# SPDX-License-Identifier: MIT
#
# The `install-help-user` target's body. Copies the Mallard help set into the user's XDG data
# directory -- where `help:<id>` resolves without root -- and prints every path it wrote.
#
# `$XDG_DATA_HOME` is honoured when it is set, and `$HOME/.local/share` is the fallback when it
# is not: that is the XDG Base Directory Specification's own stated default for the variable, and
# it is the default `help_installed_path()` falls back to as well, so the manual lands where the
# application and the desktop viewer look for it. The variable names a *data directory*, not a
# prefix -- its `share/` is not appended -- so the set goes to `<data_home>/help/C/<id>/`. An
# arbitrary `$XDG_DATA_HOME` need not end in `share`, which is exactly why this copies the tree
# rather than deferring to `cmake --install --prefix`, whose datadir is always `<prefix>/share`.
#
# Like the desktop-entry target, this runs only when it is named: `cmake --build build` never
# touches the user's data directory.
#
# Expects -DHELP_SRC= and -DHELP_NAME= on the command line.

if(DEFINED ENV{XDG_DATA_HOME} AND NOT "$ENV{XDG_DATA_HOME}" STREQUAL "")
  set(data_home "$ENV{XDG_DATA_HOME}")
elseif(DEFINED ENV{HOME} AND NOT "$ENV{HOME}" STREQUAL "")
  set(data_home "$ENV{HOME}/.local/share")
else()
  message(FATAL_ERROR
    "XDG_DATA_HOME and HOME are both unset or empty; cannot determine the user data directory")
endif()

if(NOT DEFINED HELP_SRC OR NOT DEFINED HELP_NAME)
  message(FATAL_ERROR "HELP_SRC and HELP_NAME are both required")
endif()

set(dest "${data_home}/help/C/${HELP_NAME}")

# The same filter as the install() rule, so both destinations carry the same tree: the pages and
# the figures, and nothing an editor left behind.
file(COPY "${HELP_SRC}/" DESTINATION "${dest}"
     FILES_MATCHING PATTERN "*.page" PATTERN "*.png" PATTERN "*.jpg")

# Printed because there is no uninstall target: undoing this is these paths.
file(GLOB_RECURSE installed LIST_DIRECTORIES FALSE RELATIVE "${dest}" "${dest}/*")
list(SORT installed)
foreach(path IN LISTS installed)
  message(STATUS "wrote ${dest}/${path}")
endforeach()