#!/usr/bin/env bash
# Point package managers at a China mirror before apt/apk install.
# Gitea runners in CN are far too slow against deb.debian.org /
# archive.ubuntu.com / dl-cdn.alpinelinux.org.
#
#   CST_CI_MIRROR=https://mirrors.tuna.tsinghua.edu.cn scripts/ci_pkg_mirror.sh
# Default mirror: Tsinghua TUNA. Override with CST_CI_MIRROR if needed.
set -euo pipefail

MIRROR="${CST_CI_MIRROR:-https://mirrors.tuna.tsinghua.edu.cn}"
MIRROR="${MIRROR%/}"

if [[ -f /etc/alpine-release ]]; then
  echo "==> apk mirror -> $MIRROR/alpine"
  if [[ -f /etc/apk/repositories ]]; then
    sed -i \
      -e "s|https\\?://dl-cdn.alpinelinux.org/alpine|${MIRROR}/alpine|g" \
      -e "s|https\\?://[^/[:space:]]*/alpine|${MIRROR}/alpine|g" \
      /etc/apk/repositories
  fi
  exit 0
fi

if ! command -v apt-get >/dev/null; then
  echo "==> no apt/apk; skip mirror"
  exit 0
fi

# Debian vs Ubuntu: different path under the mirror root.
id_like=""
. /etc/os-release 2>/dev/null || true
case "${ID:-}:${ID_LIKE:-}" in
  ubuntu:*|*ubuntu*)
    dist=ubuntu
    ;;
  debian:*|*debian*|*)
    dist=debian
    ;;
esac

echo "==> apt mirror -> $MIRROR/$dist (and ${dist}-security)"

rewrite() {
  local f="$1"
  [[ -f "$f" ]] || return 0
  # Classic one-line sources
  sed -i \
    -e "s|https\\?://deb.debian.org/debian-security|${MIRROR}/debian-security|g" \
    -e "s|https\\?://deb.debian.org/debian|${MIRROR}/debian|g" \
    -e "s|https\\?://security.debian.org/debian-security|${MIRROR}/debian-security|g" \
    -e "s|https\\?://security.debian.org|${MIRROR}/debian-security|g" \
    -e "s|https\\?://archive.ubuntu.com/ubuntu|${MIRROR}/ubuntu|g" \
    -e "s|https\\?://security.ubuntu.com/ubuntu|${MIRROR}/ubuntu|g" \
    -e "s|https\\?://ports.ubuntu.com/ubuntu-ports|${MIRROR}/ubuntu-ports|g" \
    "$f"
  # DEB822 (.sources): URIs: http://deb.debian.org/debian
  sed -i \
    -e "s|^URIs: *https\\?://deb.debian.org/debian-security|URIs: ${MIRROR}/debian-security|g" \
    -e "s|^URIs: *https\\?://deb.debian.org/debian|URIs: ${MIRROR}/debian|g" \
    -e "s|^URIs: *https\\?://security.debian.org/debian-security|URIs: ${MIRROR}/debian-security|g" \
    -e "s|^URIs: *https\\?://security.debian.org|URIs: ${MIRROR}/debian-security|g" \
    -e "s|^URIs: *https\\?://archive.ubuntu.com/ubuntu|URIs: ${MIRROR}/ubuntu|g" \
    -e "s|^URIs: *https\\?://security.ubuntu.com/ubuntu|URIs: ${MIRROR}/ubuntu|g" \
    "$f"
}

rewrite /etc/apt/sources.list
shopt -s nullglob
for f in /etc/apt/sources.list.d/*.list /etc/apt/sources.list.d/*.sources; do
  rewrite "$f"
done