import sys
import os
import subprocess
import configparser

# supported values: fish, bash, zsh
shell="fish"

# Defaults
print_file="cat"
pretty_print_file="less -R"
edit_file="vim"
list_directory="ls --color=auto"
change_dir="cd"
print_dir="pwd"
help_command="man"
path_locator="which"

# general function for setting a shell's environment variable
def set_runtime_var(name, value, options=""):
	if ( shell == "fish" ):
		print("set "+name+" "+options+" \""+value+"\"")
	elif ( shell == "bash" or shell == "zsh" ):
		print("export "+name+"="+"\""+value+"\"")

# checks if a file is a binary file or a plaintext file
def is_binary_file(filepathname):
    textchars = bytearray([7,8,9,10,12,13,27]) + bytearray(range(0x20, 0x7f)) + bytearray(range(0x80, 0x100))
    is_binary_string = lambda bytes: bool(bytes.translate(None, textchars))

    if is_binary_string(open(filepathname, 'rb').read(1024)):
       return True
    else:
       return False

# check if a given program is in the path environment using which
def env_has(program):
    def is_exe(fpath):
        return os.path.isfile(fpath) and os.access(fpath, os.X_OK)

    fpath, fname = os.path.split(program)
    if fpath:
        if is_exe(program):
            return True
    else:
        for path in os.environ["PATH"].split(os.pathsep):
            exe_file = os.path.join(path, program)
            if is_exe(exe_file):
                return True

    return None

# get the number of lines in a file
def file_len(fname):
    with open(fname) as f:
        for i, l in enumerate(f):
            pass
    return i + 1

# bootstrap the config
ENV_HOME=os.environ['HOME']
subprocess.call(['mkdir', '-p', ENV_HOME+'/.config/do_what'])
if ( os.path.isfile(ENV_HOME+'/.config/do_what/what.config') ):
	config = configparser.ConfigParser()
	config.read(ENV_HOME+'/.config/do_what/what.config')
	# TODO add else default configs & config flush
	if ( 'DEFAULT' in config ):
		if ( 'print_file' in config['DEFAULT'] ):
			print_file = config['DEFAULT']['print_file']
		if ( 'pretty_print_file' in config['DEFAULT'] ):
			pretty_print_file = config['DEFAULT']['pretty_print_file']
		if ( 'edit_file' in config['DEFAULT'] ):
			edit_file = config['DEFAULT']['edit_file']
		if ( 'list_directory' in config['DEFAULT'] ):
			list_directory = config['DEFAULT']['list_directory']
		if ( 'help_command' in config['DEFAULT'] ):
			help_command = config['DEFAULT']['help_command']
		if ( 'path_locator' in config['DEFAULT'] ):
			path_locator = config['DEFAULT']['path_locator']
else:
	config = configparser.ConfigParser()
	config['DEFAULT'] = {
		'list_directory': list_directory,
		'edit_file': edit_file,
		'pretty_print_file': pretty_print_file,
		'print_file': print_file,
		'help_command': help_command,
		'path_locator': path_locator,
	}
	print("echo Default config loaded.")
	with open(ENV_HOME+'/.config/do_what/what.config', 'w') as configfile:
		config.write(configfile)
		configfile.close()

# check if active mode is enabled
argiter = 0
active = False
for arg in sys.argv:
	if ( str(arg) == '-' ):
		active = True
		break
	argiter += 1

if ( (not active and len(sys.argv) == 1) or (active and len(sys.argv) == 2) ):
	# list the contents of the current directory
	if ( not active ): 
		print(list_directory)
	# print the working directory (active)
	elif ( active ):
		print(print_dir)
elif ( (not active and len(sys.argv) == 2) or (active and len(sys.argv) == 3) ):
	# absolutize the path for Python
	filearg = sys.argv[1]
	path = sys.argv[1]
	if ( path[0] != "/" and path[0] != "~" and path[0] != "." ):
		path = os.getcwd()+"/"+path
	
	# if directory, list its contents
	if ( os.path.isdir(path) and not active ):
		print(list_directory+" "+path)
	# if directory, change into it (active)
	elif ( os.path.isdir(path) and active ):
		print(change_dir+" "+path)
	# if file, display its contents
	elif ( os.path.isfile(path) and not active ):
		# check if file is binary
		if ( is_binary_file(path) ):
			print("echo Binary file.")
		else:
			trows, tcolumns = os.popen('stty size', 'r').read().split()
			# if file is taller than the terminal, pipe it to a pretty-print display
			if ( int(trows) - 5 < int(file_len(path)) ):
				set_runtime_var('LESSOPEN', '| /usr/share/source-highlight/src-hilite-lesspipe.sh %s')
				set_runtime_var('LESS', ' -R ')
				print(pretty_print_file+" "+path)
			# if file is shorter than the terminal, print its contents
			else:
				print(print_file+" "+path)
	# if file, open in editor (active)
	elif ( os.path.isfile(path) and active ):
		if ( is_binary_file(path) ):
			print("echo Binary file.")
		else:
			if ( os.access(path, os.W_OK) ):
				print(edit_file+" "+path)
			else:
				print("sudo "+edit_file+" "+path)
		
	else:
		# check if file is a path program, then list using which/man on active
		path_has = env_has(filearg)
		# print the location of the program
		if ( path_has and not active ):
			print(path_locator+" "+filearg)
		# display the help page for the program (active)
		elif ( path_has and active ):
			print(help_command+" "+filearg)
		else:
			print("echo Unknown file/directory.")