"""Digital surrogate studies for Iyeumaring M7 and M8.

No measurements in this file are measurements of photonic/neuromorphic hardware.
Python elapsed times are host timings. Energy and accelerator latency are models.
Run: OPENBLAS_NUM_THREADS=1 python hardware_study.py --output .
"""
from __future__ import annotations

import argparse
from collections import deque
from dataclasses import dataclass, asdict
import json
from pathlib import Path
import platform
import time

import numpy as np


def ci(values, seed=941, samples=3000):
    a = np.asarray(values, float)
    rng = np.random.default_rng(seed)
    b = a[rng.integers(len(a), size=(samples, len(a)))].mean(axis=1)
    return {"mean": float(a.mean()), "median": float(np.median(a)),
            "mean_ci95": [float(x) for x in np.quantile(b, [.025, .975])]}


def quantize(x, bits, low=-1.0, high=1.0):
    levels = 2**bits - 1
    return np.round((np.clip(x, low, high)-low)/(high-low)*levels)/levels*(high-low)+low


def decompose_orthogonal(q):
    """Real Givens decomposition; rotations are an abstract interferometer mesh.

    Logical all-to-all Givens connectivity is used, not a fabricated chip layout.
    """
    a = np.asarray(q).copy()
    rotations = []
    n = a.shape[0]
    for j in range(n-1):
        for i in range(n-1, j, -1):
            theta = float(np.arctan2(a[i, j], a[j, j]))
            c, s = np.cos(theta), np.sin(theta)
            aj, ai = a[j].copy(), a[i].copy()
            a[j], a[i] = c*aj+s*ai, -s*aj+c*ai
            rotations.append((j, i, theta))
    return rotations, np.diag(a).copy()


def reconstruct_orthogonal(rotations, diagonal, phase_bits=None, drift_std=0., rng=None):
    a = np.diag(diagonal)
    for j, i, theta in reversed(rotations):
        if phase_bits is not None:
            theta = float(quantize(theta, phase_bits, -np.pi, np.pi))
        if drift_std:
            theta += rng.normal(0., drift_std)
        c, s = np.cos(theta), np.sin(theta)
        aj, ai = a[j].copy(), a[i].copy()
        a[j], a[i] = c*aj-s*ai, s*aj+c*ai
    return a


