#!/bin/sh
# postinst — twiy package ONLY (twiy-raweb uses postinst-raweb).
#
# Config files live under /nginx but are NOT tracked by dpkg. The package
# ships an empty /nginx skeleton (so dpkg keeps the dirs across upgrades) plus
# a pristine copy of every config under /usr/share/twiy/defaults/nginx.
#
# Config policy for twiy:
#   - target present (identical OR admin-edited) -> NEVER replace; leave as-is.
#   - target absent                             -> ASK the admin (per file,
#                                                  Y/N) and only create it on Y.
# We never drop <file>.new and we never overwrite an existing config, so an
# upgrade can never change an admin-edited config.
#
# /hostdata is left entirely to the admin: we only make sure the dir exists,
# and we never touch or remove its contents.

set -e

# Ask the admin a yes/no question on the controlling terminal. Defaults to
# "no" (return 1) whenever we cannot prompt — noninteractive frontend or no
# usable terminal — so a config is never created without explicit consent.
prompt_yes_no() {
    msg="$1"
    if [ "${DEBIAN_FRONTEND:-}" = noninteractive ] || [ ! -r /dev/tty ]; then
        echo "twiy: $msg -> skipped (noninteractive)"
        return 1
    fi
    printf 'twiy: %s [y/N] ' "$msg" > /dev/tty
    read ans < /dev/tty || ans=""
    case "$ans" in
        [Yy]|[Yy][Ee][Ss]) return 0 ;;
        *) return 1 ;;
    esac
}

useradd -r -s /bin/false nginx 2>/dev/null || true

# Existing dirs are left exactly as they are (mkdir -p is a no-op then).
mkdir -p /nginx /hostdata

# Migration: older releases shipped /nginx/* as dpkg-tracked files, so the
# upgrade unpack deletes them before this script runs. preinst stashed a copy
# first — restore the admin's own files now, without clobbering anything
# already present (cp -n). This only puts back what dpkg removed; it never
# introduces new packaged defaults, so no prompt is needed here.
if [ -d /var/backups/twiy-nginx ]; then
    cp -an /var/backups/twiy-nginx/. /nginx/ 2>/dev/null || true
    rm -rf /var/backups/twiy-nginx
fi

# Seed packaged defaults:
#   - target present  -> do nothing (never replace, no .new).
#   - target absent   -> ask the admin; create it only if they answer yes.
seed_tree() {
    stash="$1"
    target="$2"
    [ -d "$stash" ] || return 0
    find "$stash" -type f | while IFS= read -r src; do
        rel=${src#$stash/}
        dst="$target/$rel"
        if [ -e "$dst" ]; then
            continue
        fi
        if prompt_yes_no "config '$dst' does not exist. Create it from the packaged default?"; then
            install -d "$(dirname "$dst")"
            cp -p "$src" "$dst"
            echo "twiy: created $dst"
        else
            echo "twiy: skipped $dst"
        fi
    done
}
seed_tree /usr/share/twiy/defaults/nginx /nginx

install -d /nginx/conf.d /nginx/config
install -d -o nginx -g nginx -m 0755 /var/log/nginx
chown -R nginx:nginx /var/log/nginx /nginx 2>/dev/null || true

systemctl daemon-reload  2>/dev/null || true
systemctl enable  nginx.service 2>/dev/null || true
systemctl restart nginx.service 2>/dev/null || true

exit 0