which is disabled by default in most sshd configs,
#       there is no foolproof way to prevent race conditions via filename
#       collisions or to pass the desired forward path to the remote host
#       environment. we just have to guess the path we choose is good on the
#       desination, and assume the newest matching socket is the correct one
#       after connecting. in theory, we could occlude the ssh binary on PATH
#       with an alias or script that would allow us to communicate with the
#       remote host before opening a shell, so that we can have the host
#       communicate back to the client where it wants a socket created or ask
#       the host if the path the client wants to use is writable. however, this
#       would open up too many edge cases where it wouldn't work or be clunky
#       (e.g. asking for password twice) to make it worth it.
function _gpg_socketpath {
    # dirs are percent-encoded: https://stackoverflow.com/a/64312099
    echo ${1//(#b)%([[:xdigit:]](#c2))/${(#):-0x$match[1]}}
}
if [[ ! -v _sev_setup_gpg_forward && -v commands[gpg] ]] {
    export _GNUPG_SOCK_DEST_BASE=/tmp/.gpg-agent-forward
    export _GNUPG_SOCK_DEST_EXT=$(date +%s).$RANDOM
    export _GNUPG_SOCK_DEST=$_GNUPG_SOCK_DEST_BASE.$_GNUPG_SOCK_DEST_EXT
    export _sev_gpg_forward_dir=${GNUPGHOME:-~/.gnupg}/.ssh_forward
    _sev_zcleanup gpg-forward

    # find our forwarded socket
    s=($_GNUPG_SOCK_DEST_BASE*(N=oc[1]))
    if [[ -n $s && -v SSH_CLIENT ]] {
        # create new forward dir
        export _sev_setup_gpg_forward=
        h=$_sev_gpg_forward_dir/$$
        mkdir -pm700 $h
        # XXX: is it safe to link scdaemon socket? can its name be changed?
        for x (S.scdaemon gpg.conf gpg-agent.conf sshcontrol random_seed
               pubring.kbx{,~} trustdb.gpg private-keys-v1.d crls.d) {
            ln -s ${GNUPGHOME:-~/.gnupg}/$x $h
        }
        export GNUPGHOME=$h
        unset h
        for x in $(gpgconf --list-dirs | grep 'agent-.*-\?socket:'); do
            x=$(_gpg_socketpath ${x/#agent-*socket:})
            if [[ ! -v orig ]] {
                # move forwarded socket to first valid agent socket path
                # XXX: if tmp is on different filesystem this may not work
                mv $s $x
                orig=$x
            } else {
                # make links to forwarded socket for any others
                ln -s $orig $x
            }
        done
        unset x orig
    }
    unset s

    # what we will forward if we start a new ssh connection
    # NOTE: do this after setting up GNUPGHOME to pick up new socket path;
    #       if already connected over SSH, extra should be the remote one
    export _GNUPG_SOCK_SRC=$(_gpg_socketpath \
      $(gpgconf --list-dirs agent-extra-socket))
} elif [[ ! -v _sev_setup_gpg_forward ]] {
    # required for RemoteForward to not error out if the vars are unset
    [[ ! -v _GNUPG_SOCK_SRC ]] && export _GNUPG_SOCK_SRC=/nonexistent
    [[ ! -v _GNUPG_SOCK_DEST ]] && export _GNUPG_SOCK_DEST=/nonexistent
}

