#!/bin/bash
# build.sh - Master build script for 4coder simplified build system
# Usage: ./build.sh [platform] [config] [arch]
# Examples:
#   ./build.sh macos debug x64
#   ./build.sh linux release x64
#   ./build.sh win32 debug x64

set -e  # Exit on error

# =============================================================================
# Configuration
# =============================================================================

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
BUILD_ROOT="$SCRIPT_DIR/../../build"
CONFIG_DIR="$SCRIPT_DIR/../config"
HELPERS_DIR="$SCRIPT_DIR/../helpers"

# Source configuration files
source "$CONFIG_DIR/build-config.sh"

# =============================================================================
# Utility Functions
# =============================================================================

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

print_success() {
    echo -e "${GREEN}✓${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}⚠${NC} $1"
}

print_error() {
    echo -e "${RED}✗${NC} $1"
}

print_info() {
    echo -e "${BLUE}ℹ${NC} $1"
}

print_step() {
    echo -e "${BLUE}===${NC} $1 ${BLUE}===${NC}"
}

show_usage() {
    echo "Usage: $0 [platform] [config] [arch]"
    echo ""
    echo "Parameters:"
    echo "  platform   - Target platform (auto-detect if not specified)"
    echo "               Options: macos, linux, win32"
    echo "  config     - Build configuration (default: debug)"
    echo "               Options: debug, release"
    echo "  arch       - Target architecture (auto-detect if not specified)"
    echo "               Options: x64, x86, arm64"
    echo ""
    echo "Examples:"
    echo "  $0                    # Auto-detect platform and arch, debug build"
    echo "  $0 macos debug x64    # Explicit macOS debug x64 build"
    echo "  $0 linux release x64  # Linux release build"
    echo "  $0 win32 debug x64    # Windows debug build"
    echo ""
    echo "Environment:"
    echo "  BUILD_VERBOSE=1       # Enable verbose compilation output"
    echo "  BUILD_CLEAN=1         # Clean before build"
}

# =============================================================================
# Parameter Processing
# =============================================================================

detect_platform_and_arch() {
    local detected_platform detected_arch

    if [[ -x "$HELPERS_DIR/detect-platform.sh" ]]; then
        detected_platform=$("$HELPERS_DIR/detect-platform.sh" detect 2>/dev/null)
        detected_arch=$("$HELPERS_DIR/detect-platform.sh" arch 2>/dev/null)

        if [[ -n "$detected_platform" && -n "$detected_arch" ]]; then
            # Don't print here, let the caller print after parsing
            echo "$detected_platform $detected_arch"
        else
            print_error "Failed to detect platform or architecture" >&2
            return 1
        fi
    else
        print_error "Platform detection script not found" >&2
        return 1
    fi
}

validate_parameters() {
    local platform=$1
    local config=$2
    local arch=$3

    # Validate platform
    case "$platform" in
        "macos"|"linux"|"win32")
            ;;
        *)
            print_error "Invalid platform: $platform"
            print_info "Valid platforms: macos, linux, win32"
            return 1
            ;;
    esac

    # Validate config
    case "$config" in
        "debug"|"release")
            ;;
        *)
            print_error "Invalid config: $config"
            print_info "Valid configs: debug, release"
            return 1
            ;;
    esac

    # Validate arch
    case "$arch" in
        "x64"|"x86"|"arm64")
            ;;
        *)
            print_error "Invalid architecture: $arch"
            print_info "Valid architectures: x64, x86, arm64"
            return 1
            ;;
    esac

    return 0
}

# =============================================================================
# Build Environment Setup
# =============================================================================

setup_build_environment() {
    local platform=$1
    local config=$2
    local arch=$3

    print_step "Setting up build environment"

