#!/bin/sh
# Make way for git-repo externals. chezmoi can only clone into a missing or
# empty target, and only pull in a target that is already a checkout; a
# directory with other content stops the apply (a fresh Omarchy install ships
# its own ~/.config/kitty, ghostty, omarchy, …). For each such target, ask
# whether to replace it: yes moves it aside to <target>.bak-<time> and clones
# the repo there, so chezmoi finds a checkout; no aborts the apply. Runs
# before every apply; it only stats directories unless one is in the way.
set -eu

conflicts=$(mktemp)
trap 'rm -f "$conflicts"' EXIT
check() {
    target=$1 url=$2
    [ -e "$target" ] || [ -L "$target" ] || return 0
    if [ -d "$target" ] && [ ! -L "$target" ]; then
        [ -e "$target/.git" ] && return 0
        [ -z "$(ls -A "$target")" ] && return 0
    fi
    printf '%s\t%s\n' "$target" "$url" >>"$conflicts"
}
{{- $files := glob (joinPath .chezmoi.sourceDir ".chezmoiexternals" "*.toml") }}
{{- if stat (joinPath .chezmoi.sourceDir ".chezmoiexternal.toml") }}
{{-   $files = append $files (joinPath .chezmoi.sourceDir ".chezmoiexternal.toml") }}
{{- end }}
{{- range $files }}
{{-   range $path, $ext := include . | fromToml }}
{{-     if eq (get $ext "type") "git-repo" }}
check {{ joinPath $.chezmoi.destDir $path | quote }} {{ $ext.url | quote }}
{{-     end }}
{{-   end }}
{{- end }}

[ -s "$conflicts" ] || exit 0

# A subshell: a failed redirect on the special builtin `:` would end this shell.
if ! ( : </dev/tty ) 2>/dev/null; then
    echo "error: these git-repo external targets exist and are not checkouts:" >&2
    cut -f1 "$conflicts" | sed 's/^/  /' >&2
    echo "Run chezmoi apply in a terminal to be asked about each, or move them aside." >&2
    exit 1
fi

stamp=$(date +%Y%m%d-%H%M%S)
while IFS="$(printf '\t')" read -r target url; do
    printf '%s exists and is not a git checkout. Replace it with %s (old copy kept as %s.bak-%s)? [y/N] ' \
        "$target" "$url" "$target" "$stamp" >/dev/tty
    read -r answer </dev/tty || answer=''
    case $answer in
    [yY]*) ;;
    *)
        echo "error: kept $target; chezmoi cannot apply its external. Move it aside or answer y, then apply again." >&2
        exit 1
        ;;
    esac
    mv "$target" "$target.bak-$stamp"
    if ! git clone --quiet "$url" "$target"; then
        rm -rf "$target"
        mv "$target.bak-$stamp" "$target"
        echo "error: cloning $url failed; $target restored." >&2
        exit 1
    fi
    echo "$target: cloned $url (old copy in $target.bak-$stamp)"
done <"$conflicts"