use std::{f32, f64};
use std::ops::{Index};
#[cfg(test)] use std::collections::HashMap;

use generate::{SoundGenerator, SoundParameters};


const TOTAL_SEMITONES: f32 = 120f32;
const NOISESIZE: usize = 64;
const TARGET_SAMPLE_RATE: f32 = 44100.0;
const DECAY_TIME: f32 = 4096.0 / TARGET_SAMPLE_RATE;

const NAMES: &'static [&'static str] = &[
	"seed",
	"modes",
	"fat",
	"width",
	"overtones",
	"sharpness",
	"harmonicity",
	"decaylow",
	"decayhigh",
	"filterlow",
	"fslopelow",
	"fsweeplow",
	"filterhigh",
	"fslopehigh",
	"fsweephigh",
	"gain",
	"attack",
	"release",
	"-",
	"q_decaydiff",
	"q_decaylow",
	"q_harmonicity",
	"q_sharpness",
	"q_width",
	"q_f_low",
	"q_fs_low",
	"q_fsw_low",
	"q_f_high",
	"q_fs_high",
	"q_fsw_high",
	"q_gain",
	"q_attack",
	"q_release"
];


pub struct OidosRandomData {
	data: Vec<u32>
}

impl Default for OidosRandomData {
	fn default() -> OidosRandomData {
		let mut data = Vec::with_capacity(NOISESIZE*NOISESIZE*NOISESIZE);
		let mut randomstate: [u32; 4] = [ 0x6F15AAF2, 0x4E89D208, 0x9548B49A, 0x9C4FD335 ];
		for _ in 0..NOISESIZE*NOISESIZE*NOISESIZE {
			let mut r = 0u32;
			for s in 0..3 {
				let mut rs = randomstate[s];
				rs = rs.rotate_right(rs).wrapping_add(randomstate[s+1]);
				randomstate[s] = rs;
				r = r ^ rs;
			}
			data.push(r);
		}

		OidosRandomData {
			data : data
		}
	}
}

#[test]
fn test_random_data() {
	let random = OidosRandomData::default();
	assert_eq!(random.data.len(), NOISESIZE*NOISESIZE*NOISESIZE);
	assert_eq!(*random.data.first().unwrap(), 0xCAADAA7B);
	assert_eq!(*random.data.last().unwrap(),  0xB08A4BA7);
}


fn quantize(value: f32, level: f32) -> f32 {
	let bit = 1 << ((level * 31.0).floor() as i32);
	let mask = !bit + 1;
	let add = bit >> 1;
	let mut bits = value.to_bits();
	bits = bits.wrapping_add(add) & mask;
	if bits == 0x80000000 {
		bits = 0x00000000;
	}
	f32::from_bits(bits)
}

#[derive(Clone, PartialEq)]
pub struct OidosSoundParameters {
	modes: u8,
	fat: u8,
	seed: u8,
	overtones: u8,

	decaylow: f32,
	decaydiff: f32,
	harmonicity: f32,
	sharpness: f32,
	width: f32,

	f_low: f32,
	f_slopelow: f32,
	f_sweeplow: f32,
	f_high: f32,
	f_slopehigh: f32,
	f_sweephigh: f32,

	gain: f32,

	sample_rate: f32,
	base_freq: f32
}

impl SoundParameters for OidosSoundParameters {
	fn names() -> &'static [&'static str] {
		&NAMES
	}

	fn default_value(name: &str) -> f32 {
		match name {
			"filterlow" | "fslopelow" | "fslopehigh" => 0.0,
			"fat" => 0.10,
			"gain" | "attack" => 0.25,
			"overtones" => 0.27,
			"width" => 0.34,
			"modes" => 0.40,
			"seed" | "fsweeplow" | "fsweephigh" | "release" => 0.5,
			"sharpness" => 0.9,
			"harmonicity" | "decaylow" | "decayhigh" | "filterhigh" => 1.0,
			_ => 0.0
		}
	}

	fn display<P: Index<&'static str, Output = f32>>(&self, name: &'static str, p: &P) -> (String, String) {
		let decaylow = -DECAY_TIME / (self.decaylow).log2();
		let decayhigh = -DECAY_TIME / (self.decaylow + self.decaydiff).log2();

		let pname = match name {
			"q_decaydiff" => "decaydiff",
			"q_decaylow" => "decaylow",
			"q_harmonicity" => "harmonicity",
			"q_sharpness" => "sharpness",
			"q_width" => "width",
			"q_f_low" => "filterlow",
			"q_fs_low" => "fslopelow",
			"q_fsw_low" => "fsweeplow",
			"q_f_high" => "filterhigh",
			"q_fs_high" => "fslopehigh",
			"q_fsw_high" => "fsweephigh",
			"q_gain" => "gain",
			"q_attack" => "attack",
			"q_release" => "release",
			n => n
		};

