# Copyright 2016 Julian Ospald <hasufell@posteo.de>
# Distributed under the terms of the GNU General Public License v2

# Purpose: an exlib dealing with '.desktop' files
# Maintainer: Julian Ospald <hasufell@posteo.de>
# Exports: nothing
# Side-effects: adds build dependencies


# needed for 'here_desktop_entry'
DEPENDENCIES+="
    build:
        dev-util/desktop-file-utils
"

# Like 'herebin', but for desktop entry files.
#
# Arguments: <filename>
# Side-effects: installs the desktop entry
# Inspection: $TEMP, $IMAGE
# Errors: according to 'desktop-file-validate', on missing argument
here_desktop_entry() {
    if [[ ${#} -ne 1 ]]; then
        die "exactly one argument needed."
    fi

    (
    cat > "${TEMP}/${1}"
    insinto /usr/share/applications
    doins "${TEMP}/${1}"
    )

    if ! desktop-file-validate "${IMAGE}/usr/share/applications/${1}" ; then
        eerror "${1} does not pass desktop file validation"
        die_unless_nonfatal "${1} does not pass desktop file validation"
    fi
}

# Creates and installs a desktop entry file according to
# https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-1.1.html
# Name, Comment, Exec, TryExec and Icon are initialized automatically.
# Categories may be initialized depending on 'find_desktop_file_category'.
#
# Arguments: all fields of the desktop entry spec, e.g. 'Name=myname'
# Side-effects: installs the desktop entry via 'here_desktop_entry'
# Inspection: $PN, $SUMMARY
# Errors: on invalid arguments
install_desktop_entry() {
    local Name=${PN^}
    local Comment=${SUMMARY}
    local Exec=${PN}
    local TryExec=
    local Icon=${PN}
    local Categories=$(find_desktop_file_category)
    local OtherValidFields=( Version GenericName NoDisplay Hidden OnlyShowIn
        NotShowIn DBusActivatable Path Terminal Actions MimeType Implements
        Keywords StartupNotify StartupWMClass )
    local AddFields=

    while [[ $# -gt 0 ]] ; do
        case $1 in
            Name=*)       Name=${1#*=}       ; shift ;;
            Comment=*)    Comment=${1#*=}    ; shift ;;
            Exec=*)       Exec=${1#*=}       ; shift ;;
            TryExec=*)    TryExec=${1#*=}    ; shift ;;
            Icon=*)       Icon=${1#*=}       ; shift ;;
            Categories=*) Categories=${1#*=} ; shift ;;
            *=*)
                if has ${1%%=*} ${OtherValidFields[@]} ; then
                    AddFields+="\n${1}"
                    shift
                else
                    die "invalid argument \"${1}\"!"
                fi
                ;;
            *) die "invalid argument \"${1}\"!" ;;
        esac
    done

    TryExec=${TryExec:-${Exec%% *}}

    here_desktop_entry ${PN}-${Exec// /_}.desktop << EOF
[Desktop Entry]
Name=${Name}
Type=Application
Comment=${Comment}
Exec=${Exec}
TryExec=${TryExec}
Icon=${Icon}
Categories=${Categories}$(echo -ne ${AddFields})
EOF
}

# Tries to guess the desktop file category according to ${CATEGORY}
# and puts it to stdout.
#
# Arguments: none
# Side-effects: stdout
# Inspection: $CATEGORY
# Errors: no
find_desktop_file_category() {
    # see https://specifications.freedesktop.org/menu-spec/latest/apa.html
    local maincat=
    # see https://specifications.freedesktop.org/menu-spec/latest/apas02.html
    local subcat=

    case ${CATEGORY} in
        app*) maincat="Utility"
            case ${CATEGORY##*-} in
                editors) subcat="TextEditor";;
                *) ;;
            esac
            ;;
        dev*) maincat="Development"
            case ${CATEGORY##*-} in
                db) subcat="Database";;
                *) ;;
            esac
            ;;
        games*) maincat="Game"
            case ${CATEGORY##*-} in
                action)     subcat="ActionGame" ;;
                adventure)  subcat="AdventureGame" ;;
                arcade)     subcat="ArcadeGame" ;;
                board)      subcat="BoardGame" ;;
                fps)        subcat="Shooter" ;;
                roguelike)  subcat="RolePlaying";;
                rpg)        subcat="RolePlaying";;
                simulation) subcat="Simulation" ;;
                sports)     subcat="SportsGame" ;;
                strategy)   subcat="StrategyGame" ;;
                *) ;;
            esac
            ;;
        voip) maincat="Network"; subcat="Telephony";;
        *) ;;
    esac

    [[ -n ${maincat} ]] && echo -n "${maincat};"
    [[ -n ${subcat} ]] && echo -n "${subcat};"
}