# CMakeLists.txt — Build configuration for the LIN Simulator (C++)
#
# CMAKE BASICS:
# =============
# CMake is a build system generator. It doesn't compile code directly.
# Instead, it generates platform-specific build files:
#   - macOS/Linux: Makefiles (then you run `make`)
#   - Windows: Visual Studio project files
#   - Any platform: Ninja build files (faster than Make)
#
# The workflow is:
#   1. mkdir build && cd build
#   2. cmake ..              ← generates build files from this CMakeLists.txt
#   3. cmake --build .       ← compiles and links the project
#   4. ./lin_simulator       ← run the application
#
# Qt6 integration:
#   CMake has built-in support for Qt via find_package(Qt6).
#   Qt needs special preprocessing for its features:
#     - MOC (Meta-Object Compiler): processes Q_OBJECT macros for signals/slots
#     - UIC: compiles .ui designer files to C++ headers (we don't use these)
#     - RCC: compiles resource files (icons, etc.) into the binary

cmake_minimum_required(VERSION 3.16)

project(LINSimulator
    VERSION 0.1.0
    LANGUAGES CXX
    DESCRIPTION "LIN Simulator using BabyLIN devices"
)

# C++17 standard — required for structured bindings, std::optional, etc.
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# ── Qt6 auto-processing ──
# These three lines enable Qt's special preprocessors:
#   AUTOMOC: automatically runs MOC on headers containing Q_OBJECT
#   AUTOUIC: automatically compiles .ui files (if we had any)
#   AUTORCC: automatically compiles .qrc resource files
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTORCC ON)

# ── Find Qt6 ──
# find_package searches for Qt6 on the system.
# REQUIRED means CMake will error if Qt6 is not found.
# COMPONENTS lists which Qt modules we need:
#   Widgets: GUI widgets (QMainWindow, QPushButton, etc.)
#   We'll add SerialPort in Step 5 when we need device communication.
find_package(Qt6 REQUIRED COMPONENTS Widgets)

# ── Main application target ──
# qt_add_executable is Qt's wrapper around add_executable.
# It handles platform-specific details (macOS app bundle, Windows subsystem, etc.)
qt_add_executable(lin_simulator
    src/main.cpp
    src/main_window.cpp
    src/main_window.h
)

# Link against Qt6 Widgets library
# PRIVATE means this dependency is only for building this target,
# not propagated to anything that depends on us.
target_link_libraries(lin_simulator PRIVATE Qt6::Widgets)

# ── Tests ──
# We use Qt's built-in test framework (QTest) instead of GoogleTest
# because it integrates naturally with Qt's event loop and widgets.
# QTest provides:
#   - QVERIFY(condition): assert a condition is true
#   - QCOMPARE(actual, expected): assert two values are equal
#   - QTest::mouseClick(): simulate mouse events
#   - QTest::keyClick(): simulate keyboard events
enable_testing()
find_package(Qt6 REQUIRED COMPONENTS Test)

qt_add_executable(test_main_window
    tests/test_main_window.cpp
    src/main_window.cpp
    src/main_window.h
)

target_link_libraries(test_main_window PRIVATE Qt6::Widgets Qt6::Test)
target_include_directories(test_main_window PRIVATE src)

# Register the test with CTest so `ctest` can discover and run it
add_test(NAME test_main_window COMMAND test_main_window)