import os as _os
import cv2 as _cv2
import numpy as _np
import glob as _glob
import joblib as _jb
import matplotlib.pyplot as _plt

from skimage.feature import local_binary_pattern as _lbp, graycomatrix as _gcm, graycoprops as _gcp
from sklearn.model_selection import train_test_split as _tts
from sklearn.metrics import classification_report as _cr, accuracy_score as _acc
from sklearn.svm import SVC as _S
from sklearn.ensemble import RandomForestClassifier as _RF
from sklearn.linear_model import LogisticRegression as _LR

# distances and angles for GLCM
def  generateAngles():
    angs = [_np.pi * i / 5 for i in range(5)]          # five angles at 0, π/5, 2π/5, 3π/5, 4π/5
    s = "1.2,2.2,3.1"                                     # string of distances
    dists = [float(x) for x in s.split(",")]             # parse distances to floats
    return angs, dists

(_bestangles, _bestglcmdist) =  generateAngles()

# best parameters for LBP
_bestpoints = 9
_bestradius = 1

# SVM hyperparameters
def  generateSVM_Args():
    kern = 'linear'
    Cval = 2.1
    gamma = 'scale'
    rs = 42
    return {'kernel': kern, 'C': Cval, 'gamma': gamma, 'random_state': rs}

# Random Forest hyperparameters
def  generateRF_Args():
    ne = 110
    rs = 40
    nj = -1
    return {'n_estimators': ne, 'random_state': rs, 'n_jobs': nj}

# Logistic Regression hyperparameters
def  generateLR_Args():
    mc = 'multinomial'
    solv = 'lbfgs'
    mi = 900
    rs = 37
    return {'multi_class': mc, 'solver': solv, 'max_iter': mi, 'random_state': rs}

# Color feature extraction: compute 3D histogram component A
def fun_colorA(img):
    return _cv2.calcHist([img], [0,1,2], None, (5,5,5), [0,256,0,256,0,256])

# Color feature extraction: normalize and flatten histogram
def fun_colorB(hist_raw):
    _cv2.normalize(hist_raw, hist_raw)
    return hist_raw.flatten()

# Full color histogram feature
def fun_color(img):
    return fun_colorB(fun_colorA(img))

# Convert image to grayscale for LBP
def lbpGray(img):
    return _cv2.cvtColor(img, _cv2.COLOR_BGR2GRAY)

# Compute LBP map with specified points and radius
def lbpMap(gray_img):
    return _lbp(gray_img, _bestpoints, _bestradius, method='uniform')

# Compute normalized histogram of LBP map
def lbpHist(lbp_map):
    bins = _np.arange(0, _bestpoints + 3)                 # bin edges from 0 to points+2
    h, _ = _np.histogram(lbp_map.ravel(), bins=bins, range=(0, _bestpoints + 2))
    h = h.astype('float')
    return h / (h.sum() + 1e-6)                            # avoid division by zero

# Full LBP feature pipeline: grayscale → map → histogram
def lbpFeature(img):
    g = lbpGray(img)
    lm = lbpMap(g)
    return lbpHist(lm)

# Convert image to grayscale for GLCM
def glcmGray(img):
    return _cv2.cvtColor(img, _cv2.COLOR_BGR2GRAY)

# Compute GLCM matrix given distances and angles
def glcmMatrix(gray_img):
    return _gcm(gray_img, distances=_bestglcmdist, angles=_bestangles, symmetric=True, normed=True)

# Extract a single GLCM property vector
def glcmProperties(glcm_mat, prop_name):
    return _gcp(glcm_mat, prop_name).flatten()

# Full GLCM feature pipeline: grayscale → GLCM matrix → properties
def glcmFeature(img):
    gray = glcmGray(img)
    glcm = glcmMatrix(gray)
    features = []
    properties = ["contrast", "dissimilarity", "homogeneity", "energy"]
    for prop in properties:
        features.extend(glcmProperties(glcm, prop))        # append each property’s flattened values
    return _np.array(features)

# Convert image to grayscale for Hu moments
def huGray(img):
    return _cv2.cvtColor(img, _cv2.COLOR_BGR2GRAY)

# Compute Hu Moments from grayscale image
def huMoments(img):
    g = huGray(img)
    m = _cv2.moments(g)
    return _cv2.HuMoments(m).flatten()

# Combine all feature types for a given image path
def FullFeautures(pathF):
    img = _cv2.imread(pathF)
    if img is None:
        print(f"[Warning] cannot read {pathF}")
        return None

    # compute each feature block
    ch   = fun_color(img)    # color histogram length = 125
    lbph = lbpFeature(img)      # LBP histogram length = 11
    glc  = glcmFeature(img)     # GLCM feature length = 60
    hu   = huMoments(img)   # Hu moments length = 7

    fv = []

    fv.extend(ch)
    fv.extend(lbph)
    fv.extend(glc)
    fv.extend(hu)

    return _np.array(fv)