#!/usr/bin/env sh

#! Copies the templates from `templates/*` to `build/*` and replaces every symbolic link with a
#! copy.

# Source: https://stackoverflow.com/a/20460402
# Checks if the string (arg2) starts with the substring (arg1)
#
# arg1: substring
# arg2: string
stringContain() { case $2 in $1*) return 0 ;; *) return 1 ;; esac }

ROOT="$(git rev-parse --show-toplevel)"

# TODO: Find a way to do the building step incrementally (i.e. without removing everything) <2024-06-11>
[ -n "$ROOT" ] && $DRY_RUN_CMD rm --recursive "$ROOT/build"
$DRY_RUN_CMD mkdir --parents "$ROOT/build"

cd "$ROOT" || {
    echo "No '$ROOT' (Root) ?!"
    exit 1
}

instantiate_dir() {
    dir="$1"

    fd . "$dir" --max-depth 1 --type directory | while read -r template; do
        template_path="${template#"$ROOT/"}"
        echo "Instantiating template: '$template_path'.."
        template_new_path="$ROOT/build/$(basename "$template")"

        git ls-files --cached --full-name "$template" | while read -r file; do
            new_file_path="${file#"$template_path"}"
            new_path="$template_new_path/$new_file_path"

            $DRY_RUN_CMD mkdir --parents "$(dirname "$new_path")"

            $DRY_RUN_CMD cp "$file" "$new_path"
        done

        {
            # Show directories
            fd . "$template_new_path" --type symlink --follow --hidden

            # Show simple files
            fd . "$template_new_path" --type symlink --hidden
        } | while read -r symlink; do
            symlink_path="$(readlink --canonicalize "$symlink")"

            if stringContain "$ROOT" "$symlink_path"; then
                echo "     -> Instantiating symlink: '.${symlink#"$ROOT"}'.."
                $DRY_RUN_CMD rm "$symlink"
                $DRY_RUN_CMD cp --recursive "$symlink_path" "$symlink"
            else
                echo "     -> Not instantiating symlink '.${symlink#"$ROOT"}', as it points outside the repo!"
            fi
        done
    done
}

instantiate_dir "$ROOT/templates"

# vim: ft=sh