#!/usr/bin/env bash
set -euo pipefail

# Reusable, agnostic build script
# Can be used in any Go project by adjusting configuration

# Configuration variables
BINARY_NAME="${BINARY_NAME:-$(basename $(pwd))}"
BINARY_DIR="${BINARY_DIR:-bin}"
MAIN_FILE="${MAIN_FILE:-cmd/mev-bot/main.go}"
BUILD_TAGS="${BUILD_TAGS:-}"
LDFLAGS="${LDFLAGS:-}"
OUTPUT="${OUTPUT:-$BINARY_DIR/$BINARY_NAME}"
GOOS="${GOOS:-$(go env GOOS)}"
GOARCH="${GOARCH:-$(go env GOARCH)}"

# Parse command line arguments
while [[ $# -gt 0 ]]; do
    case $1 in
        -n|--name)
            BINARY_NAME="$2"
            shift 2
            ;;
        -o|--output)
            OUTPUT="$2"
            shift 2
            ;;
        -m|--main)
            MAIN_FILE="$2"
            shift 2
            ;;
        -t|--tags)
            BUILD_TAGS="$2"
            shift 2
            ;;
        -l|--ldflags)
            LDFLAGS="$2"
            shift 2
            ;;
        --goos)
            GOOS="$2"
            shift 2
            ;;
        --goarch)
            GOARCH="$2"
            shift 2
            ;;
        -h|--help)
            echo "Usage: $0 [OPTIONS]"
            echo "Build a Go application with configurable options"
            echo ""
            echo "Options:"
            echo "  -n, --name NAME       Binary name (default: current directory name)"
            echo "  -o, --output PATH     Output path (default: bin/BINARY_NAME)"
            echo "  -m, --main PATH       Main package path (default: .)"
            echo "  -t, --tags TAGS       Build tags"
            echo "  -l, --ldflags FLAGS   Ldflags to pass to go build"
            echo "  --goos OS             Target OS (default: $(go env GOOS))"
            echo "  --goarch ARCH         Target architecture (default: $(go env GOARCH))"
            echo "  -h, --help           Show this help"
            exit 0
            ;;
        *)
            echo "Unknown option: $1"
            exit 1
            ;;
    esac
done

echo "Building $BINARY_NAME for $GOOS/$GOARCH..."

# Ensure local Go cache directories exist when not provided
PROJECT_ROOT="$(pwd)"
if [[ -z "${GOCACHE:-}" ]]; then
    export GOCACHE="${PROJECT_ROOT}/.gocache"
fi
if [[ -z "${GOMODCACHE:-}" ]]; then
    export GOMODCACHE="${PROJECT_ROOT}/.gomodcache"
fi
if [[ -z "${GOPATH:-}" ]]; then
    export GOPATH="${PROJECT_ROOT}/.gopath"
fi
if [[ -z "${GOFLAGS:-}" && -d "${PROJECT_ROOT}/vendor" ]]; then
    export GOFLAGS="-mod=vendor"
fi

mkdir -p "$GOCACHE" "$GOMODCACHE" "${GOPATH}/pkg/mod"

# Create binary directory
mkdir -p "$(dirname "$OUTPUT")"

# Set environment variables for cross-compilation
export GOOS="$GOOS"
export GOARCH="$GOARCH"

# Build the application
echo "go build -o $OUTPUT $BUILD_TAGS:+-tags $BUILD_TAGS $LDFLAGS:+-ldflags $LDFLAGS $MAIN_FILE"
go build -o "$OUTPUT" ${BUILD_TAGS:+-tags "$BUILD_TAGS"} ${LDFLAGS:+-ldflags "$LDFLAGS"} "$MAIN_FILE"

echo "Build completed successfully!"
echo "Binary: $OUTPUT"