		let value = match pname {
			"seed" => format!("{}", self.seed),
			"modes" => format!("{}", self.modes),
			"fat" => format!("{}", self.fat),
			"width" => format!("{:.3}", self.width),
			"overtones" => format!("{:.0}", self.overtones),
			"sharpness" => format!("{:+.1}", self.sharpness * 20.0 * 2f32.log10()),
			"harmonicity" => format!("{:.2}", self.harmonicity),
			"decaylow" => format!("{:.0}", 1000.0 * decaylow),
			"decayhigh" => format!("{:.0}", 1000.0 * decayhigh),
			"decaydiff" => format!("{:+.0}", 1000.0 * (decayhigh - decaylow)),
			"filterlow" => format!("{:+.0}", self.f_low),
			"fslopelow" => format!("{:.1}", 1.0 / self.f_slopelow),
			"fsweeplow" => format!("{:+.1}", self.f_sweeplow),
			"filterhigh" => format!("{:+.0}", self.f_high),
			"fslopehigh" => format!("{:.1}", 1.0 / self.f_slopehigh),
			"fsweephigh" => format!("{:+.1}", self.f_sweephigh),
			"gain" => format!("{:.2}", self.gain),
			"attack" => format!("{:.1}", 1000.0 / (OidosSoundParameters::attack(p, self.sample_rate) * self.sample_rate)),
			"release" => format!("{:.2}", 1.0 / (OidosSoundParameters::release(p, self.sample_rate) * self.sample_rate)),
			_ => "-".to_string()
		};
		let label = match pname {
			"sharpness" => "dB/oct",
			"width" | "overtones" | "filterlow" | "fslopelow" | "filterhigh" | "fslopehigh" => "ST",
			"fsweeplow" | "fsweephigh" => "ST/s",
			"decaylow" | "decayhigh" | "decaydiff" => "ms half",
			"attack" => "ms",
			"release" => "s",
			_ => ""
		}.to_string();

		(value, label)
	}

	fn influence(name: &'static str) -> Vec<&'static str> {
		match name {
			"width"         => vec!["q_width"],
			"sharpness"     => vec!["q_sharpness"],
			"harmonicity"   => vec!["q_harmonicity"],
			"decaylow"      => vec!["q_decaydiff", "q_decaylow"],
			"decayhigh"     => vec!["q_decaydiff"],
			"filterlow"     => vec!["q_f_low"],
			"fslopelow"     => vec!["q_fs_low"],
			"fsweeplow"     => vec!["q_fsw_low"],
			"filterhigh"    => vec!["q_f_high"],
			"fslopehigh"    => vec!["q_fs_high"],
			"fsweephigh"    => vec!["q_fsw_high"],
			"gain"          => vec!["q_gain"],
			"attack"        => vec!["q_attack"],
			"release"       => vec!["q_release"],

			"q_decaydiff"   => vec!["decayhigh"],
			"q_decaylow"    => vec!["decaylow", "decayhigh", "q_decaydiff"],
			"q_harmonicity" => vec!["harmonicity"],
			"q_sharpness"   => vec!["sharpness"],
			"q_width"       => vec!["width"],
			"q_f_low"       => vec!["filterlow"],
			"q_fs_low"      => vec!["fslopelow"],
			"q_fsw_low"     => vec!["fsweeplow"],
			"q_f_high"      => vec!["filterhigh"],
			"q_fs_high"     => vec!["fslopehigh"],
			"q_fsw_high"    => vec!["fsweephigh"],
			"q_gain"        => vec!["gain"],
			"q_attack"      => vec!["attack"],
			"q_release"     => vec!["release"],

			_               => vec![]
		}
	}

	fn build<P: Index<&'static str, Output = f32>>(p: &P, sample_rate: f32) -> OidosSoundParameters {
		let mut params = OidosSoundParameters {
			modes:       (p["modes"]     * 100.0 + 0.5).floor().max(1.0) as u8,
			fat:         (p["fat"]       * 100.0 + 0.5).floor().max(1.0) as u8,
			seed:        (p["seed"]      * 100.0 + 0.5).floor() as u8,
			overtones:   (p["overtones"] * 100.0 + 0.5).floor() as u8,

			decaylow:    p["decaylow"],
			decaydiff:   p["decayhigh"] - p["decaylow"],
			harmonicity: p["harmonicity"] * 2.0 - 1.0,
			sharpness:   p["sharpness"] * 5.0 - 4.0,
			width:       p["width"].powi(5) * 100.0,