### gpg agent
if [[ -v commands[gpg-connect-agent] && ( ! -v _sev_setup_gpgagent ||
        ( -v _sev_first_display && -z $_sev_first_display ) ) ]] {
    # avoid printing if we have already set up tty before
    [[ ! -v _sev_setup_gpgagent && -o interactive ]] && p=true || p=false
    if {$p} {
        print -nP '%F{blue}>>>%f GPG: '
        if [[ -v _sev_setup_gpg_forward ]] {
            a=agent
            print -nP '%F{yellow}Forwarded%f '
        } else { a=Agent }
        print -nP '%F{green}'
    }
    gpg-connect-agent /bye >/dev/null 2>&1
    if [[ $? -ne 0 ]] {
        $p && print -P '%F{red}$a communication error'
    } else {
        if [[ ${+GPG_TTY} -eq 0 && -o interactive ]]
            export GPG_TTY=$(tty)
        if [[ ( -v DISPLAY || -v WAYLAND_DISPLAY ) &&
              ${PINENTRY_USER_DATA/USE_TTY=0} == $PINENTRY_USER_DATA ]]
            export PINENTRY_USER_DATA=USE_TTY=$((
              ${+DISPLAY} + ${+WAYLAND_DISPLAY} == 0))
        # XXX: don't know if gpg-agent supports comments after directives
        # XXX: path could have #
        sed -Ei 's#^([[:space:]]*pinentry-program[[:space:]]).*$#\1'${commands[pinentry]:-/dev/null}'#' \
          ${GNUPGHOME:-~/.gnupg}/gpg-agent.conf
        # XXX: could probably check for changes before doing this to save perf
        gpg-connect-agent RELOADAGENT UPDATESTARTUPTTY /bye >/dev/null 2>&1
        $p && gpg-connect-agent /subst /serverpid \
                "/echo $a pid \${get serverpid} on $GPG_TTY" /bye
        export _sev_setup_gpgagent=
    }
    $p && print -nP '%f'
    unset p a
}

### ssh agent
if [[ ! -v _sev_setup_ssh ]] {
    # NOTE: preferred order of agents to check: okcagent, gnupg, openssh
    #       first block takes care of okcagent and openssh, second gnupg
    # XXX: doesn't actually check if ssh is enabled in gpg
    [[ -o interactive ]] && print -nP '%F{blue}>>>%f SSH: %F{green}'
    if [[ ! -v SSH_AUTH_SOCK && ( -v commands[okc-ssh-agent] ||
          ( -v commands[ssh-agent] && ! -v commands[gpg] ) ) ]] {
        okc=${commands[okc-ssh-agent]:+okc-}
        t=${_sev_tmp:-${TMPDIR:-${TEMP:-${TMP:-/tmp}}}}
        e=$t/${okc}ssh-agent-exports
        typeset sock=
        typeset -i pid=
        if [[ -f $e ]] {
            IFS=$'\0' read -r sock pid <$e
        }
        if [[ -S $sock && $pid > 0 ]] && kill -0 $pid; then
            [[ -o interactive ]] && print -P "Reusing agent PID $pid%f"
            export SSH_AUTH_SOCK=$sock
            export SSH_AGENT_PID=$pid
        else
            e='TMPDIR=$t ${okc}ssh-agent'
            # TODO: ensure ssh-agent path looks legit to avoid unsafe eval?
            # XXX: doesn't appear to be any other way to handle redirection.
            #      because eval needs to write to current scope environment
            #      subshells can't be used to capture output and print.
            if [[ -o interactive ]] {
                eval $(eval $=e)
                print -nP '%f'
            } else {
                eval $(eval $=e) >/dev/null 2>&1
            }
            echo -n $SSH_AUTH_SOCK$'\0'$SSH_AGENT_PID >!$e
        fi
        unset okc t e sock pid
    } elif [[ ! -v SSH_AUTH_SOCK && -v commands[gpg] ]] {
        # since gpg should have been started above, just export and notify
        if [[ -o interactive ]] {
            if [[ -v _sev_setup_gpg_forward ]] {
                echo 'Forwarded GPG agent'
            } else {
                gpg-connect-agent /subst /serverpid \
                  '/echo GPG agent pid ${get serverpid}' /bye
            }
            print -nP '%f'
        }
        export SSH_AUTH_SOCK=$(_gpg_socketpath \
          $(gpgconf --list-dirs agent-ssh-socket))
    } elif [[ -v SSH_AUTH_SOCK ]] {
        [[ -o interactive ]] && print -P 'Preconfigured agent%f'
    } else {
        [[ -o interactive ]] && print -P '%F{red}No agent available%f'
    }

    export _sev_setup_ssh=
}
unfunction _gpg_socketpath

### perl local lib
[[ -v commands[perl] && -d $XDG_DATA_HOME/perl5/lib/perl5 &&
   ! -v PERL_LOCAL_LIB_ROOT ]] &&
  eval $(perl -I$XDG_DATA_HOME/perl5/lib/perl5 \
              -Mlocal::lib=$XDG_DATA_HOME/perl5 2>/dev/null)


### load site-specific
if [[ -f ~/.zprofile.local ]] { source ~/.zprofile.local }

# vim: et sts=4 sw=4 ts=8 tw=79