#!/usr/bin/env bash
# set up a dummy repo
set -euo pipefail
experiment_dir="$(mktemp -d --tmpdir test_repo.XXX)"
git clone --recurse-submodules git@github.com:SKalt/dummy_repo.git "$experiment_dir"
cd "$experiment_dir"
git pull --recurse-submodules=yes

git checkout -b brnch && git checkout - # set up a dummy branch
git worktree add wrktr brnch # add a wortree
cd wrktr &&  git submodule update --init --recursive # init the recursive submodules in the worktree

tree .

tree .git

args=(
    --git-common-dir
    --git-dir
    --is-inside-git-dir
    --is-inside-work-tree
    --show-toplevel
);

padding() {
    local delimiter="$1" # must be 1ch
    local message="$2"
    local width="${3:-78}"
    printf -- "${delimiter}%.0s" $(seq 0 $(($width - ${#message})))
}

header() {
    message="$(printf "%s " "$1")"
    echo
    printf "%s" "$message"; padding "#" "$message"; echo
    echo
}
indent() {
    padding " " "$1" 22;
    printf "%s = " "$1";
}

explore() {
    local to_explore="$1"
    {
        cd "$to_explore"
        header "$to_explore"
        for arg in "${args[@]}"; do
            indent "$arg";
            git --no-pager rev-parse "$arg" 2>&1 || true;
        done

        indent "config#core.worktree"
        git --no-pager config core.worktree || echo "<missing>"

        indent "./config#core.worktree" 22
        if [ -f ./config ]; then
            git --no-pager config --file ${PWD}/config core.worktree || echo "<missing>"
        else
            echo
        fi
        indent "./gitdir"
        if [ -f ./gitdir ]; then
            cat ./gitdir;
        else
            echo
        fi
    } | sed 's/^/# /g' | sed "s#${PWD}#\${PWD}#g"
}

paths_to_explore=(
    "${PWD}"
    "${PWD}/nested"
    "${PWD}/.git"
    "${PWD}/.git/worktrees"
    "${PWD}/.git/worktrees/wrktr"
    "${PWD}/.git/worktrees/wrktr/modules/submod"
    "${PWD}/wrktr"
    "${PWD}/wrktr/submod"
    "${PWD}/submod"
    "${PWD}/.git/modules/submod"
)

for p in "${paths_to_explore[@]}"; do explore "$p"; done

#
# ${PWD} ############################################################
#
#        --git-common-dir = .git
#               --git-dir = .git
#     --is-inside-git-dir = false
#   --is-inside-work-tree = true
#         --show-toplevel = ${PWD}
#    config#core.worktree = <missing>
#  ./config#core.worktree =
#                ./gitdir =
#
# ${PWD}/nested #####################################################
#
#        --git-common-dir = ../.git
#               --git-dir = ${PWD}/.git
#     --is-inside-git-dir = false
#   --is-inside-work-tree = true
#         --show-toplevel = ${PWD}
#    config#core.worktree = <missing>
#  ./config#core.worktree =
#                ./gitdir =
#
# ${PWD}/.git #######################################################
#
#        --git-common-dir = .
#               --git-dir = .
#     --is-inside-git-dir = true
#   --is-inside-work-tree = false
#         --show-toplevel = fatal: this operation must be run in a work tree
#    config#core.worktree = <missing>
#  ./config#core.worktree = <missing>
#                ./gitdir =
#
# ${PWD}/.git/worktrees #############################################
#
#        --git-common-dir = ${PWD}/.git
#               --git-dir = ${PWD}/.git
#     --is-inside-git-dir = true
#   --is-inside-work-tree = false
#         --show-toplevel = fatal: this operation must be run in a work tree
#    config#core.worktree = <missing>
#  ./config#core.worktree =
#                ./gitdir =
#
# ${PWD}/.git/worktrees/wrktr #######################################
#
#        --git-common-dir = ${PWD}/.git
#               --git-dir = .
#     --is-inside-git-dir = true
#   --is-inside-work-tree = false
#         --show-toplevel = fatal: this operation must be run in a work tree
#    config#core.worktree = <missing>
#  ./config#core.worktree =
#                ./gitdir = ${PWD}/wrktr/.git
#
# ${PWD}/.git/worktrees/wrktr/modules/submod ########################
#
#        --git-common-dir = .
#               --git-dir = .
#     --is-inside-git-dir = false
#   --is-inside-work-tree = false
#         --show-toplevel = ${PWD}/wrktr/submod
#    config#core.worktree = ../../../../../wrktr/submod
#  ./config#core.worktree = ../../../../../wrktr/submod
#                ./gitdir =
#
# ${PWD}/wrktr ######################################################
#
#        --git-common-dir = ${PWD}/.git
#               --git-dir = ${PWD}/.git/worktrees/wrktr
#     --is-inside-git-dir = false
#   --is-inside-work-tree = true
#         --show-toplevel = ${PWD}/wrktr
#    config#core.worktree = <missing>
#  ./config#core.worktree =
#                ./gitdir =
#
# ${PWD}/wrktr/submod ###############################################
#
#        --git-common-dir = ${PWD}/.git/worktrees/wrktr/modules/submod
#               --git-dir = ${PWD}/.git/worktrees/wrktr/modules/submod
#     --is-inside-git-dir = false
#   --is-inside-work-tree = true
#         --show-toplevel = ${PWD}/wrktr/submod
#    config#core.worktree = ../../../../../wrktr/submod
#  ./config#core.worktree =
#                ./gitdir =
#
# ${PWD}/submod #####################################################
#
#        --git-common-dir = ${PWD}/.git/modules/submod
#               --git-dir = ${PWD}/.git/modules/submod
#     --is-inside-git-dir = false
#   --is-inside-work-tree = true
#         --show-toplevel = ${PWD}/submod
#    config#core.worktree = ../../../submod
#  ./config#core.worktree =
#                ./gitdir =
#
# ${PWD}/.git/modules/submod ########################################
#
#        --git-common-dir = .
#               --git-dir = .
#     --is-inside-git-dir = false
#   --is-inside-work-tree = false
#         --show-toplevel = ${PWD}/submod
#    config#core.worktree = ../../../submod
#  ./config#core.worktree = ../../../submod
#                ./gitdir =

explore_tab() {
    local to_explore="$1"
    {
        cd "$to_explore"

        printf '|`%s`' "$to_explore"
        for arg in "${args[@]}"; do
            _result="$(git --no-pager rev-parse "$arg" 2>&1 || true)"
            printf '|`%s`' "$_result"
        done
        # config#core.worktree
        printf '|`%s`' "$(git --no-pager config core.worktree || echo "<missing>")"

        # ./config#core.worktree
        printf '|'
        if [ -f ./config ]; then
            printf '`%s`' "$(
                git --no-pager config --file ${PWD}/config core.worktree || echo "<missing>"
            )"
        fi
        # ./gitdir
        printf "|"
        if [ -f ./gitdir ]; then
            printf '`%s`' "$(cat ./gitdir)";
        fi
        echo "|"
    }
}
_headers=(
    "pwd"
    "${args[@]}"
    "config#core.worktree"
    ./config#core.worktree
    ./gitdir
)
for i in "${_headers[@]}"; do printf '|`%s`' "$i"; done
echo "|"
for i in "${_headers[@]}"; do printf "|-"; done
echo "|"
for p in "${paths_to_explore[@]}"; do
  explore_tab "$p" | sed "s#${PWD}#\${PWD}#g";
done