#! /bin/env python

import sys
import numpy as np
import subprocess
import matplotlib
from math import  isnan
from pathlib import Path
from scipy import interpolate
from subprocess import PIPE, STDOUT
from matplotlib import pyplot as plt

from  utils.utils import terminate


def read_vmaf_xml(file, percentile):
    with open(file, 'r') as f:
        file = f.readlines()
        file = [x.strip() for x in file if 'vmaf="' in x]
        vmafs = []
        for i in file:
            vmf = i[i.rfind('="') + 2: i.rfind('"')]
            vmafs.append(float(vmf))

        vmafs = [float(x) for x in vmafs if isinstance(x, float)]
        calc = [x for x in vmafs if isinstance(x, float) and not isnan(x)]
        perc = round(np.percentile(calc, percentile), 2)

        return perc


def call_vmaf(source: Path, encoded: Path, model=None, return_file=False):

    if model:
        mod = f":model_path={model}"
    else:
        mod = ''

    # For vmaf calculation both source and encoded segment scaled to 1080
    # for proper vmaf calculation
    fl = source.with_name(encoded.stem).with_suffix('.xml').as_posix()
    cmd = f'ffmpeg -loglevel error -hide_banner -r 60 -i {source.as_posix()} -r 60 -i {encoded.as_posix()}  ' \
          f'-filter_complex "[0:v]scale=1920:1080:flags=spline:force_original_aspect_ratio=decrease[scaled1];' \
          f'[1:v]scale=1920:1080:flags=spline:force_original_aspect_ratio=decrease[scaled2];' \
          f'[scaled2][scaled1]libvmaf=log_path={fl}{mod}" -f null - '

    c = subprocess.run(cmd, shell=True, stdout=PIPE, stderr=STDOUT)
    call = c.stdout
    # print(c.stdout.decode())
    if 'error' in call.decode().lower():
        print('\n\nERROR IN VMAF CALCULATION\n\n',call.decode())
        terminate()

    if return_file:
        return fl

    call = call.decode().strip()
    vmf = call.split()[-1]
    try:
        vmf = float(vmf)
    except ValueError:
        vmf = 0
    return vmf


def plot_vmaf(inp: Path, out: Path, model=None):

    print('Calculating Vmaf...\r', end='')

    xml = call_vmaf(inp, out, model=model, return_file=True)

    if not Path(xml).exists():
        print(f'Vmaf calculation failed for files:\n {inp.stem} {out.stem}')
        sys.exit()

    with open(xml, 'r') as fl:
        f = fl.readlines()
        f = [x.strip() for x in f if 'vmaf="' in x]
        vmafs = []
        for i in f:
            vmf = i[i.rfind('="') + 2: i.rfind('"')]
            vmafs.append(float(vmf))

        vmafs = [round(float(x), 3) for x in vmafs if isinstance(x, float)]

    perc_1 = read_vmaf_xml(xml, 1)
    perc_25 = read_vmaf_xml(xml, 25)
    perc_75 = read_vmaf_xml(xml, 75)
    mean = round(sum(vmafs) / len(vmafs), 3)

    # Plot
    plt.figure(figsize=(15, 4))

    for i in range(0, 100):
        plt.axhline(i, color='grey', linewidth=0.4)

        if i % 5 == 0:
            plt.axhline(i, color='black', linewidth=0.6)

    plt.plot(range(len(vmafs)), vmafs,
            label=f'Frames: {len(vmafs)}\nMean:{mean}\n'
            f'1%: {perc_1} \n25%: {perc_25} \n75%: {perc_75}', linewidth=0.7)
    plt.ylabel('VMAF')
    plt.legend(loc="lower right", markerscale=0, handlelength=0, fancybox=True, )
    plt.ylim(int(perc_1), 100)
    plt.tight_layout()
    plt.margins(0)

    # Save
    file_name = str(out.stem) + '_plot.png'
    plt.savefig(file_name, dpi=500)


def x264_probes(video: Path, ffmpeg: str):
    cmd = f' ffmpeg -y -hide_banner -loglevel error -i {video.as_posix()} ' \
                  f'-r 2 -an {ffmpeg} -c:v libx264 -crf 0 {video.with_suffix(".mp4")}'
    subprocess.run(cmd, shell=True)


def encoding_fork(min_cq, max_cq, steps):
    # Make encoding fork
    q = list(np.unique(np.linspace(min_cq, max_cq, num=steps, dtype=int, endpoint=True)))

    # Moving highest cq to first check, for early skips
    # checking highest first, lowers second, for early skips
    q.insert(0, q.pop(-1))
    return q


def vmaf_probes(probe, fork, ffmpeg):
    params = " aomenc  -q --passes=1 --threads=8 --end-usage=q --cpu-used=6 --cq-level="
    cmd = [[f'ffmpeg -y -hide_banner -loglevel error -i {probe} {ffmpeg}'
            f'{params}{x} -o {probe.with_name(f"v_{x}{probe.stem}")}.ivf - ',
            probe, probe.with_name(f'v_{x}{probe.stem}').with_suffix('.ivf'), x] for x in fork]
    return cmd


def interpolate_data(vmaf_cq: list, vmaf_target):
    x = [x[1] for x in sorted(vmaf_cq)]
    y = [float(x[0]) for x in sorted(vmaf_cq)]

    # Interpolate data
    f = interpolate.interp1d(x, y, kind='cubic')
    xnew = np.linspace(min(x), max(x), max(x) - min(x))

    # Getting value closest to target
    tl = list(zip(xnew, f(xnew)))
    vmaf_target_cq = min(tl, key=lambda x: abs(x[1] - vmaf_target))
    return vmaf_target_cq, tl, f, xnew


def plot_probes(x, y, f, tl, min_cq, max_cq, probe, xnew, vmaf_target_cq, frames, temp):
    # Saving plot of vmaf calculation
    matplotlib.use('agg')
    plt.ioff()
    plt.plot(x, y, 'x', color='tab:blue', alpha=1)
    plt.plot(xnew, f(xnew), color='tab:blue', alpha=1)
    plt.plot(vmaf_target_cq[0], vmaf_target_cq[1], 'o', color='red', alpha=1)
    plt.grid(True)
    plt.xlim(min_cq, max_cq)
    vmafs = [int(x[1]) for x in tl if isinstance(x[1], float) and not isnan(x[1])]
    plt.ylim(min(vmafs), max(vmafs) + 1)
    plt.ylabel('VMAF')
    plt.xlabel('CQ')
    plt.title(f'Chunk: {probe.stem}, Frames: {frames}')
    # plt.tight_layout()
    temp = temp / probe.stem
    plt.tight_layout()
    plt.savefig(temp, dpi=300, format='png',transparent=True)
    plt.close()