cmake_minimum_required(VERSION 3.21)

project(townengine LANGUAGES C)

list(APPEND CMAKE_MODULE_PATH ${CMAKE_CURRENT_SOURCE_DIR}/cmake)

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

# dependencies
find_package(SDL2 REQUIRED GLOBAL)
find_package(SDL2_image REQUIRED GLOBAL)
find_package(SDL2_ttf REQUIRED GLOBAL)

if (NOT CMAKE_BUILD_TYPE)
        set(CMAKE_BUILD_TYPE Debug)
endif ()

set(TOWNENGINE_TARGET townengine CACHE INTERNAL "")
set(TOWNENGINE_DIR ${CMAKE_CURRENT_SOURCE_DIR} CACHE INTERNAL "")

set(PHYSFS_BUILD_SHARED FALSE)
set(PHYSFS_DISABLE_INSTALL TRUE)
set(PHYSFS_TARGETNAME_UNINSTALL "physfs_uninstall")
add_subdirectory(third-party/physfs)
add_subdirectory(third-party/libxm)


if(UNIX)
        set(SYSTEM_SOURCE_FILES
                src/system/linux/elf.c
        )
else()
        set(SYSTEM_SOURCE_FILES)
endif()

set(TOWNENGINE_SOURCE_FILES
        third-party/physfs/extras/physfsrwops.c
        third-party/stb/stb_vorbis.c
        third-party/glad/src/glad.c

        src/main.c
        src/config.h
        src/context.c src/context.h
        src/audio.c src/audio.h
        src/util.c src/util.h
        src/rendering.c src/rendering.h
        src/textures.c src/textures.h
        src/input.c src/input.h
        src/text.c src/text.h
        src/camera.c src/camera.h

        ${SYSTEM_SOURCE_FILES}
)
list(TRANSFORM TOWNENGINE_SOURCE_FILES PREPEND ${TOWNENGINE_DIR}/)

# base engine code, reused for games and tools
add_library(${TOWNENGINE_TARGET} ${TOWNENGINE_SOURCE_FILES})
source_group(TREE ${TOWNENGINE_DIR} FILES ${TOWNENGINE_SOURCE_FILES})

set_target_properties(${TOWNENGINE_TARGET} PROPERTIES
                                           C_STANDARD 11
                                           C_STANDARD_REQUIRED ON
                                           C_EXTENSIONS ON) # extensions are required by stb_ds.h

# distribution definitions
set(ORGANIZATION_NAME "wanp" CACHE STRING
                      "App developer/publisher's identifier")
set(APP_NAME "townengine" CACHE STRING
             "App identifier")
set(PACKAGE_EXTENSION "btw" CACHE STRING
                      "File extension used to look for data archives")

function(give_options target)
        if(MSVC)
                # close enough i say
                target_compile_options(${target} PRIVATE
                                                 /W4
                                                 $<$<CONFIG:Release>:/GL>)

                target_link_options(${target} PRIVATE
                                              $<$<CONFIG:Release>:/LTCG>)

        else()
                set(WARNING_FLAGS_CLANG
                        -Weverything
                        -Wno-padded
                        -Wno-declaration-after-statement
                        -Wno-unsafe-buffer-usage
                        -Wno-unused-command-line-argument)

                set(WARNING_FLAGS
                        -Wall
                        -Wextra
                        -Wpedantic
                        -Wshadow
                        -Wdouble-promotion
                        -Wconversion -Wno-sign-conversion
                        -Werror=vla
                        $<$<STREQUAL:${CMAKE_C_COMPILER_ID},Gnu>:-Wcast-align=strict>
                        $<$<STREQUAL:${CMAKE_C_COMPILER_ID},Clang>:${WARNING_FLAGS_CLANG}>)

                set(BUILD_FLAGS
                        # these SHOULDN'T break anything...
                        -fno-math-errno
                        -ffp-contract=fast
                        -fno-signed-zeros
                        -fno-trapping-math
                        -freciprocal-math)

