#!/bin/sh
# Build a statically-linked ogit binary using musl.
#
# Prerequisites:
#   - opam (>= 2.1)
#   - musl-gcc (install musl-tools on Debian/Ubuntu, sys-libs/musl on Gentoo)
#   - A C compiler (gcc or clang)
#
# This script creates a dedicated opam switch with static musl compilation,
# installs dependencies, builds, strips, and copies the binary to dist/.
#
# Usage:
#   ./scripts/build-release.sh

set -eu

SWITCH_NAME="ogit-static"
PROJECT_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
OCAML_VERSION="$(
    awk '/\(ocaml \(= / {
        version = $3
        gsub(/[()]/, "", version)
        print version
        exit
    }' "${PROJECT_ROOT}/dune-project"
)"
DIST_DIR="${PROJECT_ROOT}/dist"

if [ -z "${OCAML_VERSION}" ]; then
    echo "ERROR: Could not determine the OCaml version from dune-project."
    exit 1
fi

# Verify musl-gcc is available
if ! command -v musl-gcc >/dev/null 2>&1; then
    echo "ERROR: musl-gcc not found."
    echo "  Debian/Ubuntu: apt install musl-tools"
    echo "  Gentoo: emerge sys-libs/musl"
    echo "  Fedora: dnf install musl-gcc"
    exit 1
fi

# Verify opam is available
if ! command -v opam >/dev/null 2>&1; then
    echo "ERROR: opam not found. Install from https://opam.ocaml.org/doc/Install.html"
    exit 1
fi

echo "==> Creating opam switch '${SWITCH_NAME}' (if not exists)..."
if ! opam switch list 2>/dev/null | grep -q "${SWITCH_NAME}"; then
    opam switch create "${SWITCH_NAME}" \
        --packages="ocaml-variants.${OCAML_VERSION}+options,ocaml-option-static,ocaml-option-musl" \
        --no-install
fi

echo "==> Installing dependencies..."
opam install --switch="${SWITCH_NAME}" --deps-only --yes "${PROJECT_ROOT}"

echo "==> Building..."
opam exec --switch="${SWITCH_NAME}" -- dune build --root="${PROJECT_ROOT}" --force

BINARY="${PROJECT_ROOT}/_build/default/bin/main.exe"

if [ ! -f "${BINARY}" ]; then
    echo "ERROR: Build produced no binary at ${BINARY}"
    exit 1
fi

echo "==> Stripping binary..."
strip "${BINARY}"

echo "==> Copying to dist/..."
mkdir -p "${DIST_DIR}"
cp "${BINARY}" "${DIST_DIR}/ogit"

echo ""
echo "Done. Binary at: ${DIST_DIR}/ogit"
echo ""
file "${DIST_DIR}/ogit"
ls -lh "${DIST_DIR}/ogit"