#!/bin/bash -l

set -eE -o pipefail
trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?"' ERR


sysv() {
    e "$@"
    "$@"
}


#
if [[ -e /root/.unison && ! -L /root/.unison ]]; then
    d=/q/p/c/machine_specific/$host/.unison
    mkdir -p $d
    mv -f /root/.unison/* $d
fi


shopt -s nullglob
shopt -s extglob

# if we make a link back to the root, traversing the subdirs stops.
# This makes it so we can do subdir directories. Must call with absolute
# paths.

subdir-link-r() {
    local root="$1"
    local targets=()
    if [[ $2 ]]; then
        targets=( "$2"/!(.git) )
    else
        for f in "$1"/!(.git); do
            [[ -d $f ]] && targets+=("$f") ||:
        done
    fi
    local below="$( readlink -f "$root/..")"
    for path in "${targets[@]}"; do
        local fullpath="$(readlink -f "$path")"
        #e $fullpath $below # debug
        if [[ -f $path || $(dirname $(readlink -f "$fullpath")) == "$below" ]]; then
            sysv lnf -T "$path" "$HOME/${path#$root/}"
        elif [[ -d "$path" ]]; then
            subdir-link-r "$root" "$path"
        fi
    done
}

common-file-setup() {
    for dir in "$@"; do
        if [[ -e $dir/subdir_files ]]; then
            subdir-link-r $dir/subdir_files
        fi
        local x=( $dir/!(subdir_files|filesystem) )
        (( ${#x[@]} >= 1 )) || return 0
        sysv lnf ${x[@]} ~
        # as of this writing, it doesn't exist in /a/c, but I've used it in the past.
        if [[ -e $dir/filesystem && $USER == ian ]]; then
            sysv s cp -R $dir/filesystem/* /
        fi
    done
}

link-dirs() {
    for dir in "$@"; do
        common-file-setup $dir
        common-file-setup $dir/machine_specific/$HOSTNAME
    done
}

all_dirs=({/a/c,/p/c}{,/machine_specific/$HOSTNAME})
c_dirs=(/a/c{,/machine_specific/$HOSTNAME})
case $USER in
    ian)
        # p needs to go first so .ssh link is created, then config link inside it
        common-file-setup $dir ${all_dirs[@]}
        sudo -u traci "$BASH_SOURCE"
        ;;
    traci)
        common-file-setup ${c_dirs[@]}
        ;;
    root)
        if ! $ROOTCMD getent passwd ian; then
            common-file-setup ${all_dirs[@]}
        else
            echo "$0: error: unexpected user"; exit 1
        fi
        ;;
    *)
        echo "$0: error: unexpected user"; exit 1
        ;;
esac