def photonic_surrogate(seeds=range(12), inputs=256, m=64, n=32):
    """Program W=U Sigma Vt, with angle/DAC/ADC quantization and readout noise."""
    rows = []
    for seed in seeds:
        rng = np.random.default_rng(50000+seed)
        w = rng.normal(size=(m,n))
        u, s, vt = np.linalg.svd(w, full_matrices=True)
        s /= s.max()
        sig = np.zeros((m,n)); sig[np.arange(n),np.arange(n)] = s
        w = u@sig@vt
        ru, du = decompose_orthogonal(u)
        rv, dv = decompose_orthogonal(vt)
        x = rng.normal(size=(n,inputs)); x /= np.linalg.norm(x,axis=0)
        exact = w@x
        exact_top = np.argmax(exact,axis=0)
        margin = np.sort(exact,axis=0)[-1]-np.sort(exact,axis=0)[-2]
        for bits, drift, read_std in [(6,.0005,.002),(8,.0005,.002),(10,.0005,.002),(8,.005,.01)]:
            # Independent hardware draw per configuration; seed replicates paired
            # digital data. Drift is fixed during a 256-vector calibration block.
            hrng = np.random.default_rng(100000+seed*100+bits+int(drift*1e6))
            uq = reconstruct_orthogonal(ru,du,bits,drift,hrng)
            vq = reconstruct_orthogonal(rv,dv,bits,drift,hrng)
            sq = quantize(s,8,0,1)
            sigq = np.zeros((m,n)); sigq[np.arange(n),np.arange(n)]=sq
            effective_w = uq@sigq@vq
            noisy = effective_w@quantize(x,8)
            # Signed homodyne amplitude readout, after calibrated loss compensation.
            noisy += hrng.normal(0,read_std,size=noisy.shape)
            adc_saturated_inputs = np.any(np.abs(noisy)>1.,axis=0)
            noisy = quantize(noisy,8)
            err = np.max(np.abs(noisy-exact),axis=0)
            top = np.argmax(noisy,axis=0)
            # A posteriori sufficient certificate, using known exact scores only
            # in this simulation. Real hardware requires a validated error bound.
            certified = margin > 2*err
            # Uniform probabilistic error certificate, assuming the effective
            # matrix has been calibrated exactly. This cannot use exact Wx.
            # DAC and ADC half-bin errors plus a Gaussian union-bound envelope.
            alpha = 1e-3
            matrix_error = np.linalg.norm(effective_w-w,axis=1)[:,None]*np.linalg.norm(x,axis=0)[None,:]
            dac_error = np.abs(effective_w).sum(axis=1)[:,None]/255
            noise_envelope = read_std*np.sqrt(2*np.log(2*m*inputs/alpha))
            bound = matrix_error+dac_error+noise_envelope+1/255
            upper = noisy+bound
            selected_lower = (noisy-bound)[top,np.arange(inputs)]
            upper[top,np.arange(inputs)] = -np.inf
            calibrated_certified = (selected_lower > upper.max(axis=0)) & ~adc_saturated_inputs
            order = np.argsort(noisy,axis=0)[-4:]
            top4 = np.any(order == exact_top[None,:],axis=0)
            rows.append({"seed":seed,"phase_bits":bits,"drift_std_rad":drift,
                         "readout_std_normalized":read_std,"top1_agreement":float(np.mean(top==exact_top)),
                         "top4_recall":float(np.mean(top4)),
                         "relative_rmse":float(np.linalg.norm(noisy-exact)/np.linalg.norm(exact)),
                         "certified_fraction":float(np.mean(certified)),
                         "certificate_errors":int(np.sum(certified&(top!=exact_top))),
                         "calibrated_certified_fraction":float(np.mean(calibrated_certified)),
                         "calibrated_certificate_errors":int(np.sum(calibrated_certified&(top!=exact_top))),
                         "adc_saturated_inputs":int(adc_saturated_inputs.sum()),
                         "median_score_gap":float(np.median(margin))})
    groups=[]
    for bits,drift,noise in [(6,.0005,.002),(8,.0005,.002),(10,.0005,.002),(8,.005,.01)]:
        sel=[r for r in rows if r['phase_bits']==bits and r['drift_std_rad']==drift]
        groups.append({"phase_bits":bits,"drift_std_rad":drift,"readout_std_normalized":noise,
                       **{k:ci([r[k] for r in sel]) for k in ['top1_agreement','top4_recall','relative_rmse','certified_fraction','calibrated_certified_fraction']},
                       "certificate_errors":sum(r['certificate_errors'] for r in sel),
                       "calibrated_certificate_errors":sum(r['calibrated_certificate_errors'] for r in sel)})
    return {"dimensions":[m,n],"inputs_per_seed":inputs,"seeds":list(seeds),
            "rows":rows,"summary":groups,
            "certificate_note":"certified_fraction uses exact-reference error and is only a posteriori. calibrated_certified_fraction uses matrix perturbation/DAC/ADC bounds and a Gaussian union bound alpha=0.001 per 256-input block, conditional on exact calibration of the effective matrix; real calibration uncertainty must be added."}


@dataclass
class CostAssumptions:
    digital_mac_per_second: float = 1e13
    digital_energy_per_mac_J: float = .5e-12
    digital_control_static_W: float = .5
    host_launch_s: float = 50e-9
    host_batch: int = 1024
    interface_s: float = 5e-9
    dac_s: float = 1e-9
    optical_propagation_s: float = .1e-9
    adc_s: float = 2e-9
    phase_program_s: float = 50e-6
    phase_program_energy_each_J: float = 1e-9
    calibration_s: float = 100e-6
    calibration_every_vectors: int = 100000
    calibration_energy_J: float = 10e-6
    dac_energy_each_J: float = 2e-12
    adc_energy_each_J: float = 5e-12
    io_energy_each_J: float = 2e-12
    memory_energy_each_J: float = 2e-12
    control_static_W: float = .5
    thermo_phase_static_each_W: float = .005
    low_static_phase_each_W: float = 1e-6
    photons_per_output: int = 100000
    wavelength_m: float = 1550e-9
    laser_wall_plug_efficiency: float = .2
    local_oscillator_multiplier: float = 10.
    fixed_loss_dB: float = 6.
    loss_per_mesh_stage_dB: float = .03
    memory_bandwidth_B_per_s: float = 512e9