			f_low:       (p["filterlow"] * 2.0 - 1.0)    * TOTAL_SEMITONES,
			f_slopelow:  (1.0 - p["fslopelow"]).powi(3),
			f_sweeplow:  (p["fsweeplow"] - 0.5).powi(3)  * TOTAL_SEMITONES * 100.0,
			f_high:      (p["filterhigh"] * 2.0 - 1.0)   * TOTAL_SEMITONES,
			f_slopehigh: (1.0 - p["fslopehigh"]).powi(3),
			f_sweephigh: (p["fsweephigh"] - 0.5).powi(3) * TOTAL_SEMITONES * 100.0,

			gain:        4096f32.powf(p["gain"] - 0.25),

			sample_rate: sample_rate,
			base_freq:   440.0 * 2f32.powf(-57.0 / 12.0) / sample_rate * 2.0 * f32::consts::PI
		};

		params.decaylow = quantize(params.decaylow, p["q_decaylow"]);
		params.decaydiff = quantize(params.decaydiff, p["q_decaydiff"]);
		params.harmonicity = quantize(params.harmonicity, p["q_harmonicity"]);
		params.sharpness = quantize(params.sharpness, p["q_sharpness"]);
		params.width = quantize(params.width, p["q_width"]);

		params.f_low = quantize(params.f_low, p["q_f_low"]);
		params.f_slopelow = quantize(params.f_slopelow, p["q_fs_low"]);
		params.f_sweeplow = quantize(params.f_sweeplow / TARGET_SAMPLE_RATE, p["q_fsw_low"]) * TARGET_SAMPLE_RATE;
		params.f_high = quantize(params.f_high, p["q_f_high"]);
		params.f_slopehigh = quantize(params.f_slopehigh, p["q_fs_high"]);
		params.f_sweephigh = quantize(params.f_sweephigh / TARGET_SAMPLE_RATE, p["q_fsw_high"]) * TARGET_SAMPLE_RATE;

		params.gain = quantize(params.gain, p["q_gain"]);

		params
	}

	fn attack<P: Index<&'static str, Output = f32>>(p: &P, sample_rate: f32) -> f32 {
		let attack = p["attack"];
		quantize(if attack == 0.0 {
			2.0
		} else {
			1.0 / (attack * attack * sample_rate)
		}, p["q_attack"])
	}

	fn release<P: Index<&'static str, Output = f32>>(p: &P, sample_rate: f32) -> f32 {
		let release = p["release"];
		quantize(if release == 0.0 {
			2.0
		} else {
			1.0 / (release * sample_rate)
		}, p["q_release"])
	}

}

#[test]
fn test_oidos_sound_parameters() {
	let names = OidosSoundParameters::names();
	let mut map = HashMap::new();
	for name in names {
		map.insert(*name, OidosSoundParameters::default_value(name));
	}
	let param = OidosSoundParameters::build(&map, 44100.0);
	assert_eq!(param.base_freq, 0.00232970791933f32);
}


pub struct OidosSoundGenerator {
	n_partials:  usize,

	state_re:    Vec<f64>,
	state_im:    Vec<f64>,
	step_re:     Vec<f64>,
	step_im:     Vec<f64>,
	filter_low:  Vec<f64>,
	filter_high: Vec<f64>,

	f_add_low:   f64,
	f_add_high:  f64,

	gain:        f64,

	avx_support: bool
}

impl SoundGenerator for OidosSoundGenerator {
	type Parameters = OidosSoundParameters;
	type Output = f32;
	type Global = OidosRandomData;

	fn new(param: &OidosSoundParameters, tone: u8, time: usize, random: &OidosRandomData) -> OidosSoundGenerator {
		let n_partials = param.modes as usize * param.fat as usize;
		let n_partials_in_array = (n_partials + 3) & !3;
		let mut gen = OidosSoundGenerator {
			n_partials:   n_partials,

			state_re:     Vec::with_capacity(n_partials_in_array),
			state_im:     Vec::with_capacity(n_partials_in_array),
			step_re:      Vec::with_capacity(n_partials_in_array),
			step_im:      Vec::with_capacity(n_partials_in_array),
			filter_low:   Vec::with_capacity(n_partials_in_array),
			filter_high:  Vec::with_capacity(n_partials_in_array),

			f_add_low:    (-param.f_sweeplow * param.f_slopelow / param.sample_rate) as f64,
			f_add_high:   (param.f_sweephigh * param.f_slopehigh / param.sample_rate) as f64,

			gain:         param.gain as f64,

			avx_support:  unsafe { supports_avx() }
		};

