#!/usr/bin/env python3
# -*- coding: utf-8 -*-
           
import os, os.path
import filecmp
import subprocess

from metafile import Metafile, MalformedMetafileError

# -----------------------------------------------------------------------------
def init(parser):
    """Initialize check subcommand"""

    parser.add_argument( "app",
                         type=str,
                         nargs="?",
                         help="The app to check" )

    parser.add_argument( "files",
                         type=str,
                         nargs="*",
                         default=[],
                         help="The files to check ; default to all "          \
                              "added files" )
    
    parser.add_argument( "-d", "--diff",
                         action="store_true",
                         help="Print the diff between the saved and the new " \
                              "files" )


# -----------------------------------------------------------------------------
def run(args, persoconf, logger):

    logger.debug("Starting 'check' command")

    difftool = None
    if args.diff:
        difftool = os.environ.get('DIFFTOOL', 'vimdiff')
        logger.info("Selecting %s as diff tool" % difftool)

    # app == None => check all apps
    apps_to_check = {}
    if args.app is None:
        apps_to_check = persoconf.list_apps(logger=logger)

    else:
        try:
            appmeta = Metafile(
                                json_path = os.path.join( persoconf.path,
                                                          args.app,
                                                          persoconf.metafile )
                              )

            apps_to_check[appmeta.name] = appmeta

        except FileNotFoundError:
            logger.error( "Metafile %s does not exist for app %s"
                          % (persoconf.metafile, args.app) )
            exit(1)

        except MalformedMetafileError:
            logger.error( "Malformed metafile %s in app %s"
                           % (persoconf.metafile, args.app) )
            exit(1)


    for app in apps_to_check:

        logger.info( "App %s:" % app )

        if args.files != []:

            dstdic = apps_to_check[app].get_files_dst2src() # Get that here
                                                            # for optimization

            # The filenames can be confnames or real files names. For each
            # we'll assume first that it's a confname, then that it's a file
            # name if that fails.
            for f in args.files:

                # 1) It's probably a confname
                if f in apps_to_check[app].files:

                    persoconf_backup_path = os.path.join( persoconf.path,
                                                          app,
                                                          f )

                    original_file_path = apps_to_check[app].files[f]["dest"]

                    _compare_and_log( original_file_path,
                                      persoconf_backup_path,
                                      logger,
                                      difftool )

                # 2) If not, it must be a real filename
                else:

                    absf = contractuser(os.path.abspath(os.path.expanduser(f)))
                    if absf in dstdic:


                        persoconf_backup_path = os.path.join( persoconf.path,
                                                              app,
                                                              dstdic[absf]  )

                        original_file_path = absf

                        _compare_and_log( original_file_path,
                                          persoconf_backup_path,
                                          logger,
                                          difftool )


                    # 3) Otherwise, no idea what it is
                    else:
                        logger.warning( "Cannot find file %s in app data; "   \
                                        "ignoring it"
                                        % f )
                        continue

        # If they were no 'file' args, it means we need to update all files in
        # the app
        else:

            for f in apps_to_check[app].files:

                persoconf_backup_path = os.path.join( persoconf.path,
                                                      app,
                                                      f )

                original_file_path = apps_to_check[app].files[f]["dest"]

                _compare_and_log( original_file_path,
                                  persoconf_backup_path,
                                  logger,
                                  difftool )


# -----------------------------------------------------------------------------
def _compare_and_log( original_file_path,
                      persoconf_backup_path,
                      logger,
                      difftool = None ):
    """Compare a file with its persoconf backup and log the result (at info
       level if the files are matching, warning level if they are not)."""
    
    resolved_ofp = os.path.expanduser(original_file_path)
    resolved_pbp = os.path.expanduser(persoconf_backup_path)

    is_dir = os.path.isdir( resolved_ofp )

    if is_dir:
        dcmp = filecmp.dircmp(resolved_ofp, resolved_pbp)
        if (    len(dcmp.diff_files) > 0
             or len(dcmp.left_only)  > 0
             or len(dcmp.right_only) > 0 ):
            logger.warning( "Dir %s/ was modified"
                            % original_file_path )
        else:
            logger.info( "No modification on %s/"
                         % original_file_path )

    else:
        try:
            if filecmp.cmp(resolved_ofp, resolved_pbp) :
                logger.info( "No modification on %s"
                             % original_file_path )

            else:
                logger.warning( "File %s was modified"
                                % original_file_path )
                if difftool:
                    subprocess.call([ difftool, resolved_pbp, resolved_ofp ])

        except FileNotFoundError as err:
            if err.filename == resolved_pbp:
                logger.warning( "File %s was modified (no backup file)"
                                % original_file_path )
            else:
                logger.warning( "File %s was deleted!"
                                % original_file_path )