renseq

#!/bin/env python

import argparse
import itertools
import os
import shutil
import sys


def create_parser():
    description = ("Rename and/or renumber a file.\n"
        "Set the padding on the source and destination files using c-style formatting "
        "(e.g. \"%04d\" for 4 number padding)."
    )
    parser = argparse.ArgumentParser(description=description)
    parser.add_argument(
        "source",
        help="The source sequence template."
    )
    parser.add_argument(
        "--destination",
        "-d",
        required=False,
        help="The destination template. If not passed, uses the source and assumes renumbering of files."
    )
    parser.add_argument(
        "--first",
        "-f",
        required=True,
        type=int,
        help="The first frame of the original sequence."
    )
    parser.add_argument(
        "--last",
        "-l",
        required=True,
        type=int,
        help="The last frame of the original sequence."
    )
    parser.add_argument(
        "--start",
        "-s",
        required=True,
        type=int,
        help="The new start frame."
    )
    parser.add_argument(
        "--step",
        "-x",
        default=1,
        type=int,
        help="The step between frames (default=1)."
    )
    parser.add_argument(
        "--respect-breaks",
        "-b",
        action="store_true",
        help="Respect the breaks in source sequences, otherwise create a contiguous sequence (default)."
    )
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="Dry run mode."
    )
    return parser


def rename(src, dest, dry_run):
    print "Copying '{}' -> '{}'".format(src, dest)
    if not dry_run:
        try:
            shutil.copy2(src, dest)
        except:
            print "A copying error has occured", sys.exc_info[1]
            raise
        else:
            print "Copy complete, removing source."
            os.remove(src)


def try_rename(sources, destinations, dry_run):
    visited = []
    for source, dest in itertools.izip(sources, destinations):
        try:
            rename(source, dest, dry_run)
            visited.append((dest, source))
        except Exception as err:
            print str(err)
            print "Reverting changes..."
            for src, dst in visited:
                rename(src, dst, dry_run)
            return False
    return True


def rename_files(src, dest, first, last, start, step, breaks, dry_run):
    if not dest:
        dest = src
    
    use_temp = dest == src and start >= first and start <= last
    
    new_frame = itertools.count(start, step)
    frames = xrange(first, last+1)
    
    sources = []
    temp_destinations = []
    destinations = []
    
    for frame in frames:
        source = src % frame
        if not os.path.exists(source):
            print "'{}' does not exist. Skipping...".format(source)
            if breaks:
                print "Advancing new frame number to respect sequence break"
                new_frame.next()
            continue
        sources.append(source)
        destination = dest % new_frame.next()
        destinations.append(destination)
        temp_dest = "TMP" + destination
        temp_destinations.append(temp_dest)
    
    if any(map(os.path.exists, set(destinations) - set(sources))):
        result = raw_input("Some destination paths are going to overwrite existing files. Continue anyway? y/n")
        while result not in ["y", "n"]:
            result = input("ERROR: Response must be either 'y' or 'n'")
        if result == "n":
            return
    
    if use_temp:        
        print "Copying to temp location..."
        if not try_rename(sources, temp_destinations, dry_run):
            return
    else:
        temp_destinations = sources
        
    print "Copying to final location..."
    if not try_rename(temp_destinations, destinations, dry_run) and use_temp:
        for source, temp in itertools.izip(sources, temp_destinations):
            rename(temp, source, dry_run)
        
    print "COMPLETE!"


if __name__ == "__main__":
    parser = create_parser()
    args = parser.parse_args()

    rename_files(
        args.source,
        args.destination,
        args.first,
        args.last,
        args.start,
        args.step,
        args.respect_breaks,
        args.dry_run
    )
    sys.exit()