#!/bin/bash

source /a/bin/errhandle/errcatch-function
source /a/bin/errhandle/bash-trace-function

errcatch

m() {
    echo "$*"
    "$@"
}
s() { sudo "$@"; }
lnf() { /a/exe/lnf "$@"; }


shopt -s nullglob
shopt -s extglob # note, already set with bash -l

# If we make a link back to the root, we stop going deeper into subdir_files.
# This makes it so we can do subdir directories.
#
# Also note, under filesystem/, symlinks are expanded.

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")) == "$below" ]]; then
            m lnf -T "$path" "$HOME/${path#$root/}"
        elif [[ -d "$path" ]]; then
            subdir-link-r "$root" "$path"
        fi
    done
}

common-file-setup() {
    local dir fs x
    for dir in "$@"; do
        fs=$dir/filesystem
        if [[ -e $fs && $USER == ian ]]; then
            # note, symlinks get resolved, not copied.
            m s cp -RLT --preserve=mode,timestamps $fs /
        fi
        if [[ -e $dir/subdir_files ]]; then
            subdir-link-r $dir/subdir_files
        fi
        local x=( $dir/!(subdir_files|filesystem|machine_specific|..|.) )
        (( ${#x[@]} >= 1 )) || continue
        m lnf ${x[@]} ~
    done
}

all_dirs=({/a/c,/p/c}{,/machine_specific/$HOSTNAME})
# note, we assume a group of hosts does not have the
# same name as a single host, which is no problem on our scale.
for x in /p/c/machine_specific/*.hosts; do
    if grep -qxF $HOSTNAME $x; then all_dirs+=( ${x%.hosts} ); fi
done

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 ${all_dirs[@]}
        sudo -u traci "$BASH_SOURCE"
        ;;
    traci)
        common-file-setup ${c_dirs[@]}
        ;;
    *)
        echo "$0: error: unexpected user"; exit 1
        ;;
esac