from __future__ import print_function,division

import logging
log = logging.getLogger(__name__)  # __name__ is "foo.bar" here

import numpy as np
np.seterr(all='ignore')
import os
import glob
import pathlib
import re
import numbers
from . import storage as storage

try:
  import matplotlib.pyplot as plt
except ImportError:
  log.warn("Can't import matplotlib !")

_time_regex =      re.compile( "(-?\d+\.?\d*(?:ps|ns|us|ms)?)")
_timeInStr_regex = re.compile("_(-?\d+\.?\d*(?:ps|ns|us|ms)?)")

def getFiles(folder,basename="*.edf*",nFiles=None):
  files = glob.glob(folder + "/" + basename)
  files.sort()
  if nFiles is not None: files = files[:nFiles]
  return files

def getEdfFiles(folder,**kw):
  return getFiles(folder,basename="*.edf*",**kw)

def getDelayFromString(string) :
  match = _timeInStr_regex.search(string)
  return match and match.group(1) or None

_time_regex = re.compile("(-?\d+\.?\d*)((?:s|fs|ms|ns|ps|us)?)")

def strToTime(delay) :
  if isinstance(delay,bytes): delay = delay.decode('ascii')
  _time2value = dict( fs = 1e-15, ps = 1e-12, ns = 1e-9, us = 1e-6, ms = 1e-3, s = 1)

  match = _time_regex.search(delay)
  if match:
    n,t = float(match.group(1)),match.group(2)
    value = _time2value.get(t,1)
    return n*value
  else:
    return None

def timeToStr(delay,fmt="%+.0f"):
  a_delay = abs(delay)
  if a_delay >= 1:
    ret = fmt % delay + "s"
  elif 1e-3 <= a_delay < 1: 
    ret = fmt % (delay*1e3) + "ms"
  elif 1e-6 <= a_delay < 1e-3: 
    ret = fmt % (delay*1e6) + "us"
  elif 1e-9 <= a_delay < 1e-6: 
    ret = fmt % (delay*1e9) + "ns"
  elif 1e-12 <= a_delay < 1e-9: 
    ret = fmt % (delay*1e12) + "ps"
  elif 1e-15 <= a_delay < 1e-12: 
    ret = fmt % (delay*1e12) + "fs"
  elif 1e-18 <= a_delay < 1e-15: 
    ret = fmt % (delay*1e12) + "as"
  else:
    ret = str(delay) +"s"
  return ret

def removeExt(fname):
  """ special remove extension meant to work with compressed files.edf and .edf.gz files """
  if fname[-3:] == ".gz": fname = fname[-3:]
  return os.path.splitext(fname)[0]

def getBasename(fname):
  return removeExt(os.path.basename(fname));

def findSlice(array,lims):
  start = np.ravel(np.argwhere(array>lims[0]))[0]
  stop  = np.ravel(np.argwhere(array<lims[1]))[-1]
  return slice(int(start),int(stop))

def removeBackground(x,data,xlims=None,max_iter=100,background_regions=[],**kw):
  from dualtree import dualtree
  if data.ndim == 1: data = data[np.newaxis,:]
  if xlims is not None:
    idx = findSlice(x,xlims)
    x = x[idx]
    data = data[:,idx].copy()
  else:
    data = data.copy(); # create local copy
  # has to be a list of lists ..
  if background_regions != [] and isinstance(background_regions[0],numbers.Real):
    background_regions = [background_regions,]
  background_regions = [findSlice(x,brange) for brange in background_regions]
  for i in range(len(data)):
    data[i] = data[i] - dualtree.baseline(data[i],max_iter=max_iter,
                        background_regions=background_regions,**kw)
  return x,np.squeeze(data)
  

def plotdata(*args,x=None,plot=True,showTrend=True,title=None,clim='auto',fig=None):
  if isinstance(args[0],storage.DataStorage):
    q = args[0].q; data=args[0].data;
    if title is None: title = args[0].folder
  else:
    q,data = args
  if not (plot or showTrend): return
  if x is None: x = np.arange(data.shape[0])
  if clim == 'auto': clim = np.nanpercentile(data,(1.5,98.5))
  one_plot = showTrend or plot
  two_plot = showTrend and plot
  if one_plot and not two_plot:
    if fig is None:
      fig,ax = plt.subplots(1,1)
    else:
      fig.clear()
      ax = fig.axes
  if two_plot:
    if fig is None:
      fig,ax = plt.subplots(2,1,sharex=True)
    else:
      ax = fig.axes

