find_program(FFMPEG_EXECUTABLE ffmpeg)
if ("${FFMPEG_EXECUTABLE}" STREQUAL "FFMPEG_EXECUTABLE-NOTFOUND")
	message(FATAL_ERROR "ffmpeg not found!")
else()
	message(STATUS "Found ffmpeg: ${FFMPEG_EXECUTABLE}")
endif()

add_custom_target(generate)
add_dependencies(tests generate)

set(loglevel quiet)
if (CONFIG_TESTING_VERBOSE)
	set(loglevel warning)
endif()

set(FFMPEG_ARGS  -hide_banner -nostdin -f s16le -i /dev/zero -codec libvorbis -loglevel ${loglevel})

function(gen_track num len title)
	set(track "${ALBUM}/${num} - ${title}.ogg")
	add_custom_command(TARGET generate PRE_BUILD COMMAND
			${FFMPEG_EXECUTABLE} ${FFMPEG_ARGS} -t ${len}
						 -metadata TITLE=${title}
						 -metadata ARTIST=${ARTIST}
						 -metadata ALBUM=${ALBUM}
						 -metadata GENRE=${GENRE}
						 -metadata DATE=${YEAR}
						 -metadata TRACKNUMBER=${num}
						 "${track}" || true VERBATIM)
endfunction()


#
# Generate Hyrule Symphony album
#
add_custom_command(TARGET generate PRE_BUILD COMMAND mkdir -p Hyrule\ Symphony/)
set(ARTIST "Koji Kondo")
set(ALBUM  "Hyrule Symphony")
set(YEAR   1998)
set(GENRE  "Game")
gen_track(01 243 "Title Theme")
gen_track(02 130 "Kokiri Forest")
gen_track(03 227 "Hyrule Field")
gen_track(04 130 "Hyrule Castle")
gen_track(05 206 "Lon Lon Ranch")
gen_track(06 186 "Kakariko Village")
gen_track(07 178 "Death Mountain")
gen_track(08 221 "Zora's Domain")
gen_track(09 273 "Gerudo Valley")
gen_track(10  66 "Ganondorf")
gen_track(11 185 "Princess Zelda")
gen_track(12 232 "Ocarina Medley")
gen_track(13 288 "The Legend of Zelda Medley")


#
# Generate Ocarina of Time album
#
add_custom_command(TARGET generate PRE_BUILD COMMAND mkdir -p Ocarina\ of\ Time/)
set(ALBUM "Ocarina of Time")
set(YEAR  1998)
set(GENRE "Video Game")
gen_track(01 170 "Title Theme")
gen_track(02  80 "Deku Tree")
gen_track(03  46 "Fairy Flying")
gen_track(04  71 "House")
gen_track(05 112 "Kokiri Forest")
gen_track(06 133 "Shop")
gen_track(07 134 "Battle")
gen_track(08 164 "Inside the Deku Tree")
gen_track(09 153 "Boss Battle")
gen_track(10 327 "Hyrule Field Main Theme")
gen_track(11 103 "Market")
gen_track(12  90 "Hyrule Castle Courtyard")
gen_track(13  62 "Ocarina Songs")
gen_track(14 101 "Ocarina of Time")
gen_track(15 271 "LonLon Ranch")
gen_track(16 204 "Kakariko Village")
gen_track(17  75 "Lost Woods")
gen_track(18 171 "Zora's Domain")
gen_track(19  72 "Great Fairy's Fountain")
gen_track(20 159 "Temple of Time")
gen_track(21 124 "Chamber of the Sages")
gen_track(22  98 "Horse Race")
gen_track(23 193 "Kakariko Village Orchestra")
gen_track(24  99 "Windmill Hut")
gen_track(25 172 "Gerudo Valley")
gen_track(26 147 "Ganondorf Battle")
gen_track(27 191 "Last Battle")
gen_track(28  34 "Zelda's Ocarina")
gen_track(29 433 "Staff Credits Theme")
gen_track(30  18 "Minuet of Forest")
gen_track(31  24 "Bolero of Fire")
gen_track(32  24 "Serenade of Water")
gen_track(33  25 "Nocturne of Shadow")
gen_track(34  23 "Prelude of Light")
gen_track(35  27 "Requiem of Spirit")

#
# Generate an invalid track
#
file(WRITE invalid_track "abcdefghijklmnopqrstuvwxyz")