#!/usr/bin/env sh
# gfix installer — https://gitfix.pro/install
# Downloads the right binary for your OS+arch, verifies SHA256, installs to
# /usr/local/bin/gfix. Proprietary EULA: https://github.com/ameyypawar/gfix
set -eu

VERSION="${GFIX_VERSION:-latest}"
PREFIX="${PREFIX:-/usr/local}"
REPO="ameyypawar/gfix"

usage() {
    cat <<EOF
gfix installer.

Usage:
  curl -fsSL https://gitfix.pro/install | sh
  curl -fsSL https://gitfix.pro/install | sh -s -- --help

Env:
  GFIX_VERSION   Version tag to install (default: latest). e.g. v0.1.0-alpha.1
  PREFIX         Install prefix (default: /usr/local). Binary lands at \$PREFIX/bin/gfix

After install:
  gfix --version
  claude mcp add --scope user gfix \$PREFIX/bin/gfix mcp

Docs: https://github.com/ameyypawar/gitfix-docs
EOF
}

case "${1:-}" in
    --help|-h) usage; exit 0 ;;
esac

# Detect OS
os="$(uname -s)"
case "$os" in
    Darwin) os_tag="apple-darwin" ;;
    Linux)  os_tag="unknown-linux-gnu" ;;
    *) echo "gfix: unsupported OS: $os (macOS and Linux only for alpha)" >&2; exit 1 ;;
esac

# Detect arch
arch="$(uname -m)"
case "$arch" in
    x86_64|amd64) arch_tag="x86_64" ;;
    arm64|aarch64) arch_tag="aarch64" ;;
    *) echo "gfix: unsupported arch: $arch" >&2; exit 1 ;;
esac

target="${arch_tag}-${os_tag}"

# Resolve version
if [ "$VERSION" = "latest" ]; then
    VERSION="$(curl -fsSL "https://api.github.com/repos/${REPO}/releases/latest" \
        | grep '"tag_name":' | head -1 | cut -d'"' -f4)"
    [ -n "$VERSION" ] || { echo "gfix: could not resolve latest version" >&2; exit 1; }
fi

tarball="gfix-${VERSION}-${target}.tar.gz"
url="https://github.com/${REPO}/releases/download/${VERSION}/${tarball}"
sums_url="https://github.com/${REPO}/releases/download/${VERSION}/SHA256SUMS.txt"

echo "gfix: installing ${VERSION} for ${target} → ${PREFIX}/bin/gfix"

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

curl -fsSL "$url" -o "${tmpdir}/${tarball}" \
    || { echo "gfix: download failed from ${url}" >&2; exit 1; }
curl -fsSL "$sums_url" -o "${tmpdir}/SHA256SUMS.txt" \
    || { echo "gfix: could not fetch SHA256SUMS.txt" >&2; exit 1; }

# Verify SHA256
expected="$(grep " ${tarball}\$" "${tmpdir}/SHA256SUMS.txt" | cut -d' ' -f1)"
[ -n "$expected" ] || { echo "gfix: ${tarball} not listed in SHA256SUMS.txt" >&2; exit 1; }

if command -v sha256sum >/dev/null 2>&1; then
    actual="$(sha256sum "${tmpdir}/${tarball}" | cut -d' ' -f1)"
elif command -v shasum >/dev/null 2>&1; then
    actual="$(shasum -a 256 "${tmpdir}/${tarball}" | cut -d' ' -f1)"
else
    echo "gfix: need sha256sum or shasum; neither found" >&2; exit 1
fi

[ "$expected" = "$actual" ] \
    || { echo "gfix: SHA256 mismatch! expected=${expected} actual=${actual}" >&2; exit 1; }

tar -xzf "${tmpdir}/${tarball}" -C "$tmpdir"

# Install (try without sudo, then with)
install_dir="${PREFIX}/bin"
if [ -w "$install_dir" ]; then
    mv "${tmpdir}/gfix" "${install_dir}/gfix"
elif command -v sudo >/dev/null 2>&1; then
    echo "gfix: ${install_dir} not writable; using sudo"
    sudo mv "${tmpdir}/gfix" "${install_dir}/gfix"
else
    echo "gfix: ${install_dir} not writable and no sudo available" >&2; exit 1
fi
chmod +x "${install_dir}/gfix"

echo ""
echo "gfix installed: ${install_dir}/gfix"
echo ""

# macOS unsigned-binary callout
if [ "$os" = "Darwin" ]; then
    echo "macOS note: the alpha binary is unsigned. If Gatekeeper complains,"
    echo "  on first run, clear the quarantine attribute:"
    echo ""
    echo "  xattr -d com.apple.quarantine ${install_dir}/gfix"
    echo ""
fi

echo "Verify:    gfix --version"
echo "Wire MCP:  claude mcp add --scope user gfix ${install_dir}/gfix mcp"
echo "Setup:     https://github.com/ameyypawar/gitfix-docs"