    # Create build directories
    mkdir -p "$BUILD_ROOT"
    mkdir -p "$BUILD_ROOT/temp"

    # Export build variables
    export BUILD_PLATFORM="$platform"
    export BUILD_CONFIG="$config"
    export BUILD_ARCH="$arch"
    export BUILD_ROOT="$BUILD_ROOT"
    export CODE_DIR="$CODE_DIR"
    export CUSTOM_DIR="$CUSTOM_DIR"
    export FOREIGN_DIR="$FOREIGN_DIR"

    print_success "Build environment ready"
    print_info "Platform: $platform"
    print_info "Config: $config"
    print_info "Architecture: $arch"
    print_info "Build root: $BUILD_ROOT"
}

# =============================================================================
# Build Execution
# =============================================================================

execute_platform_build() {
    local platform=$1
    local config=$2
    local arch=$3

    local platform_script="$SCRIPT_DIR/build-$platform.sh"

    if [[ -x "$platform_script" ]]; then
        print_step "Executing platform-specific build"
        print_info "Running: $platform_script $config $arch"

        # Execute platform-specific build script
        "$platform_script" "$config" "$arch"

        return $?
    else
        print_error "Platform-specific build script not found: $platform_script"
        return 1
    fi
}

# =============================================================================
# Clean Build Support
# =============================================================================

clean_build() {
    print_step "Cleaning build directory"

    if [[ -d "$BUILD_ROOT" ]]; then
        print_info "Removing $BUILD_ROOT"
        rm -rf "$BUILD_ROOT"
    fi

    print_success "Build directory cleaned"
}

# =============================================================================
# Main Build Process
# =============================================================================

main() {
    local platform="${1:-}"
    local config="${2:-debug}"
    local arch="${3:-}"

    # Handle help request
    if [[ "$1" == "help" || "$1" == "-h" || "$1" == "--help" ]]; then
        show_usage
        return 0
    fi

    # Handle clean request
    if [[ "$1" == "clean" ]]; then
        clean_build
        return 0
    fi

    print_step "4coder Simplified Build System"

    # Auto-detect platform and arch if not provided
    if [[ -z "$platform" || -z "$arch" ]]; then
        local detected_info detected_platform detected_arch
        detected_info=$(detect_platform_and_arch)
        if [[ $? -ne 0 ]]; then
            print_error "Failed to auto-detect platform and architecture"
            return 1
        fi
        read -r detected_platform detected_arch <<< "$detected_info"

        platform="${platform:-$detected_platform}"
        arch="${arch:-$detected_arch}"

        print_info "Auto-detected platform: $platform"
        print_info "Auto-detected architecture: $arch"
    fi

    # Validate parameters
    if ! validate_parameters "$platform" "$config" "$arch"; then
        echo ""
        show_usage
        return 1
    fi

    # Clean if requested
    if [[ "${BUILD_CLEAN:-}" == "1" ]]; then
        clean_build
    fi

    # Setup build environment
    if ! setup_build_environment "$platform" "$config" "$arch"; then
        return 1
    fi

    # Record build start time
    local build_start_time
    build_start_time=$(date +%s)

    # Execute platform-specific build
    print_step "Starting build process"

    if execute_platform_build "$platform" "$config" "$arch"; then
        local build_end_time build_duration
        build_end_time=$(date +%s)
        build_duration=$((build_end_time - build_start_time))

        print_step "Build completed successfully!"
        print_success "Build time: ${build_duration}s"
        print_info "Outputs in: $BUILD_ROOT"

        # List built artifacts
        print_info "Built artifacts:"
        if [[ -f "$BUILD_ROOT/4ed" ]]; then
            print_success "  4ed (main executable)"
        fi
        if [[ -f "$BUILD_ROOT/4ed_app.so" ]]; then
            print_success "  4ed_app.so (core engine)"
        fi
        if [[ -f "$BUILD_ROOT/custom_4coder.so" ]]; then
            print_success "  custom_4coder.so (custom layer)"
        fi

        return 0
    else
        print_error "Build failed"
        return 1
    fi
}

# Only run main if script is executed directly (not sourced)
if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
    main "$@"
fi