# SPDX-License-Identifier: MIT
#
# The `desktop-entry` target's body. Copies the generated entry and the two app icons into
# $XDG_DATA_HOME, validates the entry, refreshes the caches that make the shell notice, and
# prints every path it wrote.
#
# This runs only when the target is named. The project deliberately has no install step -- that
# is the stated reason its icons are a GResource -- and a target that does nothing until asked
# preserves that while still producing a working entry.
#
# Expects -DENTRY=, -DICON= and -DSYMBOLIC= on the command line.

if(DEFINED ENV{XDG_DATA_HOME} AND NOT "$ENV{XDG_DATA_HOME}" STREQUAL "")
  set(data_home "$ENV{XDG_DATA_HOME}")
else()
  set(data_home "$ENV{HOME}/.local/share")
endif()

# Fail visibly if both fallback paths are unusable. The script needs a directory to install into;
# a missing $HOME in a sandboxed CI environment should not silently install to the filesystem root.
if(NOT DEFINED ENV{XDG_DATA_HOME} OR "$ENV{XDG_DATA_HOME}" STREQUAL "")
  if(NOT DEFINED ENV{HOME} OR "$ENV{HOME}" STREQUAL "")
    message(FATAL_ERROR "XDG_DATA_HOME and HOME are both unset or empty; cannot determine install directory")
  endif()
endif()

set(apps_dir "${data_home}/applications")
set(icon_dir "${data_home}/icons/hicolor/scalable/apps")
set(sym_dir "${data_home}/icons/hicolor/symbolic/apps")

# The icons are copied from the source tree rather than extracted from the GResource: the same
# two files serve both the in-binary resource and the installed theme, so there is one copy to
# edit. `file(COPY)` creates the directories.
file(COPY "${ENTRY}" DESTINATION "${apps_dir}")
file(COPY "${ICON}" DESTINATION "${icon_dir}")
file(COPY "${SYMBOLIC}" DESTINATION "${sym_dir}")

get_filename_component(entry_name "${ENTRY}" NAME)
get_filename_component(icon_name "${ICON}" NAME)
get_filename_component(sym_name "${SYMBOLIC}" NAME)

# Validated here rather than left to the shell, which ignores a malformed entry in silence: the
# failure belongs at the moment the entry is asked for.
find_program(DESKTOP_FILE_VALIDATE desktop-file-validate)
if(DESKTOP_FILE_VALIDATE)
  execute_process(COMMAND "${DESKTOP_FILE_VALIDATE}" "${apps_dir}/${entry_name}"
                  RESULT_VARIABLE validate_result)
  if(NOT validate_result EQUAL 0)
    message(FATAL_ERROR "desktop-file-validate rejected ${apps_dir}/${entry_name}")
  endif()
  message(STATUS "desktop-file-validate: ok")
else()
  message(STATUS "desktop-file-validate: not on PATH, entry not validated")
endif()

find_program(UPDATE_DESKTOP_DATABASE update-desktop-database)
if(UPDATE_DESKTOP_DATABASE)
  execute_process(COMMAND "${UPDATE_DESKTOP_DATABASE}" "${apps_dir}")
endif()

find_program(GTK4_UPDATE_ICON_CACHE gtk4-update-icon-cache)
if(GTK4_UPDATE_ICON_CACHE)
  execute_process(COMMAND "${GTK4_UPDATE_ICON_CACHE}" -f -t "${data_home}/icons/hicolor")
endif()

# Printed because there is no uninstall target: undoing this is these three paths.
message(STATUS "wrote ${apps_dir}/${entry_name}")
message(STATUS "wrote ${icon_dir}/${icon_name}")
message(STATUS "wrote ${sym_dir}/${sym_name}")