                set(BUILD_FLAGS_RELEASE
                        -O3
                        -flto
                        -mavx -mavx2
                        -Wl,--gc-sections
                        -fdata-sections
                        -ffunction-sections
                        -funroll-loops
                        -fomit-frame-pointer
                        $<$<STREQUAL:${CMAKE_C_COMPILER_ID},Gnu>:-fallow-store-data-races>)

                set(BUILD_FLAGS_DEBUG
                        -O0
                        -g3
                        -gdwarf
                        -fno-omit-frame-pointer
                        -fstack-protector-all
                        -fsanitize=undefined
                        -fsanitize=address)

                target_compile_options(${target} PRIVATE
                                                 ${WARNING_FLAGS}
                                                 ${BUILD_FLAGS}
                                                 $<$<CONFIG:Release>:${BUILD_FLAGS_RELEASE}>
                                                 $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>)

                target_link_options(${target} PRIVATE
                                              ${BUILD_FLAGS}
                                              $<$<CONFIG:Release>:${BUILD_FLAGS_RELEASE}>
                                              $<$<CONFIG:Debug>:${BUILD_FLAGS_DEBUG}>)
                                                    
        endif()

        target_compile_definitions(${target} PRIVATE
                                             ORGANIZATION_NAME="${ORGANIZATION_NAME}"
                                             APP_NAME="${APP_NAME}"
                                             PACKAGE_EXTENSION="${PACKAGE_EXTENSION}")
endfunction()


function(link_and_include_deps target)
        # header-only libraries should be marked as "system includes"
        # to suppress compiler warnings in their code (it's not my problem after all)
        set(THIRD_PARTY_INCLUDES
                third-party/physfs/src
                third-party/physfs/extras
                third-party/libxm/include
                third-party/glad/include
                third-party/stb
        )
        list(TRANSFORM THIRD_PARTY_INCLUDES PREPEND ${TOWNENGINE_DIR}/)
        target_include_directories(${target} SYSTEM PRIVATE ${THIRD_PARTY_INCLUDES})

        # allow access to headers from any point in source tree
        target_include_directories(${target} PRIVATE ${TOWNENGINE_DIR})

        target_link_libraries(${target} PUBLIC
                                        SDL2::SDL2
                                        SDL2::SDL2main
                                        SDL2_image::SDL2_image
                                        SDL2_ttf::SDL2_ttf
                                        physfs-static
                                        xms
        )
endfunction()


function(use_townengine target)
        # system libraries
        find_library(MATH_LIBRARY m)
        if(MATH_LIBRARY)
                target_link_libraries(${target} PUBLIC ${MATH_LIBRARY})
        endif()

        give_options(${target})
        link_and_include_deps(${target})

        # third-party libraries
        target_link_libraries(${target} PUBLIC
                                        ${TOWNENGINE_TARGET}
                                        SDL2::SDL2
                                        SDL2::SDL2main
                                        SDL2_image::SDL2_image
                                        SDL2_ttf::SDL2_ttf
                                        physfs-static
                                        xms
        )

        # copy dlls for baby windows
        add_custom_command(TARGET ${target} POST_BUILD
                COMMAND ${CMAKE_COMMAND} -E copy -t $<TARGET_FILE_DIR:${target}>
                                                    $<TARGET_RUNTIME_DLLS:${target}>
                COMMAND_EXPAND_LISTS
        )
endfunction()

give_options(${TOWNENGINE_TARGET})
link_and_include_deps(${TOWNENGINE_TARGET})

add_subdirectory(apps/testgame)

# zip up assets
# currently, you must run cmake from the project root dir for this to work correctly
#file(ARCHIVE_CREATE OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/data.${PACKAGE_EXTENSION}
#                    PATHS ${PROJECT_SOURCE_DIR}/assets
#                    FORMAT zip
#)