# ==============================================================================
# Compiler and Linker Flags
# ==============================================================================
# This module sets platform-specific and compiler-specific flags, libraries,
# and definitions used throughout the build system.
#
# Variables set:
#   BASE_LIBRARIES   - Libraries to link based on target platform
#   BASE_DEFINITIONS - Preprocessor definitions based on target platform
#   BASE_OPTIONS     - Compiler warning flags (C/C++ only, not applied to Swift)
#
# Requires: Platform.cmake must be included first (for IS_* variables)
# ==============================================================================

# ------------------------------------------------------------------------------
# Framework Detection Helper
# ------------------------------------------------------------------------------

# find_and_link_framework(<OUT_VAR> <FRAMEWORK_NAME> <DISPLAY_NAME>)
#
# Searches for an Apple framework and, if found, appends -framework <name> to
# the output list.
#
# Parameters:
#   - OUT_VAR         Name of the list variable to append the flag to
#   - FRAMEWORK_NAME  The framework name to search for (e.g. "IOKit")
#   - DISPLAY_NAME    Human-readable name for status messages
function(find_and_link_framework OUT_VAR FRAMEWORK_NAME DISPLAY_NAME)
    find_library(_FOUND_LIB ${FRAMEWORK_NAME})
    if (_FOUND_LIB)
        message(STATUS "  [x] ${DISPLAY_NAME} (-framework ${FRAMEWORK_NAME})")
        list(APPEND ${OUT_VAR} "-framework ${FRAMEWORK_NAME}")
        set(${OUT_VAR} "${${OUT_VAR}}" PARENT_SCOPE)
    else()
        message(STATUS "  [ ] ${DISPLAY_NAME} (-framework ${FRAMEWORK_NAME})")
    endif()
    unset(_FOUND_LIB CACHE)
endfunction()

# ------------------------------------------------------------------------------
# Platform-Specific Link Libraries
# ------------------------------------------------------------------------------
# These frameworks are required for USB access, crypto and (later) audio.
# They are linked into the final executable; static libraries reference the
# symbols and resolution happens at final link time.

set(BASE_LIBRARIES "")
if (IS_MACOS)
    message(STATUS "macOS link libraries:")
    find_and_link_framework(BASE_LIBRARIES "IOKit"          "IOKit (USB transport)")
    find_and_link_framework(BASE_LIBRARIES "CoreFoundation" "Core Foundation")
    find_and_link_framework(BASE_LIBRARIES "Security"       "Security (crypto/ECDH)")
elseif (IS_IOS)
    message(FATAL_ERROR "iOS is not supported yet!")
endif()

# ------------------------------------------------------------------------------
# Platform-Specific Definitions
# ------------------------------------------------------------------------------
set(BASE_DEFINITIONS "")

# ------------------------------------------------------------------------------
# Compiler Warning Flags
# ------------------------------------------------------------------------------
# These are stored in BASE_OPTIONS and applied per-target via
# target_compile_options() to avoid polluting external dependencies.
# NOTE: Applied to C/C++ targets only; swiftc does not share these flags.
set(BASE_OPTIONS "")
if (IS_CLANG_OR_GCC)
    set(BASE_OPTIONS
        "-Wall"                          # Enable all common warnings
        "-Wextra"                        # Enable extra warnings
        "-Werror"                        # Treat warnings as errors
    )
elseif (IS_MSVC)
    set(BASE_OPTIONS
        "/W4"              # Warning level 4 (high)
        "/WX"              # Treat warnings as errors
        "/utf-8"           # Set source and execution character set to UTF-8
        "/Zc:__cplusplus"  # Report correct C++ standard version in __cplusplus
    )
endif()