cmake_minimum_required(VERSION 3.24)

# MobileGL headless GPU integration tests.
#
# These are not unit tests: each scenario brings up a real EGL context on a
# pbuffer, renders real frames through a real backend and asserts on
# glReadPixels output. They need a GPU, so the module is OFF by default
# (MOBILEGL_BUILD_INTEGRATION_TEST) and every scenario skips cleanly - never
# fails, never hangs - on a machine without one. "Cleanly" is not a hope: the
# harness runs the whole bring-up in a forked child first, because MobileGL
# ABORTS rather than returning an error on an unusable platform (HeadlessGL.cpp).
#
# A clean skip is also indistinguishable from a pass, so set
# MOBILEGL_ITEST_REQUIRE_GPU wherever the machine is supposed to have a GPU.
#
# Backend selection is latched at initialization from MOBILEGL_BACKEND_TYPE, so
# one process is one backend: the same binary is registered twice, once per
# backend, under the `integration-gpu` label.

message(STATUS "Generating build files for MobileGL Integration Test...")

set(CMAKE_CXX_STANDARD 23)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

set(MGL_ITEST_ROOT ${CMAKE_CURRENT_LIST_DIR}/../..)

# Only meaningful where MobileGL_s exists (i.e. not Android).
if (NOT TARGET MobileGL_s)
    message(STATUS "MobileGL_s is not available; skipping the integration test module")
    return()
endif()

# MG_Test already pulls googletest in when MOBILEGL_BUILD_TEST is ON. Stand on
# our own feet when it is not, so this module can be built by itself.
if (NOT TARGET GTest::gtest)
    include(FetchContent)
    FetchContent_Declare(
        googletest
        GIT_REPOSITORY https://github.com/google/googletest.git
        GIT_TAG        v1.17.0
    )
    set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
    FetchContent_MakeAvailable(googletest)
endif()

add_executable(MobileGLIntegrationTest
    Main.cpp
    Harness/HeadlessGL.cpp
    Scenarios/OrientationScenario.cpp
    Scenarios/CrossFrameBufferScenario.cpp
    Scenarios/ResidentIndexScenario.cpp
    Scenarios/MultiDrawScenario.cpp
    Scenarios/DrawParametersScenario.cpp
    Scenarios/AsyncCompileScenario.cpp
    Scenarios/XfbAfterClipDistanceScenario.cpp
    Scenarios/ThreeChannelAttachmentScenario.cpp
    Scenarios/PipelineFailureScenario.cpp
    Scenarios/AdvertisedLimitsScenario.cpp
    Scenarios/PixelStoreSweepScenario.cpp
    Scenarios/FragCoordOriginScenario.cpp
    Scenarios/ClearThenReadPixelsScenario.cpp
    Scenarios/DepthStencilReadbackScenario.cpp
    Scenarios/SsboArrayLengthScenario.cpp
    Scenarios/UniformInitializerScenario.cpp
    Scenarios/SwizzleAccessRoutineScenario.cpp
    Scenarios/ProgramPipelineScenario.cpp
    Scenarios/ImageLoadStoreSsoScenario.cpp
    Scenarios/SsboDeclarationFormScenario.cpp
    Scenarios/Glsl420DeclarationScenario.cpp
    Scenarios/FragmentOutputArrayIndexScenario.cpp
    Scenarios/BufferTextureScenario.cpp
)

target_include_directories(MobileGLIntegrationTest PRIVATE
    ${MGL_ITEST_ROOT}/include
    ${MGL_ITEST_ROOT}/MobileGL
)

# gtest, not gtest_main: Main.cpp installs the harness banner itself.
target_link_libraries(MobileGLIntegrationTest PRIVATE
    GTest::gtest
    MobileGL_s
)

if (MSVC)
    # Same reason as MG_Test/Backend/DirectVulkan: the GLES headers declare gl*
    # as dllimport on Windows, so the in-library GL entry-point definitions only
    # resolve if the whole static library is part of the link.
    target_link_options(MobileGLIntegrationTest PRIVATE /WHOLEARCHIVE:MobileGL_s)
endif()
target_compile_definitions(MobileGLIntegrationTest PRIVATE -DNOMINMAX)

