cmake_minimum_required(VERSION 3.16)
project(bexcli LANGUAGES C CXX)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)

# ── Release Optimization Flags ────────────────────────────────────────────
# Full static binary, size-optimized, no debug symbols in release mode.
if(CMAKE_BUILD_TYPE STREQUAL "Release")
    # Strip all debug symbols from the final binary
    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -ffunction-sections -fdata-sections")
    set(CMAKE_EXE_LINKER_FLAGS_RELEASE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} -s -Wl,--gc-sections -Wl,--strip-all")
    # Optimize for size
    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -Os")
endif()

# ── Build Configuration ──────────────────────────────────────────────────
if(NOT CMAKE_BUILD_TYPE)
    set(CMAKE_BUILD_TYPE Release)
endif()

# ── Bex Engine Integration ───────────────────────────────────────────────
# This CMake is designed to be self-contained and reusable.
# Copy this directory into any C++ project and it will automatically
# find and link the Rust Bex Engine static library.
#
# Requirements:
#   1. Build the Rust library first: cargo build -p bex-runtime --release
#   2. Set BEX_ENGINE_ROOT if this directory is not inside the bex-engine repo
#
# The Rust library exports a pure C ABI via bex_engine.h — no bridge crate needed.

# Find the Bex Engine root directory
if(NOT BEX_ENGINE_ROOT)
    # Default: assume we're inside bex-engine/cpp-cli/
    get_filename_component(_BEX_ROOT "${CMAKE_SOURCE_DIR}/.." ABSOLUTE)
    if(EXISTS "${_BEX_ROOT}/Cargo.toml")
        set(BEX_ENGINE_ROOT "${_BEX_ROOT}")
    else()
        message(FATAL_ERROR
            "Cannot find Bex Engine root. Set -DBEX_ENGINE_ROOT=/path/to/bex-engine\n"
            "The bex-engine directory should contain Cargo.toml and the crates/ directory."
        )
    endif()
endif()

message(STATUS "Bex Engine root: ${BEX_ENGINE_ROOT}")

# ── Rust Target Directory ────────────────────────────────────────────────
# CMake uses "Release" / "Debug", but Rust uses "release" / "debug"
if(CMAKE_BUILD_TYPE STREQUAL "Release" OR CMAKE_BUILD_TYPE STREQUAL "RelWithDebInfo" OR CMAKE_BUILD_TYPE STREQUAL "MinSizeRel")
    set(RUST_PROFILE "release")
else()
    set(RUST_PROFILE "debug")
endif()

set(RUST_TARGET_DIR "${BEX_ENGINE_ROOT}/target/${RUST_PROFILE}")

# ── Detect the Rust library name ─────────────────────────────────────────
# bex-runtime compiles as both cdylib and staticlib. The produced filename
# differs by platform/toolchain: Windows (MSVC) -> "bex_runtime.lib"/.dll,
# GNU toolchain -> "libbex_runtime.a"/.so. Prefer static when available.

if(WIN32)
    set(RUST_STATIC_LIB "${RUST_TARGET_DIR}/bex_runtime.lib")
    set(RUST_SHARED_LIB "${RUST_TARGET_DIR}/bex_runtime.dll")
else()
    set(RUST_STATIC_LIB "${RUST_TARGET_DIR}/libbex_runtime.a")
    set(RUST_SHARED_LIB "${RUST_TARGET_DIR}/libbex_runtime.so")
endif()

if(EXISTS "${RUST_STATIC_LIB}")
    set(BEX_LINK_MODE "static")
    set(BEX_LIB_PATH "${RUST_STATIC_LIB}")
    message(STATUS "Found Rust static library: ${BEX_LIB_PATH}")
elseif(EXISTS "${RUST_SHARED_LIB}")
    set(BEX_LINK_MODE "shared")
    set(BEX_LIB_PATH "${RUST_SHARED_LIB}")
    message(STATUS "Found Rust shared library: ${BEX_LIB_PATH}")
else()
    message(WARNING
        "Rust library not found at ${RUST_STATIC_LIB} or ${RUST_SHARED_LIB}\n"
        "Build it first: cd ${BEX_ENGINE_ROOT} && cargo build -p bex-runtime --release"
    )
    set(BEX_LINK_MODE "static")
    set(BEX_LIB_PATH "${RUST_STATIC_LIB}")
endif()

if(WIN32)
    set(BEX_WINDOWS_SYS_LIBS bcrypt userenv ntdll advapi32)
endif()

