#!/bin/sh
# script/bootstrap: install all dependencies needed to build and develop
# this repo. Idempotent: every install is guarded by a check so already
# installed tools are skipped. Base tools, node and yarn come from nix,
# apt, brew, or apk (detected in that order), with no version and no
# hash, because the distribution is trusted. It installs node, yarn and
# the node packages only when yarn.lock is in the tree. Assumes nothing
# is present.
set -eu

ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"

PKGMGR=""
SUDO=""
APT_UPDATED=""

detect_pkgmgr() {
    [ -n "$PKGMGR" ] && return 0
    if command -v nix-env >/dev/null 2>&1; then
        PKGMGR="nix"
    elif command -v apt-get >/dev/null 2>&1; then
        PKGMGR="apt"
    elif command -v brew >/dev/null 2>&1; then
        PKGMGR="brew"
    elif command -v apk >/dev/null 2>&1; then
        PKGMGR="apk"
    else
        echo "bootstrap: no supported package manager (nix, apt, brew, apk)" >&2
        exit 1
    fi
    if [ "$PKGMGR" = "apt" ]; then
        export DEBIAN_FRONTEND=noninteractive
        if [ "$(id -u)" != "0" ]; then
            SUDO="sudo"
        fi
    fi
}

# pkg_install <nix-attr> <apt-pkg> <brew-formula> <apk-pkg>
pkg_install() {
    detect_pkgmgr
    case "$PKGMGR" in
        nix) nix-env -iA "nixpkgs.$1" ;;
        apt)
            # Package lists may be empty (fresh images); refresh once per run.
            if [ -z "$APT_UPDATED" ]; then
                $SUDO env DEBIAN_FRONTEND=noninteractive apt-get update
                APT_UPDATED=1
            fi
            $SUDO env DEBIAN_FRONTEND=noninteractive apt-get install -y "$2"
            ;;
        brew) brew install "$3" ;;
        apk) apk add --no-cache "$4" ;;
    esac
}

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

# Debian and Ubuntu name the yarn command yarnpkg.
run_yarn() {
    if command -v yarn >/dev/null 2>&1; then
        yarn "$@"
    elif command -v yarnpkg >/dev/null 2>&1; then
        yarnpkg "$@"
    else
        echo "no yarn; run script/bootstrap first" >&2
        exit 1
    fi
}

main() {
    cd "$ROOT"

    if missing make; then pkg_install gnumake make make make; fi
    if missing git; then pkg_install git git git git; fi

    # A Dockerfile stage that needs no yarn copies no yarn.lock.
    if [ -f yarn.lock ]; then
        if missing node; then pkg_install nodejs nodejs node nodejs; fi
        if missing yarn && missing yarnpkg; then
            pkg_install yarn yarnpkg yarn yarn
        fi

        # Debian 13 and Ubuntu 26.04 package yarn 4, which refuses a yarn 1
        # yarn.lock, or rewrites it in its own format.
        yarn_version="$(run_yarn --version)"
        if [ "${yarn_version%%.*}" != "1" ]; then
            echo "bootstrap: yarn $yarn_version refuses this yarn 1 yarn.lock;" \
                "use a distribution that packages yarn 1" >&2
            exit 1
        fi

        run_yarn install --frozen-lockfile
    fi

    echo "bootstrap complete"
}

main "$@"