def hardware_costs(a=CostAssumptions()):
    """Scenario calculation, NOT a hardware benchmark. All inputs explicit."""
    rows=[]
    for m,n in [(64,32),(128,128),(512,512)]:
        phases=(m*(m-1)+n*(n-1))//2
        loss_db=a.fixed_loss_dB+a.loss_per_mesh_stage_dB*(m+n)
        eta=10**(-loss_db/10)
        photon_energy=6.62607015e-34*299792458/a.wavelength_m
        laser=a.photons_per_output*m*photon_energy*a.local_oscillator_multiplier/(eta*a.laser_wall_plug_efficiency)
        for reuse in [100,10000,1000000]:
            launch=a.host_launch_s/a.host_batch
            memtime=2*(m*n/reuse+m+n)/a.memory_bandwidth_B_per_s
            td=launch+max(m*n/a.digital_mac_per_second,memtime)
            ed=(m*n*a.digital_energy_per_mac_J+m*n/reuse*a.memory_energy_each_J+
                (m+n)*a.io_energy_each_J+a.digital_control_static_W*td)
            for mode,perphase in [('thermo_optic',a.thermo_phase_static_each_W),('low_static_hypothesis',a.low_static_phase_each_W)]:
                po=a.control_static_W+phases*perphase
                to=(launch+a.interface_s+a.dac_s+a.optical_propagation_s+a.adc_s+
                    a.phase_program_s/reuse+a.calibration_s/a.calibration_every_vectors)
                eo=(laser+n*a.dac_energy_each_J+m*a.adc_energy_each_J+po*to+
                    phases*a.phase_program_energy_each_J/reuse+
                    a.calibration_energy_J/a.calibration_every_vectors+
                    (m+n)*a.io_energy_each_J)
                rows.append({"shape":[m,n],"weight_reuse":reuse,"phase_mode":mode,
                             "phase_count":phases,"loss_dB":loss_db,"static_power_W":po,
                             "within_50W_static_envelope":po<=50,
                             "digital_time_ns":td*1e9,"optical_time_ns":to*1e9,
                             "modeled_speed_ratio_digital_over_optical":td/to,
                             "digital_energy_nJ":ed*1e9,"optical_energy_nJ":eo*1e9,
                             "modeled_energy_ratio_digital_over_optical":ed/eo})
    return {"status":"analytical scenario; assumptions not measurements or vendor specifications",
            "assumptions":asdict(a),"rows":rows,
            "omissions":["routing-layout feasibility","fan-out and wavelength-specific crosstalk",
                         "laser relative-intensity noise spectral model","full chip heat transport",
                         "nonlinear activation and optimizer cost","hardware-specific host synchronization"],
            "loss_note":"Losses are scenario input, not a layout-extracted result. Effective loss is compensated in the ranking simulation; resulting readout noise is an independent normalized input."}


def delayed_data(seed,k,train=12000,test=3000,horizon=12,rho=.9):
    rng=np.random.default_rng(200000+seed)
    ids=rng.integers(k,size=train+test)
    amplitudes=rng.choice([-1.,1.],size=train+test)
    theta=rng.normal(size=k)
    rewards=np.zeros(train+test)
    hist=deque()
    for t,(idx,amp) in enumerate(zip(ids,amplitudes)):
        hist.append((t,int(idx),amp))
        if len(hist)>horizon:hist.popleft()
        rewards[t]=sum((rho**(t-ti))*v*theta[j] for ti,j,v in hist)+rng.normal(0,.1)
    return ids,amplitudes,rewards,theta,train


def dense_trace(ids,amplitudes,rewards,k,train,horizon=12,rho=.9,lr=.035):
    w=np.zeros(k);e=np.zeros(k);errors=[]
    start=time.perf_counter()
    for t,(idx,amp,reward) in enumerate(zip(ids,amplitudes,rewards)):
        e*=rho;e[idx]+=amp
        if t>=horizon:e[ids[t-horizon]]-=rho**horizon*amplitudes[t-horizon]
        delta=reward-w@e
        if t<train:w+=lr*delta*e
        else:errors.append(delta**2)
    return w,np.asarray(errors),time.perf_counter()-start


def sparse_trace(ids,amplitudes,rewards,k,train,horizon=12,rho=.9,lr=.035):
    w=np.zeros(k);e={};counts={};errors=[];max_active=0;active_sum=0
    start=time.perf_counter()
    for t,(idx,amp,reward) in enumerate(zip(ids,amplitudes,rewards)):
        idx=int(idx)
        for j in e:e[j]*=rho
        e[idx]=e.get(idx,0.)+amp;counts[idx]=counts.get(idx,0)+1
        if t>=horizon:
            old=int(ids[t-horizon]);counts[old]-=1
            if counts[old]==0:del e[old];del counts[old]
            else:e[old]-=rho**horizon*amplitudes[t-horizon]
        delta=reward-sum(w[j]*v for j,v in e.items())
        if t<train:
            for j,v in e.items():w[j]+=lr*delta*v
        else:errors.append(delta**2)
        max_active=max(max_active,len(e));active_sum+=len(e)
    return w,np.asarray(errors),time.perf_counter()-start,max_active,active_sum/len(ids)


def immediate_bandit(ids,amplitudes,rewards,k,train,lr=.035):
    w=np.zeros(k);errors=[]
    start=time.perf_counter()
    for t,(idx,amp,reward) in enumerate(zip(ids,amplitudes,rewards)):
        delta=reward-w[idx]*amp
        if t<train:w[idx]+=lr*delta*amp
        else:errors.append(delta**2)
    return w,np.asarray(errors),time.perf_counter()-start


