#!/usr/bin/env bash
# build-deb.sh — Build a .deb package for LlamaLink
set -euo pipefail

VERSION="${1:-}"
ARCH="${2:-$(dpkg --print-architecture 2>/dev/null || echo "amd64")}"

if [[ -z "$VERSION" ]]; then
    VERSION=$(git describe --tags --always --dirty 2>/dev/null || echo "dev")
fi

VERSION="${VERSION#v}"

if ! command -v dpkg-deb &>/dev/null; then
    echo "Error: dpkg-deb not found. Install with: sudo apt install dpkg" >&2
    exit 1
fi

if [[ "$(uname)" != "Linux" ]]; then
    echo "Error: .deb packages can only be built on Linux." >&2
    exit 1
fi

DEB_VERSION="${VERSION}-1"
BUILD_DIR="dist/deb-build"
PKG_DIR="${BUILD_DIR}/llamalink-${DEB_VERSION}_${ARCH}"

echo "==> Building llamalink_${DEB_VERSION}_${ARCH}.deb"

rm -rf "$BUILD_DIR"
mkdir -p "$PKG_DIR"/{DEBIAN,usr/local/bin,etc/llamalink,etc/systemd/system,opt/llamalink/data,var/log/llamalink}

# Binary (must exist)
if [[ ! -f "bin/llamalink" ]]; then
    echo "Error: bin/llamalink not found. Run 'make build' first." >&2
    exit 1
fi
cp bin/llamalink "$PKG_DIR/usr/local/bin/"
chmod 755 "$PKG_DIR/usr/local/bin/llamalink"

# Config template
cp .env.example "$PKG_DIR/etc/llamalink/env"
chmod 644 "$PKG_DIR/etc/llamalink/env"

# Systemd unit
cp deploy/llamalink.service "$PKG_DIR/etc/systemd/system/llamalink.service"

# DEBIAN/control
cat > "$PKG_DIR/DEBIAN/control" <<EOF
Package: llamalink
Version: ${DEB_VERSION}
Section: net
Priority: optional
Architecture: ${ARCH}
Maintainer: LlamaLink <hello@llamalink.dev>
Description: API Gateway for local LLM inference via llama.cpp
 Provides a REST API with API key authentication, rate limiting,
 and multi-model hot-swap for llama.cpp server instances.
Homepage: https://github.com/llamalink/llamalink
Depends: libc6
EOF

# DEBIAN/conffiles
echo "/etc/llamalink/env" > "$PKG_DIR/DEBIAN/conffiles"

# DEBIAN/postinst
cat > "$PKG_DIR/DEBIAN/postinst" <<'POSTINST'
#!/bin/sh
set -e
if [ "$1" = "configure" ]; then
    if ! id llamalink > /dev/null 2>&1; then
        useradd --system --no-create-home --shell /usr/sbin/nologin llamalink 2>/dev/null || true
    fi
    mkdir -p /opt/llamalink/data /var/log/llamalink
    chown llamalink:llamalink /opt/llamalink/data /var/log/llamalink 2>/dev/null || true
    if command -v systemctl >/dev/null 2>&1; then
        systemctl daemon-reload 2>/dev/null || true
    fi
fi
POSTINST
chmod 755 "$PKG_DIR/DEBIAN/postinst"

# DEBIAN/prerm
cat > "$PKG_DIR/DEBIAN/prerm" <<'PRERM'
#!/bin/sh
set -e
if [ "$1" = "remove" ] || [ "$1" = "purge" ]; then
    if command -v systemctl >/dev/null 2>&1; then
        systemctl stop llamalink.service 2>/dev/null || true
        systemctl disable llamalink.service 2>/dev/null || true
    fi
fi
PRERM
chmod 755 "$PKG_DIR/DEBIAN/prerm"

# DEBIAN/postrm
cat > "$PKG_DIR/DEBIAN/postrm" <<'POSTRM'
#!/bin/sh
set -e
if [ "$1" = "purge" ]; then
    rm -rf /opt/llamalink/data /var/log/llamalink
    if id llamalink > /dev/null 2>&1; then
        userdel llamalink 2>/dev/null || true
    fi
    if command -v systemctl >/dev/null 2>&1; then
        systemctl daemon-reload 2>/dev/null || true
    fi
fi
POSTRM
chmod 755 "$PKG_DIR/DEBIAN/postrm"

# Build .deb
mkdir -p dist
dpkg-deb --build "$PKG_DIR" "dist/llamalink_${DEB_VERSION}_${ARCH}.deb"

echo "==> Created dist/llamalink_${DEB_VERSION}_${ARCH}.deb"
rm -rf "$BUILD_DIR"