#! /usr/bin/env python

"""Show file statistics by extension."""

import os

import sys

class Stats:

    def __init__(self):

        self.stats = {}

    def statargs(self, args):

        for arg in args:

            if os.path.isdir(arg):

                self.statdir(arg)

            elif os.path.isfile(arg):

                self.statfile(arg)

            else:

                sys.stderr.write("Can't find %s\n" % arg)

                self.addstats("<???>", "unknown", 1)

    def statdir(self, dir):

        self.addstats("<dir>", "dirs", 1)

        try:

            names = os.listdir(dir)

        except os.error, err:

            sys.stderr.write("Can't list %s: %s\n" % (dir, err))

            self.addstats("<dir>", "unlistable", 1)

            return

        names.sort()

        for name in names:

            if name.startswith(".#"):

                continue # Skip CVS temp files

            if name.endswith("~"):

                continue# Skip Emacs backup files

            full = os.path.join(dir, name)

            if os.path.islink(full):

                self.addstats("<lnk>", "links", 1)

            elif os.path.isdir(full):

                self.statdir(full)

            else:

                self.statfile(full)

    def statfile(self, filename):

        head, ext = os.path.splitext(filename)

        head, base = os.path.split(filename)

        if ext == base:

            ext = "" # E.g. .cvsignore is deemed not to have an extension

        ext = os.path.normcase(ext)

        if not ext:

            ext = "<none>"

        self.addstats(ext, "files", 1)

        try:

            f = open(filename, "rb")

        except IOError, err:

            sys.stderr.write("Can't open %s: %s\n" % (filename, err))

            self.addstats(ext, "unopenable", 1)

            return

        data = f.read()

        f.close()

        self.addstats(ext, "bytes", len(data))

        if '\0' in data:

            self.addstats(ext, "binary", 1)

            return

        if not data:

            self.addstats(ext, "empty", 1)

        #self.addstats(ext, "chars", len(data))

        lines = data.splitlines()

        self.addstats(ext, "lines", len(lines))

        del lines

        words = data.split()

        self.addstats(ext, "words", len(words))

    def addstats(self, ext, key, n):

        d = self.stats.setdefault(ext, {})

        d[key] = d.get(key, 0) + n

    def report(self):

        exts = self.stats.keys()

        exts.sort()

        # Get the column keys

        columns = {}

        for ext in exts:

            columns.update(self.stats[ext])

        cols = columns.keys()

        cols.sort()

        colwidth = {}

        colwidth["ext"] = max([len(ext) for ext in exts])

        minwidth = 6

        self.stats["TOTAL"] = {}

        for col in cols:

            total = 0

            cw = max(minwidth, len(col))

            for ext in exts:

                value = self.stats[ext].get(col)

                if value is None:

                    w = 0

                else:

                    w = len("%d" % value)

                    total += value

                cw = max(cw, w)

            cw = max(cw, len(str(total)))

            colwidth[col] = cw

            self.stats["TOTAL"][col] = total

        exts.append("TOTAL")

        for ext in exts:

            self.stats[ext]["ext"] = ext

        cols.insert(0, "ext")

        def printheader():

            for col in cols:

                print "%*s" % (colwidth[col], col),

            print

        printheader()

        for ext in exts:

            for col in cols:

                value = self.stats[ext].get(col, "")

                print "%*s" % (colwidth[col], value),

            print

        printheader() # Another header at the bottom

def main():

    args = sys.argv[1:]

    if not args:

        args = [os.curdir]

    s = Stats()

    s.statargs(args)

    s.report()

if __name__ == "__main__":

    main()