#!/usr/bin/env bash
set -euo pipefail

# loadout bootstrap:
# - downloads repo tarball
# - runs per-OS installer
# - installs a `loadout` helper command for future runs
#
# Usage (stdin + args):
#   curl -fsSL https://loadout.timlind.net | bash -s -- ubuntu --dev --gaming
#   wget -qO-  https://loadout.timlind.net | bash -s -- ubuntu --dev --gaming

log() { printf "[loadout-bootstrap] %s\n" "$*"; }
die() { printf "[loadout-bootstrap] ERROR: %s\n" "$*" >&2; exit 1; }

have_cmd() { command -v "$1" >/dev/null 2>&1; }

sudo_run() {
  if [[ "${EUID:-$(id -u)}" -eq 0 ]]; then
    "$@"
  else
    have_cmd sudo || die "sudo is required for: $*"
    sudo "$@"
  fi
}

choose_fetcher() {
  local pref="${LOADOUT_FETCHER:-}"
  if [[ -n "$pref" ]]; then
    if have_cmd "$pref"; then
      printf "%s" "$pref"
      return 0
    fi
    die "Requested fetcher not found: $pref (set via LOADOUT_FETCHER)"
  fi

  if have_cmd curl; then
    printf "curl"
    return 0
  fi
  if have_cmd wget; then
    printf "wget"
    return 0
  fi

  die "Need curl or wget to bootstrap."
}

fetch_url() {
  local fetcher="$1"
  local url="$2"
  case "$fetcher" in
    curl) curl -fsSL "$url" ;;
    wget) wget -qO- "$url" ;;
    *) die "Unknown fetcher: $fetcher" ;;
  esac
}

install_loadout_helper() {
  local url="$1"
  local fetcher="$2"
  local default_os="$3"

  local target_user="${SUDO_USER:-${USER:-}}"
  local target_home="${HOME:-}"
  if [[ -n "$target_user" ]]; then
    target_home="$(getent passwd "$target_user" | cut -d: -f6 || true)"
  fi
  [[ -n "$target_home" ]] || die "Cannot resolve target home directory."

  # Config is per-user even if the helper is installed system-wide.
  local cfg_dir="$target_home/.config/loadout"
  mkdir -p "$cfg_dir"

  local cfg_file="$cfg_dir/bootstrap.env"
  cat >"$cfg_file" <<EOF
# Generated by loadout bootstrap.
LOADOUT_URL=${url}
LOADOUT_FETCHER_DEFAULT=${fetcher}
LOADOUT_DEFAULT_OS=${default_os}
EOF

  # If we’re running as root (or via sudo), ensure the target user can read/write config.
  if [[ "${EUID:-$(id -u)}" -eq 0 && -n "$target_user" && "$target_user" != "root" ]]; then
    chown -R "$target_user":"$target_user" "$cfg_dir" 2>/dev/null || true
  fi

  # Install helper where it's immediately discoverable on PATH.
  local helper_dir=""
  if [[ -w /usr/local/bin ]]; then
    helper_dir="/usr/local/bin"
  else
    # Try /usr/local/bin via sudo, fall back to ~/.local/bin.
    if have_cmd sudo; then
      helper_dir="/usr/local/bin"
    else
      helper_dir="$target_home/.local/bin"
      mkdir -p "$helper_dir"
    fi
  fi

  local tmp_helper
  tmp_helper="$(mktemp)"
  cat >"$tmp_helper" <<'EOF'
#!/usr/bin/env bash
set -euo pipefail

die() { printf "[loadout] ERROR: %s\n" "$*" >&2; exit 1; }
have_cmd() { command -v "$1" >/dev/null 2>&1; }

cfg="${XDG_CONFIG_HOME:-$HOME/.config}/loadout/bootstrap.env"
if [[ -f "$cfg" ]]; then
  # shellcheck disable=SC1090
  source "$cfg"
fi

url="${LOADOUT_URL:-https://loadout.timlind.net}"
default_os="${LOADOUT_DEFAULT_OS:-ubuntu}"

os="$default_os"
if [[ "${1:-}" != "" && "${1:-}" != "-"* ]]; then
  # Allow overriding the OS explicitly: `loadout ubuntu --dev`.
  os="$1"
  shift
fi

fetcher="${LOADOUT_FETCHER:-${LOADOUT_FETCHER_DEFAULT:-}}"
if [[ -n "$fetcher" ]] && ! have_cmd "$fetcher"; then
  fetcher=""
fi
if [[ -z "$fetcher" ]]; then
  if have_cmd curl; then
    fetcher="curl"
  elif have_cmd wget; then
    fetcher="wget"
  else
    die "Need curl or wget."
  fi
fi

case "$fetcher" in
  curl) curl -fsSL "$url" | bash -s -- "$os" "$@" ;;
  wget) wget -qO- "$url" | bash -s -- "$os" "$@" ;;
  *) die "Unknown fetcher: $fetcher" ;;
esac
EOF
  chmod +x "$tmp_helper"

  local helper="$helper_dir/loadout"
  if [[ "$helper_dir" == "/usr/local/bin" && ! -w /usr/local/bin ]]; then
    # Needs sudo to place in /usr/local/bin.
    sudo_run install -m 0755 "$tmp_helper" "$helper"
  else
    install -m 0755 "$tmp_helper" "$helper"
  fi
  rm -f "$tmp_helper"

  log "Installed helper: $helper"
  if [[ ":${PATH:-}:" != *":$helper_dir:"* ]]; then
    log "NOTE: '$helper_dir' is not on PATH in this shell."
    log "      Start a new shell, or run: export PATH=\"$helper_dir:\$PATH\""
  fi
  log "Run: loadout --help"
}

os="${1:-}"
if [[ -z "$os" || "$os" == "-"* ]]; then
  die "Missing OS argument. Example: bash -s -- ubuntu --dev --gaming"
fi
shift

REPO_OWNER="${LOADOUT_GH_OWNER:-timlindnet}"
REPO_NAME="${LOADOUT_GH_REPO:-loadout}"
REF="${LOADOUT_GH_REF:-main}"

LOADOUT_URL="${LOADOUT_URL:-https://loadout.timlind.net}"

TARBALL_URL="https://github.com/${REPO_OWNER}/${REPO_NAME}/archive/refs/heads/${REF}.tar.gz"

tmp="$(mktemp -d)"
trap 'rm -rf "$tmp"' EXIT

fetcher="$(choose_fetcher)"

log "Downloading ${REPO_OWNER}/${REPO_NAME}@${REF}..."
fetch_url "$fetcher" "$TARBALL_URL" >"$tmp/repo.tgz"

log "Extracting..."
tar -xzf "$tmp/repo.tgz" -C "$tmp"

repo_dir=""
for d in "$tmp"/*; do
  if [[ -d "$d" ]]; then
    repo_dir="$d"
    break
  fi
done
[[ -n "$repo_dir" && -d "$repo_dir" ]] || die "Could not locate extracted repo directory."

log "Running install for OS '$os'..."
bash "$repo_dir/$os/install.sh" "$@"

install_loadout_helper "$LOADOUT_URL" "$fetcher" "$os"