# PDFium integration.
#
# PDFium is NOT a vcpkg package — it is built from source via depot_tools/GN/Ninja
# (see third_party/pdfium/). That build installs into:
#
#     third_party/pdfium/install/
#       include/    public PDFium headers (fpdfview.h, fpdf_*.h, ...)
#       lib/        the static library (pdfium.lib / libpdfium.a)
#
# This module turns that install tree into an imported target: pdfium::pdfium
#
# Behaviour:
#   PDFENGINE_WITH_PDFIUM = OFF (default)
#       No target is created. The engine compiles with PDFium code paths
#       #ifdef-ed out. This keeps Phase 0 unblocked before PDFium is built.
#   PDFENGINE_WITH_PDFIUM = ON
#       The install tree MUST exist; otherwise this is a hard error directing
#       the developer to the build script.

if(NOT PDFENGINE_WITH_PDFIUM)
    message(STATUS "PDFium: disabled (PDFENGINE_WITH_PDFIUM=OFF). "
                   "Engine builds without raw PDFium linkage.")
    return()
endif()

set(PDFIUM_INSTALL_DIR "${CMAKE_SOURCE_DIR}/third_party/pdfium/install"
    CACHE PATH "Root of the PDFium install tree produced by build_pdfium.*")

find_path(PDFIUM_INCLUDE_DIR
    NAMES fpdfview.h
    PATHS "${PDFIUM_INSTALL_DIR}/include"
    NO_DEFAULT_PATH)

find_library(PDFIUM_LIBRARY
    NAMES pdfium libpdfium
    PATHS "${PDFIUM_INSTALL_DIR}/lib"
    NO_DEFAULT_PATH)

if(NOT PDFIUM_INCLUDE_DIR OR NOT PDFIUM_LIBRARY)
    message(FATAL_ERROR
        "PDFENGINE_WITH_PDFIUM=ON but no PDFium install tree was found under:\n"
        "    ${PDFIUM_INSTALL_DIR}\n"
        "Build PDFium first (one-time, slow):\n"
        "    Windows:  pwsh third_party/pdfium/build_pdfium.ps1\n"
        "    Unix:     ./third_party/pdfium/build_pdfium.sh\n"
        "See third_party/pdfium/README.md.")
endif()

add_library(pdfium::pdfium STATIC IMPORTED GLOBAL)
set_target_properties(pdfium::pdfium PROPERTIES
    IMPORTED_LOCATION "${PDFIUM_LIBRARY}"
    INTERFACE_INCLUDE_DIRECTORIES "${PDFIUM_INCLUDE_DIR}")

# PDFium is a C++ static lib; consumers on Linux also need the C++ runtime and
# pthreads. These are no-ops where irrelevant.
if(UNIX AND NOT APPLE)
    set_property(TARGET pdfium::pdfium APPEND PROPERTY
        INTERFACE_LINK_LIBRARIES pthread dl)
endif()

message(STATUS "PDFium: found")
message(STATUS "  include .. ${PDFIUM_INCLUDE_DIR}")
message(STATUS "  library .. ${PDFIUM_LIBRARY}")