--constants
TRACK_SWITCH_DELTA = 3000			-- switch between tracks delta
MAX_DIST = 100						-- max distance for dynamic sound stopping
MIN_DIST = 75						-- min distance for dynamic sound playing
THEME_FADE_UPDATE_DELTA = 100       -- update theme volume fade twice per second
AMBIENT_FADE_UPDATE_DELTA = 200     -- update ambient volume fade twice per second
VOLUME_DELTA = 0					-- sound volume fade delta (is set on initialize)
-- global variables (used from other scripts)
npc_table = {}
-- local variables (reinit on initialize())
ambient_vol = get_console_cmd(2,"snd_volume_music")
m_ambient_vol = 0
FadeTo_ambient = 0
m_theme_volume = 0
FadeTo_theme = 0

cur_theme_number = 0
cur_track_number = 0
next_track_start_time = 0
theme = nil
-- local variables
local init_failed = false
local themes_inited = false
local prev_fade_time = 0
local force_fade = false
local was_in_silence = false
local _tmr

local combat_themes ={
	{
		"music\\combat\\theme1_part_1",
		"music\\combat\\theme1_part_2",
		"music\\combat\\theme1_part_3"
	},
	{
		"music\\combat\\theme2_part_1",
		"music\\combat\\theme2_part_2",
		"music\\combat\\theme2_part_3"
	},
	{
		"music\\combat\\theme3_part_1",
		"music\\combat\\theme3_part_2",
		"music\\combat\\theme3_part_3"
	},
	{
		"music\\combat\\theme4_part_1",
		"music\\combat\\theme4_part_2",
		"music\\combat\\theme4_part_3"
	}
}
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
feature_is_active = nil
local function main_loop()
	local tg = time_global()
	if (_tmr and tg < _tmr) then 
		return false 
	end
	_tmr = tg + 1000
	
	if not (db.actor) then
		return false
	end
	
	if (init_failed) then
		return true -- destroy add_call
	end
	
	if (surge_manager.sound_started()) then
		if (surge_manager.is_killing_all()) then
			force_fade = true
			FadeTo_ambient = ambient_vol
			fade_ambient()
			force_fade = false
		else
			FadeTo_ambient = 0
			fade_ambient()
		end
	end
	
	if not (themes_inited) then
		initialize_themes()
	end

	if (theme) then
		theme:update(m_theme_volume)
	end
	
	local state = get_theme_state()
	if (state=="start") then
		start_theme()
	elseif (state=="idle") then
		if (theme_is_fading()) then
			fade_theme()
		elseif (ambient_is_fading()) then
			fade_ambient()
		end
		if (time_global()>next_track_start_time) then
			select_next_track()
		end
	elseif (state=="finish") then
		finish_theme()
	end
	
	return false
end

function activate_feature()
	if (feature_is_active) then
		return 
	end
	feature_is_active = true
	AddUniqueCall(main_loop)
	RegisterScriptCallback("on_game_end",on_actor_destroy)
end 

function deactivate_feature()
	if not (feature_is_active) then
		return 
	end
	feature_is_active = false
	RemoveUniqueCall(main_loop)
	UnregisterScriptCallback("on_game_end",on_actor_destroy)
	finish_theme()
end

function on_game_start()
	if (IsDynamicMusic()) then
		activate_feature()
	end
end

function initialize_themes()
	m_ambient_vol = ambient_vol
	m_theme_volume = ambient_vol
	FadeTo_theme = ambient_vol
	FadeTo_ambient = ambient_vol

	cur_theme_number = 0
	cur_track_number = 0
	next_track_start_time = 0
	theme = nil