def neuromorphic_study(seeds=range(8),dimensions=(256,4096,16384),train=12000,test=3000):
    rows=[]
    for k in dimensions:
        for seed in seeds:
            ids,amps,r,theta,nt=delayed_data(seed,k,train,test)
            # Alternate order limits systematic timing order bias.
            if seed%2:
                ws,es,ts,ma,aa=sparse_trace(ids,amps,r,k,nt)
                wd,ed,td=dense_trace(ids,amps,r,k,nt)
            else:
                wd,ed,td=dense_trace(ids,amps,r,k,nt)
                ws,es,ts,ma,aa=sparse_trace(ids,amps,r,k,nt)
            wb,eb,tb=immediate_bandit(ids,amps,r,k,nt)
            rows.append({"seed":seed,"candidate_fragments":k,"dense_trace_mse":float(ed.mean()),
                         "sparse_trace_mse":float(es.mean()),"immediate_bandit_mse":float(eb.mean()),
                         "dense_host_seconds":td,"sparse_host_seconds":ts,"immediate_host_seconds":tb,
                         "dense_over_sparse_host_speed_ratio":td/ts,
                         "max_weight_difference":float(np.max(np.abs(wd-ws))),
                         "max_squared_error_difference":float(np.max(np.abs(ed-es))),
                         "max_active_traces":ma,"mean_active_traces":aa,
                         "approx_trace_touch_ratio_dense_over_sparse":k/aa,
                         "dense_trace_storage_float64_bytes":8*k,
                         "sparse_trace_payload_float64_bytes":8*ma,
                         "weight_storage_float64_bytes_both":8*k})
    summary=[]
    for k in dimensions:
        sel=[r for r in rows if r['candidate_fragments']==k]
        summary.append({"candidate_fragments":k,
                        **{key:ci([r[key] for r in sel]) for key in ['dense_trace_mse','sparse_trace_mse','immediate_bandit_mse','dense_over_sparse_host_speed_ratio','approx_trace_touch_ratio_dense_over_sparse']},
                        "max_weight_difference":max(r['max_weight_difference'] for r in sel),
                        "max_squared_error_difference":max(r['max_squared_error_difference'] for r in sel)})
    return {"seeds":list(seeds),"train_events":train,"test_events":test,"horizon":12,"rho":.9,
            "learning_rate":.035,"reward_noise_std":.1,"rows":rows,"summary":summary,
            "baseline_note":"Dense and sparse are mathematically identical finite-horizon eligibility regression. Immediate bandit deliberately lacks delayed features and is a diagnostic baseline, not a competitive delayed-credit algorithm. No e-prop or BrainTrace reproduction is claimed."}


def self_tests():
    rng=np.random.default_rng(123)
    q,_=np.linalg.qr(rng.normal(size=(13,13)))
    rotations,diagonal=decompose_orthogonal(q)
    qr=reconstruct_orthogonal(rotations,diagonal)
    assert np.max(np.abs(q-qr))<1e-12
    assert np.max(np.abs(qr.T@qr-np.eye(13)))<1e-12
    ids,amps,r,_,nt=delayed_data(100,31,train=300,test=100)
    wd,ed,_=dense_trace(ids,amps,r,31,nt)
    ws,es,_,ma,_=sparse_trace(ids,amps,r,31,nt)
    assert np.max(np.abs(wd-ws))<1e-12
    assert np.max(np.abs(ed-es))<1e-11
    assert ma<=12
    costs=hardware_costs()
    assert all(r['digital_time_ns']>0 and r['optical_time_ns']>0 and r['optical_energy_nJ']>0 for r in costs['rows'])
    return {"checks_passed":5,"max_mesh_reconstruction_error":float(np.max(np.abs(q-qr))),
            "max_trace_weight_error":float(np.max(np.abs(wd-ws)))}


def main():
    p=argparse.ArgumentParser();p.add_argument('--output',default='.');p.add_argument('--quick',action='store_true')
    args=p.parse_args();out=Path(args.output);out.mkdir(parents=True,exist_ok=True)
    start=time.perf_counter()
    tests=self_tests()
    results={"environment":{"python":platform.python_version(),"numpy":np.__version__,"platform":platform.platform()},
             "self_tests":tests,"photonic":photonic_surrogate(seeds=range(3) if args.quick else range(12)),
             "hardware_cost_model":hardware_costs(),
             "neuromorphic":neuromorphic_study(seeds=range(2) if args.quick else range(8),train=2000 if args.quick else 12000,test=500 if args.quick else 3000)}
    results['study_host_seconds']=time.perf_counter()-start
    (out/'hardware_results.json').write_text(json.dumps(results,indent=2))
    print(json.dumps({"self_tests":tests,"photonic_summary":results['photonic']['summary'],
                      "neuromorphic_summary":results['neuromorphic']['summary'],"study_host_seconds":results['study_host_seconds']},indent=2))


if __name__=='__main__':main()