# General purpose pkg-config macros

# Determine if a package is available
# 1: Name of variable to assign result into
# 2: Name of package to search for
define pkg_config_package_available
  ifeq ($$(PKGCONFIG),)
    $$(error pkg-config is required to auto-detect package availability)
  endif

  ifeq ($$(shell $$(PKGCONFIG) --exists $(2) && echo yes),yes)
    $(1) := yes
  else
    $(1) := no
  endif

endef

# Retrieve the version of a package
# 1: Name of variable to assign result into
# 2: Name of package to search for
define pkg_config_package_version
  ifeq ($$(PKGCONFIG),)
    $$(error pkg-config is required to auto-detect package version)
  endif

  $(1) := $$(shell $$(PKGCONFIG) --modversion $(2))

endef

# Test the presence of a minimum version of a package
# 1: Name of variable to assign result into
# 2: Name of package to search for
# 3: Lowest accepted version number
define pkg_config_package_min_version
  ifeq ($$(PKGCONFIG),)
    $$(error pkg-config is required to auto-detect package version)
  endif

  ifeq ($$(shell $$(PKGCONFIG) --atleast-version=$(3) $(2) && echo yes),yes)
     $(1) := yes
  else
     $(1) := no
  endif

endef

# Test the presence of a minimum version of a package
# 1: Name of variable to assign result into
# 2: Name of package to search for
# 3: Lowest accepted version number
# 4: Highest accepted version number
define pkg_config_package_compare_version
  ifeq ($$(PKGCONFIG),)
    $$(error pkg-config is required to auto-detect package version)
  endif

  ifeq ($$(shell $$(PKGCONFIG) --atleast-version=$(3) $(2) && echo yes),yes)
     ifeq ($$(shell $$(PKGCONFIG) --max-version=$(4) $(2) && echo yes),yes)
       $(1) := yes
     else
       $(1) := no
     endif
  else
     $(1) := no
  endif

endef

# Add package to compiler/linker flags
# 1: Name of package to add details of
# 2: CFLAGS variable to extend, or none
# 3: LDFLAGS variable to extend, or none
define pkg_config_package_add_flags
  ifeq ($$(PKGCONFIG),)
    $$(error pkg-config is required to auto-detect package version)
  endif

  ifneq ($(2),)
    $(2) := $$($(2)) $$(shell $$(PKGCONFIG) --cflags $(1))
  endif

  ifneq ($(3),)
    $(3) := $$($(3)) $$(shell $$(PKGCONFIG) --libs $(1))
  endif

endef

# Obtain the value of a pkg-config variable
# 1: Name of variable to assign result into
# 2: Name of package to search for
# 3: Name of pkg-config variable to retrieve
define pkg_config_get_variable
  ifeq ($$(PKGCONFIG),)
    $$(error pkg-config is required to auto-detect package version)
  endif

  $(1) := $$(shell $$(PKGCONFIG) --variable=$(3) $(2))

endef