  ax = np.atleast_1d(ax)
  if showTrend:
    plt.sca(ax[1])
    plt.pcolormesh(q,x,data)
    plt.ylabel("image number, 0 being older")
    plt.xlabel(r"q ($\AA^{-1}$)")
    plt.clim( *clim )
  if plot:
      ax[0].plot(q,np.nanmean(data,axis=0))
  if (plot or showTrend) and title is not None:
    plt.title(title)


def plotdiffs(*args,select=None,err=None,absSignal=None,absSignalScale=10,
              showErr=False,cmap=plt.cm.jet,fig=None,title=None):
  # this selection trick done in this way allows to keep the same colors when 
  # subselecting (because I do not change the size of diffs)
  if isinstance(args[0],storage.DataStorage):
    q = args[0].q; t = args[0].scan; err = args[0].err
    diffs = args[0].data
    diffs_abs = args[0].dataAbsAvScanPoint
  else:
    q,diffs,t = args
    diffs_abs = None
  if select is not None:
    indices = range(*select.indices(t.shape[0]))
  else:
    indices = range(len(t))

  if fig is None: fig = plt.gcf() 
#  fig.clear()

  lines_diff = []
  lines_abs = []
  if absSignal is not None:
    line = plt.plot(q,absSignal/absSignalScale,lw=3,
                    color='k',label="absSignal/%s"%str(absSignalScale))[0]
    lines.append(line)
  for linenum,idiff in enumerate(indices):
    color = cmap(idiff/(len(diffs)-1))
    label = timeToStr(t[idiff])
    kw = dict( color = color, label = label )
    if err is not None and showErr:
      line = plt.errorbar(q,diffs[idiff],err[idiff],**kw)[0]
      lines_diff.append(line)
    else:
      line = plt.plot(q,diffs[idiff],**kw)[0]
      lines_diff.append(line)
      if diffs_abs is not None:
        line = plt.plot(q,diffs_abs[idiff],color=color)[0]
        lines_abs.append(line)
  if title is not None: fig.axes[0].set_title(title)
  legend = plt.legend(loc=4)
  plt.grid()
  plt.xlabel(r"q ($\AA^{-1}$)")
  # we will set up a dict mapping legend line to orig line, and enable
  # picking on the legend line
  lined = dict()
  for legline, origline in zip(legend.get_lines(), lines_diff):
    legline.set_picker(5)  # 5 pts tolerance
    lined[legline] = origline
 
  def onpick(event):
    # on the pick event, find the orig line corresponding to the
    # legend proxy line, and toggle the visibility
    legline = event.artist
    origline = lined[legline]
    vis = not origline.get_visible()
    origline.set_visible(vis)
    # Change the alpha on the line in the legend so we can see what lines
    # have been toggled
    if vis:
        legline.set_alpha(1.0)
    else:
        legline.set_alpha(0.2)
    fig    = plt.gcf() 
    fig.canvas.draw()

  fig.canvas.mpl_connect('pick_event', onpick)
  return lines_diff,lines_abs

def updateLines(lines,data):
  for l,d in zip(lines,data):
    l.set_ydata(d)


#def getScan

def saveTxt(fname,q,data,headerv=None,info=None,overwrite=True,columns=''):
  """ Write data to file 'fname' in text format.
      Inputs:
        q = x vector
        data = one or 2D array (first axis is q)
        info = dictionary (saved as '# key : value') or string
        headerv = vector to be used as header or string
  """
  if os.path.isfile(fname) and not overwrite:
    log.warn("File %s exists, returning",fname)
    return
  if isinstance(info,dict):
    header = [ "# %s : %s" %(k,str(v)) for (k,v) in info.items() ]
    header = "\n".join(header); # skip first #, will be added by np
  elif isinstance(info,str):
    header = info
  else:
    header = ""
  if isinstance(headerv,str): header += "\n%s" % headerv
  if data.ndim == 1:
    x = np.vstack( (q,data) )
  elif data.ndim == 2:
    x = np.vstack( (q,data) )
    if headerv is not None:
      headerv = np.concatenate(( (data.shape[1],),headerv))
      x = np.hstack( (headerv[:,np.newaxis],x) )
  if columns != '':
    s = "#" + " ".join( [str(c).center(12) for c in columns] )
    header = header + "\n" + s if header != '' else s
  np.savetxt(fname,x.T,fmt="%+10.5e",header=header,comments='')