		let f_lowlimit = param.f_low as f64 + tone as f64;
		let f_highlimit = param.f_high as f64 + tone as f64;

		for m in 0..param.modes as usize {
			let mut random_index = m * 256 + param.seed as usize;
			let mut getrandom = || {
				let r = random.data[random_index];
				random_index += 1;
				r as i32 as f64 / 0x80000000u32 as f64
			};

			let subtone = getrandom().abs();
			let reltone = subtone * param.overtones as f64;
			let decay = param.decaylow as f64 + subtone * param.decaydiff as f64;
			let ampmul = decay.powf((1.0 / DECAY_TIME / param.sample_rate) as f64);

			let relfreq = 2f64.powf(reltone / 12.0);
			let relfreq_ot = (relfreq + 0.5).floor();
			let relfreq_h = relfreq + (relfreq_ot - relfreq) * param.harmonicity as f64;
			let reltone = relfreq_h.log2() * 12.0;
			let mtone = tone as f64 + reltone;
			let mamp = getrandom() * 2f64.powf(reltone * param.sharpness as f64 / 12.0);

			for _ in 0..param.fat as usize {
				let ptone = mtone + getrandom() * param.width as f64;
				let phase = param.base_freq as f64 * 2f64.powf(ptone / 12.0);
				gen.step_re.push(ampmul * phase.cos());
				gen.step_im.push(ampmul * phase.sin());

				let angle = getrandom() * f64::consts::PI + phase * time as f64;
				let amp = mamp * ampmul.powi(time as i32);
				gen.state_re.push(amp * angle.cos());
				gen.state_im.push(amp * angle.sin());

				let f_startlow = 1.0 - (f_lowlimit - ptone) * param.f_slopelow as f64;
				let f_starthigh = 1.0 - (ptone - f_highlimit) * param.f_slopehigh as f64;
				gen.filter_low.push(f_startlow + gen.f_add_low * time as f64);
				gen.filter_high.push(f_starthigh + gen.f_add_high * time as f64);
			}
		}

		for _ in n_partials..n_partials_in_array {
			gen.state_re.push(0.0);
			gen.state_im.push(0.0);
			gen.step_re.push(0.0);
			gen.step_im.push(0.0);
			gen.filter_low.push(0.0);
			gen.filter_high.push(0.0);
		}

		gen
	}

	fn produce_sample(&mut self) -> f32 {
		let s = unsafe {
			if self.avx_support {
				additive_core_avx(self.state_re.as_mut_ptr(), self.state_im.as_mut_ptr(),
				                  self.step_re.as_ptr(), self.step_im.as_ptr(),
				                  self.filter_low.as_mut_ptr(), self.filter_high.as_mut_ptr(),
				                  self.f_add_low, self.f_add_high, self.n_partials)
			} else {
				additive_core_sse2(self.state_re.as_mut_ptr(), self.state_im.as_mut_ptr(),
				                   self.step_re.as_ptr(), self.step_im.as_ptr(),
				                   self.filter_low.as_mut_ptr(), self.filter_high.as_mut_ptr(),
				                   self.f_add_low, self.f_add_high, self.n_partials)
			}
		};
		(s * (self.gain / (self.n_partials as f64 + (self.gain - 1.0) * s * s)).sqrt()) as f32
	}
}

impl OidosSoundGenerator {
	/// Functionally equivalent to the vectorized asm versions, but much slower.
	#[allow(unused)]
	fn additive_core(&mut self) -> f64 {
		let mut s = 0f64;
		for i in 0..self.n_partials {
			let re = self.state_re[i] * self.step_re[i] - self.state_im[i] * self.step_im[i];
			let im = self.state_re[i] * self.step_im[i] + self.state_im[i] * self.step_re[i];
			self.state_re[i] = re;
			self.state_im[i] = im;

			let f = self.filter_low[i].min(self.filter_high[i]).min(1.0).max(0.0);
			self.filter_low[i] += self.f_add_low;
			self.filter_high[i] += self.f_add_high;

			s += re * f;
		}

		s
	}
}

extern "cdecl" {
	fn supports_avx() -> bool;
	fn additive_core_sse2(state_re: *mut f64, state_im: *mut f64, step_re: *const f64, step_im: *const f64,
	                      filter_low: *mut f64, filter_high: *mut f64, f_add_low: f64, f_add_high: f64, n: usize) -> f64;
	fn additive_core_avx(state_re: *mut f64, state_im: *mut f64, step_re: *const f64, step_im: *const f64,
	                     filter_low: *mut f64, filter_high: *mut f64, f_add_low: f64, f_add_high: f64, n: usize) -> f64;
}