import subprocess
import os
import shutil

import ogGlobals
import SystemLib
import CacheLib
import FileSystemLib

def ogCalculateChecksum(*args):
    # Check if help is requested
    if "help" in args:
        print("ogCalculateChecksum [ str_repo | int_ndisk int_npartition ] path_filepath")
        print("ogCalculateChecksum REPO ubuntu.img  ==>  ef899299caf8b517ce36f1157a93d8bf")
        return

    # Get the file path
    file_path = ogGetPath(*args)
    if not file_path:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return

    # Calculate the checksum
    result = subprocess.run(["tail", "-c1M", file_path], capture_output=True)
    checksum = result.stdout.decode().split()[0]

    return checksum

def ogCompareChecksumFiles(*args):
    # Variables locales.
    ARGS = args
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_filepath", "if $FUNCNAME REPO ubuntu.img CACHE ubuntu.img; then ...;  fi")
        return

    ARGS = args
    if args[0].startswith("/"):
        # Camino completo.          */ (Comentario Doxygen)
        SOURCE = ogGetPath(*args[:1])
        args = args[1:]
    elif args[0].isdigit():
        # ndisco npartición.
        SOURCE = ogGetPath(*args[:3])
        args = args[3:]
    else:
        # Otros: repo, cache, cdrom (no se permiten caminos relativos).
        SOURCE = ogGetPath(*args[:2])
        args = args[2:]

    TARGET = ogGetPath(*args)

    try:
        with open(f"{SOURCE}.sum", "r") as source_file:
            source_checksum = source_file.read().strip()
        with open(f"{TARGET}.sum", "r") as target_file:
            target_checksum = target_file.read().strip()

        return source_checksum == target_checksum
    except FileNotFoundError:
        return False

def ogCalculateFullChecksum(*args):
    # Variables locales.
    FILE = None
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_filepath", "$FUNCNAME REPO ubuntu.img  ==>  ef899299caf8b517ce36f1157a93d8bf")
        return

    # Comprobar que existe el fichero y devolver sus datos.
    FILE = ogGetPath(*args)
    if not FILE:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return

    # Calculate the checksum
    result = subprocess.run(["md5sum", FILE, "-b"], capture_output=True)
    checksum = result.stdout.decode().split()[0]

    return checksum

def ogCopyFile(*args):
    # Variables locales.
    ARGS = args
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_source [ str_repo | int_ndisk int_npartition ] path_target", "$FUNCNAME REPO newfile.txt 1 2 /tmp/newfile.txt")
        return

    ARGS = args
    if args[0].startswith("/"):
        # Camino completo.          */ (Comentrio Doxygen)
        SOURCE = ogGetPath(*args[:1])
        args = args[1:]
    elif args[0].isdigit():
        # ndisco npartición.
        SOURCE = ogGetPath(*args[:3])
        args = args[3:]
    else:
        # Otros: repo, cache, cdrom (no se permiten caminos relativos).
        SOURCE = ogGetPath(*args[:2])
        args = args[2:]

    TARGET = ogGetPath(*args)

    # Comprobar fichero origen y directorio destino.
    if not SOURCE:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args[:-1])
        return
    if not TARGET:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return

    # Copiar fichero (para evitar problemas de comunicaciones las copias se hacen con rsync en vez de cp).
    result = subprocess.run(["rsync", "--progress", "--inplace", "-avh", SOURCE, TARGET])
    return result.returncode

def ogDeleteFile(*args):
    # Variables locales.
    FILE = None
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_file", "$FUNCNAME 1 2 /tmp/newfile.txt")
        return

    # Comprobar que existe el fichero y borrarlo.
    FILE = ogGetPath(*args)
    if not FILE:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return
    try:
        os.remove(FILE)
    except OSError as e:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return
    
def ogDeleteTree(*args):
    # Variables locales.
    DIR = None
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_dir", "$FUNCNAME 1 2 /tmp/newdir")
        return

    # Comprobar que existe el directorio y borrarlo con su contenido.
    DIR = ogGetPath(*args)
    if not DIR:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return
    try:
        shutil.rmtree(DIR)
    except OSError as e:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return


#/**
#         ogGetPath [ str_repo | int_ndisk int_npartition ] path_filepath
#@brief   Inicia el proceso de arranque de un sistema de archivos.
#@param   path_filepath   camino del fichero (independiente de mayúsculas)
#@param   str_repo        repositorio de ficheros
#@param   int_ndisk       nº de orden del disco
#@param   int_npartition  nº de orden de la partición
#@return  path_file - camino completo real del fichero.
#@note    repo = { REPO, CACHE, CDROM }
#@note    Requisitos: \c grep \c sed
#@exception OG_ERR_FORMAT    Formato incorrecto.
#@exception OG_ERR_NOTFOUND  Fichero o dispositivo no encontrado.
#@exception OG_ERR_PARTITION Tipo de partición desconocido o no se puede montar.
#@warning En caso de error, sólo devuelve el código y no da mensajes.
#@todo    Terminar de definir parámetros para acceso a repositorios.
#*/ ##
#ogGetPath (file='/mnt/sda1/windows/system32')   ==> '/mnt/sda1/WINDOWS/System32'
#ogGetPath (src='REPO', file='/etc/fstab')       ==> '/opt/opengnsys/images/etc/fstab'
#ogGetPath (src='1 1', file='/windows/system32') ==> '/mnt/sda1/WINDOWS/System32'
def ogGetPath (src=None, file=None):
    if file is None:
        raise TypeError ('missing required argument: "file"')

