#!/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 tooling comes from nix, apt, brew,
# or apk (detected in that order); assumes NOTHING is present (not git,
# make, or go). golangci-lint is packaged in nix, brew, and apk; on apt
# it is installed from a hash-verified GitHub release archive (never
# curl | sh). CGO image libraries (pkg-config, vips, libheif) are
# installed for the govips bindings.
set -eu

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

# Pinned versions, 2026-07-07. Never "latest"; exact versions only.
GOLANGCI_LINT_VERSION="2.10.1"
# sha256 of golangci-lint-2.10.1-linux-<arch>.tar.gz release archives
GOLANGCI_LINT_SHA256_AMD64="dfa775874cf0561b404a02a8f4481fc69b28091da95aa697259820d429b09c99"
GOLANGCI_LINT_SHA256_ARM64="6652b42ae02915eb2f9cb2a2e0cac99514c8eded8388d88ae3e06e1a52c00de8"

PKGMGR=""
SUDO=""

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) $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
}

# verify_sha256 <file> <expected-hash>
verify_sha256() {
    if command -v sha256sum >/dev/null 2>&1; then
        actual="$(sha256sum "$1" | cut -d' ' -f1)"
    else
        actual="$(shasum -a 256 "$1" | cut -d' ' -f1)"
    fi
    if [ "$actual" != "$2" ]; then
        echo "bootstrap: sha256 mismatch for $1" >&2
        echo "  expected: $2" >&2
        echo "  actual:   $actual" >&2
        exit 1
    fi
}

# apt has no golangci-lint package: install a pinned release archive
# from GitHub, verified by hardcoded sha256 (never curl | sh).
install_golangci_lint_release() {
    case "$(uname -m)" in
        x86_64) goarch="amd64"; sha="$GOLANGCI_LINT_SHA256_AMD64" ;;
        aarch64|arm64) goarch="arm64"; sha="$GOLANGCI_LINT_SHA256_ARM64" ;;
        *)
            echo "bootstrap: unsupported architecture $(uname -m)" >&2
            exit 1
            ;;
    esac
    if missing curl; then pkg_install curl curl curl curl; fi
    name="golangci-lint-${GOLANGCI_LINT_VERSION}-linux-${goarch}"
    tmp="$(mktemp -d)"
    curl -fsSL -o "$tmp/$name.tar.gz" \
        "https://github.com/golangci/golangci-lint/releases/download/v${GOLANGCI_LINT_VERSION}/${name}.tar.gz"
    verify_sha256 "$tmp/$name.tar.gz" "$sha"
    tar -xzf "$tmp/$name.tar.gz" -C "$tmp"
    $SUDO install -m 0755 "$tmp/$name/golangci-lint" /usr/local/bin/golangci-lint
    rm -rf "$tmp"
}

ensure_golangci_lint() {
    if ! missing golangci-lint; then return 0; fi
    detect_pkgmgr
    case "$PKGMGR" in
        apt) install_golangci_lint_release ;;
        *) pkg_install golangci-lint golangci-lint golangci-lint golangci-lint ;;
    esac
}

# CGO dependencies for govips (image processing)
ensure_cgo_deps() {
    if missing pkg-config; then
        pkg_install pkg-config pkg-config pkg-config pkgconfig
    fi
    if ! pkg-config --exists vips; then
        pkg_install vips libvips-dev vips vips-dev
    fi
    if ! pkg-config --exists libheif; then
        pkg_install libheif libheif-dev libheif libheif-dev
    fi
}

main() {
    cd "$ROOT"

    # Base tooling
    if missing git; then pkg_install git git git git; fi
    if missing make; then pkg_install gnumake make make make; fi

    # Go toolchain and linter
    if missing go; then pkg_install go golang go go; fi
    ensure_golangci_lint

    # CGO image libraries
    ensure_cgo_deps

    go mod download

    echo "bootstrap complete"
}

main "$@"