# --- ctest wiring --------------------------------------------------------
# A bare libEGL on a glvnd box resolves to whatever vendor comes first, which is
# usually Mesa/llvmpipe - a software rasteriser silently replacing the GPU under
# a GPU test. Pin the vendor/ICD json the same way MG_Benchmark's
# run_driver_bench.sh does.
#
# Leaving these empty is not a neutral default, it is the failure mode: an
# unpinned libEGL lands on llvmpipe and the suite goes green having tested a
# software rasteriser. So they are DETECTED here rather than defaulted to empty,
# and an empty result is a loud warning.
#
# mgl_itest_find_driver_json(<outVar> <description> <glob> [<glob>...])
#   Picks the first json a real hardware vendor owns, in preference order, and
#   never picks a software rasteriser (llvmpipe / lavapipe / swrast) - landing on
#   one of those silently is the exact accident this pinning exists to prevent.
function(mgl_itest_find_driver_json outVar)
    set(candidates "")
    foreach(pattern IN LISTS ARGN)
        file(GLOB matches "${pattern}")
        list(APPEND candidates ${matches})
    endforeach()
    list(SORT candidates)
    # Vendors ship an i686 json beside the x86_64 one and it sorts first. Pinning
    # the wrong word size is worse than not pinning at all - the loader finds no
    # driver and the whole suite skips - so drop the mismatched ones outright.
    if (CMAKE_SIZEOF_VOID_P EQUAL 8)
        list(FILTER candidates EXCLUDE REGEX "i686|i386")
    else()
        list(FILTER candidates EXCLUDE REGEX "x86_64|aarch64")
    endif()
    set(software "")
    foreach(vendor IN ITEMS nvidia amdgpu amd radeon intel_hasvk intel broadcom freedreno panfrost)
        foreach(candidate IN LISTS candidates)
            get_filename_component(leaf "${candidate}" NAME)
            string(TOLOWER "${leaf}" leaf)
            if (leaf MATCHES "${vendor}")
                set(${outVar} "${candidate}" PARENT_SCOPE)
                return()
            endif()
        endforeach()
    endforeach()
    # Nothing recognised as hardware. Report the first non-software entry if there
    # is one; otherwise report nothing, so the warning below fires.
    foreach(candidate IN LISTS candidates)
        get_filename_component(leaf "${candidate}" NAME)
        string(TOLOWER "${leaf}" leaf)
        if (NOT leaf MATCHES "lvp|llvmpipe|lavapipe|swrast|softpipe")
            set(${outVar} "${candidate}" PARENT_SCOPE)
            return()
        endif()
        set(software "${candidate}")
    endforeach()
    set(${outVar} "" PARENT_SCOPE)
endfunction()

set(MGL_ITEST_DETECTED_EGL_VENDOR "")
set(MGL_ITEST_DETECTED_VK_ICD "")
if (UNIX AND NOT APPLE AND NOT ANDROID)
    mgl_itest_find_driver_json(MGL_ITEST_DETECTED_EGL_VENDOR
        "/usr/share/glvnd/egl_vendor.d/*.json"
        "/etc/glvnd/egl_vendor.d/*.json")
    mgl_itest_find_driver_json(MGL_ITEST_DETECTED_VK_ICD
        "/usr/share/vulkan/icd.d/*.json"
        "/etc/vulkan/icd.d/*.json")
endif()

set(MOBILEGL_ITEST_EGL_VENDOR "${MGL_ITEST_DETECTED_EGL_VENDOR}" CACHE FILEPATH
    "glvnd EGL vendor json to pin for the integration tests (empty: leave the loader alone)")
set(MOBILEGL_ITEST_VK_ICD "${MGL_ITEST_DETECTED_VK_ICD}" CACHE FILEPATH
    "Vulkan ICD json to pin for the DirectVulkan integration tests (empty: leave the loader alone)")

if (MOBILEGL_ITEST_EGL_VENDOR)
    message(STATUS "Integration tests: pinning EGL vendor ${MOBILEGL_ITEST_EGL_VENDOR}")
else()
    message(WARNING
        "Integration tests: no EGL vendor json found or configured (MOBILEGL_ITEST_EGL_VENDOR is empty). "
        "An unpinned libEGL on a glvnd system resolves to whichever vendor comes first, which is usually "
        "Mesa/llvmpipe - the scenarios would then go green against a software rasteriser instead of the GPU. "
        "Set -DMOBILEGL_ITEST_EGL_VENDOR=/usr/share/glvnd/egl_vendor.d/<vendor>.json.")
endif()
if (MOBILEGL_ITEST_VK_ICD)
    message(STATUS "Integration tests: pinning Vulkan ICD ${MOBILEGL_ITEST_VK_ICD}")
else()
    message(WARNING
        "Integration tests: no Vulkan ICD json found or configured (MOBILEGL_ITEST_VK_ICD is empty). "
        "DirectVulkan would then load whichever ICD the loader enumerates first, quite possibly lavapipe. "
        "Set -DMOBILEGL_ITEST_VK_ICD=/usr/share/vulkan/icd.d/<vendor>.json.")
endif()

# Turns "no usable GPU" from a clean skip into a failure - see ScenarioFixture.h.
# Without it the integration-gpu label is unfalsifiable: a run that skipped every
# scenario and a run that passed every scenario are the same green in ctest.
option(MOBILEGL_ITEST_REQUIRE_GPU
    "Fail (rather than skip) the integration scenarios when the headless harness is unusable" OFF)

# No EGL_PLATFORM knob here on purpose. The harness pins EGL_PLATFORM=surfaceless
# itself before its first EGL call (HeadlessGL.cpp, EnsureHeadlessPlatform) so a
# developer's machine and a CI runner take the SAME path whether or not a window
# system happens to be running. This used to inject "x11", which is how the lane
# came up green on a workstation with WSLg and died on a runner with no X server.
#
# A build-system knob would not just be redundant, it would be a trap: `set(...
# CACHE ...)` does not rewrite an existing cache, so every build directory
# configured before this change would keep injecting EGL_PLATFORM=x11 and go on
# binding to a window system - silently, and only on the machines that have one.
# Someone reproducing a platform-specific bug sets EGL_PLATFORM in their own
# environment, which the harness still honours.