def reshapeToBroadcast(what,ref):
  """ expand the 1d array 'what' to allow broadbasting to match 
      multidimentional array 'ref'. The two arrays have to same the same 
      dimensions along the first axis
  """
  if what.shape == ref.shape: return what
  assert what.shape[0] == ref.shape[0]
  shape  = [ref.shape[0],] + [1,]*(ref.ndim-1)
  return what.reshape(shape)

def radToQ(theta,**kw):
  """ theta is the scattering angle (theta_out - theta_in);
      kw should be have either E or wavelength
      it returns the scattering vector in the units of wavelength """
  # Energy or wavelength should be in kw
  assert "E" in kw or "wavelength" in kw
  # but not both
  assert not ("E" in kw and "wavelength" in kw)
  if "E" in kw: kw["wavelength"] = 12.398/kw["E"]
  return 4*np.pi/kw["wavelength"]*np.sin(theta)

def degToQ(theta,**kw):
  theta = theta/180.*np.pi
  return radToQ(theta,**kw)
degToQ.__doc__ = radToQ.__doc__

def qToTheta(q,asDeg=False,**kw):
  """ Return scattering angle from q (given E or wavelength) """
  # Energy or wavelength should be in kw
  assert "E" in kw or "wavelength" in kw
  # but not both
  assert not ("E" in kw and "wavelength" in kw)
  if "E" in kw: kw["wavelength"] = 12.398/kw["E"]
  theta = np.arcsin(q*kw["wavelength"]/4/np.pi)
  if asDeg: theta = np.rad2deg(theta)
  return theta

def attenuation_length(compound, density=None, natural_density=None,energy=None, wavelength=None):
  """ extend periodictable.xsf capabilities """
  import periodictable.xsf
  if energy is not None: wavelength = periodictable.xsf.xray_wavelength(energy)
  assert wavelength is not None, "scattering calculation needs energy or wavelength"
  if (np.isscalar(wavelength)): wavelength=np.array( [wavelength] )
  n = periodictable.xsf.index_of_refraction(compound=compound,
                           density=density, natural_density=natural_density,
                           wavelength=wavelength)
  attenuation_length = (wavelength*1e-10)/ (4*np.pi*np.imag(n))
  return np.abs(attenuation_length)

def transmission(material='Si',thickness=100e-6, density=None, natural_density=None,energy=None, wavelength=None):
  """ extend periodictable.xsf capabilities """
  att_len = attenuation_length(material,density=density,
            natural_density=natural_density,energy=energy,wavelength=wavelength)
  return np.exp(-thickness/att_len)


def chargeToPhoton(chargeOrCurrent,material="Si",thickness=100e-6,energy=10,e_hole_pair=3.6):
  """
    Function to convert charge (or current to number of photons (or number 
    of photons per second)
    
    Parameters
    ----------
    
    chargeOrCurrent: float or array
    material : str
       Used to calculate 
     
  """
  # calculate absortption
  A = 1-transmission(material=material,energy=energy,thickness=thickness)
  chargeOrCurrent = chargeOrCurrent/A

  e_hole_pair_energy = 3.6e-3
  n_charge_per_photon = energy/e_hole_pair_energy
  # convert to Q
  charge_per_photon = n_charge_per_photon*1.60217662e-19
  nphoton = chargeOrCurrent/charge_per_photon
 
  if len(nphoton) == 1: nphoton = float(nphoton)
  return nphoton

  
def logToScreen():
  """ It allows printing to terminal on top of logfile """
  # define a Handler which writes INFO messages or higher to the sys.stderr
  console = logging.StreamHandler()
  console.setLevel(logging.INFO)
  # set a format which is simpler for console use
  formatter = logging.Formatter('%(message)s')
  # tell the handler to use this format
  console.setFormatter(formatter)
  # add the handler to the root logger (if needed)
  if len(logging.getLogger('').handlers)==1:
    logging.getLogger('').addHandler(console)