const std = @import("std");
const math = std.math;
const print = std.debug.print;

const ArrayList = std.ArrayList;
const Endian = std.builtin.Endian;

const SoundNode = @import("soundnode.zig").SoundNode;
const Activity = @import("activity.zig").Activity;
const SoundSettings = @import("settings.zig").SoundSettings;


pub fn singleSineTick(st: *SoundSettings, freq: u16, t: u64) f64 {
	const ft: f64 = @floatFromInt(t);
	const fr: f64 = @floatFromInt(freq);
	return math.sin(st.sine_multiplier * fr * ft);
	//return math.sin(st.sine_multiplier * @as(f64, freq) * ft);
}


pub fn main() !void {
	
	var gpa = std.heap.GeneralPurposeAllocator(.{}){};
	const allocator = gpa.allocator();
	
	var settings: SoundSettings = SoundSettings{};	
	
	const start_tick: u64 = 0;
	const end_tick: u64 = 44100 * 2;
	
	var sn1: SoundNode = try SoundNode.init(allocator, "sine");
	defer sn1.deinit();
	
	var a = Activity{
		.start_tick = 0,
		.end_tick = 0,
		.opcode = 1,
		.soundnode = &sn1,
		.operands = undefined,
	};
		
	try sn1.activities.append(&a);
	
	var soundnodes = ArrayList(*SoundNode).init(allocator);
	defer soundnodes.deinit();
	
	try soundnodes.append(&sn1);
	
	var tick: u64 = start_tick;
	
	//STARTING WAV
	const stdout_file = std.io.getStdOut().writer();
	var bw = std.io.bufferedWriter(stdout_file);
	const stdout = bw.writer();
	
	//WRITING WAV HEADER
	try stdout.writeAll("RIFF");
	
	try stdout.writeInt(
		u64,
		36 + (end_tick * 2 * settings.sample_width),
		Endian.little,
	);
	
	try stdout.writeAll("WAVE");
	try stdout.writeAll("fmt ");
		
	try stdout.writeInt(u32, 16, Endian.little);
	try stdout.writeInt(u16, 1, Endian.little);
	try stdout.writeInt(u16, 2, Endian.little);
	try stdout.writeInt(u32, settings.sample_rate, Endian.little);
	
	const block_align: u16 = @intCast(2 * settings.sample_width);
	
	try stdout.writeInt(u32, @as(u32, block_align) * settings.sample_rate, Endian.little);
	try stdout.writeInt(u16, block_align, Endian.little);
	try stdout.writeInt(u16, settings.bit_depth, Endian.little);

	try stdout.writeAll("data");
	try stdout.writeInt(
		u64,
		end_tick * 2 * settings.sample_width,
		Endian.little,
	);
	
	var sample: i24 = 0.0;
		
	while (tick < end_tick) {
		
		for (soundnodes.items, 0..) |soundnode, i| {
			
			for (soundnode.activities.items, 0..) |activity, j| {
				
				try activity.do();
				_ = j;
			
			}
			
			var amp: f64 = 0;
			var it = soundnode.freqmap.iterator();
			
			while (it.next()) |entry| {
				
				amp += entry.value_ptr.* * singleSineTick(&settings,  @as(u16, entry.key_ptr.*), tick);
			}
		
			sample = @intFromFloat(amp * @as(f64, @floatFromInt(settings.max_amp)));
			
			try stdout.writeInt(i24, sample, Endian.little);
			try stdout.writeInt(i24, sample, Endian.little);
			
			_ = i;
		}
		
		tick += 1;
	
	}
	
	try bw.flush();
	
}