set(MGL_ITEST_COMMON_ENV "")
if (MOBILEGL_ITEST_EGL_VENDOR)
    list(APPEND MGL_ITEST_COMMON_ENV "__EGL_VENDOR_LIBRARY_FILENAMES=${MOBILEGL_ITEST_EGL_VENDOR}")
endif()
unset(MOBILEGL_ITEST_EGL_PLATFORM CACHE) # see above: an old cache must not resurrect x11
if (MOBILEGL_ITEST_REQUIRE_GPU)
    list(APPEND MGL_ITEST_COMMON_ENV "MOBILEGL_ITEST_REQUIRE_GPU=1")
endif()

set(MGL_ITEST_VULKAN_ENV ${MGL_ITEST_COMMON_ENV})
if (MOBILEGL_ITEST_VK_ICD)
    list(APPEND MGL_ITEST_VULKAN_ENV "VK_ICD_FILENAMES=${MOBILEGL_ITEST_VK_ICD}")
endif()

# The ENVIRONMENT test property is itself a `;`-list, and gtest_discover_tests
# forwards PROPERTIES as a flat list - so a plain `;`-joined value arrives as
# four separate arguments and everything after the first is silently read as
# another property name. Escaping the separators keeps the whole thing one list
# element until set_tests_properties expands it back. Without this only
# MOBILEGL_BACKEND_TYPE reaches the test and the vendor/ICD pinning is lost.
function(mgl_itest_join_environment outVar)
    set(joined "")
    foreach(entry IN LISTS ARGN)
        if (joined)
            string(APPEND joined "\\;${entry}")
        else()
            set(joined "${entry}")
        endif()
    endforeach()
    set(${outVar} "${joined}" PARENT_SCOPE)
endfunction()

mgl_itest_join_environment(MGL_ITEST_GLES_ENVIRONMENT
    "MOBILEGL_BACKEND_TYPE=DirectGLES" ${MGL_ITEST_COMMON_ENV})
mgl_itest_join_environment(MGL_ITEST_VULKAN_ENVIRONMENT
    "MOBILEGL_BACKEND_TYPE=DirectVulkan" ${MGL_ITEST_VULKAN_ENV})
mgl_itest_join_environment(MGL_ITEST_VULKAN_ASYNC_ENVIRONMENT
    "MOBILEGL_BACKEND_TYPE=DirectVulkan" "MOBILEGL_ASYNC_SHADER_COMPILE=1" ${MGL_ITEST_VULKAN_ENV})

# TIMEOUT on every entry: a GPU test that wedges must fail the run, not hang it.
set(MGL_ITEST_TIMEOUT 120)

include(GoogleTest)

# Discovery runs `--gtest_list_tests`, which does not construct the harness and
# so needs no GPU. One registration per backend; TEST_PREFIX keeps the two sets
# of ctest names apart.
gtest_discover_tests(MobileGLIntegrationTest
    TEST_PREFIX "DirectGLES."
    DISCOVERY_TIMEOUT 30
    PROPERTIES
        LABELS integration-gpu
        TIMEOUT ${MGL_ITEST_TIMEOUT}
        ENVIRONMENT "${MGL_ITEST_GLES_ENVIRONMENT}"
)

gtest_discover_tests(MobileGLIntegrationTest
    TEST_PREFIX "DirectVulkan."
    DISCOVERY_TIMEOUT 30
    PROPERTIES
        LABELS integration-gpu
        TIMEOUT ${MGL_ITEST_TIMEOUT}
        ENVIRONMENT "${MGL_ITEST_VULKAN_ENVIRONMENT}"
)

# A third registration, of ONE scenario, with asynchronous shader compilation
# pinned on. Not a second code path in the renderer: a second ALLOCATION pattern.
# The async pipeline's job objects change which of the freed blocks the capture
# phase is handed, and that is what decides whether the destroyed-VAO address is
# reached at all - on the ablated (pre-fix) tree async=1 reproduced 3 runs out of
# 3 where the ambient default reproduced 2 of 3. Pinning it here means the
# high-signal configuration runs whatever the shipped default becomes, instead of
# the suite quietly weakening the day that default flips. It must be process-wide
# (the ENVIRONMENT property), not an in-process scope: the compile pool and its
# threads are stood up at initialization, and their allocations are half the
# point. DirectVulkan only - the memo this pins is DirectVulkan's.
gtest_discover_tests(MobileGLIntegrationTest
    TEST_PREFIX "DirectVulkan.AsyncCompile."
    TEST_FILTER "XfbAfterClipDistanceScenario.*"
    DISCOVERY_TIMEOUT 30
    PROPERTIES
        LABELS integration-gpu
        TIMEOUT ${MGL_ITEST_TIMEOUT}
        ENVIRONMENT "${MGL_ITEST_VULKAN_ASYNC_ENVIRONMENT}"
)