	VOLUME_DELTA = m_ambient_vol/50

	themes_inited = true
end

function on_actor_destroy()
	if (theme) and (theme:playing()) then
		theme:stop()
	end
	exec_console_cmd("snd_volume_music "..ambient_vol)
end

function main_menu_on()
	exec_console_cmd("snd_volume_music "..ambient_vol)
end

function main_menu_off()
	ambient_vol = get_console_cmd(2,"snd_volume_music")
	
	if (IsDynamicMusic()) then
		activate_feature()
		exec_console_cmd("snd_volume_music "..m_ambient_vol)
	else 
		deactivate_feature()
	end 
end

function get_theme_state()
	local actor = db.actor
	force_fade = false

	if not (actor:alive()) then
		if(theme) then
			FadeTo_theme = 0
			FadeTo_ambient = ambient_vol
			if(theme_is_fading() or ambient_is_fading()) then
				return "idle"
			else
				exec_console_cmd("snd_volume_music "..ambient_vol)
				return "finish"
			end
		end
		return nil
	end

	if (actor_in_silence_zone()) then
		if(theme) then
			was_in_silence = true
			FadeTo_theme = 0
			FadeTo_ambient = 0
			return "idle"
		end
		return nil
	end

	if(was_in_silence) then
		was_in_silence = false
		FadeTo_ambient = ambient_vol
	end

	local has_enemy
	for id,v in pairs(xr_combat_ignore.fighting_with_actor_npcs) do
		local npc = db.storage[id] and db.storage[id].object
		if (npc and IsStalker(npc)) then
			has_enemy = true
			break
		end
	end

	if not (has_enemy) then
		if(theme) then
			FadeTo_theme = 0
			FadeTo_ambient = ambient_vol
			if(theme_is_fading() or ambient_is_fading()) then
				return "idle"
			else
				exec_console_cmd("snd_volume_music "..ambient_vol)
				return "finish"
			end
		end
		return nil
	end

	force_fade = true
	FadeTo_theme = ambient_vol
	FadeTo_ambient = 0
	if(theme) then
		return "idle"
	else
		return "start"
	end
end

function theme_is_fading()
	return m_theme_volume~=FadeTo_theme
end

function ambient_is_fading()
	return m_ambient_vol~=FadeTo_ambient
end

function actor_in_silence_zone()
	local silence_zones = db.storage.silence_zone_table
	if (silence_zones) then
		local actor_pos = db.actor:position()
		for k,v in pairs(silence_zones) do
			local zone = db.zone_by_name[v]
			if(zone:inside(actor_pos)) then
				return true
			end
		end
	end

	if (utils_obj.npc_in_zone(db.actor, "zat_a2_sr_no_assault")) then
		return true
	end

	if (utils_obj.npc_in_zone(db.actor, "jup_a6_sr_no_assault")) then
		return true
	end

	if (utils_obj.npc_in_zone(db.actor, "jup_b41_sr_no_assault")) then
		return true
	end

	return false
end

function start_theme()
	--utils_data.debug_write("xrs_dyn_music:start_theme start")
	m_ambient_vol = 0
	exec_console_cmd("snd_volume_music "..m_ambient_vol)

	m_theme_volume = ambient_vol

	cur_theme_number = math.random(1, #combat_themes)
	cur_track_number = math.random(1, #combat_themes[cur_theme_number])
	if(theme==nil) then
		theme = this.stereo_sound()
	end
	theme:initialize(combat_themes[cur_theme_number][cur_track_number], m_theme_volume)
	next_track_start_time = theme:play() - TRACK_SWITCH_DELTA
	theme:update(m_theme_volume)
	--utils_data.debug_write("xrs_dyn_music:start_theme end")
end

function fade_theme()
	local g_time = time_global()
	if (g_time-prev_fade_time<=THEME_FADE_UPDATE_DELTA) then
		return
	end
	prev_fade_time = g_time