# ── C Header Location ────────────────────────────────────────────────────
set(BEX_INCLUDE_DIR "${CMAKE_SOURCE_DIR}")

# ── Bex Engine Library (Imported Target) ─────────────────────────────────
# Create an INTERFACE library target so other projects can simply do:
#   target_link_libraries(myapp PRIVATE bex::engine)
#   target_include_directories(myapp PRIVATE ${BEX_INCLUDE_DIR})
add_library(bex_engine_lib INTERFACE)
add_library(bex::engine ALIAS bex_engine_lib)

target_include_directories(bex_engine_lib INTERFACE "${BEX_INCLUDE_DIR}")

if(BEX_LINK_MODE STREQUAL "static")
    if(WIN32)
        target_link_libraries(bex_engine_lib INTERFACE
            "${BEX_LIB_PATH}"
            ${BEX_WINDOWS_SYS_LIBS}
        )
    else()
        target_link_libraries(bex_engine_lib INTERFACE
            "${BEX_LIB_PATH}"
            dl
            pthread
            m
        )
        target_link_directories(bex_engine_lib INTERFACE "${RUST_TARGET_DIR}/deps")
    endif()
else()
    if(WIN32)
        target_link_libraries(bex_engine_lib INTERFACE
            "${BEX_LIB_PATH}"
        )
    else()
        target_link_libraries(bex_engine_lib INTERFACE
            "${BEX_LIB_PATH}"
            dl
            pthread
            m
        )
    endif()
endif()

# ── Executable: bexcli ───────────────────────────────────────────────────
add_executable(bexcli bexcli.cpp)

target_include_directories(bexcli PRIVATE "${BEX_INCLUDE_DIR}")

target_link_libraries(bexcli PRIVATE bex_engine_lib)

# ── Static Linking for Release ────────────────────────────────────────────
# Produce a fully static binary in release mode (no runtime dependencies).
if(CMAKE_BUILD_TYPE STREQUAL "Release" AND NOT WIN32)
    target_link_options(bexcli PRIVATE -static)
endif()

# ── Helper Target: Build Rust Library ────────────────────────────────────
add_custom_target(rustlib
    COMMAND ${CMAKE_COMMAND} -E env cargo build -p bex-runtime --release
    WORKING_DIRECTORY ${BEX_ENGINE_ROOT}
    COMMENT "Building Rust bex-runtime library (pure C ABI)..."
    VERBATIM
)

# Make bexcli depend on rustlib if the library file doesn't exist yet
if(NOT EXISTS "${BEX_LIB_PATH}")
    add_dependencies(bexcli rustlib)
endif()

# ── Install Rules (for integration into other projects) ──────────────────
install(TARGETS bexcli RUNTIME DESTINATION bin)
install(FILES
    "${CMAKE_SOURCE_DIR}/bex_engine.h"
    DESTINATION include/bex
)

# ── Print Configuration Summary ──────────────────────────────────────────
message(STATUS "")
message(STATUS "=== Bex CLI Configuration (Pure C ABI) ===")
message(STATUS "  Build type:       ${CMAKE_BUILD_TYPE}")
message(STATUS "  Rust profile:     ${RUST_PROFILE}")
message(STATUS "  Engine root:      ${BEX_ENGINE_ROOT}")
message(STATUS "  Rust target dir:  ${RUST_TARGET_DIR}")
message(STATUS "  Link mode:        ${BEX_LINK_MODE}")
message(STATUS "  Library path:     ${BEX_LIB_PATH}")
message(STATUS "  Include dir:      ${BEX_INCLUDE_DIR}")
message(STATUS "  FFI:              Pure C ABI (bex_engine.h)")
message(STATUS "==========================================")
message(STATUS "")