    f = file
    if src is not None:
        if 'REPO' == src:
            f = os.path.join (ogGlobals.OGIMG, file.strip('/'))
        elif 'CACHE' == src:
            mntdir = CacheLib.ogMountCache()
            if not mntdir: return None
            f = os.path.join (mntdir, ogGlobals.OGIMG.strip('/'), file.strip('/'))
        elif 'CDROM' == src:
            mntdir = FileSystemLib.ogMountCdrom()
            if not mntdir: return None
            f = os.path.join (mntdir, file.strip('/'))
        else:
            try:
                disk, part = src.split()
            except ValueError:
                SystemLib.ogRaiseError ([], ogGlobals.OG_ERR_FORMAT, '')
                return
            mntdir = FileSystemLib.ogMount (disk, part)
            if not mntdir: return None
            f = os.path.join (mntdir, file.strip('/'))

    f = os.path.normpath (f)

    if os.path.exists (f):
        filepath = f
        #print (f'f ({f}) existe, filepath=f ({filepath})')
    else:
        # Buscar el nombre correcto en cada subdirectorio del camino.
        prevfile = ''
        filepath = '/'
        #print (f'f ({f}) prevfile ({prevfile})')
        while f != prevfile:
            #print ('\nno son iguales, nueva iteracion...')
            f_first_component = f.split ('/')[0] ## take 1st component
            ls_path = os.path.join (filepath, f_first_component)   ## "ls" makes reference to the original bash version
            #print (f'f_first_component ({f_first_component}) ls_path ({ls_path})')

            ## build filepath to return
            if os.path.exists (ls_path):
                filepath = ls_path
                #print (f'ls_path existe, filepath ({filepath})')
            else:
                filepath = subprocess.run (['find', filepath, '-maxdepth', '1', '-iname', f_first_component, '-print'], capture_output=True, text=True).stdout.strip()
                #print (f'ls_path no existe, filepath ({filepath})')

            prevfile = f
            f = '/'.join (f.split('/')[1:])      ## remove 1st component
            #print (f'f ({f}) prevfile ({prevfile})')

    return filepath


#/**
#         ogGetParentPath [ str_repo | int_ndisk int_npartition ] path_filepath
#@brief   Metafunción que devuelve el camino del directorio padre.
#@see     ogGetPath
#*/ ##

#ogGetParentPath ([ str_repo | int_ndisk int_npartition ] path_filepath
#ogGetParentPath (            file='/mnt/sda1/windows/system32')  ==> '/mnt/sda1/WINDOWS'
#ogGetParentPath (src='REPO', file='/etc/fstab')                  ==> '/opt/opengnsys/images/etc'
#ogGetParentPath (src='1 1',  file='/windows/system32')           ==> '/mnt/sda1/WINDOWS'
def ogGetParentPath (src=None, file=None):
    if file is None:
        SystemLib.ogRaiseError ([], ogGlobals.OG_ERR_FORMAT, '')
        return

    if src is None:
        return ogGetPath (file=os.path.dirname (file))
    else:
        return ogGetPath (src=src, file=os.path.dirname('/'+file))

def ogIsNewerFile(*args):
    # Variables locales.
    ARGS = args
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_source [ str_repo | int_ndisk int_npartition ] path_target", "if $FUNCNAME REPO ubuntu.img CACHE ubuntu.img; then ...  fi")
        return

    ARGS = args
    if args[0].startswith("/"):
        # Camino completo.          */ (Comentrio Doxygen)
        SOURCE = ogGetPath(*args[:1])
        args = args[1:]
    elif args[0].isdigit():
        # ndisco npartición.
        SOURCE = ogGetPath(*args[:3])
        args = args[3:]
    else:
        # Otros: repo, cache, cdrom (no se permiten caminos relativos).
        SOURCE = ogGetPath(*args[:2])
        args = args[2:]

    TARGET = ogGetPath(*args)

    # Comprobar que existen los ficheros origen y destino.
    if not SOURCE:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args[:-1])
        return
    if not TARGET:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return

    # Devolver si el primer fichero se ha modificado después que el segundo.
    return os.path.getmtime(SOURCE) > os.path.getmtime(TARGET)

def ogMakeChecksumFile(*args):
    # Variables locales.
    FILE = None
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_filepath", "$FUNCNAME REPO ubuntu.img")
        return

    # Comprobar que existe el fichero y guardar su checksum.
    FILE = ogGetPath(*args)
    if not FILE:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return
    checksum = ogCalculateChecksum(FILE)
    with open(f"{FILE}.sum", "w") as f:
        f.write(checksum)

def ogMakeDir(*args):
    # Variables locales.
    PARENT = None
    DIR = None
    if "help" in args:
        SystemLib.ogHelp("$FUNCNAME", "$FUNCNAME [ str_repo | int_ndisk int_npartition ] path_dir", "$FUNCNAME 1 2 /tmp/newdir")
        return

    PARENT = ogGetParentPath(*args)
    if not PARENT:
        SystemLib.ogRaiseError(OG_ERR_NOTFOUND, *args)
        return

    DIR = os.path.basename(args[-1])
    os.makedirs(os.path.join(PARENT, DIR), exist_ok=True)