import glob
import os
import pipes
import sys

import numpy as np
import torch
from core.utils.general_utils import str2int


class CheckpointHandler:
    @staticmethod
    def get_ckpt_name(epoch):
        return 'weights_ep{}.pth'.format(epoch)
    
    @staticmethod
    def get_epochs(path):
        checkpoint_names = glob.glob(os.path.abspath(path) + "/*.pth")
        if len(checkpoint_names) == 0:
            raise ValueError("No checkpoints found at {}!".format(path))
        processed_names = [file.split('/')[-1].replace('weights_ep', '').replace('.pth', '')
                           for file in checkpoint_names]
        epochs = list(filter(lambda x: x is not None, [str2int(name) for name in processed_names]))
        return epochs
    
    @staticmethod
    def get_resume_ckpt_file(resume, path):
        print("Loading from: {}".format(path))
        if resume == 'latest':
            max_epoch = np.max(CheckpointHandler.get_epochs(path))
            resume_file = CheckpointHandler.get_ckpt_name(max_epoch)
        elif str2int(resume) is not None:
            resume_file = CheckpointHandler.get_ckpt_name(resume)
        elif '.pth' not in resume:
            resume_file = resume + '.pth'
        else:
            resume_file = resume
        return os.path.join(path, resume_file)

    @staticmethod
    def load_weights(weights_file, model, load_step=False, load_opt=False, optimizer=None, strict=True, model_key=None,
                     device=None):
        success = False
        if os.path.isfile(weights_file):
            print(("=> loading checkpoint '{}'".format(weights_file)))
            checkpoint = torch.load(weights_file, map_location=device if device is not None else model.device)
            if model_key is None:
                model.load_state_dict(checkpoint['state_dict'], strict=strict)
            else:
                model.load_state_dict(checkpoint[model_key], strict=strict)
            if load_step:
                start_epoch = checkpoint['epoch'] + 1
                global_step = checkpoint['global_step']
            if load_opt:
                try:
                    optimizer.load_state_dict(checkpoint['optimizer'])
                except (RuntimeError, ValueError) as e:
                    if not strict:
                        print("Could not load optimizer params because of changes in the network + non-strict loading")
                        pass
                    else:
                        raise e
            print(("=> loaded checkpoint '{}' (epoch {})"
                  .format(weights_file, checkpoint['epoch'])))
            success = True
        else:
            # print(("=> no checkpoint found at '{}'".format(weights_file)))
            # start_epoch = 0
            raise ValueError("Could not find checkpoint file in {}!".format(weights_file))
        
        if load_step:
            return global_step, start_epoch, success
        else:
            return success

    @staticmethod
    def rename_parameters(dict, old, new):
        """ Renames parameters in the network by finding parameters that contain 'old' and replacing 'old' with 'new'
        """
        replacements = [key for key in dict if old in key]
        
        for key in replacements:
            dict[key.replace(old, new)] = dict.pop(key)


def get_config_path(path):
    conf_names = glob.glob(os.path.abspath(path) + "/*.py")
    if len(conf_names) == 0:
        raise ValueError("No configuration files found at {}!".format(path))

    # The standard conf
    if 'conf.py' in map(lambda x: x.split('/')[-1], conf_names):
        return os.path.join(path, 'conf.py')

    # Get latest conf
    arrays = [np.array(file.split('__')[-1].replace('_', '-').replace('.py', '').split('-'),
                       dtype=float) for file in filter(lambda x: '__' in x, conf_names)]
    # Converts arrays representing time to values that can be compared
    values = np.array(list([ar[5] + 100 * ar[4] + (100 ** 2) * ar[3] + (100 ** 3) * ar[2]
                            + (100 ** 4) * ar[1] + (100 ** 5) * 10 * ar[0]
                            for ar in arrays]))
    conf_ind = np.argmax(values)
    return conf_names[conf_ind]
    
    
def save_git(base_dir):
  # save code revision
  print('Save git commit and diff to {}/git.txt'.format(base_dir))
  cmds = ["echo `git rev-parse HEAD` > {}".format(
    os.path.join(base_dir, 'git.txt')),
    "git diff >> {}".format(
      os.path.join(base_dir, 'git.txt'))]
  print(cmds)
  os.system("\n".join(cmds))


def save_cmd(base_dir):
  train_cmd = 'python ' + ' '.join([sys.argv[0]] + [pipes.quote(s) for s in sys.argv[1:]])
  train_cmd += '\n\n'
  print('\n' + '*' * 80)
  print('Training command:\n' + train_cmd)
  print('*' * 80 + '\n')
  with open(os.path.join(base_dir, "cmd.txt"), "a") as f:
    f.write(train_cmd)


