#!/usr/bin/env bash
# Cross-compile quicproquo for musl targets (OpenWrt / embedded Linux).
#
# Produces statically linked, stripped binaries optimised for size.
# Requires: cargo-zigbuild (preferred) or cross.
#
# Usage:
#   ./scripts/cross-compile.sh                    # all targets
#   ./scripts/cross-compile.sh x86_64-unknown-linux-musl  # single target
#
# Output: target/<triple>/release/qpq-server (stripped)

set -euo pipefail

TARGETS=(
    x86_64-unknown-linux-musl
    armv7-unknown-linux-musleabihf
    aarch64-unknown-linux-musl
)

MAX_SIZE_MB=5

# Size-optimised release profile overrides.
export CARGO_PROFILE_RELEASE_OPT_LEVEL=s
export CARGO_PROFILE_RELEASE_LTO=true
export CARGO_PROFILE_RELEASE_CODEGEN_UNITS=1
export CARGO_PROFILE_RELEASE_STRIP=symbols

# Detect build tool.
if command -v cargo-zigbuild &>/dev/null; then
    BUILD_CMD="cargo zigbuild"
elif command -v cross &>/dev/null; then
    BUILD_CMD="cross build"
else
    echo "ERROR: Install cargo-zigbuild or cross first:" >&2
    echo "  cargo install cargo-zigbuild   # recommended" >&2
    echo "  cargo install cross            # alternative" >&2
    exit 1
fi

# If arguments provided, use those as targets.
if [ $# -gt 0 ]; then
    TARGETS=("$@")
fi

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
PROJECT_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
cd "$PROJECT_ROOT"

echo "=== quicproquo cross-compilation ==="
echo "Build tool: $BUILD_CMD"
echo "Targets: ${TARGETS[*]}"
echo ""

FAILED=()
for target in "${TARGETS[@]}"; do
    echo "--- Building for $target ---"
    if $BUILD_CMD --release --target "$target" --bin qpq-server; then
        BINARY="target/$target/release/qpq-server"
        if [ -f "$BINARY" ]; then
            SIZE=$(stat -c%s "$BINARY" 2>/dev/null || stat -f%z "$BINARY")
            SIZE_MB=$(echo "scale=2; $SIZE / 1048576" | bc)
            MAX_BYTES=$((MAX_SIZE_MB * 1048576))
            echo "  Binary: $BINARY"
            echo "  Size: ${SIZE_MB} MB"
            if [ "$SIZE" -gt "$MAX_BYTES" ]; then
                echo "  WARNING: Binary exceeds ${MAX_SIZE_MB} MB size limit!"
                FAILED+=("$target (size: ${SIZE_MB} MB)")
            else
                echo "  OK: within ${MAX_SIZE_MB} MB limit"
            fi
        else
            echo "  ERROR: Binary not found at $BINARY"
            FAILED+=("$target (binary not found)")
        fi
    else
        echo "  ERROR: Build failed for $target"
        FAILED+=("$target (build failed)")
    fi
    echo ""
done

if [ ${#FAILED[@]} -gt 0 ]; then
    echo "=== FAILURES ==="
    for f in "${FAILED[@]}"; do
        echo "  - $f"
    done
    exit 1
fi

echo "=== All targets built successfully ==="