	FadeTo_theme = clamp(FadeTo_theme, 0, ambient_vol)

	if (m_theme_volume>FadeTo_theme) then
		if (force_fade) then
			m_theme_volume = FadeTo_theme
		else
			m_theme_volume = m_theme_volume - VOLUME_DELTA
		end
		m_theme_volume = clamp(m_theme_volume, FadeTo_theme, m_theme_volume)
	elseif (m_theme_volume<FadeTo_theme) then
		if (force_fade) then
			m_theme_volume = FadeTo_theme
		else
			m_theme_volume = m_theme_volume + VOLUME_DELTA
		end
		m_theme_volume = clamp(m_theme_volume, m_theme_volume, FadeTo_theme)
	end
end

function fade_ambient()
	local g_time = time_global()
	if (g_time-prev_fade_time<=AMBIENT_FADE_UPDATE_DELTA) then
		return
	end
	prev_fade_time = g_time

	FadeTo_ambient = clamp(FadeTo_ambient, 0, ambient_vol)

	if (m_ambient_vol>FadeTo_ambient) then
		if (force_fade) then
			m_ambient_vol = FadeTo_ambient
		else
			m_ambient_vol = m_ambient_vol - VOLUME_DELTA
		end
		m_ambient_vol = clamp(m_ambient_vol, FadeTo_ambient, m_ambient_vol)
	elseif (m_ambient_vol<FadeTo_ambient) then
		if (force_fade) then
			m_ambient_vol = FadeTo_ambient
		else
			m_ambient_vol = m_ambient_vol + VOLUME_DELTA
		end
		m_ambient_vol = clamp(m_ambient_vol, m_ambient_vol, FadeTo_ambient)
	end
	exec_console_cmd("snd_volume_music "..m_ambient_vol)
end

function select_next_track()
	if (cur_theme_number==nil or combat_themes[cur_theme_number]==nil) then
		print_table(combat_themes)
		log("-------->cur_theme_number="..tostring(cur_theme_number))
		log("-------->cur_track_number="..tostring(cur_track_number))
		log("-------->theme="..tostring(theme~=nil))
		if (theme) then
			log("-------->theme is playing="..tostring(theme:playing()~=nil))
		end
		log("-------->cur_state="..tostring(get_theme_state()))
		printf("wrong theme number")
	end
	if (cur_track_number<#combat_themes[cur_theme_number]) then
		cur_track_number = cur_track_number + 1
	else
		cur_track_number = 1
	end
	if (theme) then
		next_track_start_time = theme:play_at_time(next_track_start_time + TRACK_SWITCH_DELTA,combat_themes[cur_theme_number][cur_track_number],m_theme_volume) - TRACK_SWITCH_DELTA
	end
end

function finish_theme()
	if (theme) and (theme:playing()) then
		theme:stop()
	end
	themes_inited = false
end

-----------------------------
class "stereo_sound"
function stereo_sound:__init()
	self.both = nil
	self.end_time=nil
end

function stereo_sound:initialize(sound,lvl)
	if self.both then self:stop() end	
	self.both = sound_object(sound)
	self.end_time = nil
	if not self.both then
		abort("stereo_sound:initialize: Cannot open sound file "..sound)
		return
	end
	if lvl then
		self:set_volume(lvl)
	end
end

function stereo_sound:play()
    if not db.actor then
		return
	end	
	self.both:play(db.actor,0, sound_object.s2d)
	self.end_time = time_global() + self.both:length()	
	return self.end_time
end

function stereo_sound:play_at_time(time, sound, lvl)
	self.end_time = nil
	self.both:attach_tail(sound)
	if lvl then
		self:set_volume(lvl)
	end
	self.both_tail = sound_object(sound)
	if not self.both_tail then
		abort("stereo_sound:initialize: Cannot open sound file "..sound)
		return
	end
	self.end_time = time + self.both_tail:length()	
	return self.end_time
end

function stereo_sound:playing()
	return self.both and self.both:playing()
end

function stereo_sound:update(vol)
	if vol and self:playing() then self:set_volume(vol)end
end

function stereo_sound:stop()
	if self.both and self.both:playing() then self.both:stop() end
end

function stereo_sound:length()
	return self.both and self.both:length() or 1
end

function stereo_sound:set_volume(num)
	if self.both then self.both.volume=num end
end